Texas Instruments TRF7960A User manual

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An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications,
intellectual property matters and other important disclaimers. PRODUCTION DATA.
TRF7960A
SLOS732G –JUNE 2011–REVISED MARCH 2020
TRF7960A Multiprotocol Fully Integrated 13.56-MHz RFID Reader/Writer IC
1 Device Overview
1
1.1 Features
1
• Completely Integrated Protocol Handling for
ISO/IEC 15693, ISO/IEC 18000-3,
ISO/IEC 14443A, ISO/IEC 14443B, NFC Forum
Device Types 2 to 5, and FeliCa™
• Input Voltage Range: 2.7 VDC to 5.5 VDC
• Programmable Output Power:
+20 dBm (100 mW) or +23 dBm (200 mW)
• Programmable I/O Voltage Levels:
1.8 VDC to 5.5 VDC
• Programmable System Clock Frequency Output
(RF, RF/2, RF/4)
• Programmable Modulation Depth
• Dual Receiver Architecture With RSSI for
Elimination of "Read Holes" and Adjacent Reader
System or Ambient In-Band Noise Detection
• Programmable Power Modes for Ultra-Low-Power
System Design (Power Down <0.5 µA)
• Parallel or SPI Interface
• Integrated Voltage Regulator for Microcontroller
Supply
• Temperature Range: –40°C to 110°C
• 32-Pin QFN Package (5 mm × 5 mm) (RHB)
1.2 Applications
• Secure Access Control
• Product Authentication
• Digital Door Locks
• Public Transport or Event Ticketing
• Medical Systems
• Remote Sensor Applications
1.3 Description
The TRF7960A device is an integrated analog front-end (AFE) and multiprotocol data-framing device for a
13.56-MHz RFID reader/writer system that supports ISO/IEC 14443 A and B, Sony FeliCa, and
ISO/IEC 15693. Built-in programming options make it suitable for a wide range of applications for
proximity and vicinity identification systems.
The reader is configured by selecting the desired protocol in the control registers. Direct access to all
control registers allows fine tuning of various reader parameters as needed.
The TRF7960A device supports data rates up to 848 kbps with all framing and synchronization tasks for
the ISO protocols onboard. The device also supports reader/writer mode for NFC Forum tag types 1, 2, 3,
4, and 5. NFC Forum tag types 2, 3, 4, and 5 are supported with the built-in protocol decoders used in
Direct Mode 2. NFC Forum tag type 1 requires the use of Direct Mode 0. Other standards and custom
protocols can also be implemented by using Direct Mode 0. Direct Mode 0 lets the user fully control the
AFE and also gain access to the raw subcarrier data or the unframed, but already ISO-formatted, data and
the associated (extracted) clock signal.
The receiver system has a dual-input receiver architecture to maximize communication robustness. The
receivers also include various automatic and manual gain control options. The received signal strength
from transponders, ambient sources, or internal levels is available in the RSSI register.
A SPI or parallel interface can be used for the communication between the MCU and the TRF7960A
reader. When the built-in hardware encoders and decoders are used, transmit and receive functions use a
12-byte FIFO register. For direct transmit or receive functions, the encoders or decoders can be bypassed
so the MCU can process the data in real time.
The TRF7960A device supports a wide supply voltage range of 2.7 V to 5.5 V and data communication
levels from 1.8 V to 5.5 V for the MCU I/O interface.
The transmitter has selectable output power levels of 100 mW (+20 dBm) or 200 mW (+23 dBm)
equivalent into a 50-Ωload when using a 5-V supply and supports OOK and ASK modulation with
selectable modulation depth.

TRF796xA MCU
(MSP430 or ARM)
Matching
VDD_X VDD_I/O
TX_OUT
RX_IN 1
RX_IN 2
VSS VIN
Parallel
or SPI
Supply
2.7 V to 5.5 V
VDD
VDD
Crystal
13.56 MHz
XIN
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Device Overview Copyright © 2011–2020, Texas Instruments Incorporated
The built-in programmable auxiliary voltage regulator delivers up to 20 mA to supply an MCU and
additional external circuits within the reader system.
To evaluate the latest products in the TRF79xx product family – TRF7970A and TRF7964A – see the NFC
Transceiver Booster Pack.
Documentation,Tools, Reference Designs, and Software,Samples
(1) For more information, see Section 9,Mechanical Packaging and Orderable Information.
Device Information(1)
PART NUMBER PACKAGE BODY SIZE
TRF7960ARHB VQFN (32) 5 mm × 5 mm
1.4 Application Block Diagram
Figure 1-1 shows a typical application block diagram.
Figure 1-1. Application Block Diagram

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Table of ContentsCopyright © 2011–2020, Texas Instruments Incorporated
Table of Contents
1 Device Overview ......................................... 1
1.1 Features .............................................. 1
1.2 Applications........................................... 1
1.3 Description............................................ 1
1.4 Application Block Diagram ........................... 2
2 Revision History ......................................... 4
3 Device Characteristics.................................. 5
3.1 Related Products ..................................... 5
4 Terminal Configuration and Functions.............. 6
4.1 Pin Diagrams ......................................... 6
4.2 Signal Descriptions................................... 6
5 Specifications ............................................ 8
5.1 Absolute Maximum Ratings .......................... 8
5.2 ESD Ratings.......................................... 8
5.3 Recommended Operating Conditions................ 8
5.4 Electrical Characteristics ............................. 9
5.5 Thermal Resistance Characteristics ................ 10
5.6 Switching Characteristics ........................... 10
6 Detailed Description ................................... 11
6.1 Functional Block Diagram........................... 11
6.2 Power Supplies ..................................... 11
6.3 Supply Arrangements ............................... 12
6.4 Supply Regulator Settings .......................... 13
6.5 Power Modes ....................................... 14
6.6 Receiver – Analog Section.......................... 17
6.7 Receiver – Digital Section........................... 18
6.8 Oscillator Section ................................... 21
6.9 Transmitter - Analog Section........................ 22
6.10 Transmitter - Digital Section ........................ 22
6.11 Transmitter – External Power Amplifier or
Subcarrier Detector ................................. 23
6.12 Communication Interface............................ 23
6.13 Direct Commands from MCU to Reader ............ 42
6.14 Register Description................................. 45
7 Applications, Implementation, and Layout........ 62
7.1 TRF7960A Reader System Using SPI With SS
Mode ................................................ 62
7.2 System Design ...................................... 63
8 Device and Documentation Support ............... 65
8.1 Getting Started and Next Steps..................... 65
8.2 Device Nomenclature ............................... 65
8.3 Tools and Software ................................. 66
8.4 Documentation Support............................. 66
8.5 Support Resources.................................. 66
8.6 Trademarks.......................................... 66
8.7 Electrostatic Discharge Caution..................... 67
8.8 Export Control Notice ............................... 67
8.9 Glossary............................................. 67
9 Mechanical, Packaging, and Orderable
Information .............................................. 68

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Revision History Copyright © 2011–2020, Texas Instruments Incorporated
2 Revision History
NOTE: Page numbers for previous revisions may differ from page numbers in the current version.
Changes from May 18, 2017 to March 11, 2020 Page
• Removed references to obsolete EVMs .......................................................................................... 2
• Corrected typo (changed "...and 3.4 V for VDD_A and VDD_A" to "...and 3.4 V for VDD_A and VDD_X") in
Section 6.3,Supply Arrangements................................................................................................ 13

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Device CharacteristicsCopyright © 2011–2020, Texas Instruments Incorporated
3 Device Characteristics
Table 3-1 lists the supported protocols.
Table 3-1. Supported Protocols
DEVICE ISO/IEC 14443 A AND B ISO/IEC 15693 ISO/IEC 18000-3
MODE 1 NFC Forum TYPES 1 TO 5
106 kbps 212 kbps 424 kbps 848 kbps
TRF7960A ✓ ✓ ✓ ✓ ✓ ✓ ✓
3.1 Related Products
For information about other devices in this family of products or related products, see the following links.
Products for TI Wireless Connectivity Connect more with the industry’s broadest wireless connectivity
portfolio.
Products for NFC / RFID TI provides one of the industry’s most differentiated NFC and RFID product
portfolios and is your solution to meet a broad range of NFC connectivity and RFID
identification needs.
Companion Products for TRF7960A Review products that are frequently purchased or used with this
product.
Reference Designs for TRF7960A The TI Designs Reference Design Library is a robust reference
design library that spans analog, embedded processor, and connectivity. Created by TI
experts to help you jump start your system design, all TI Designs include schematic or block
diagrams, BOMs, and design files to speed your time to market. Search and download
designs at ti.com/tidesigns.

1
2
3
4
5
6
7
8
I/O_6
I/O_5
I/O_4
I/O_3
I/O_2
I/O_1
I/O_0
I/O_7
VIN
VDD_RF
VDD_PA
TX_OUT
VSS_PA
VSS_RX
RX_IN1
VDD_A
OSC_IN
OSC_OUT
VSS_D
EN
SYS_CLK
DATA_CLK
EN2
VDD_X
VSS
BG
ASK/OOK
IRQ
MOD
VSS_A
VDD_I/O
RX_IN2
24
23
22
21
20
19
18
17
9 10 11 13 1412 15 16
32 31 30 28 2729 26 25
Thermal Pad
(connect to ground)
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Terminal Configuration and Functions Copyright © 2011–2020, Texas Instruments Incorporated
(1) SUP = Supply, INP = Input, BID = Bidirectional, OUT = Output
4 Terminal Configuration and Functions
4.1 Pin Diagrams
Figure 4-1 shows the pinout for the 32-pin RHB package.
Figure 4-1. 32-Pin RHB Package (Top View)
4.2 Signal Descriptions
Table 4-1 describes the signals.
Table 4-1. Signal Descriptions
TERMINAL TYPE (1) DESCRIPTION
NO. NAME
1 VDD_A OUT Internal regulated supply (2.7 V to 3.4 V) for analog circuitry
2 VIN SUP External supply input to chip (2.7 V to 5.5 V)
3 VDD_RF OUT Internal regulated supply (2.7 V to 5 V); normally connected to VDD_PA (pin 4)
4 VDD_PA INP Supply for PA; normally connected externally to VDD_RF (pin 3)
5 TX_OUT OUT RF output (selectable output power: 100 mW or 200 mW, with VDD = 5 V)
6 VSS_PA SUP Negative supply for PA; normally connected to circuit ground
7 VSS_RX SUP Negative supply for receive inputs; normally connected to circuit ground
8 RX_IN1 INP Main receive input
9 RX_IN2 INP Auxiliary receive input
10 VSS SUP Chip substrate ground
11 BAND_GAP OUT Bandgap voltage (VBG = 1.6 V); internal analog voltage reference
12 ASK/OOK BID Selection between ASK and OOK modulation (0 = ASK, 1 = OOK) for direct mode 0 and 1.
It can be configured as an output to provide the received analog signal output.
13 IRQ OUT Interrupt request
14 MOD INP External data modulation input for direct mode 0 or 1
OUT Subcarrier digital data output (see register 0x1A and 0x1B definitions)
15 VSS_A SUP Negative supply for internal analog circuits. Connected to GND.
16 VDD_I/O INP Supply for I/O communications (1.8 V to VIN) level shifter. VIN should be never exceeded.
17 I/O_0 BID I/O pin for parallel communication
18 I/O_1 BID I/O pin for parallel communication
19 I/O_2 BID I/O pin for parallel communication

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Terminal Configuration and FunctionsCopyright © 2011–2020, Texas Instruments Incorporated
Table 4-1. Signal Descriptions (continued)
TERMINAL TYPE (1) DESCRIPTION
NO. NAME
20 I/O_3 BID I/O pin for parallel communication
21 I/O_4 BID I/O pin for parallel communication
Slave select signal in SPI mode
22 I/O_5 BID I/O pin for parallel communication
Data clock output in direct mode 1
23 I/O_6 BID
I/O pin for parallel communication
MISO for serial communication (SPI)
Serial bit data output in direct mode 1 or subcarrier signal in direct mode 0
24 I/O_7 BID I/O pin for parallel communication.
MOSI for serial communication (SPI)
25 EN2 INP Selection of power down mode. If EN2 is connected to VIN, then VDD_X is active during power
down mode 2 (for example, to supply the MCU).
26 DATA_CLK INP Data clock input for MCU communication (parallel and serial)
27 SYS_CLK OUT If EN = 1 (EN2 = don't care) the system clock for the MCU is configured with register 0x09 (off,
3.39 MHz, 6.78 MHz, or 13.56 MHz).
If EN = 0 and EN2 = 1, the system clock is set to 60 kHz.
28 EN INP Chip enable input (if EN = 0, then the chip is in sleep or power-down mode)
29 VSS_D SUP Negative supply for internal digital circuits
30 OSC_OUT OUT Crystal or oscillator output
31 OSC_IN INP Crystal or oscillator input
32 VDD_X OUT Internally regulated supply (2.7 V to 3.4 V) for digital circuit and external devices (for example, an
MCU)
PAD PAD SUP Chip substrate ground

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Specifications Copyright © 2011–2020, Texas Instruments Incorporated
(1) Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. These are stress ratings
only and functional operation of the device at these or any other conditions beyond those indicated under Recommended Operating
Conditions are not implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.
(2) All voltage values are with respect to substrate ground terminal VSS.
(3) The maximum junction temperature for continuous operation is limited by package constraints. Operation above this temperature may
result in reduced reliability or lifetime of the device.
5 Specifications
5.1 Absolute Maximum Ratings (1)
over operating free-air temperature range (unless otherwise noted) (2)
MIN MAX UNIT
Input voltage range, VIN –0.3 6 V
Maximum current, IIN 150 mA
Maximum operating virtual junction temperature, TJ(3) Any condition 140 °C
Continuous operation, long-term reliability 125
Storage temperature, TSTG –55 150 °C
(1) JEDEC document JEP155 states that 500-V HBM allows safe manufacturing with a standard ESD control process.
(2) JEDEC document JEP157 states that 250-V CDM allows safe manufacturing with a standard ESD control process.
5.2 ESD Ratings
VALUE UNIT
V(ESD) Electrostatic discharge Human-body model (HBM), per ANSI/ESDA/JEDEC JS-001(1) ±2000 VCharged-device model (CDM), per JEDEC specification JESD22‑C101(2) ±500
Machine model (MM) ±200
5.3 Recommended Operating Conditions
over operating free-air temperature range (unless otherwise noted) MIN NOM MAX UNIT
VIN Operating input voltage 2.7 5 5.5 V
TAOperating ambient temperature –40 25 110 °C
TJOperating virtual junction temperature –40 25 125 °C

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SpecificationsCopyright © 2011–2020, Texas Instruments Incorporated
(1) Antenna driver output resistance
(2) Measured with subcarrier signal at RX_IN1 or RX_IN2 and measured the digital output at MOD pin with register 0x1A bit 6 = 1
(3) Depending on the crystal parameters and components
(4) Recommended DATA_CLK speed is 2 MHz; higher data clock depends on the capacitive load. Maximum SPI clock speed should not
exceed 10 MHz. This clock speed is acceptable only when external capacitive load is less than 30 pF. MISO driver has a typical output
resistance of 400 Ω(12-ns time constant when 30-pF load is used).
5.4 Electrical Characteristics
TYP operating conditions are TA= 25°C, VIN = 5 V, full-power mode (unless otherwise noted)
MIN and MAX operating conditions are over recommended ranges of supply voltage and operating free-air temperature
(unless otherwise noted)
PARAMETER TEST CONDITIONS MIN TYP MAX UNIT
IPD1 Supply current in power down mode 1 All building blocks disabled, including supply- voltage regulators; measured after 500-ms
settling time (EN = 0, EN2 = 0) <0.5 5 µA
IPD2 Supply current in power down mode 2
(sleep mode) The SYS_CLK generator and VDD_X remain
active to support external circuitry, measured
after 100-ms settling time (EN = 0, EN2 = 1) 120 200 µA
ISTBY Supply current in standby mode Oscillator running, supply-voltage regulators in
low-consumption mode (EN = 1, EN2 = x) 1.9 3.5 mA
ION1 Supply current without antenna driver
current Oscillator, regulators, RX, and AGC are active, TX is off 10.5 14 mA
ION2 Supply current in TX (half power) Oscillator, regulators, RX, AGC, and TX
active, POUT = 100 mW 70 78 mA
ION3 Supply current in TX (full power) Oscillator, regulators, RX, AGC, and TX
active, POUT = 200 mW 130 170 mA
VPOR Power-on reset voltage Input voltage at VIN 1.4 2 2.6 V
VBG Bandgap voltage (pin 11) Internal analog reference voltage 1.5 1.6 1.7 V
VDD_A Regulated output voltage for analog
circuitry (pin 1) VIN = 5 V 3.1 3.5 3.8 V
VDD_X Regulated supply for external circuitry Output voltage pin 32, VIN = 5 V 3.1 3.4 3.8 V
IVDD_Xmax Maximum output current of VDD_X Output current pin 32, VIN = 5 V 20 mA
RRFOUT Antenna driver output resistance(1) Half-power mode, VIN = 2.7 V to 5.5 V 8 12 Ω
Full-power mode, VIN = 2.7 V to 5.5 V 4 6
RRFIN RX_IN1 and RX_IN2 input resistance 4 10 20 kΩ
VRF_INmax Maximum RF input voltage at RX_IN1
or RX_IN2 VRF_INmax should not exceed VIN 3.5 Vpp
VRF_INmin Minimum RF input voltage at RX_IN1
or RX_IN2 (input sensitivity)(2) fSUBCARRIER = 424 kHz 1.4 2.5 mVpp
fSUBCARRIER = 848 kHz 2.1 3
fSYS_CLK SYS_CLK frequency In power mode 2, EN = 0, EN2 = 1 25 60 120 kHz
fCCarrier frequency Defined by external crystal 13.56 MHz
tCRYSTAL Crystal run-in time Time until oscillator stable bit is set (register
0x0F) (3) 5 ms
fD_CLKmax Maximum DATA_CLK frequency(4) Depends on capacitive load on the I/O lines,
recommendation is 2 MHz(4) 2 4 10 MHz
VIL Input voltage, logic low I/O lines, IRQ, SYS_CLK, DATA_CLK, EN,
EN2 0.2 × VDD_I/O V
VIH Input voltage threshold, logic high I/O lines, IRQ, SYS_CLK, DATA_CLK, EN,
EN2 0.8 × VDD_I/O V
ROUT Output resistance, I/O_0 to I/O_7 500 800 Ω
RSYS_CLK Output resistance RSYS_CLK 200 400 Ω

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Specifications Copyright © 2011–2020, Texas Instruments Incorporated
(1) This data was taken using the JEDEC standard high-K test PCB.
(2) Power rating is determined with a junction temperature of 125°C. This is the point where distortion starts to increase substantially.
Thermal management of the final PCB should strive to keep the junction temperature at or below 125°C for best performance and long-
term reliability.
5.5 Thermal Resistance Characteristics
PACKAGE RθJC RθJA(1) POWER RATING(2)
TA≤25°C TA≤85°C
RHB (32) 31°C/W 36.4°C/W 2.7 W 1.1 W
(1) Recommended DATA_CLK speed is 2 MHz; higher data clock depends on the capacitive load. Maximum SPI clock speed should not
exceed 10 MHz. This clock speed is acceptable only when external capacitive load is less than 30 pF. MISO driver has a typical output
resistance of 400 Ω(12-ns time constant when 30-pF load is used).
5.6 Switching Characteristics
over operating free-air temperature range (unless otherwise noted)
PARAMETER TEST CONDITIONS MIN TYP MAX UNIT
tLO/HI DATA_CLK time, high or low (one half
of DATA_CLK at 50% duty cycle) Depends on capacitive load on the I/O lines (1) 50 62.5 250 ns
tSTE,LEAD Slave select lead time, slave select
low to clock 200 ns
tSTE,LAG Slave select lag time, last clock to
slave select high 200 ns
tSU,SI MOSI input data setup time 15 ns
tHD,SI MOSI input data hold time 15 ns
tSU,SO MISO input data setup time 15 ns
tHD,SO MISO input data hold time 15 ns
tVALID,SO MISO output data valid time DATA_CLK edge to MISO valid, CL= <30 pF 30 50 75 ns

MUX
RX_IN1
RX_IN2
Phase and
Amplitude
Detector
Gain RSSI
(AUX)
Logic
Level Shifter
State
Control
Logic
(Control
Registers and
Command
Logic)
12-Byte
FIFO
MCU
Interface
VDD_I/O
I/O_0
I/O_1
I/O_2
I/O_3
I/O_4
I/O_5
I/O_6
I/O_7
IRQ
SYS_CLK
DATA_CLK
ISO
Protocol
Handling Decoder
RSSI
(External)
Gain
RSSI
(Main)
Filter
and AGC Digitizer
Bit
Framing
Framing
Serial
Conversion
CRC and Parity
Transmitter
Analog Front End
TX_OUT
VDD_PA
VSS_PA
Digital Control
State Machine
Crystal or Oscillator
Timing System
EN
EN2
ASK/OOK
MOD
OSC_IN
OSC_OUT
Voltage Supply Regulator Systems
(Supply Regulators and Reference Voltages)
VSS_A
VSS_RF
VDD_RF
VDD_X
VSS_D
VSS
VIN
VDD_A
BAND_GAP
Phase and
Amplitude
Detector
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Detailed DescriptionCopyright © 2011–2020, Texas Instruments Incorporated
6 Detailed Description
6.1 Functional Block Diagram
Figure 6-1 shows the functional block diagram.
Figure 6-1. Functional Block Diagram
6.2 Power Supplies
The TRF7960A positive supply input VIN (pin 2) sources three internal regulators with output voltages
VDD_RF, VDD_A, and VDD_X. All regulators require external bypass capacitors for supply noise filtering
and must be connected as indicated in reference schematics. These regulators provide a high power
supply reject ratio (PSRR) as required for RFID reader systems. All regulators are supplied by VIN (pin 2).
The regulators are not independent and have common control bits in register 0x0B for output voltage
setting. The regulators can be configured to operate in either automatic or manual mode (register 0x0B, bit
7). The automatic regulator setting mode ensures an optimal compromise between PSRR and the highest
possible supply voltage for RF output (to ensure maximum RF power output). The manual mode lets the
user manually configure the regulator settings.

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6.3 Supply Arrangements
Regulator Supply Input: VIN
The positive supply at VIN (pin 2) has an input voltage range of 2.7 V to 5.5 V. VIN provides the supply
input sources for three internal regulators with the output voltages VDD_RF, VDD_A, and VDD_X.
External bypass capacitors for supply noise filtering must be used (per reference schematics).
NOTE
VIN must be the highest voltage supplied to the TRF7960A.
RF Power Amplifier Regulator: VDD_RF
The VDD_RF (pin 3) regulator is supplying the RF power amplifier. The voltage regulator can be set for
either 5-V or 3-V operation. External bypass capacitors for supply noise filtering must be used (per
reference schematics). When configured for 5-V manual operation, the VDD_RF output voltage can be set
from 4.3 V to 5 V in 100-mV steps. In 3-V manual operation, the output can be programmed from 2.7 V to
3.4 V in 100-mV steps (see Table 6-2). The maximum output current capability for 5-V operation is 150
mA and for 3-V operation is 100 mA.
Analog Supply Regulator: VDD_A
Regulator VDD_A (pin 1) supplies the analog circuits of the device. The output voltage setting depends on
the input voltage and can be set for 5-V and 3-V operation. When configured for 5-V manual operation,
the output voltage is fixed at 3.4 V. External bypass capacitors for supply noise filtering must be used (per
reference schematics). When configured for 3-V manual operation, the VDD_A output can be set from 2.7
V to 3.4 V in 100-mV steps (see Table 6-2).
NOTE
The configuration of VDD_A and VDD_X regulators are not independent from each other.
The VDD_A output current should not exceed 20 mA.
Digital Supply Regulator: VDD_X
The digital supply regulator VDD_X (pin 32) provides the power for the internal digital building blocks and
can also be used to supply external electronics within the reader system. When configured for 3-V
operation, the output voltage can be set from 2.7 to 3.4 V in 100-mV steps. External bypass capacitors for
supply noise filtering must be used (refer to the reference schematics).
NOTE
The configuration of the VDD_A and VDD_X regulators are not independent from each other.
The VDD_X output current should not exceed 20 mA.
The RF power amplifier regulator (VDD_RF), analog supply regulator (VDD_A), and digital supply
regulator (VDD_X) can be configured to operate in either automatic or manual mode described in Table 6-
1. The automatic regulator setting mode ensures an optimal compromise between PSRR and the highest
possible supply voltage to ensure maximum RF power output.
By default, the regulators are set in automatic regulator setting mode. In this mode, the regulators are
automatically set every time the system is activated by setting EN input High or each time the automatic
regulator setting bit, B7 in register 0x0B is set to a 1. The action is started on the 0 to 1 transition. This
means that, if the user wants to rerun the automatic setting from a state in which the automatic setting bit
is already high, the automatic setting bit (B7 in register 0x0B) should be changed: 1-0-1.

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Detailed DescriptionCopyright © 2011–2020, Texas Instruments Incorporated
(1) x = don't care
By default, the regulator setting algorithm sets the regulator outputs to a "Delta Voltage" of 250 mV below
VIN, but not higher than 5 V for VDD_RF and 3.4 V for VDD_A and VDD_X. The "Delta Voltage" in
automatic regulator mode can be increased up to 400 mV (for more details, see bits B0 to B2 in register
0x0B).
Power Amplifier Supply: VDD_PA
The power amplifier of the TRF7960A is supplied through VDD_PA (pin 4). The positive supply pin for the
RF power amplifier is externally connected to the regulator output VDD_RF (pin 3).
I/O Level Shifter Supply: VDD_I/O
The TRF7960A has a separate supply input VDD_I/O (pin 16) for the build in I/O level shifter. The
supported input voltage ranges from 1.8 V to VIN, however not exceeding 5.5 V. Pin 16 is used to supply
the I/O interface pins (I/O_0 to I/O_7), IRQ, SYS_CLK, and DATA_CLK pins of the reader. In typical
applications, VDD_I/O is directly connected to VDD_X while VDD_X also supplies the MCU. This ensures
that the I/O signal levels of the MCU match with the logic levels of the TRF7960A.
Negative Supply Connections: VSS, VSS_RX, VSS_A, VSS_PA
The negative supply connections VSS_X of each functional block are all externally connected to GND.
The substrate connection is VSS (pin 10), the analog negative supply is VSS_A (pin 15), the logic
negative supply is VSS_D (pin 29), the RF output stage negative supply is VSS_PA (pin 6), and the
negative supply for the RF receiver VSS_RX (pin 7).
6.4 Supply Regulator Settings
The input supply voltage mode of the reader must be selected. This is done in the Chip Status Control
register (0x00). Bit 0 in register 0x00 selects either 5-V or 3-V input supply voltage. The default
configuration is 5 V, which reflects an operating supply voltage range of 4.3 V to 5.5 V. If the supply
voltage is below 4.3 V, the 3-V configuration should be used.
The various regulators can be configured to operate in automatic or manual mode. This is done in the
Regulator and I/O Control register (0x0B) (see Table 6-1 and Table 6-2).
Table 6-1. Supply Regulator Setting: 5-V System
REGISTER
ADDRESS
OPTION BITS SETTING IN REGULATOR CONTROL
REGISTER(1) COMMENTS
B7 B6 B5 B4 B3 B2 B1 B0
Automatic Mode (default)
0B 1 x x x x x 1 1 Automatic regulator setting with 250-mV difference
0B 1 x x x x x 1 0 Automatic regulator setting with 350-mV difference
0B 1 x x x x x 0 0 Automatic regulator setting with 400-mV difference
Manual Mode
0B 0 x x x x 1 1 1 VDD_RF = 5 V, VDD_A = 3.4 V, VDD_X = 3.4 V
0B 0 x x x x 1 1 0 VDD_RF = 4.9 V, VDD_A = 3.4 V, VDD_X = 3.4 V
0B 0 x x x x 1 0 1 VDD_RF = 4.8 V, VDD_A = 3.4 V, VDD_X = 3.4 V
0B 0 x x x x 1 0 0 VDD_RF = 4.7 V, VDD_A = 3.4 V, VDD_X = 3.4 V
0B 0 x x x x 0 1 1 VDD_RF = 4.6 V, VDD_A = 3.4 V, VDD_X = 3.4 V
0B 0 x x x x 0 1 0 VDD_RF = 4.5 V, VDD_A = 3.4 V, VDD_X = 3.4 V
0B 0 x x x x 0 0 1 VDD_RF = 4.4 V, VDD_A = 3.4 V, VDD_X = 3.4 V
0B 0 x x x x 0 0 0 VDD_RF = 4.3 V, VDD_A = 3.4 V, VDD_X = 3.4 V

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Table 6-2. Supply Regulator Setting: 3-V System
REGISTER
ADDRESS
OPTION BITS SETTING IN REGULATOR CONTROL
REGISTER(1) COMMENTS
B7 B6 B5 B4 B3 B2 B1 B0
Automatic Mode (default)
0B 1 x x x x x 1 1 Automatic regulator setting with 250-mV difference
0B 1 x x x x x 1 0 Automatic regulator setting with 350-mV difference
0B 1 x x x x x 0 0 Automatic regulator setting with 400-mV difference
Manual Mode
0B 0 x x x x 1 1 1 VDD_RF = 3.4 V, VDD_A = 3.4 V, VDD_X = 3.4 V
0B 0 x x x x 1 1 0 VDD_RF = 3.3 V, VDD_A = 3.3 V, VDD_X = 3.3 V
0B 0 x x x x 1 0 1 VDD_RF = 3.2 V, VDD_A = 3.2 V, VDD_X = 3.2 V
0B 0 x x x x 1 0 0 VDD_RF = 3.1 V, VDD_A = 3.1 V, VDD_X = 3.1 V
0B 0 x x x x 0 1 1 VDD_RF = 3.0 V, VDD_A = 3.0 V, VDD_X = 3.0 V
0B 0 x x x x 0 1 0 VDD_RF = 2.9 V, VDD_A = 2.9 V, VDD_X = 2.9 V
0B 0 x x x x 0 0 1 VDD_RF = 2.8 V, VDD_A = 2.8 V, VDD_X = 2.8 V
0B 0 x x x x 0 0 0 VDD_RF = 2.7 V, VDD_A = 2.7 V, VDD_X = 2.7 V
The regulator configuration function adjusts the regulator outputs by default to 250 mV below VIN level,
but not higher than 5 V for VDD_RF, 3.4 V for VDD_A and VDD_X. This ensures the highest possible
supply voltage for the RF output stage while maintaining an adequate PSRR (power supply rejection
ratio).
To further improve the PSRR, it is possible to increase the target voltage difference across VDD_X and
VDD_A from its default to 350 mV or even 400 mV (for details, see Regulator and I/O Control register
0x0B definition and Table 6-2.)
6.5 Power Modes
The chip has several power states, which are controlled by two input pins (EN and EN2) and several bits
in the Chip Status Control register (0x00).
Table 6-3 lists the configuration for the different power modes when using a 5-V or 3-V system supply.
The main reader enable signal is pin EN. When EN is set high, all of the reader regulators are enabled,
the 13.56-MHz oscillator is running, and the SYS_CLK (output clock for external microcontroller) is also
available.
The Regulator Control register settings shown are for optimized power out. The automatic setting
(normally 0x87) is optimized for best PSRR and noise reduction.

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Table 6-3. Power Modes(1)
MODE EN2 EN
CHIP STATUS
CONTROL
REGISTER
(0X00)
REGULATOR
CONTROL
REGISTER
(0X0B)
TRANS-
MITTER RECEIVER SYS_CLK (13.56 MHz) SYS_CLK (60 kHz) VDD_X TYPICAL
CURRENT
(mA)
TYPICAL
POWER
OUT (dBm)
TIME
(FROM
PREVIOUS
STATE)
Mode 4
(full power)
5 VDC x 1 21 07 On On On x On 130 23 20 to 25 µs
Mode 4
(full power)
3.3 VDC x 1 20 07 On On On x On 67 18
Mode 3
(half power)
5 VDC x 1 31 07 On On On x On 70 20 20 to 25 µs
Mode 3
(half power)
3.3 VDC x 1 30 07 On On On x On 53 15
Mode 2
5 VDC x 1 03 07 Off On On x On 10.5 — 20 to 25 µs
Mode 2
3.3 VDC x 1 02 00 Off On On x On 9 —
Mode 1
5 VDC x 1 01 07 Off Off On x On 5 — 20 to 25 µs
Mode 1
3.3 VDC x 1 00 00 Off Off On x On 3
Standby mode
5 VDC x 1 81 07 Off Off On x On 3 — 4.8 ms
Standby mode
3.3 VDC x 1 80 00 Off Off On x On 2 —
Sleep mode 1 0 x x Off Off Off On On 0.120 — 1.5 ms
Power down 0 0 x x Off Off Off Off Off <0.001 — Start

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The input pin EN2 has two functions:
• A direct connection from EN2 to VIN to ensure the availability of the regulated supply VDD_X and an
auxiliary clock signal (60 kHz, SYS_CLK) for an external MCU. This mode (EN = 0, EN2 = 1) is
intended for systems in which the MCU is also being supplied by the reader supply regulator (VDD_X)
and the MCU clock is supplied by the SYS_CLK output of the reader. This lets the MCU supply and
clock be available during sleep mode.
• EN2 enables the start-up of the reader system from complete power down (EN = 0, EN2 = 0). In this
case, the EN input is being controlled by the MCU (or other system device) that is without supply
voltage during complete power down (thus unable to control the EN input). A rising edge applied to the
EN2 input (which has an approximately 1-V threshold level) starts the reader supply system and
13.56‑MHz oscillator (identical to condition EN = 1).
When the user MCU controls EN and EN2, use a delay of 5 ms between EN and EN2. When the MCU
controls only EN, TI recommends connecting EN2 to either VIN or GND, depending on the application
MCU requirements for VDD_X and SYS_CLK.
NOTE
Using EN = 1 and EN2 = 1 in parallel at start-up should not be done as it may cause
incorrect operation.
This start-up mode lasts until all of the regulators have settled and the 13.56-MHz oscillator has stabilized.
If the EN input is set high (EN = 1) by the MCU (or other system device), the reader stays active. If the EN
input is not set high (EN = 0) within 100 µs after the SYS_CLK output is switched from auxiliary clock
(60 kHz) to high-frequency clock (derived from the crystal oscillator), the reader system returns to
complete Power-Down Mode 1. This option can be used to wake the reader system from complete power
down (PD Mode 1) by using a push-button switch or by sending a single pulse.
After the reader EN line is high, the other power modes are selected by control bits within the Chip Status
Control register (0x00). The power mode options and states are listed in Table 6-3.
When EN is set high (or on rising edge of EN2 and then confirmed by EN = 1) the supply regulators are
activated and the 13.56-MHz oscillator started. When the supplies are settled and the oscillator frequency
is stable, the SYS_CLK output is switched from the auxiliary frequency of 60 kHz to the 13.56-MHz
frequency derived from the crystal oscillator. At this time, the reader is ready to communicate and perform
the required tasks. The MCU can then program the Chip Status Control register 0x00 and select the
operation mode by programming the additional registers.
• Standby mode (bit 7 = 1 of register 0x00), the reader is capable of recovering to full operation in
100 µs.
• Mode 1 (active mode with RF output disabled, bit 5 = 0 and bit 1 = 0 of register 0x00) is a low-power
mode that lets the reader recover to full operation within 25 µs.
• Mode 2 (active mode with only the RF receiver active, bit 1 = 1 of register 0x00) can be used to
measure the external RF field (as described in RSSI measurements paragraph) if reader-to-reader
anticollision is implemented.
• Mode 3 and Mode 4 (active modes with the entire RF section active, bit 5 = 1 of register 0x00) are the
modes used for typical transmit and receive operations.

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6.6 Receiver – Analog Section
6.6.1 Main and Auxiliary Receiver
The TRF7960A has two receiver inputs: RX_IN1 (pin 8) and RX_IN2 (pin 9). Each of the inputs is
connected to an external capacitive voltage divider to ensure that the modulated signal from the tag is
available on at least one of the two inputs. This architecture eliminates any possible communication holes
that may occur from the tag to the reader.
The two RX inputs (RX_IN1 and RX_IN2) are multiplexed into two receivers–the main receiver and the
auxiliary receiver. Only the main receiver is used for reception; the auxiliary receiver is used for signal
quality monitoring. Receiver input multiplexing is controlled by bit B3 in the Chip Status Control register
(address 0x00).
After start-up, RX_IN1 is multiplexed to the main receiver which is composed of an RF envelope detection,
first gain and band-pass filtering stage, second gain and filtering stage with AGC. Only the main receiver
is connected to the digitizing stage which output is connected to the digital processing block. The main
receiver also has an RSSI measuring stage, which measures the strength of the demodulated signal
(subcarrier signal).
The primary function of the auxiliary receiver is to monitor the RX signal quality by measuring the RSSI of
the demodulated subcarrier signal (internal RSSI). After start-up, RX_IN2 is multiplexed to the auxiliary
receiver. The auxiliary receiver has an RF envelope detection stage, first gain and filtering with AGC stage
and finally the auxiliary RSSI block.
The default MUX setting is RX_IN1 connected to the main receiver and RX_IN2 connected to the auxiliary
receiver. To determine the signal quality, the response from the tag is detected by the "main" (pin RX_IN1)
and "auxiliary" (pin RX_IN2) RSSI. Both values measured and stored in the RSSI level register (address
0x0F). The MCU can read the RSSI values from the TRF7960A RSSI register and decide if swapping the
input signals is preferable or not. Setting B3 in the Chip Status Control register (address 0x00) to 1
connects RX_IN1 (pin 8) to the auxiliary receiver and RX_IN2 (pin 9) to the main receiver.
The main and auxiliary receiver input stages are RF envelope detectors. The RF amplitude at RX_IN1 and
RX_IN2 should be approximately 3 VPP for a VIN supply level greater than 3.3 V. If the VIN level is lower,
the RF input peak-to-peak voltage level should not exceed the VIN level.
6.6.2 Receiver Gain and Filter Stages
The first gain and filtering stage has a nominal gain of 15 dB with an adjustable band-pass filter. The
band-pass filter has programmable 3-dB corner frequencies from 110 kHz to 450 kHz for the high-pass
filter and from 570 kHz to 1500 kHz for the low-pass filter. After the band-pass filter, there is another gain-
and-filtering stage with a nominal gain of 8 dB and with frequency characteristics identical to the first band-
pass stage.
The internal filters are configured automatically depending on the selected ISO communication standard in
the ISO Control register (address 0x01). If required, additional fine tuning can be done by writing directly
to the RX special setting registers (address 0x0A).
Table 6-4 shows the various settings for the receiver analog section. Setting B4, B5, B6, and B7 to 0
results in a band-pass characteristic of 240 kHz to 1.4 MHz, which is appropriate for ISO/IEC 14443 B
data rate of 106 kbps, ISO/IEC 14443 A or B data rates of 212 kbps and 424 kbps, and FeliCa data rate
of 424 kbps.

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Table 6-4. RX Special Setting Register (0x0A)
BIT FUNCTION COMMENTS
B7 Band-pass filter from 110 kHz to 570 kHz Appropriate for any 212-kHz subcarrier systems like FeliCa
B6 Band-pass filter from 200 kHz to 900 kHz Appropriate for 424-kHz subcarrier systems (for example, used in ISO/IEC 15693).
B5 Band-pass filter from 450 kHz to 1.5 MHz Appropriate for Manchester-coded 106-kbps 848-kHz subcarrier systems (for
example, used in ISO/IEC 14443 A).
B4 Band-pass filter from 100 kHz to 1.5 MHz Appropriate for highest bit rate (848 kbps) used in high-bit-rate ISO/IEC 14443 B.
Gain is reduced by 7 dB.
B3 00 = No gain reduction
01 = Gain reduction for 5 dB
10 = Gain reduction for 10 dB
11 = Gain reduction for 15 dB
Sets the RX digital gain reduction (changing the window of the digitizing
comparator).
B2
B1 Reserved
B0 Reserved
6.7 Receiver – Digital Section
The output of the TRF7960A analog receiver block is a digitized subcarrier signal and is the input to the
digital receiver block, which consists of two sections that partly overlap. The digitized subcarrier signal is a
digital representation of the modulation signal on the RF envelope. The two sections of the digital receiver
block are the protocol bit decoder section and the framing logic section.
The protocol bit decoder section converts the subcarrier coded signal into a serial bit stream and a data
clock. The decoder logic is designed for maximum error tolerance. This tolerance lets the decoder section
successfully decode even partly corrupted subcarrier signals that would otherwise be lost due to noise or
interference.
The framing logic section formats the serial bit stream data from the protocol bit decoder stage into data
bytes. During the formatting process, special signals such as the start of frame (SOF), end of frame
(EOF), start of communication, and end of communication are automatically removed. The parity bits and
CRC bytes are also checked and removed. The end result is "clean" or "raw" data that is then sent to the
12-byte FIFO register where it can be read by the external microcontroller system. Providing the data this
way, in conjunction with the timing register settings of the TRF7960A, means the firmware developer must
know about much less of the finer details of the ISO protocols to create a very robust application,
especially in low-cost platforms where code space is at a premium and high performance is still required.
The start of the receive operation (successfully received SOF) sets the IRQ flags in the IRQ Status
register (0x0C). The end of the receive operation is signaled to the external system MCU by setting pin 13
(IRQ) to high. When data is received in the FIFO, an interrupt is sent to the MCU to signal that there is
data to be read from the FIFO. The FIFO Status register (0x1C) should be used to provide the number of
bytes that should be clocked out during the actual FIFO read. Additionally, an interrupt is sent to the MCU
when the received data occupies 75% of the FIFO capacity to signal that the data should be removed
from the FIFO. That interrupt is triggered when the received data packet is longer than 9 bytes.
Any error in the data format, parity, or CRC is detected and notified to the external system by an interrupt
request pulse. The source condition of the interrupt request pulse is available in the IRQ Status register
(0x0C). The main register controlling the digital part of the receiver is the ISO Control register (0x01). By
writing to this register, the user selects the protocol to be used. With each new write in this register, the
default presets are reloaded in all related registers, so no further adjustments in other registers are
needed for proper operation.
NOTE
If additional register setting changes are needed to fine-tune the system, set the ISO Control
register (0x01) before making the additional changes.

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The framing section also supports the bit-collision detection as specified in ISO/IEC 14443 A and
ISO/IEC 15693. When a bit collision is detected, an interrupt request is sent and a flag is set in the IRQ
Status register (0x0C). For ISO/IEC 14443 A specifically, the position of the bit collision is written in two
registers: partly in the Collision Position register (0x0E) and partly in the Collision Position and Interrupt
Mask register (0x0D) (bits B6 and B7).
The collision position is presented as sequential bit number, where the count starts immediately after the
start bit. This means a collision in the first bit of a UID would give the value 00 0001 0000 in these
registers when their contents are combined after being read. (the count starts with 0 and the first 16 bits
are the command code and the number of valid bits [NVB] byte).
The receive section also includes two timers. The RX wait time timer is controlled by the value in the RX
Wait Time register (0x08). This timer defines the time interval after the end of the transmit operation in
which the receive decoders are not active (held in reset state). This prevents false detections resulting
from transients following the transmit operation. The value of the RX Wait Time register (0x08) defines the
time in increments of 9.44 µs. This register is preset at every write to ISO Control register (0x01)
according to the minimum tag response time defined by each standard.
The RX no response timer is controlled by the RX No Response Wait Time register (0x07). This timer
measures the time from the start of slot in the anticollision sequence until the start of tag response. If there
is no tag response in the defined time, an interrupt request is sent and a flag is set in the IRQ Status
register (0x0C). This enables the external controller to be relieved of the task of detecting empty slots. The
wait time is stored in the register in increments of 37.76 µs. This register is also automatically preset for
every new protocol selection.
6.7.1 Received Signal Strength Indicator (RSSI)
The TRF7960A incorporates three independent RSSI building blocks: Internal Main RSSI, Internal
Auxiliary RSSI, and External RSSI. The internal RSSI blocks are measuring the amplitude of the
subcarrier signal, and the external RSSI block measures the amplitude of the RF carrier signal at the
receiver input.
6.7.1.1 Internal RSSI – Main and Auxiliary Receivers
Each receiver path has its own RSSI block to measure the envelope of the demodulated RF signal
(subcarrier). Internal Main RSSI and Internal Auxiliary RSSI are identical except that they are connected to
different RF input pins. The Internal RSSI is intended for diagnostic purposes to set the correct RX path
conditions.
The Internal RSSI values can be used to adjust the RX gain settings or decide which RX path (main or
auxiliary) provides the greater amplitude and, hence, to decide if the MUX may need to be reprogrammed
to swap the RX input signal. The measuring system latches the peak value, so the RSSI level can be read
after the end of each receive packet. The RSSI register values are reset with every transmission (TX) by
the reader. This guarantees an updated RSSI measurement for each new tag response.
The Internal RSSI has 7 steps (3 bit) with a typical increment of approximately 4 dB. The operating range
is 600 mVpp to 4.2 Vpp with a typical step size of approximately 600 mV. Both RSSI values "Internal
Main" and "Internal Aux" RSSI are stored in the RSSI Levels and Oscillator Status register (0x0F).
Figure 6-2 shows the nominal relationship between the input RF peak level and the RSSI value.

0
1
2
3
4
5
6
7
0 25 50 75 100 125 150 175 200 225 250 275 300 325
RF Input Voltage Level at Pin RF_IN1 (mV )
PP
RSSI Levels and Oscillator Status Register Value (0x0F)
0
1
2
3
4
5
6
7
0 0.25 0.5 0.75 1 1.25 1.5 1.75 2 2.25 2.5 2.75 3 3.25 3.5 3.75 4 4.25
Input RF Carrier Level (V )
PP
RSSI Levels and Oscillator Status Register Value (0x0F)
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Figure 6-2. Digital Internal RSSI (Main and Auxiliary) Value vs RF Input Level
This RSSI measurement is done during the communication to the Tag; this means the TX must be on.
Bit 1 in the Chip Status Control register (0x00) defines if internal RSSI or the external RSSI value is stored
in the RSSI Levels and Oscillator Status register 0x0F. Direct command 0x18 is used to trigger an internal
RSSI measurement.
6.7.1.2 External RSSI
The external RSSI is mainly used for test and diagnostic to sense the amplitude of any 13.56-MHz signal
at the receiver's RX_IN1 input. The external RSSI measurement is typically done in active mode when the
receiver is on but transmitter output is off. The level of the RF signal received at the antenna is measured
and stored in the RSSI Levels and Oscillator Status register (0x0F).
Figure 6-3 shows the relationship between the voltage at the RX_IN1 input and the 3-bit code.
Figure 6-3. Digital External RSSI Value vs RF Input Level