NXP Semiconductors A3M38SL039 User manual

NXP reserves the right to change the detail specifications as may be required to permit
improvements in the design of its products.
The A3M38SL039 is a fully integrated Doherty power amplifier module
designed for wireless infrastructure applications that demand high
performance in the smallest footprint. Ideal for applications in massive MIMO
systems, outdoor small cells and low power remote radio heads. The field-
proven LDMOS power amplifiers are designed for TDD LTE and 5G systems.
The module integrates an autobias feature with the option to overwrite
production settings. Autobias automatically sets and regulates transistor bias
over temperature upon power up. An integrated sensor for monitoring
temperature is also present. Communications to the module can be
accomplished via either I2C or SPI.
3600–4000 MHz
Typical LTE Performance: Pout = 8 W Avg., VDD = 30 Vdc, 1 × 20 MHz LTE,
Input Signal PAR = 8 dB @ 0.01% Probability on CCDF.1
Carrier Center
Frequency
Gain
(dB)
ACPR
(dBc)
PAE
(%)
3610 MHz 28.2 –29.1 32.7
3800 MHz 28.2 –28.9 34.1
3990 MHz 28.1 –27.2 31.8
1. All data measured with device soldered in NXP reference circuit.
Features
• Advanced high performance in-package Doherty
• Fully matched (50 ohm input/output, DC blocked)
• Designed for low complexity digital linearization systems
• Autobias on power up
• Temperature sensing
• Digital interface (I2C or SPI)
• Embedded registers and DACs for setting bias conditions
• Tx Enable control pin for TDD operation
A3M38SL039I
A3M38SL039S
3600–4000 MHz, 28 dB,
8 W Avg. Airfast Power
Amplifier Module with
Autobias Control
10 mm × 8 mm Module
A3M38SL039
Airfast Power Amplifier Module with Autobias Control
Rev. 0
—
September 2022
Data Sheet: Technical Data

A3M38SL039 Airfast Power Amplifier Module with Autobias Control, Rev. 0, September 2022
Data Sheet: Technical Data 2/ 33
Contents
1Pinout configuration and function ..................3
1.1 Pin connections...............................................3
1.2 Functional pin description................................4
2Electrical characteristics..................................4
2.1 Ratings ............................................................4
2.1.1 Maximum ratings.............................................4
2.1.2 Lifetime............................................................5
2.1.3 ESD protection characteristics ........................5
2.1.4 Moisture sensitivity level..................................5
2.2 Operating characteristics.................................5
2.2.1 Nominal DAC settings .....................................5
2.2.2 Functional tests ...............................................6
2.2.3 Wideband ruggedness ....................................6
2.2.4 Typical performance........................................6
3Register map and OTP memory.......................7
3.1 One-time programmable memory....................7
3.2 Register map...................................................7
4Power supply sequence .................................10
5Autobias functionality ....................................11
5.1 General overview ..........................................11
5.2 Operational overview.....................................11
5.3 Tx enable control........................................... 12
5.4 Sense_DAC ..................................................12
5.5 VGS_DAC .....................................................13
5.6 Engineering Mode (EM) ................................13
6Ordering information ......................................13
7Component layout and parts list ................... 14
7.1 Component layout......................................... 14
7.2 Component designations and values ............ 15
8Temperature sensor .......................................15
9Communication interfaces............................. 16
9.1 SPI ................................................................ 16
9.1.1 SPI timing diagram........................................ 16
9.1.2 SPI instruction set definition.......................... 16
9.2 I2C ................................................................. 17
9.2.1 I2C addressing............................................... 17
9.2.2 I2C instruction set .......................................... 18
9.2.3 I2C Device ID Read instruction...................... 19
9.3 I2C electrical specification and timing for I/O
stages and bus lines ..................................... 20
9.3.1 I2C SCLK and SDA characteristics................ 21
9.3.2 I2C bus electrical characteristics ................... 22
10 Design considerations ...................................22
10.1 Power on sequence ...................................... 22
10.2 Programming guidelines to avoid hardware
failure or damage .......................................... 23
10.3 Group programming ...................................... 23
11 Product marking .............................................25
12 Package information.......................................26
13 Product software and tools............................32
14 Failure analysis...............................................32
15 Revision history.............................................. 32

Pinout configuration and function
A3M38SL039 Airfast Power Amplifier Module with Autobias Control, Rev. 0, September 2022
Data Sheet: Technical Data 3/ 33
1 Pinout configuration and function
1.1 Pin connections
Figure 1. Pin connections

Electrical characteristics
A3M38SL039 Airfast Power Amplifier Module with Autobias Control, Rev. 0, September 2022
Data Sheet: Technical Data 4/ 33
1.2 Functional pin description
Table 1. Functional pin description
Pin Number Pin Function Pin Description
1 VDC2 Carrier Drain Supply, Stage 2
2 VDC1 Carrier Drain Supply, Stage 1
3, 5, 6, 8, 14, 17, 22, 23, 25, 26, 27, 28, 29,
30, 31, 32, 33, 34, 35, 36, 37, 38
GND Ground
4, 18, 21 N.C. No Connection
7 RFin RF Input Signal @ 50 Ohm
9 A1 I2C Address A1 (tri-state, tie to 5 V, tie to ground or leave
floating)
10 A0 I2C Address A0 (tri-state, tie to 5 V, tie to ground or leave
floating)
11 SCLK SPI/I2C Serial Clock Signal (1.8 V JEDEC compatible)
12 SDA SPI/I2C Serial Data Signal (1.8 V JEDEC compatible)
13 CS_B Chip Selection Bar for SPI (1.8 V JEDEC compatible)
15 Tx_EN PA Enable Signal (1.8 V JEDEC compatible)
16 VCC_+5V 5 V VCC Power Source for Autobias Chip
19 VDP1 Peaking Drain Supply, Stage 1
20 VDP2 Peaking Drain Supply, Stage 2
24 RFout RF Output Signal @ 50 Ohm
2 Electrical characteristics
2.1 Ratings
2.1.1 Maximum ratings
Table 2. Maximum ratings
Rating Symbol Value Unit
Operating Voltage Range VCC_+5V 4.75 to 5.25 Vdc
5 VCC Slew Rate, TC= 25°C VCC_+5V_SLEW 9.5 ms
Operating Voltage Range VDD 24 to 30 Vdc
Operating Voltage Range A1, A0 4.75 to 5.25 Vdc
Operating Voltage Range CS_B, SDA, SCLK,
Tx_EN
1.65 to 1.95 Vdc
Storage Temperature Range Tstg –65 to +150 °C
Case Operating Temperature TC 125 °C
Peak Input Power
(3800 MHz, Pulsed CW, 10 µsec(on), 10% Duty Cycle)
Pin 25 dBm

Electrical characteristics
A3M38SL039 Airfast Power Amplifier Module with Autobias Control, Rev. 0, September 2022
Data Sheet: Technical Data 5/ 33
2.1.2 Lifetime
Table 3. Lifetime
Characteristic Symbol Value Unit
Mean Time to Failure
Case Temperature 125°C, Internal Sense Temperature 108°C, 8 W Avg.,
75% Duty Cycle, 30 Vdc
MTTF >10 Years
2.1.3 ESD protection characteristics
Table 4. ESD protection characteristics
Test Methodology Class
Human Body Model (per JS-001-2017) 3A
Charge Device Model (per JS-002-2014) C3
2.1.4 Moisture sensitivity level
Table 5. Moisture sensitivity level
Test Methodology Rating Package Peak Temperature Unit
Per JESD22-A113, IPC/JEDEC J-STD-020 3 260 °C
2.2 Operating characteristics
2.2.1 Nominal DAC settings
Table 6. Nominal DAC settings1
Characteristic Symbol Typ Unit
Gate Quiescent DAC
(VDS = 30 Vdc, A_SENSE_DAC = 40, A_VGS1_DAC = 6)
IDQ1C 26 mA
Gate Quiescent DAC
(VDS = 30 Vdc, A_SENSE_DAC = 40, A_VGS2_DAC = 34)
IDQ2C 72 mA
Gate Quiescent DAC
(VDS = 30 Vdc, B_SENSE_DAC = 34, B_VGS1_DAC = 60)
IDQ1P1 mA
Gate Quiescent DAC
(VDS = 30 Vdc, B_SENSE_DAC = 34, B_VGS2_DAC = 80)
IDQ2P 1 mA
1. Each side of device measured separately.

Electrical characteristics
A3M38SL039 Airfast Power Amplifier Module with Autobias Control, Rev. 0, September 2022
Data Sheet: Technical Data 6/ 33
2.2.2 Functional tests
Table 7. Functional tests
Characteristic
Symbol
Min
Typ
Max
Unit
Functional Tests — 3600 MHz1(In NXP Doherty Production ATE2Test Fixture, 50 ohm system) VDD = 30 Vdc, Nominal
DAC Settings, Tx_EN = High, Pout = 8 W Avg., 1-tone CW, f = 3600 MHz.
Gain
G
24.6
26.8
—
dB
Drain Efficiency
η
D
28.0
33.0
—
%
Pout @ 3 dB Compression Point P3dB 45.7 46.9 — dBm
Functional Tests — 4000 MHz1(In NXP Doherty Production ATE2Test Fixture, 50 ohm system) VDD = 30 Vdc, Nominal
DAC Settings, Tx_EN = High, Pout = 8 W Avg., 1-tone CW, f = 4000 MHz.
Gain
G
25.5
27.6
—
dB
Drain Efficiency ηD 27.0 32.8 — %
Pout @ 3 dB Compression Point P3dB 45.5 46.8 — dBm
2.2.3 Wideband ruggedness
Table 8. Wideband ruggedness
Characteristic
Symbol
Min
Typ
Max
Unit
Wideband Ruggedness
3 (In NXP Doherty Power Amplifier Module Reference Circuit, 50 ohm system) Nominal DAC
Settings, Tx_EN = High, f = 3800 MHz, Additive White Gaussian Noise (AWGN) with 10 dB PAR
ISBW of 400 MHz at 30 Vdc, 3 dB Input Overdrive from 8 W
Avg. Modulated Output Power
No Device Degradation
2.2.4 Typical performance
Table 9. Typical performance
Characteristic
Symbol
Min
Typ
Max
Unit
Typical Performance
3 (In NXP Doherty Power Amplifier Module Reference Circuit, 50 ohm system) VDD = 30 Vdc, Nominal
DAC Settings, Tx_EN = High, Pout = 8 W Avg., 3800 MHz
VBW Resonance Point, 2-tone, 1 MHz Tone Spacing
(IMD Third Order Intermodulation Inflection Point)
VBWres — 400 — MHz
1-carrier 20 MHz LTE, 8 dB Input Signal PAR
Gain
G
—
28.2
—
dB
Power Added Efficiency PAE — 34.1 — %
Adjacent Channel Power Ratio ACPR — –28.9 — dBc
Adjacent Channel Power Ratio ALT1 — –42.1 — dBc
Adjacent Channel Power Ratio
ALT2
—
–52.4
—
dBc
Gain Flatness
4
G
F
—
0.1
—
dB
Fast CW, 27 ms Sweep
Pout @ 3 dB Compression Point P3dB — 47.8 — dBm
AM/PM @ P3dB
Φ
—
–13
—
°
Gain Variation @ Avg. Power over Temperature
(–40
°
C to +105
°
C)
ΔG
—
0.023
—
dB/
°
C
P3dB Variation over Temperature
(–40°C to +105°C)
P3dB — 0.008 — dB/°C
1. Part input and output matched to 50 ohms.
2. ATE is a socketed test environment.
3. All data measured in fixture with device soldered in NXP reference circuit.
4. Gain flatness = Max(G(fLow to fHigh)) – Min(G(fLow to fHigh))

Register map and OTP memory
A3M38SL039 Airfast Power Amplifier Module with Autobias Control, Rev. 0, September 2022
Data Sheet: Technical Data 7/ 33
3 Register map and OTP memory
3.1 One-time programmable memory
The A3M38SL039 contains a one-time programmable (OTP) memory array that is used to store register values for the
integrated autobias controller. The data sheet IDQ target values are determined and programmed into the OTP memory during
NXP’s production testing. When programmed, the OTP memory is used to store these values for automatic loading into
autobias registers at power on or reset. These values can be overwritten using the Engineering Mode (EM) sequence;
however, the overwritten values do not persist after a power cycle or a reset.
The OTP memory can be programmed only by NXP during the manufacturing process and cannot be changed by the user.
The values in OTP memory have been selected to allow the device to operate in a wide variety of applications.
3.2 Register map
There are nine 8-bit user accessible registers available in the A3M38SL039. The register mapping is listed in Table 10.
Address 0 RW register is designed to control soft reset, refresh OTP and read the chip version. Address 1−6 registers are RW
and/or OTP controlled and provide settings for the two RF transistor group DACs. Address 15 is read only for temperature
sense functionality. Address 17 is a virtual write only register for enabling Engineering Mode.

Register map and OTP memory
A3M38SL039 Airfast Power Amplifier Module with Autobias Control, Rev. 0, September 2022
Data Sheet: Technical Data 8/ 33
Table 10. Register map
Address
(in Decimal)
Register
Attribute
Register
Name
Register Definition Default
Valuebit7 bit6 bit5 bit4 bit3 bit2 bit1 bit0
0 RW System_Reg N/A Soft
Reset
Refresh
OTP
N/A Chip Version [3:0] (Read
only)
8'b0000_0001
1 OTP
COPY
(RW)
A_Sense_DAC Reserved Group A Sense DAC OTP value
2 OTP
COPY
(RW)
A_VGS1_DAC Group A VGS1DAC OTP value
3 OTP
COPY
(RW)
A_VGS2_DAC Group A VGS2DAC OTP value
4 OTP
COPY
(RW)
B_Sense_DAC Reserved Group B Sense DAC OTP value
5 OTP
COPY
(RW)
B_VGS3_DAC Group B VGS3DAC OTP value
6 OTP
COPY
(RW)
B_VGS4_DAC Group B VGS4DAC OTP value
7–14 — — Reserved —
15 RO Temp_ADC Temperature Sensor [7:0] —
16 — — Reserved —
17 Virtual W
only
EM_Passcode Engineering Mode (EM) passcode 8'hE3 —
Read Only register (RO)
Read Write register (RW)
Read Write register with OTP overwrite at Startup (RW)
Reserved non-accessible register
Write Only register

Register map and OTP memory
A3M38SL039 Airfast Power Amplifier Module with Autobias Control, Rev. 0, September 2022
Data Sheet: Technical Data 9/ 33
Table 11. Register overview and bit description
Address
Register
Name Bit Bit Descriptions
Power
On/Reset
Value1
Overwritten
by OTP Attribute
EM
Mode
0 System_Reg 7 Not available N/A N/A N/A N/A
6 Soft Reset. A 1 written to this register
will perform a reset of all registers to
their default values. A 0 should be
written after the reset operation is
completed.
0 No RW
5 Refresh OTP. A 1 written to this
register will overwrite values stored
in OTP into registers identified in the
"Overwritten by OTP" column. A 0
should be written after the reset
operation is completed.
0 No
4 Not available N/A N/A N/A
0–3 Chip version bits. Inserted by NXP to
provide revision information. Cannot
be changed.
N/A No R
1 A_Sense_DAC 6–7 Not available N/A N/A N/A
0–5 Sense DAC A 6-bit logic value for
carrier amplifiers. DAC A sets the
reference voltage to compare to the
VDS across the reference device.
Minimum typical value is 6'b001000
and maximum value is 6'b111111.
Recommendation is that the value in
this register be set higher than
6'b010000.
6'h20 Yes RW2Yes
2 A_VGS1_DAC 0–7 Sets 8-bit DAC logic value for carrier
amplifier driver stage. 8'h00 sets
gate to equal ceiling voltage. 8'hFF
reduces gate voltage by a max
value.
8'h80
3 A_VGS2_DAC 0–7 Sets 8-bit DAC logic value for carrier
amplifier final stage. 8'h00 sets gate
to equal ceiling voltage. 8'hFF
reduces gate voltage by a max
value.
8'h80
(continued)

Power supply sequence
A3M38SL039 Airfast Power Amplifier Module with Autobias Control, Rev. 0, September 2022
Data Sheet: Technical Data 10 / 33
Table 11. Register overview and bit description (continued)
Address
Register
Name Bit Bit Descriptions
Power
On/Reset
Value1
Overwritten
by OTP Attribute
EM
Mode
4 B_Sense_DAC 6–7 Not available N/A N/A N/A No
0–5 Sense DAC B 6-bit logic value for
peaking amplifiers. DAC B sets the
reference voltage to compare to the
VDS across the reference device.
Minimum typical value is 6'b001000
and maximum value is 6'b111111.
Recommendation is that the value in
this register be set higher than
6'b010000.
6'h20 Yes RW2Yes
5 B_VGS3_DAC 0–7 Sets 8-bit DAC logic value for
peaking driver stage. 8'h00 sets gate
to equal ceiling voltage. 8'hFF
reduces gate voltage by a max
value.
8'h80
6 B_VGS4_DAC 0–7 Sets 8-bit DAC logic value for
peaking final stage. 8'h00 sets gate
to equal ceiling voltage. 8'hFF
reduces gate voltage by a max
value.
8'h80
7–14 Reserved N/A Not available N/A N/A N/A No
15 Temp_ADC 0–7 Temperature sensor 8-bit DAC
value. 8'h00 is lowest temperature,
8'hFF is highest temperature.
8'h00 No R No
16 Reserved N/A Not available N/A N/A N/A No
17 EM_Passcode 0–7 Engineering Mode (EM). By writing
8'hE3 to this register the user can
enter engineering mode. EM can be
cleared by writing any other code to
this register. In EM registers
identified in EM mode column can be
changed.
N/A No W Yes
1. At power on or reset, OTP values set by NXP are automatically loaded into registers indicated with a “Yes” in the
“Overwritten by OTP” column. For these registers, values shown in the “Power On/Reset Value column” will be loaded
only if OTP has not been programmed to prevent damage to the device.
2. Register can be read at any time. Can write to register only when in Engineering Mode (EM).
4 Power supply sequence
Power Up Sequence
1. VCC_+5V: 5 V power up
2. SPI/I2C interface is active
3. VDP1,VDP2,VDC1,VDC2 power up

Autobias functionality
A3M38SL039 Airfast Power Amplifier Module with Autobias Control, Rev. 0, September 2022
Data Sheet: Technical Data 11 / 33
Power Down Sequence
1. VDP1,VDP2,VDC1,VDC2 power down
2. SPI/I2C interface deactivated
3. VCC_+5V: 5 V power down
Note: All digital interfaces (SDA, SCLK, CS_B,Tx_EN) are 1.8 V logic.
5 Autobias functionality
5.1 General overview
After power up, the integrated bias controller develops and applies a thermally compensated quiescent bias voltage to the gate
of each of the four RF transistors contained within the power amplifier module (PAM) based on the preset OTP values. See
Section 3.1 for more information on the OTP memory. This achieves optimal RF performance over the full temperature range.
The standard SPI or I2C interface can be used to read the temperature sensor and overwrite preset DAC values. The device
can be used without the programming interface. The thermal compensation circuit is analog and not programmable; however,
the preset DAC values can be overwritten to provide an alternate thermal compensation scheme via the SPI or I2C interface.
This section describes the operation and programming of the bias controller.
5.2 Operational overview
Figure 2 shows a detailed view of the carrier side (Group A) autobias controller. The peaking side (Group B) controller is a
duplicate of the carrier; however, the RF transistor peripheries and quiescent operating points will be different as required by
the Doherty operation. The module contains four RF LDMOS field-effect transistors (FET) consisting of a driver and final for
the carrier amplifier (on a single IC die) and a driver and final for the peaking amplifier (on a single IC die). Each IC die also
contains a small periphery reference FET that is designed to match the properties of the larger RF transistors with regard to
part-to-part process and temperature-dependent variations. The bias controller interfaces with each of the RF FETs and
provides flexibility to control the biasing of each transistor independently.
The bias controller operates by establishing a known current through the reference FET typically in the range of 1−2 mA per
reference FET. This in turn establishes a gate-source operating voltage by sensing the voltage drop across an integrated, high
tolerance resistor placed between VCC (5 V) and the reference device drain terminal. The bias controller VCC_+5V pin should
be operated from a 5 V supply with tolerance of ±5%. The reference voltage across the precision resistor R1 is compared to a
voltage programmed in the bias controller (A_Sense_DAC and B_Sense_DAC), thereby providing fine incremental adjustment
to the default bias current of the reference FET. Because the reference FET and RF FET are manufactured on the same die in
close proximity, they exhibit similar process and temperature dependencies.

Autobias functionality
A3M38SL039 Airfast Power Amplifier Module with Autobias Control, Rev. 0, September 2022
Data Sheet: Technical Data 12 / 33
Figure 2. Block diagram of carrier (A) autobias functionality. Peaking (B) autobias functionality is identical.
The initial bias condition is set via the A_Sense_DAC register. The bias condition is then sensed and adjusted as temperature
changes via the closed-loop feedback. The feedback mechanism adjusts the DAC ceiling voltage to maintain a constant IDS
current through the reference FET. The temperature compensated DAC ceiling voltage can either be passed to the carrier PA
final and carrier PA driver directly, or reduced by values set in the A_VGS1_DAC and A_VGS2_DAC to the DAC floor voltage.
5.3 Tx enable control
A 1.8 V JEDEC compliant enable signal (Tx_EN) is included for bias On/Off operation to support TDD operation. The controller
provides capability to quickly switch the RF FETs between ON and OFF modes in less than 100 ns. With Tx_EN in an ON
state, the RF FET gate terminals are internally decoupled with sufficient capacitance providing a low impedance for wide
baseband signals. The large capacitance also serves as a charge holding cap for reducing switching transient time in TDD
operation. In Tx OFF mode, RF FET device gates are grounded shutting them OFF.
Table 12. TX_EN Off-State Typical Currents
Characteristic Typical Value Unit
VCC_+5V Supply Current 11 mA
Combined Drain Supply Currents (VDC1, VDC2, VDP1, VDP2) 20 μA
5.4 Sense_DAC
The current in the reference FET is controlled and programmed with 6 bits (two MSBs of the 8-bit register are not used) via the
sense DAC (A_Sense_DAC and B_Sense_DAC). By programming the sense DAC, the RF stage DAC ceiling voltage
reference operating point can be optimally set. The DAC ceiling voltage reference point impacts both RF PA stages (driver and
final) simultaneously. After OTP has been programmed, the Sense_DAC is loaded with the programmed values and are then
only programmable in Engineering Mode.
The factory programmed values for A_Sense_DAC and B_Sense_DAC are decimal 40 and 34 respectively. These values
have been optimized for best power, linearity and efficiency tradeoffs.

Ordering information
A3M38SL039 Airfast Power Amplifier Module with Autobias Control, Rev. 0, September 2022
Data Sheet: Technical Data 13 / 33
5.5 VGS_DAC
The VGS_DAC voltage is determined via the Sense_DAC setting, creating the top end or ceiling of the VGS_DAC voltage
range and a fixed offset voltage creating the bottom end or floor of the VGS_DAC voltage range. With a decimal VGS_DAC
setting of 0, the gate voltage developed on the reference FET is buffered with minimum offset to the gates of the RF
transistors in the carrier amplifier. As the VGS_DAC value increases, the voltage applied to the gates of the RF transistors
decreases, which also reduces IDQ. This allows the operating point of the four RF devices to be set to any desired value, from
Class AB to Class C.
The reference FETs and RF FETs exhibit approximately the same current density (that is, IDQ/mm gate width). It is important to
note that, because the reference device and RF transistors are manufactured on the same die in close proximity, they exhibit
similar process and temperature dependencies. Both the peaking amplifier and the carrier amplifier operate in the same way
with regard to the reference device and the RF transistors.
5.6 Engineering Mode (EM)
Flexibility exists to overwrite the OTP memory values, if needed. A special Engineering Mode (EM) is available to allow the
user to overwrite data that has been placed into the OTP memory space. To enter EM, issue the write address d’17 command
with the predefined EM passcode (see Table 10). After entering EM, all DAC OTP registers (address 1–6) can be overwritten
with the normal I2C/SPI write instruction. This interface programmed value will be valid so long the VCC supply power is
maintained. The VCC power cycle will load OTP programmed DAC settings again. If the user writes the address d’17 register
with any value other than the passcode, EM will automatically exit.
6 Ordering information
Table 13. Ordering information
Device Tape and Reel Information
Digital
Interface Package
A3M38SL039IAAT2 T2 Suffix = 2,000 Units, 24 mm Tape Width, 13-inch Reel I2C 10 mm × 8 mm Module

Component layout and parts list
A3M38SL039 Airfast Power Amplifier Module with Autobias Control, Rev. 0, September 2022
Data Sheet: Technical Data 14 / 33
7 Component layout and parts list
7.1 Component layout
Figure 3. A3M38SL039 reference circuit component layout
RF
OUT
RF
IN
Rev. 4.0
C2
C4
C1
NC
VDC2
A1
A0
GND GND
TX_EN
VCC_+5V
GND
NC
VDP1
VDP2
NC
VCC
VCC
SDACS_B
SCLK
GNDGND
B1
C14
aaa-042694
C15
L1
C17
C12
C10
R1
D157947
C18
Q1

Temperature sensor
A3M38SL039 Airfast Power Amplifier Module with Autobias Control, Rev. 0, September 2022
Data Sheet: Technical Data 15 / 33
7.2 Component designations and values
Table 14. A3M38SL039 reference circuit component designations and values
Part Description Part Number Manufacturer
B1 30 Ω Ferrite Bead BLM15PD300SN1 Murata
C1, C2, C14, C15 10 µF Chip Capacitor GRM31CR61H106KA12 Murata
C4, C10, C12 1 µF Chip Capacitor GRM188R61H105KAAL Murata
C17 1000 pF Chip Capacitor GRM022R71A102KA12L Murata
C18 220 µF, 50 V Electrolytic Capacitor UUJ1H221MNQ1MS Nichicon
L1 13 nH Chip Inductor LQW15AN13NG80D Murata
Q1 Power Amplifier Module A3M38SL039 NXP
R1 0 Ω, 1/8 W Chip Resistor CRCW08050000Z0EA Vishay
PCB Rogers RO4350B, 0.020″, εr= 3.66 D139037 MTL
Note: Component numbers C3, C5, C6, C7, C8, C9, C11, C13 and C16 are intentionally omitted.
8 Temperature sensor
The temperature value is converted from the 8-bit temperature sense ADC value (stored in the Temp_ADC register) via the
following equation.
Temperature (°C) = (0.67798 × Temp_ADC) – 36.64
A plot of this equation is shown in Figure 4.
Figure 4. Die temperature versus ADC code
Table 15. Temperature sensor accuracy
Characteristic Value Unit
Operating Die Temperature, TJ= 25°C to 125°C ±3 °C
Operating Die Temperature, TJ= –35°C to 125°C ±5 °C
DIE TEMPERATURE ( C)
ADC CODE (DECIMAL)
140
100
60
80
40
20
0
–20
2560 6432 112 160208
–60
–40
120
16 48 96 128192224240
160
80 176144

Communication interfaces
A3M38SL039 Airfast Power Amplifier Module with Autobias Control, Rev. 0, September 2022
Data Sheet: Technical Data 16 / 33
9 Communication interfaces
The A3M38SL039 device contains a digital interface that supports either a 3-pin SPI or 2-pin I2C interface. The digital interface
is used to both read and write data to and from the device. The preferred interface type must be set at the factory prior to
shipment. For I2C functionality, order part number A3M38SL039I. For SPI functionality, order part number A3M38SL039S.
9.1 SPI
The A3M38SL039S can be programmed and the Tx bias settings and temperature read through the 3-pin SPI interface.
9.1.1 SPI timing diagram
The SPI interface timing of A3M38SL039S complies with SPI mode3 as shown in Figure 5.
Figure 5. Serial interface timing diagram
Table 16. Serial interface timing specification
Symbol Parameter Min (ns)
tSC Setup timing requirement of CS_B (both rising and falling) in relation to the rising edge of SCLK 50
tWH clk high duration 160
tWL clk low duration 160
tSD Date to clock rising edge setup 20
tHD clk rising edge to data hold time 20
tHC clk to CS_B hold time 50
tWH + tWL Minimum clock period 400
9.1.2 SPI instruction set definition
The SPI instruction set is determined by the first byte after releasing the CS_B signal. The order of SPI instruction is MSB sent
first, LSB sent last. Bit 7 of the SPI instruction set is defined as read (1) or write (0) command. Bits 6−5 define the burst width
in the range of 1−4 bytes: 00 is for 1 byte data, 01 for 2 bytes data, 10 for 3 bytes data and 11 is for 4 bytes data. Bits 4−0 are
defined as the register address that is to be accessed.

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A3M38SL039 Airfast Power Amplifier Module with Autobias Control, Rev. 0, September 2022
Data Sheet: Technical Data 17 / 33
Figure 6. SPI instruction sets diagram
SPI instruction set information:
•R/W read = 1, write = 0
•N1, N0
o2’b00 1 byte
o2’b01 2 bytes
o2’b10 3 bytes
o2’b11 4 bytes
•A4, A3, A2, A1, A0 decode for address 0–15
•MSB sent first, LSB last
9.2 I2C
The A3M38SL039I follows the I2C protocol standard. It supports I2C fast mode with a bit rate up to 400 Kbit/s. It also supports
I2C standard mode with bit rate up to 100 Kbit/s.
9.2.1 I2C addressing
The two external tri-state address pins A0 and A1 use 5 V logic levels and are decoded into 7-bit I2C addresses as shown
in Table 17. The three LSBs of the 7-bit address are set via the A0 and A1 pins. The four MSBs are the base address, which is
fixed at 1000.
Table 17. I2C 7-bit address assignment
A1 A0 I2C 7-Bit Address
0 0 Not translated
0 Z 1000 000
0 1 1000 001
Z 0 1000 010
Z Z 1000 011
Z 1 1000 100
1 0 1000 101
1 Z 1000 110
1 1 1000 111

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A3M38SL039 Airfast Power Amplifier Module with Autobias Control, Rev. 0, September 2022
Data Sheet: Technical Data 18 / 33
9.2.2 I2C instruction set
I2C Write instruction
Figure 7. I2C Write instruction
I2C Read instruction
Figure 8. I2C Read instruction

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A3M38SL039 Airfast Power Amplifier Module with Autobias Control, Rev. 0, September 2022
Data Sheet: Technical Data 19 / 33
I2C Write and Read combination sequence
Figure 9. I2C Write and Read combination sequence
9.2.3 I2C Device ID Read instruction
The Device ID is read only, hardwired in the device and can be accessed as follows:
1. START condition
2. The leader sends the Reserved Device ID I2C bus address followed by the R/W bit set to ‘0’ (write): ‘1111 1000’.
3. The leader sends the I2C bus follower address of the follower device it must identify. The LSB is a “don’t care” value. Only
one device must acknowledge this byte (the device that has the I2C bus follower address).
4. The leader sends a RESTART condition.
Remark: A STOP condition followed by a START condition resets the follower state machine and the Device ID read cannot
be performed. Also, a STOP condition or a RESTART condition followed by an access to another follower device resets the
follower state machine and the Device ID read cannot be performed.
1. The leader sends the Reserved Device ID I2C bus address followed by the R/W bit set to ‘1’ (read): ‘1111 1001’.
2. The Device ID read can be completed, starting with the 12 manufacturer bits (first byte + four MSBs of the second byte),
followed by the nine part identification bits (four LSBs of the second byte + five MSBs of the third byte), and then the three
die revision bits (three LSBs of the third byte).
3. The leader ends the reading sequence by NACKing the last byte, thus resetting the follower device state machine and
allowing the leader to send the STOP condition.
Remark: The reading of the Device ID can be stopped anytime by sending a NACK.

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A3M38SL039 Airfast Power Amplifier Module with Autobias Control, Rev. 0, September 2022
Data Sheet: Technical Data 20 / 33
Table 18. I2C Device Read instructions
Leader to
Follower
Leader to
Follower
Leader to
Follower
Leader to
Follower
Leader to
Follower
Follower to
Leader
Leader to
Follower
Leader to
Follower
START 1111 1000 XXXXXXX+‘0/1’ RESTART 1111 1001 3 bytes ID NACK STOP
9.3 I2C electrical specification and timing for I/O stages and bus lines
Note: VIL = 0.3 VDD, VIH = 0.7 VDD
Figure 10. I2C electrical specification and timing for I/O stages and bus lines
aaa-042715
tf
70 %
30 %
SDA
tf
70 %
30 %
S
tr
70 %
30 %
70 %
30 %
tHD;DAT
SCLK
1 / fSCLK
1st clock cycle
70 %
30 %
70 %
30 %
tr
tVD;DAT
cont.
cont.
SDA
SCLK
tSU;STA tHD;STA
Sr
tSP tSU;STO
tBUF
PS
tHIGH
9th clock
tHD;STA tLOW
70 %
30 %
tVD;ACK
9th clock
tSU;DAT