Texas Instruments TPS650231EVM User manual

User's Guide
SLVU394–October 2010
TPS65023B/TPS650231EVM
The characteristics, operation, and use of the TPS65023B/TPS650231EVM-664 evaluation module (EVM)
are described in this document. This EVM is designed to help the user evaluate and test the various
operating modes of the TPS65023B/TPS650231. This user’s guide includes setup instructions for the
hardware and software, a schematic diagram, a bill of materials, and PCB layout drawings for the
evaluation module.
Contents
1 Introduction .................................................................................................................. 1
2 Electrical Performance Specification ..................................................................................... 2
3 Input/Output Connector Description ...................................................................................... 3
4 Board Layout ................................................................................................................ 6
5 Schematic and Bill of Materials .......................................................................................... 11
List of Figures
1 Assembly Layer ............................................................................................................. 6
2 Top Layer Routing .......................................................................................................... 7
3 Layer-2 Routing, GND Plane.............................................................................................. 8
4 Layer-3 Routing, Vin Plane................................................................................................ 9
5 Bottom Layer Routing..................................................................................................... 10
6 TPS65023B/TPS650231EVM-664 Schematic......................................................................... 11
List of Tables
1 EVM Ordering Options ..................................................................................................... 2
2 Default LDO Output Voltages TPS65023B.............................................................................. 2
3 Default LDO Output Voltages TPS650231 .............................................................................. 2
4 TPS65023B/TPS650231EVM-664 Bill of Materials................................................................... 12
1 Introduction
The Texas Instruments TPS65023B/TPS650231EVM is an integrated power management integrated
circuit (IC) for applications that are powered with one Li-ion or Li-polymer cell and require multiple power
rails. The TPS65023B/TPS650231 contains three highly efficient switching step-down converters, two
LDOs, and additional status and I/O pins. The device is controlled via an I2C interface (HPA172).
1.1 Requirements
In order for this EVM to operate properly, the following components must be connected and properly
configured.
1.1.1 Personal Computer
A personal computer with a USB port is required to operate this EVM. The TPS65023B/TPS650231
interface software, which is run on the personal computer (PC), communicates with the EVM via the PC
USB port. The user sends commands to the EVM as well as reads the contents of the
TPS65023B/TPS650231 internal registers through the USB port.
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Electrical Performance Specification www.ti.com
1.1.2 Printed-Circuit Board Assembly
The TPS65023B/TPS650231EVM-664 PCB contains the TPS65023B/TPS650231 IC and its required
external components. This board contains several jumpers and connectors that allow the user to
customize the board for specific operating conditions.
1.1.3 USB-to- I2C Adapter
The USB-to-I2C Adapter, also known as the HPA172, is the link that allows the PC and the EVM to
communicate. The adapter connects to the PC with the supplied USB cable on one side and to the EVM
though the supplied ribbon cable on the other. When the user writes a command to the EVM, the interface
program, which is run from the PC, sends the command to the PC USB port. The adapter receives the
USB command and converts the signal to an I2C protocol. It then sends the I2C signal to the
TPS65023B/TPS650231 board. When the user reads a status register from the EVM, the PC sends a
command to read a register on the EVM. When the EVM receives the command, it reports the status of
the register via the I2C interface. The adapter receives the information on the I2C interface, converts it to a
USB protocol, and sends it to the PC.
1.1.4 Software
Texas Instruments provides software to assist the user in evaluating this EVM. To install the software, go
to the Texas Instruments Web page and download the latest software version from the TPS65023B or
TPS650231 product folder. Once you have downloaded the software, execute the setup file, and follow
the instructions given.
1.2 Features
• Three high-efficiency DC/DC step-down converters (1.7 A/1.2 A/1 A)
• 2 x 200-mA low-dropout (LDO) regulators
• 30-mA RTC (Reel Time Clock) LDO
• I2C Interface (100-ns setup and hold time)
• Dynamic voltage scaling DCDC1
2 Electrical Performance Specification
Table 1. EVM Ordering Options
Default Output Voltages
Orderable EVM Device Part
Number Number DCDC1 DCDC2 DCDC3 LDO1 LDO2
TPS65023BEVM-664 TPS65023B 1.2V / 1.6V 1/8V / 3.3V 1.8V / 3.3V SeeTable 2 SeeTable 2
TPS650231EVM-664 TPS650231 1.2V / 1.6V n/a 1.8V / 3.3V See Table 3 See Table 3
Table 2. Default LDO Output Voltages TPS65023B
DEFLDO2 DEFLDO1 VLDO1 VLDO2
0 0 1.3 V 3.3 V
0 1 2.8 V 3.3 V
1 0 1.3 V 1.8 V
1 1 1.8 V 3.3 V
Table 3. Default LDO Output Voltages TPS650231
DEFLDO2 DEFLDO1 VLDO1 VLDO2
0 0 1.3 V 3.3 V
0 1 2.8 V 3.3 V
1 0 1.3 V 1.8 V
1 1 2.1 V 3.3 V
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www.ti.com Input/Output Connector Description
3 Input/Output Connector Description
This section describes the jumpers and connectors on the EVM, as well as how to properly connect, set
up, and use the TPS65023B/TPS650231EVM-664.
J1 – VINInput voltage from external power supply, recommended maximum 5.5 V. Input current depends
on load but typically is less than 2 A.
J2 – GND
This is the return connection for VIN.
J3 – VINLDO/GND
Input voltage and return for LDO1 and LDO2. Resistor R20 connects this pin to VIN. If an
external power supply is used, remove R20. Recommended maximum input voltage is 5.5 V.
J4 – VSYSIN/GND
Input voltage and return for VSYSIN, one of the input voltages for RTC. Resistor R21 can be
used to connect this input to VIN. If an external power supply is used, remove R21.
Recommended maximum input voltage is 4 V.
J5 – VBACKUP/GND
Input voltage and return for VBACKUP, one of the input voltages for RTC. There are no onboard
connections to a voltage input. Recommended maximum input voltage is 4 V.
J6 – VRTC/GND
Output voltage from RTC circuit.
J7 – Fault Outputs
Four fault outputs are available on this connector:
PWRFAIL – Fault occurs when input voltage is less than 3 V. Pulled up to VRTC when safe; low
for fail.
INT – Fault occurs when a fail is on an input or output voltage; acts as a sum fail. Pulled up to
VIN when safe; low for fail.
RESPWRON – Low reset signal is controlled by SW1, 144 ms. Pulled up to VIN normally.
LOWBAT – Fault occurs when input voltage is less than 3.6 V. Pulled up to VIN when safe; low
for fail.
J8 – I2CThis header duplicates the I2C signals from the J20 interface connector. I2C data (SDA) and
clock (SCL) can be accessed on this header
J9 – VDCDC1
Output from DCDC1 switching regulator maximum output current 1.7 A; default voltage setting is
3.3 V.
J10 – GND
Return for VDCDC1.
J11 – VDCDC2
Output from DCDC2 switching regulator; maximum output current 1.2 A.
J12 – GND
Return for VDCDC2
J13 – VLDO1
Output from low-dropout regulator VLDO1; maximum output current 200 mA.
J14 – GND
Return for VLDO1
J15 – VLDO2
Output from low-dropout regulator VLDO2; maximum output current 200 mA.
J16 – GND
Return for VLDO2.
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Input/Output Connector Description www.ti.com
J17 – VDCDC3
Output from switching regulator DCDC3; maximum output current 1 A.
J18– GND
Return for VDCDC3.
J19 – J19 is the interface connector for the I2C interface. Connect a 10-pin ribbon cable between J13
and the USB-to-GPIO interface.
JP1 – DEF1
Sets default voltage for DCDC1, 1.2 V or 1.6 V.
JP2 – DEF2
Sets default voltage for DCDC2, 3.3 V or 1.8 V, in TPS65023B (HPA664-001) configuration. In
the TPS650231, no default output voltage options are available. In this case, the output voltage
is adjustable with an external voltage divider R3, R2. The default setup is 1.2 V in the factory
EVM (HPA664-002) configuration. See section x for advanced voltage scaling options..
JP3 – DEF3
Sets default voltage for DCDC3, 3.3 V or 1.8 V.
JP4 – DCDC1 ON/OFF
EN for DCDC1 converter; default setting is ON
JP5 – DCDC2 ON/OFF
EN for DCDC2 converter; default setting is ON.
JP6 – DCDC3 ON/OFF
EN for DCDC3 converter; default setting is ON.
JP7 – LDO ON/OFF
EN for both LDO1 and LDO2 regulators; default setting is ON.
JP8 – DEFLDO1
Sets default voltage for LDO1 and LDO2 in combination with DEFLDO2. (See Table 2 for
TPS65023B and Table 3 for TPS650231 - defaults LDO output voltages.)
JP9 – DEFLDO2
Sets default voltage for LDO1 and LDO2 in combination with DEFLDO1. (See Table 2 for
TPS65023B and Table 3 for TPS650231 - defaults LDO output voltages.)
S1 – HOT_RST
S1 is a normally open, momentary pushbutton switch that, when pressed, connects the
HOT_RST input of the TPS650231 to GND, generating the HOT_RESET pulse. HOT_RESET
pin is pulled up externally.
3.1 Setup
The following steps must be followed before the EVM can be operated.
1. Install the TPS65023B/TPS650231EVM software.
2. Connect input voltages and loads to the EVM.
3. Configure all EVM jumpers to factory setting.
JP4–ON JP1–1.6V JP3–1.8V
JP2–1.8V JP5–ON JP6–ON
JP7–ON JP9–High JP8–High
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)
R
R
()VLDOREF_V())
R
R
(REF_VDCDC_Vout 3
1
2
2
1
12 ´-++´=
www.ti.com Input/Output Connector Description
4. Connect the ribbon cable between the EVM and the USB-TO-GPIO (HPA172) adapter.
5. Connect the USB cable between the computer and the HPA172EVM.
6. Turn on all supplies.
7. Run the TPS65023B/TPS650231EVM software
3.2 Modifications
3.2.1 Setting the Output Voltage
The TPS65023B features two default output voltages. These output voltages can be selected by pulling
DEFDCDC2 high – selecting the higher default output voltage – or pulling DEFDCDC2 low – selecting the
lower default output voltage.
In addition, the output voltage of DCDC2 can be externally adjusted with the resistor divider network R3
and R6. The default configuration of the TPS65023BEVM-664 is that R3 and R6 are not assembled. The
default output voltage of DCDC2 can be selected with JP2.
Note that the default output voltage is selected once at startup of the device. Changing logic level of
DEFDCDC2 during operation does not affect the output voltage and is not allowed.
3.2.2 Setting the Output Voltage for DCDC2, TPS650231
The TPS650231 does not feature these default output voltages. The output voltages of DCDC2 is
externally adjustable only. The default configuration of the TPS650231EVM-664 is that R3 and R6 are not
assembled. JP2 is not assembled.
TPS650231 does not have the default output voltage feature, and this provides the benefit of external
voltage scaling options.
3.2.3 Simple Two-Point Voltage Scaling, TPS650231
DCDC2 does not have the previously described preset default output voltages. An external voltage scaling
circuit is on the EVM, and the output voltage of DCDC2 can be switched between two preset voltages.
This useful feature reduces the power consumption of an application processor in Low Power mode.
The voltage scaling circuit consists of JP2,Q1, R3, R6, and R24. The circuit uses a transistor (Q1) to
connect a resistor (R24) in parallel to the lower resistor of the feedback network (R6) of DCDC2.
Modifying the resistor network by paralleling R24 and R6 reduces the overall resistance of the lower
resistor and therefore increases the output voltage of the DC/DC converter. See Equation 1 and
Equation 2 to design R24. In the factory configuration, the components JP2, Q1, and R24 are not
assembled on the board.
3.2.4 Scaling the Output Voltage of DCDC2 From LDO2
Another approach to scale the DC/DC converter output voltage is to use an external adjustable voltage.
Any external adjustable voltage source can be used, e.g., output voltage of an digital-to-analog converter.
In the TPS65023B/TPS650231, LDO1 and LDO2 can be adjusted via I2C. The TPS65023B/TPS650231
provides the ability to feed the output voltage of LDO2 back to the resistor divider network, using R25, and
therefore scale the output voltage of DCDC2 based on the LDO2 output voltage.
In this configuration, R25, R3, and R6 need to be assembled. R24, R26, Q1, and R3 need to be removed.
(1)
From Equation 2 it can be seen that maximum DCDC1 output voltage occurs for minimum VLDO2, and
minimum DCDC1 output voltage occurs for maximum VLDO2.
To ensure that the desired DCDC1 output voltages can be adjusted, design the resistors R25, R3, and R6
according to and Equation 2 and Equation 2.
5
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)
R
R
(max),VLDOREF_V())
R
R
(REF_Vmin,DCDC_Vout 3
1
2
2
1
12 ´-++´=
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R
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(min),VLDOREF_V())
R
R
(REF_Vmax,DCDC_Vout 3
1
2
2
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Board Layout www.ti.com
(2)
(3)
The most straight forward way is to choose a value for R6 according to the recommendations in the
converter data sheet.
4 Board Layout
This section provides the TPS65023B/TPS650231EVM-664 board layout and illustrations.
4.1 Layout
Board layout is critical for all switch mode power supplies. Figure 1 through Figure 5 show the board
layout for the TPS65023B/TPS650231EVM-664 PCB. The nodes with high switching frequencies and
currents are short and are isolated from the noise-sensitive feedback circuitry. Careful attention has been
given to the routing of high-frequency current loops. See the data sheet for specific layout guidelines.
Figure 1. Assembly Layer
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www.ti.com Board Layout
Figure 2. Top Layer Routing
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Board Layout www.ti.com
Figure 3. Layer-2 Routing, GND Plane
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www.ti.com Board Layout
Figure 4. Layer-3 Routing, Vin Plane
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Board Layout www.ti.com
Figure 5. Bottom Layer Routing
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