Texas Instruments TPS650231EVM, TPS65023B 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.
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
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.
List of Tables
SLVU394–October 2010 TPS65023B/TPS650231EVM
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Electrical Performance Specification
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.
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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
Orderable EVM Device Part
Number Number
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
Default Output Voltages
DCDC1 DCDC2 DCDC3 LDO1 LDO2
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
2
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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 – VIN
Input 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 – I2C
This 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.
Input/Output Connector Description
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Input/Output Connector Description
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.
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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.
4
TPS65023B/TPS650231EVM SLVU394–October 2010
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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()VLDOREF_V())
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(REF_VDCDC_Vout
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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.
Input/Output Connector Description
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.
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.
(1)
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.
SLVU394–October 2010 TPS65023B/TPS650231EVM
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