Datasheet

Circuit Details and Configuration

www.ti.com

2.2.2 Circuit Isolation DIP Switch (S2)

The eight-position DIP switch (S2) allows the user to isolate the MSP430 circuit from the bq76925 circuit.

Circuit isolation may be needed to measure some performance characteristics of the bq76925 or during

MSP430 programming.

CAUTION

Use silkscreen labeling and square pin 1 pad to determine orientation and

operation of the eight-position DIP switch. Ignore numbers actually printed on

the switch.

Table 12. DIP Switch, S2

Switch Name Terminal Label Purpose

S2 1 V3P3 Controls application of V3P3 from bq76925 to MSP430

2 Therm Isolates the THERM circuit when opened.

3 VCOUT Isolates the VCOUT circuit when opened.

4 VIOUT Isolates the VIOUT circuit when opened.

5 SDA Isolates the SDA circuit when opened.

6 SCL Isolates the SCL circuit when opened.

7 ALERT Isolates the ALERT circuit when opened.

8 VRef Isolates the VREF circuit when opened.

2.3 Pushbuttons (S1, S3)

The two pushbuttons on the EVM are normally open, momentary-style buttons. The pushbutton labeled

RESET (S1) is the reset button for the MSP430. Pressing this button restarts the MSP430.

The pushbutton labeled LEDs (S3) is intended to be a display control for the state of charge (SOC) display

formed by the four LEDs (D8 –D11). Pressing this button triggers an input on the MSP430 that

incrementally lights the four LEDs – despite what the actual SOC of the battery may be that is connected

to the EVM. This is the default functionality defined by the firmware. The user can choose to use the

pushbutton in another way by creating new firmware for the MSP430.

2.4 Test Points

Twenty-nine test loops are located on the EVM. Table 13 names the circuit connected to each test point.

The first 20 test points correspond one-to-one to the pin number on the bq76925.

Table 13. Test Points

Label Ground Reference Test Point

TP1 VCTL

TP2 BAT

TP3 VC6

TP4 VC5

TP5 VC4

TP6 VC3

TP7 VC2

TP8 VC1

TP9 VC0

TP10 VSS

TP11 SENSEN

TP12 SENSEP

bq76925EVM Evaluation Module SLUU514– July 2011

Submit Documentation Feedback