Test Procedure
•
Adjust VBAT to 3.6 V
–
Measure on A #2
→
I
CHRG
= 120 mA ±20 mA
–
Measure on A #1
→
I
IN
= 100 mA ±20 mA
•
Change the Charge Current to 1000 mA and the Input Current Limit to 900 mA and Battery
Regulation Voltage to 4.2 V
•
• Adjust VBAT to 3.6 V
–
Measure on A #2
→
I
CHRG
= 1000 mA ±100 mA
–
Measure on A #1
→
I
IN
= 650 mA ±50 mA
–
Measure on V #3
→
V
BAT
= 3.6 V ±10 mV
–
Measure on V #2
→
V
SYS
= 3.64 V ±30 mV
–
Make sure D1 and D2 are ON (STAT and INT)
•
Change JP4 to jumper shorting pin TS and Var
•
Measure TS pin on JP15 as you change the value of the potentiometer R7
•
Change R7 until VTS = 3 V
–
Measure on A #2
→
I
CHRG
= 0 mA ±20 mA
•
Change R7 until V
TS
= 2.5 V
–
Measure on A #2
→
I
CHRG
= 1000 mA ±30 mA
•
Change R7 until V
TS
= 1 V
–
Measure on A #2
→
I
CHRG
= 0 mA ±20 mA
•
Change JP4 back to jumper shorting pin TS and Fix
5.5.3
D+/D– Detection in Standalone Mode (ONLY for bq24251 and bq24257)
1. Ensure that the recommended test setup is followed
2. Follow
for initial setup
3. Ensure the CE is low by shorting JP3 to GND and jumper shorting pin TS and Fix.
4. Enable PS #2 or equivalent battery and adjust PS #2 so that the voltage measured by VM #3, across
BAT and GND, measures 3.2 V ±50 mV
5. Remove the jumper at JP1, if present
6. Adjust VBAT to 3.2 V
7. Use a standard USB-to-micro-USB cable and plug in from a computer USB port to the micro-USB port
on the EVM (J1)
•
Measure on A #2
→
ICHRG = 110 mA ±10 mA
•
Now we are in dead battery prevision
•
Measure voltage on D+ (D+, JP1) to be 0.6 V
•
Open the software
•
Click Read in the software and Status for D+/D– Detection should read SDP Detected or EN2=1,
EN1=0
•
Set in the Input Current Limit to 500 mA
•
Check Clear VD+ Source box and uncheck it
•
Measure voltage on D+ (D+, JP2) to 0 V
•
Now you are exited the dead battery provision
11
SLUUA08A – March 2013 – Revised April 2013
bq2425xEVM-150, Single-Cell Li-Ion Switch-Mode Charger
Copyright © 2013, Texas Instruments Incorporated
