Test Summary
5
SLUUC73 – March 2020
Copyright © 2020, Texas Instruments Incorporated
BQ25616, BQ25616J BMS026 Evaluation Module
2.3
Test Procedure
2.3.1
Initial Settings
1. Ensure
steps have been followed.
2. Adjust R22 potentiometer to increase input current limit to the maximum value. To do this, turn R22
clockwise until a click is heard.
3. Turn on PS1
•
Measure
→
VSYS (SYS-TP14 and PGND-TP24) = 4.20V±0.3V
NOTE:
Completely disconnect Load #1 from BAT pin if different voltage value is seen.
2.3.2
Charge Mode Verification
1. PS1 should be on from
2. Enable Load #1.
3. Adjust R12 potentiometer to increase the charge current limit to 1A
•
Measure
→
IBAT (current into Load #1) = 1.0A±25mA
•
Record IBAT measurement
4. Change Load #1 to 2.5V
•
Measure
→
VSYS (SYS-TP14 and PGND-TP24) = 3.65V±0.3V
•
Measure
→
IBAT (current into Load #1) = 5% of previous IBAT result
≈
50mA±15mA
2.3.3
Boost Mode Verification
1. Turn off and disconnect PS1.
2. Set Load #1 to 3.7V and 2A current limit.
NOTE:
If Load #1 connected from BATTERY-J5(2) to PGND-J5(1) is not a four quadrant supply,
remove Load #1 and use PS1 (disconnected previously), set to 3.7V, 2A current limit and
connect across BATTERY-J5(2) to PGND-J5(1).
3. Remove shunt JP20 to enable boost mode.
4. Connect Load #2 across VAC-J1(2) and GND-J1(1).
•
Measure
→
VBUS (VBUS-TP7 and PGND-TP25) = 5.0V±0.2V
5. Turn off and disconnect power supply.
6. Remove Load #2 from connection.
7. Reconnect shunt JP20.
2.3.4
Helpful Tips
•
The leads and cables to the various power supplies, batteries and loads have resistance. The current
meters also have series resistance. The charger dynamically reduces charge current depending on the
voltage sensed at its VAC/VBUS pin (using the VINDPM feature), BAT pin (as part of normal
termination), and TS pin (through its battery temperature monitoring feature via battery thermistor).
Therefore, voltmeters must be used to measure the voltage as close to the IC pins as possible instead
of relying on the digital readouts of the power supply. If a battery thermistor is not available, make sure
shunt jp16 is in place.
•
When using a source meter that can source and sink current as your battery simulator, TI highly
recommends adding a large (1000+
μ
F) capacitor at the EVM BATTERY and GND connectors in order
to prevent oscillations at the BAT pin due to mismatched impedances of the charger output and source
meter input within their respective regulation loop bandwidths.
Configuring the source meter for 4-wire sensing eliminates the need for a separate voltmeter to