Texas Instruments BMS027, User Manual

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Test Setup and Results
7 SLUUC51A – June 2020 – Revised July 2020
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BQ25790EVM (BMS027) Evaluation Module User's Guide
should appear at the top of the page.
NOTE: If the device is not communicating and does not ACK, verify that Section 2.2 and
Section 2.4.1 steps have been followed. Verify the voltage across TP42 (PULLUP) and
TP49 (AGND) is approximately 3.3 V.
2. Select Field View in the top right of the screen. Note there are two tabs, one for 8-bit registers and
one for 16-bit registers. In the 8-bit tab, there are sections for chip, charger and OTG single-bit and
multi-bit registers. In the 16-bit tab are the charger and OTG multi-bit registers for setting voltages and
currents. In addition, the ADC registers are on the 16-bit tab.
3. Prepare the charge mode charger register settings in the following way if not already set there by
default:
• On the 8-bit Registers tab in the Chip Config Multi-bit Registers section
– REG10b[2:0] = 000 to disable watchdog time
• On the 8-bit Registers tab in the Chip Config Single-bit Registers section
– REG14b[7] = 1 to tell the charger that the ShipFET is present
• On the 8-bit Registers tab in the Charger Multi-bit Registers section
– REG08b[5:0] = 000110 to set the pre-charge current regulation limit to 240 mA.
– REG05b[7:0] = 00101000 to set the input voltage regulation limit (VINDPM) to 4000 mV.
• On the 16-bit Registers tab in the Charger Multi-bit Registers section
– REG00b[5:0] = 001110 to set the minimum system voltage to 7000 mV.
– REG01b[10:0] = 00111000010 to set the maximum constant voltage (CV) charging regulation
limit to 8400 mV.
– REG03b[8:0] = 001100100 to set the maximum constant current (CC) charging regulation limit
to 500 mA.
– REG06b[8:0] = 100101100 to set the input current regulation limit (IINDPM) to 3000 mA.
2.4.3 Charge Mode Verification
Use the following steps for charge mode verification, including pre-charge, CC and CV phases for boost
operation:
1. PS1 and Load #1 should be on from Section 2.4.1 . In the EVM GUI, it is generally recommended to
read REG22-REG27 (or READ ALL REGISTERS) one time in order to show all the interrupts (from
status changes, automated routine completion, faults) that occurred since the last read. Reading those
registers a second clears the interrupts. After reading the registers,
• Verify ➡ REG1B reports all Normal, meaning no DPM loops active and no WD timer fault (bits 7-
4), VAC1 Present (bit2), VBUS Present (bit 0) and Power Good (bit 3)
2. Reinstall the shunt on jumper J19 to enable charge
• Verify ➡ ➡ STAT LED (D14) is lit
3. Take measurements as follows:
• Measure ➡ ➡ V
VBUS-PGND
(TP21 and TP45) = 5.0 V ±0.2 V
• Measure ➡ ➡ V
BAT-PGND
(TP27 and TP46) = 5.0 V ±0.2 V
• Measure ➡ ➡ I
BAT_SENSE
(voltage across 0.01 ohm resistor between TP17 and TP18) = 240 mA ±60
mA
• Click READ ALL REGISTERS and Verify ➡ REG1Cb[7:5] reports pre charge
4. Increase Load #1 regulation voltage to 8.0 V and take measurements as follows:
• Measure ➡ ➡ V
VBUS-PGND
(TP21 and TP45) = 5.0 V ±0.2 V
• Measure ➡ ➡ V
BAT-PGND
(TP27 and TP46) = 8.0 V ±0.1 V
• Measure ➡ ➡ I
BAT_SENSE
(voltage across 0.01- Ω resistor between TP17 and TP18) = 500 mA ±50 mA
• Measure ➡ ➡ I
VAC1_SENSE
(voltage across 0.01- Ω resistor between TP1 and TP2) = 900 mA ±60 mA