Use the following steps for OTG mode verification
for boost operation:
- Power up then turn off Load#2
output. Set to CR = 12 V/0.5 A = 24 Ω. Disconnect PS1 from J1 and attach Load#2
to J1 (VIN1 and GND).
- Increase Load #1 regulation voltage
to 8.0 V and take measurements as follows:
- Measure ?
VBAT-PGND (TP29 and TP46) = 8.0 V ±0.1 V
- Prepare the OTG mode charger
register settings in the following way:
- In the Chip
Configuration page below the Chip Configuration section
- Uncheck "EN Charge"
to disable charge mode
- Check "EN OTG Mode"
to enable OTG mode
- Check "EN ADRV1" to
enable ACDR1 FETs
- In the OTG
Configuration page below the OTG Configuration section
- Set the OTG Reg
Voltage to 12.000 mV.
- Set the IOTG
Limit to 1.000 A
- Take measurements as follows:
- Measure ?
VVBUS-PGND (TP23 and TP44) = 12.0 V ±0.2 V
- Measure ?
VAC1-PGND (TP24 and TP44) = 12.0 V ±0.2 V. Note that the
PCB silk screen for VAC1 and VAC2 are reversed.
- Click READ ALL
REGISTERS
- Verify ?
REG1Bb[6] reports VINDPM or OTG
- Verify ?
REG1Cb[4:1] reports VBUS Status as Normal OTG
- Turn on Load#2 output set to
constant resistance (CR) of 24 Ω.
- Take measurements as follows:
- Measure ?
VAC1-PGND (TP23 and TP44) = 12.0 V ±0.2 V
- Measure ?
IAC1-SENSE (TP1 and TP2) = 500 mA ±0.10 A
- Lower the Load#2 to constant
resistance (CR) to 10 Ω.
- Take measurements as follows to
confirm OTG current limit function:
- Measure ?
VAC1-PGND (TP23 and TP44) < 12.0 V ±0.2 V
- Measure ?
IAC1-SENSE (TP1 and TP2) = 1000 mA ±0.10 A
- Click READ ALL REGISTERS
and Verify ? REG1Bb[7] reports IINDPM
- Hints for further OTG testing:
- Enabling OTG mode is a
two-step process, first enable OTG and then turn on the appropriate AC
drive FETs.