Disable the AUX_3v3 on BeagleBoard-xm rev B to reduce the power consumption

Disable Aux_3v3 on BeagleBoard-Xm :

AUX_3v3 Provides Supply Rail to D5 Power LED, DVI-D , RS232 Level converter and RS232 Line Divider. Output Disable Pin of the AUX_3v3 connected to TPS65950 GPIO.1 on N12 Pin.

Connection:

TPS65950 GPIO.1 on N12 pin → LDO_EN pin on TPS2141 PWP ( AUX_3v3) →Power Rail ( D5 LED, DVI-D, RS232 Level Convertor (Txs0102dco) and RS232 Line Divider(SN65c3221) ).

AUX_3v3 supply can be turned off by Activating GPIO1 on TPS65950 to 1. Power management IC TPS65950 on BeagleBoard-Xm has Provision of communication with BeagleBoard-Xm through Specific I2C (Inter-IC) Module I2C.1. This Activating of GPIO1 on TPS65950 Done by I2C communication with BeaglBoard-Xm.

Install the i2c-tools_3.0.3-r0_armv7a.ipk package on BeagleBoard-Xm.

$opkg install i2c-tools_3.0.3-r0_armv7a.ipk

By Default GPIO.1 on TPS65950 set to 0 .

Command to set the GPIO.1 on TPS65950 to 1.

$i2c -f -y 1 0x49 0x000000a4 0x02

0x49 → Chip Address of TPS65950

0x000000a4 → SetGPIODATAOUT1 Register Address

0x02 → Value to Set GPIO.1 on TPS65950

This command test can Be Done by Verifying D5 POWER LED on Board, RS232 Communication.

This Result save Power Consumption of 120mA.

Command to RESET GPIO.1 on TPS65950

$i2c -f -y 1 0x49 0x000000a4 0x02

0x49 → Chip Address of TPS65950

0x000000a4 → ClearGPIODATAOUT1 Register Address

0x02 → Value to Set GPIO.1 on TPS65950