SLVUB62B June 2017 – November 2020
LEDs, D5 and D3, are for the variable DC/DC on port A, and port B, respectively. When powering up the EVM, these LEDs lights up blue. They also provide a voltage discharge path for high to low PD contracts. For higher voltage PD contracts, D5 and D3 are brighter. Figure 5-39 highlights these features and Table 5-3 summarizes the LED behavior.
LED Indicator | GPIO | Function |
---|---|---|
D20 - PA_PDO0 | GPIO_12 | PDO TT bit 0 |
D21 - PA_PDO1 | GPIO_13 | PDO TT bit 1 |
D23 - PB_PDO1 | GPIO_14 | PDO TT bit 1 |
D22 - PB_PDO0 | GPIO_15 | PDO TT bit 0 |
D5 - PA_VAR_DCDC | GPIO_16 | VAR-A enable |
D3 - PB_VAR_DCDC | GPIO_17 | VAR-B enable |
The PDO LEDs in Table 5-4 are high, depending on which PDO is negotiated. By activating these LEDs, the output voltage of the variable DC/DC can be changed. Table 5-4 summarizes the PDO LED behavior.
PDO | PDO LED 1 | PDO LED 0 | R1 | R2 | Output Voltage |
---|---|---|---|---|---|
PDO 1 (5 V) | 0 | 0 | 60.4 kΩ | 19.1 kΩ | 5.15 V |
PDO 2 (9 V) | 0 | 1 | 60.4 kΩ | 9.27 kΩ | 9.26 V |
PDO 3 (15 V) | 1 | 0 | 60.4 kΩ | 5.2 kΩ | 15.62 V |
PDO 4 (20 V) | 1 | 1 | 60.4 kΩ | 4.04 kΩ | 19.78 V |