2.3.4 Power Channel Default Start-up Voltage

In MCP16503, the default start-up voltage of all power channels can be configured through pin VSETx and VSETLy. By connecting a resistor on those pins against ground, or shorting the pins to ground or SVIN, 16 start-up voltage options can be configured for each channel. The table below shows an overview of all configurations. The option “short the pin to ground” is reserved for disabling the corresponding power channel in a start-up sequence. The other 15 options define 15 different start-up voltages. The PMIC only reads (decodes) the resistors connected to the VSETx and VSETLx pins during power-up. After start-up, the user can then change the output voltage through I²C (see section VSET[5:0] Codes Definition).

Table 2-2. Configuring MCP16503 Default Start-Up Voltage
R (Ω)	BCK1	BCK2	BCK3	BCK4	LDO1	LDO2
Short to GND	Disabled during sequencing
187	1.2V	0.6V	0.6V	0.6V	1.2V	1.2V
487	1.25V	0.8V	0.8V	0.8V	1.25V	1.25V
976	1.3V	0.9V	0.9V	0.9V	1.3V	1.3V
1740	1.35V	1V	1V	1V	1.35V	1.35V
2940	1.4V	1.05V	1.05V	1.05V	1.4V	1.4V
4870	1.5V	1.1V	1.1V	1.1V	1.5V	1.5V
8060	1.6V	1.15V	1.15V	1.15V	1.6V	1.6V
13000	1.8V	1.2V	1.2V	1.2V	1.8V	1.8V
21000	2.5V	1.25V	1.25V	1.25V	2.5V	2.5V
34000	2.8V	1.275V	1.275V	1.275V	2.8V	2.8V
54900	3.0V	1.35V	1.35V	1.35V	3.0V	3.0V
86600	3.15V	1.375V	1.375V	1.375V	3.15V	3.15V
140000	3.3V	1.4V	1.4V	1.4V	3.3V	3.3V
226000	3.4V	1.5V	1.5V	1.5V	3.4V	3.4V
Short to SVIN	3.6V	1.8V	1.8V	1.8V	3.6V	3.6V

Figure 2-1. Finite State Machine (FSM) States Diagram for MCP16503

The figure below illustrates a simplified flow chart for INIT mode.

Figure 2-2. INIT Mode Simplified Flow Chart

The identified default start-up voltage configurations are memorized in the corresponding VSET[5:0] registers in OUTx-A, LDOx-A registers and copied into VSET[5:0] in OUTx-LPM, OUTx- HIB, OUTx-HPM, LDOx-LPM, LDOx- HIB and LDOx-HPM.