User`s guide

SMPS AC/DC Reference Design User’s Guide

Table 1-4 shows the dsPIC DSC resources used by Multi-Phase as well as

Single-Phase Synchronous Buck converters.

TABLE 1-4: RESOURCES REQUIRED FOR SECONDARY SIDE SYNCHRONOUS BUCK

CONVERTERS

Description/Signal Name Type of Signal

dsPIC

DSC Resources

Used

Expected Signal Level

5V Buck Current Analog AN0, CMP1A 1.25V (maximum)

5V Buck Output Analog AN1 2.7V (nominal)

3.3V Buck Current 1 Analog AN2, CMP2A 1V (maximum)

3.3V Buck Current 2 Analog AN4, CMP3A 1V (maximum)

3.3V Buck Current 3 Analog AN6, CMP4A 1V (maximum)

3.3V Buck Output Analog AN3 1.65V (nominal)

5V Buck Gate Drive Single-Phase Synchronous

Buck Drive

PWM4H, PWM4L —

3.3V Buck Gate Drive Multi-Phase Synchronous

Buck Drive

PWM1H, PWM1L,

PWM2H, PWM2L,

PWM3H, PWM3L,

—

12V Bus Sense Analog AN5 2.79V

12V Digital Feedback Digital UART1 Transmit —

RS232_RX Digital UART1 Receive —

Temperature Sense Analog AN8 1.4V

MCLR

Digital MCLR —

PGC Digital PGC —

PGD Digital PGD —

Fault_Reset Digital RC6 —