PD77020

Pins

Data Sheet

© 2023 Microchip Technology Inc. and its subsidiaries

DS60001824A - 8

3.2

Pin Descriptions

The following table lists the functional pin descriptions of the PD77020 device.

Table 3-1. PD77020 Pin Descriptions

PD77020

Designation

Type

Description

1

I2C_OUT_SDA

IN/OUT

I2C bidirectional data to PD77728 devices

It is required to add a 2 KΩ pull-up resistor.

2

I2C_OUT_SCL

OUT

I2C SCL signal to PD77728 devices

It is required to add a 2 KΩ pull-up resistor.

3

xRESET_OUT

OUT

Reset output (active low) to PD77728 devices

4

xINT_N

IN

An open-drain interrupt input from the common INT_OUT_N

output from all PD77728 devices

This pin is active low. Connect a pull-up resistor to VDD.

5

RESERVED

—

Unused, leave floating

6

RESERVED

—

Unused, leave floating

7

OSS_OUT

OUT

DATA output for OSS signaling to the PD77728 device

8

RESERVED

—

Unused, leave floating

9

VDDA

Supply

Main supply 3.3V

10

VSSA

GND

Ground

11

I2C_ADDR_MEAS

Analog_IN

Analog input to determine the I2C address

See Figure 3-2 and Table 3-2 for details.

12

LED_SCK

OUT

LED stream Clock out

13

xLED_SS

OUT

LED stream Client-Select (active low)

14

LED_DO

OUT

LED stream Data out

15

xLED_OE

OUT

LED stream Output Enable (active low)

16

RESERVED

—

Unused, leave floating

17

PG1

IN

Power Good input 1

18

PG2

IN

Power Good input 2

19

PG3

IN

Power Good input 3

20

PG4

IN

Power Good input 4

21

I2C_IN_SDA

IN/OUT

I2C bidirectional data

15-byte protocol messages are transmitted on this line. Pull-

up required, see AN4896 for details.

22

I2C_IN_SCL

IN

I2C clock from the host master

Speed is limited to 400 KHz. Pull-up required.

23

xSys_OK

OUT

System validity indication

The behavior of this output is controlled by individual

software mask (active low). This pin is a push-pull output.

24

xDISABLE_PORTS

IN

Disable all PoE ports. When this input is asserted low, the

controller shuts down all PoE ports in the system. See

AN4896 for pin connection requirements (active low).

25

xINT_OUT

OUT

Interrupt output indication

This line is asserted low when a pre-configured event is in

progress (active low). This pin is an open-drain output with

internal pull up.

26

xRESET_IN

IN

Host Reset input (active low)

27

xI2C_MESSAGE_READY

OUT

I2C message ready indication to the host

This signal is LOW when a message is ready to be read. I2C

read cycle must be invoked only if this signal is low. After

reading the message, the pin is set high again, until next

message is ready.