MCP2557FD datasheet(6/36 Pages) MICROCHIP

6 / 36 page

MCP2557FD/8FD

DS20005533A-page 6

 2016 Microchip Technology Inc.

1.7

Pin Descriptions

The descriptions of the pins are listed in Table 1-1.

1.7.1

TRANSMITTER DATA

INPUT PIN (TXD)

The CAN transceiver drives the differential output pins

CANH and CANL according to TXD. It is usually

connected to the transmitter data output of the CAN

controller device. When TXD is Low, CANH and CANL

are in the Dominant state. When TXD is High, CANH

and CANL are in the Recessive state, provided that

another CAN node is not driving the CAN bus with a

Dominant state. TXD is connected from an internal pull-

up resistor (nominal 33 k

) to VDD or VIO, in the

MCP2557FD or MCP2558FD, respectively.

1.7.2

GROUND SUPPLY PIN (VSS)

Ground supply pin.

1.7.3

SUPPLY VOLTAGE PIN (VDD)

Positive supply voltage pin. Supplies transmitter and

receiver.

1.7.4

RECEIVER DATA OUTPUT PIN (RXD)

RXD is a CMOS-compatible output that drives High or

Low depending on the differential signals on the CANH

and CANL pins, and is usually connected to the

receiver data input of the CAN controller device. RXD is

High when the CAN bus is Recessive, and Low in the

Dominant state. RXD is supplied by VDD or VIO, in the

MCP2557FD or MCP2558FD, respectively.

1.7.5

NC PIN (MCP2557FD)

No Connect. This pin can be left open or connected to

VSS.

1.7.6

VIO PIN (MCP2557FD)

Supply for digital I/O pins. In the MCP2557FD, the

supply for the digital I/O (TXD, RXD and S) is internally

connected to VDD.

1.7.7

DIGITAL I/O

The MCP2557FD/8FD enable easy interfacing to

MCUs with I/O ranges from 1.8V to 5V.

1.7.7.1

MCP2557FD

The VIH(MIN) and VIL(MAX) for TXD are independent of

VDD. They are set at levels that are compatible with 3V

and 5V microcontrollers.

The RXD pin is always driven to VDD; therefore, a 3V

microcontroller will need a 5V tolerant input.

1.7.7.2

MCP2558FD

VIH and VIL for S and TXD depend on VIO. The RXD pin

is driven to VIO.

1.7.8

CAN LOW PIN (CANL)

The CANL output drives the Low side of the CAN

differential bus. This pin is also tied internally to the

receive input comparator. CANL disconnects from the

bus when the MCP2557FD/8FD devices are not

powered.

1.7.9

CAN HIGH PIN (CANH)

The CANH output drives the high side of the CAN

differential bus. This pin is also tied internally to the

receive input comparator. CANH disconnects from the

bus when the MCP2557FD/8FD devices are not

powered.

TABLE 1-1:

MCP2557FD/8FD PIN DESCRIPTIONS

MCP2557FD

3x 3DFN,

2x 3TDFN

MCP2557FD

SOIC

MCP2558FD

3x 3DFN,

2x3 TDFN

MCP2558FD

SOIC

Symbol

Pin Function

1111

TXD

Transmit Data Input

2222

VSS

Ground

3333

VDD

Supply Voltage

4444

RXD

Receive Data Output

—

No Connect (MCP2557FD only)

——

VIO

Digital I/O Supply Pin

(MCP2558FD only)

6666

CANL

CAN Low-Level Voltage I/O

7777

CANH

CAN High-Level Voltage I/O

8888

Silent Mode Input

—

Exposed Thermal Pad

MCP2557FD Datasheet(PDF) 6 Page - Microchip Technology

MCP2557FD Datasheet(HTML) 6 Page - Microchip Technology

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36

Datasheet Download

Link URL