MIC2550A

Micrel, Inc.

M9999-031805

2

March 2005

Pin Description

Pin Name

Pin Number

Pin Number

Pin Function

MIC2550ABTS

MIC2550ABML

VIF

1

15

System Interface Supply Voltage (Input): Determines logic voltage levels for

system interface signaling to logic controller.

SPD

2

1

Speed (Input): Edge rate control. Logic high selects full-speed edge rates.

Logic low selects low-speed edge rates.

RCV

3

2

Receive Data (Output): System interface receive data interface to logic

controller.

VP

4

3

Plus (Input/Output): System interface signal to logic controller. If OE# is

logic 1, VP is a receiver output (+); If OE# is logic 0, VP is a driver input (+).

VM

5

4

Minus (Input/Output): System interface signal to logic controller. If OE# is

logic 1, VM is a receiver output (–); If OE# is logic 0, VM is a driver input (–).

NC

6, 13

5, 8, 13 16

Not internally connected

GND

7

6

Ground: Power supply return and signal reference.

SUS

8

7

Suspend (Input): Logic high turns off internal circuits to reduce supply

current.

OE#

9

9

Output Enable (Input): Active low system interface input signal from logic

controller. Logic low causes transceiver to transmit data onto the bus. Logic

high causes the transceiver to receive data from the bus.

D–

10

10

USB Differential Data Line – (Input/Output)

D+

11

11

USB Differential Data Line + (Input/Output)

VTRM

12

12

Termination Supply (Output): 3.3V speed termination resistor supply output.

VBUS

14

14

USB Supply Voltage (Input): Transceiver supply.

Pin Configuration

1

VIF

SPD

RCV

VP

VM

NC

GND

14 VBUS

NC

VTRM

D+

D–

OE#

SUS

13

12

11

10

9

8

2

3

4

5

6

7

14-Pin TSSOP (TM)

1

2

3

4

12

11

10

9

16 15 14 13

5678

SPD

RCV

VP

VM

VTRM

D+

D–

OE#

16-Pin MLF™ (ML)