MIC2551A

Micrel, Inc.

M9999-112008

2

November 2008

Pin Configuration

1

VIF

SPD

RCV

VP

VM

CON

GND

14 VBUS

VPU

VTRM

D+

D-

OE#

SUS

13

12

11

10

9

8

2

3

4

5

6

7

14-Pin TSSOP

1

2

3

4

12

11

10

9

16 15 14 13

5678

SPD

RCV

VP

VM

VTRM

D+

D–

OE#

Pin Description

Pin Number

Pin Number

Pin Name

I/O

Pin Function

MIC2551ABTS MIC2551ABML

115

VIF

I

System Interface Supply Voltage: Used to provide reference

supply voltage for system I/O interface signaling.

21

SPD

I

Edge Rate Control: A logic HIGH operates at edge rates for “full

speed” operation. A logic LOW operates edge rates for “low

speed” operation.

32

RCV*

O

Receive Data: Output for USB differential data.

43

VP*

I/O

If OE# = 1, VP = Receiver output (+)

If OE# = 0, VP = Driver input (+)

54

VM*

I/O

If OE# = 1 VM, = Receiver output (-)

If OE# = 0, VM = Driver input (-)

65

CON

I

CONNECT (Input): Controls state of VPU. Refer to VPU pin

description for detail.

76

GND

Ground Reference.

87

SUS

I

Suspend: Active-High. Turns off internal circuits to reduce supply

current.

99

OE#*

I

Output Enable: Active-Low. Enables the transceiver to transmit

data onto the bus. When inactive, the transceiver is in the receive

mode.

10/11

10/11

D–, D+*

I/O

Differential data lines conforming to the USB standard.

12

12

VTRM

O

3.3V Reference Supply Output: Requires a minimum 0.1µF

decoupling capacitor for stability. A 1µF capacitor is recom-

mended

13

13

VPU

O

Pull-up Supply Voltage Output: Used to connect 1.5kΩ pull-up

speed detect resistor. If CON = 1, VPU is high impedance.

If CON = 0, VPU = 3.3V.

14

14

VBUS

I

USB Bus Supply Voltage: Used to power USB transceiver and

internal circuitry.

8,16

NC

No connect.

* See Table 1 for description of logic states.