MIC2551A
Micrel
Pin Configuration
NC
VIF
VBUS
VPU
16 15 14 13
SPD
RCV
VP
VM
1
2
3
4
5 6 7 8
CON
GND
SUS
NC
12
11
10
9
VTRM
D+
D—
OE#
VIF 1
SPD 2
RCV 3
VP 4
VM 5
CON 6
GND 7
14 VBUS
13 VPU
12 VTRM
11 D+
10 D-
9 OE#
8 SUS
14-Pin TSSOP
16-Pin MLF™ (ML)
Pin Description
Pin Number
Pin Number
MIC2551ABTS MIC2551ABML
1
2
15
1
Pin Name
VIF
SPD
I/O
I
I
Pin Function
System Interface Supply Voltage: Used to provide reference
supply voltage for system I/O interface signaling.
Edge Rate Control: A logic HIGH operates at edge rates for “full
speed” operation. A logic LOW operates edge rates for “low
speed” operation.
Receive Data: Output for USB differential data.
If OE# = 1, VP = Receiver output (+)
If OE# = 0, VP = Driver input (+)
If OE# = 1 VM, = Receiver output (-)
If OE# = 0, VM = Driver input (-)
CONNECT (Input): Controls state of VPU. Refer to VPU pin
description for detail.
Ground Reference.
I
I
Suspend: Active-High. Turns off internal circuits to reduce supply
current.
Output Enable: Active-Low. Enables the transceiver to transmit
data onto the bus. When inactive, the transceiver is in the receive
mode.
Differential data lines conforming to the USB standard.
3.3V Reference Supply Output: Requires a minimum 0.1µF
decoupling capacitor for stability. A 1µF capacitor is recom-
mended
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.
USB Bus Supply Voltage: Used to power USB transceiver and
internal circuitry.
No connect.
3
4
5
6
7
8
9
2
3
4
5
6
7
9
RCV*
VP*
VM*
CON
GND
SUS
OE#*
O
I/O
I/O
I
10/11
12
10/11
12
D–, D+*
VTRM
I/O
O
13
13
VPU
O
14
14
8,16
VBUS
NC
I
* See Table 1 for description of logic states.
M9999-051004
2
May 2004
MICREL [ MICREL SEMICONDUCTOR ]
