MIC2551A MICREL [Micrel Semiconductor], MIC2551A Datasheet - Page 7

• Manufacturer Part Number: MIC2551A
• Description: USB TRANSCEIVER
• Manufacturer: MICREL [Micrel Semiconductor]

Functional Diagram
Applications Information
The MIC2551A is designed to provide USB connectivity in
mobile systems where available system supply voltages are
not able to satisfy USB requirements. The MIC2551A can
operate down to supply voltages of 1.6V and still meet USB
physical layer specifications. As shown in the circuit above,
the MIC2551A takes advantage of the USB supply voltage,
V
used to set the reference voltage used by the digital I/O lines
interfacing to the system controller. Internal circuitry provides
translation between the USB and system voltage domains.
V
controller.
May 2004
MIC2551A
BUS
IF
will typically be the main supply voltage rail for the
, to operate the transceiver. The system voltage, V
CON
RCV
SPD
SUS
OE#
VIF
VM
VP
IF
MIC2551A
GND
, is
To Internal
Circuitry
7
In addition, a 3.3V, 10% termination supply voltage, (V
provided to support speed selection. V
enabled under software control via the CON input. This
allows for software-controlled connect or disconnect states.
A 1.5k resistor is required to be connected between this pin
and the D+ or D– lines to respectively specify high speed or
low speed operation.
The use of ESD transient protection devices is not required
for operation, but is recommended. The MIC2551A is ESD
rated for 11kV at the VBUS and D+, D– pins and 2kV for all
other pins.
Regulator
LDO
VBUS
VTERM
VPU
D+
D–
PU
can be disabled or
M9999-051004
PU
Micrel
), is