
Samsung ASIC
4-81
STDM110
USB (Universal Serial Bus) I/O Buffers
(Under Development)
Overview
USB I/O buffer consists of a differential input receiver, a differential output driver, two single-ended receivers,
and two pads. The differential input receiver has the 0.8V ~ 2.5V common mode input voltage range and
both of the two single-ended receivers have 0.8V and 2.0V as their low and high input threshold voltages,
V
IL
, V
IH
, respectively.
For low power consumption in a stand-by mode, the suspend pin (SUSPND) of the receiver and the driver
should be in the high state. The differential output drivers have a Low/Full speed control pin (SPEED) to
select the operation speed and have Output Enable Negative pin (OEN) to achieve a bi-directional half
duplex operation.
Features
—
—
—
—
Complies with universal serial bus specification 1.0
Supports 12Mbps “Full speed” and 1.5Mbps “Low speed” serial data transmission
Supports both “Full speed” and “Low speed” Design Kits
Supports both “Full speed only” and “Low speed only” cells to reduce silicon area
Electrical Specifications
DC Electrical Characteristics
Parameter
Supply Current
Suspend Device
Leakage Current
Hi-Z State Input Leakage
Input Levels
Differential Input Sensitivity
Differential Common Mode Range
Single Ended Receiver Threshold
Output Levels
Static Output Low
Static Output High
Capacitance
Transceiver Capacitance
Full Speed Output Buffer Electrical Characteristics
Parameter
Driver Characteristics
Transition Time
Rise Time
Fall Time
Rise/Fall Time Matching
Output Signal Crossover Voltage
Drive Output Resistance
Symbol
Condition (Notes 1, 2)
Min
Max
Unit
I
CCS
10
μ
A
I
LO
0V < VIN < 3.3V
–10
10
μ
A
V
DI
V
CM
V
SE
I (D+)
(D-) I
Includes V
DI
range
0.2
0.8
0.8
V
2.5
2.0
V
OL
V
OH
RL of 1.5K
to 3.6V
RL of 15K
to GND
0.3
3.6
V
2.8
C
IN
Pin to GND
20
pF
Symbol
Condition (Notes 1, 2, 3)
Min
Max
Unit
T
R
T
F
T
RFM
V
CRS
Z
DRV
Notes 5 and Figure 1
CL = 50pF
CL = 50pF
(T
R
/T
F
)
4.0
4.0
90
1.3
28
20.0
20.0
110
2.0
43
ns
%
V
Steady state drive