USB1T1102 View Datasheet(PDF) - Fairchild Semiconductor
Part Name
Description
Manufacturer
USB1T1102 Datasheet PDF : 14 Pages
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Terminal Descriptions (Continued)
Terminal Number
MLP14 MLP16
13
15
Terminal
Name
VPU (3.3V)
14
16
Config
Exposed Exposed
Diepad Diepad
GND
I/O
Terminal Description
I
GND
Pull-up Supply Voltage (3.3V ± 10%):
Connect an external 1.5kΩ resistor on D+ (FS data rate);
Pin function is controlled by Config input pin:
Config = LOW − VPU (3.3V) is floating (High Impedance) for zero pull-up current.
Config = HIGH − VPU (3.3V) = 3.3V; internally connected to VREG (3.3V).
USB connect or disconnect software control input.
Configures 3.3V to external 1.5kΩ resistor on D+ when HIGH.
GND supply down bonded to exposed diepad to be connected to the PCB GND.
Functional Description
The USB1T1102 transceiver is designed to convert CMOS
data into USB differential bus signal levels and to convert
USB differential bus signal to CMOS data.
To minimize EMI and noise the outputs are edge rate con-
trolled with the rise and fall times controlled and defined for
full speed data rates only (12Mbits/s). The rise, fall times
are balanced between the differential pins to minimize
skew.
The USB1T1102 differs from earlier USB Transceiver in
that the Vp/Vm and Vpo/Vmo pins are now I/O pins rather
than discrete input and output pins. Table 1 describes the
specific pin functionality selection. Table 2 and Table 3
describe the specific Truth Tables for Driver and Receiver
operating functions.
The USB1T1102 also has the capability of various power
supply configurations to support mixed voltage supply
applications (see Table 4) and Section 2.1 for detailed
descriptions.
Functional Tables
TABLE 1. Function Select
SUSPND
OE
D+, D−
RCV
Vp/Vpo
Vm/Vmo
Function
L
L
Driving & Active Vpo Input Vmo Input Normal Driving
Receiving
(Differential Receiver Active)
L
H
Receiving Active Vp Output Vm Output Receiving
(Note 1)
H
L
Driving Inactive Vpo Input Vmo Input Driving during Suspend
(Note 2)
(Differential Receiver Inactive)
H
H
3-STATE Inactive Vp Output Vm Output Low Power State
(Note 1) (Note 2)
Note 1: Signal levels is function of connection and/or pull-up/pull-down resistors.
Note 2: For SUSPND = HIGH mode the differential receiver is inactive and the output RCV is forced LOW. The out-of-suspend signaling (K) is detected via
the single-ended receivers of the Vp/Vpo and Vm/Vmo pins.
TABLE 2. Driver Function (OE = L) using Differential Input Interface
Vm/Vmo
L
L
H
H
Vp/Vpo
L
H
L
H
Data
SE0 (Note 3)
Differential Logic 1
Differential Logic 0
Illegal State
Note 3: SE0 = Single Ended Zero
TABLE 3. Receiver Function (OE = H)
D+, D−
Differential Logic 1
Differential Logic 0
SE0
RCV
H
L
X
Vp/Vpo
H
L
L
Vm/Vmo
L
H
L
X = Don’t Care
3
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