1ꢀ5k EꢁDꢂ-rotected UꢁB Transceivers with
External/Internal -ullup Resistors
Sharing Mode
Table 3. Transmit Truth Table
(OE = 0)
Connect V to a system power supply and leave V
L
BUS
(or V
and V
) unconnected or connect to GND.
BUS
TRM
D+ and D- enter a tri-state mode, allowing other circuitry
INPUTS
OUTPUTS
to share the USB D+ and D- lines. V consumes less
L
VP
0
VM
0
D+
0
D-
0
than 20µA of supply current. D+ and D- withstand exter-
nal signals up to +5.5V in sharing mode (Table 2).
0
1
0
1
Device Control
1
0
1
0
OE
OE controls the direction of communication. Drive OE
low to transfer data from the logic side to the USB side.
For OE = low, VP and VM serve as differential driver
inputs to the USB transmitter. Drive OE high to transfer
data from the USB side to the logic side. For OE = high,
VP and VM serve as single-ended receiver outputs
from the USB inputs (D+ and D-). RCV serves as a dif-
ferential receiver output, regardless of the state of OE.
1
1
1
1
Table 4a. Receive Truth Table
(OE = 1)
INPUTS
OUTPUTS
D+
0
D-
0
VP
0
VM
0
RCV
ENUM (MAX13481E/MAX13482E)
The MAX13481E/MAX13482E feature an active-low enu-
merate function that allows software control of the 1.5kΩ
pullup resistor and switch to D+ for full-speed operation.
RCV*
0
1
0
1
0
1
X
1
0
1
0
1
1
1
1
For the MAX13481E, connect a 1.5kΩ pullup resistor
between D+ and VPU. The MAX13481E provides an
internal switch that pulls VPU to a +3.3V voltage. Drive
ENUM high to disconnect VPU from voltage. Drive
ENUM low to connect VPU and the external pullup resis-
tor to the +3.3V voltage.
* = Last state
X = Undefined
Table 4b. Receive Truth Table
(OE = 1, SUS = 1)
The MAX13482E has an internal 1.5kΩ resistor that
connects at VPUR. Connect VPUR directly to D+. Drive
ENUM high to disconnect the internal pullup resistor at
VPUR. Drive ENUM low to connect the internal pullup
resistor to VPUR.
INPUTS
OUTPUTS
D+
0
D-
0
VP
0
VM
0
RCV
0
0
0
0
SUS
The SUS state determines whether the MAX13481E/
MAX13482E/MAX13483E operate in normal mode or in
suspend mode. Connect SUS to GND to enable normal
operation. Drive SUS high to enable suspend mode.
RCV asserts low and VP and VM remain active in sus-
pend mode (Tables 3 and 4). In suspend mode, supply
current is reduced.
0
1
0
1
1
0
1
0
1
1
1
1
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9
MAXIM [ MAXIM INTEGRATED PRODUCTS ]
