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MAX3453E–MAX3456E
±15kV ESD-Protected USB Transceivers
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11
Disable Mode
Connect VBUS to a system power supply and leave VL
unconnected or connect to GND. D+ and D- enter a tri-
state mode and VBUS (or VBUS and VTRM) consumes
less than 20A of supply current. D+ and D- withstand
external signals up to +5.5V in disable mode (Table 2).
Sharing Mode
Connect VL to a system power supply and leave VBUS
(or VBUS and VTRM) unconnected or connect to GND.
D+ and D- enter a tri-state mode, allowing other circuitry
to share the USB D+ and D- lines, and VL consumes less
than 20A of supply current. D+ and D- withstand
external signals up to +5.5V in sharing mode (Table 2).
Device Control
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 differential receiver out-
put, regardless of the state of OE.
ENUM (MAX3453E/MAX3454E)
The MAX3453E/MAX3454E feature an enumerate func-
tion that allows software control of USB enumeration.
USB protocol requires a 1.5k
pullup resistor to D+ or
D- to indicate the transmission speed to the host (see
the SPD section). The MAX3453E/MAX3454E provide
an internal 1.5k
pullup resistor. Disconnect the pullup
resistor from the circuit to simulate the removal of a
device from the USB. Drive ENUM low to disconnect
the internal pullup resistor. Drive ENUM high to connect
the internal pullup resistor. The SPD state (MAX3454E
only) determines whether the pullup resistor connects
to D+ or D-. For ENUM = high, the internal pullup resis-
tor connects to D+ when SPD = VL (full speed) or to D-
when SPD = GND (low speed). The MAX3453E only
supports full-speed operation; therefore, the pullup
resistor only connects to D+ or is disconnected.
Figure 1. Rise and Fall Times
VOHD
VOLD
90%
10%
90%
10%
tFR, tLR
tFF, tLF
Table 3a. Transmit Truth Table
(OE = 0, SUS = 0)
INPUTS
OUTPUTS
VP
VM
D+
D-
RCV
OUTPUT STATE
00
00X
SE0
0
1
0
1
0
Logic 0
1
0
1
0
1
Logic 1
1
X
Undefined
X = Undefined.
Table 3b. Transmit Truth Table
(OE = 0, SUS = 1)
INPUTS
OUTPUTS
VP
VM
D+
D-
RCV
OUTPUT STATE
00
0
SE0
0
1
0
1
0
Logic 0
1
0
1
0
Logic 1
1
0
Undefined
Table 4a. Receive Truth Table
(OE = 1 and SUS = 0)
INPUTS
OUTPUTS
D+
D-
VP
VM
RCV
OUTPUT STATE
0
000
X
SE0
0
1010
Logic 0
1
0101
Logic 1
1
X
Undefined
X = Undefined.
Table 4b. Receive Truth Table
(OE = 1 and SUS = 1)
INPUTS
OUTPUTS
D+
D-
VP
VM
RCV
OUTPUT STATE
0
0000
SE0
0
1010
Logic 0
1
0100
Logic 1
1
1110
Undefined