MAX3344E/MAX3345E
±15kV ESD-Protected USB Transceivers
in UCSP with USB Detect
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The MAX3344E/MAX3345E system-side outputs are
VPI, VMI, and RCV. The MAX3344E/MAX3345E send
data through VPI, VMI, and RCV. VPI and VMI are out-
puts to the single-ended receivers and RCV is the out-
put of the differential receiver.
Output enable (OE) controls data transmission. Drive OE
low to enable data transmission on D+ and D-. Drive OE
high to disable data transmission or receive data.
MODE
MODE is a control input that selects whether differential
or single-ended logic signals are recognized by the
system side of the MAX3344E/MAX3345E. Drive MODE
high to select differential mode with VPO as the positive
terminal and VMO as the negative terminal. Drive
MODE low to select single-ended mode with VPO as
the data input (Table 3).
VTRM
VTRM is the 3.3V output of the internal linear voltage
regulator. VTRM powers the internal circuitry of the USB
side of the MAX3344E/MAX3345E. Connect a 1µF (min)
low-ESR ceramic or plastic capacitor from VTRM to
GND, as close to VTRM as possible. Do not use VTRM
to power external circuitry.
V
CC
Bypass V
CC
to GND with a 1µF ceramic capacitor as
close to the device as possible. If V
CC
drops below the
USB detect threshold, supply current drops
below 20µA avoiding excessive V
CC
current consump-
tion, and D+/D- enter a high-impedance state allowing
other devices to drive the lines.
USB Detect
USB detect output (USB_DET) signals that V
CC
is pre-
sent. A high at USB_DET indicates that V
CC
is present,
while a low at USB_DET indicates that V
CC
is not pre-
sent. The MAX3344E USB_DET threshold is between
3.6V (min) and 4V (max), while the MAX3345E USB_DET
threshold is between 1V (min) and 2.8V (max).
SUSP
Suspend (SUSP) is a control input. Force SUSP high to
place the MAX3344E/MAX3345E in a low-power state.
In this state, the quiescent supply current into V
CC
is
less than 40µA and RCV goes low.
In suspend mode, VPI and VMI remain active as
receive outputs and VTRM stays on. The MAX3344E/
MAX3345E continue to receive data from the USB,
allowing the µP to sense activity on the D+/D- lines and
wake up the MAX3344E/MAX3345E.
The MAX3344E/MAX3345E can also transmit data to
D+ and D- while in suspend mode. This function is
used to signal a remote wake-up by driving a signal on
D+ and D- for a period of 1ms to 15ms. In suspend
mode, data can only be transmitted with full-speed
slope control.
Figure 1c. IEC 1000-4-2 ESD Test Model
