MAX3344E Ver la hoja de datos (PDF) - Maxim Integrated
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MAX3344E Datasheet PDF : 15 Pages
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±15kV ESD-Protected USB Transceivers
in UCSP with USB Detect
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.
VCC
Bypass VCC to GND with a 1µF ceramic capacitor as
close to the device as possible. If VCC drops below the
USB detect threshold, supply current drops
below 20µA avoiding excessive VCC 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 VCC is pre-
sent. A high at USB_DET indicates that VCC is present,
while a low at USB_DET indicates that VCC 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 VCC 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
RC
1MΩ
RD
1500Ω
CHARGE-CURRENT-
LIMIT RESISTOR
DISCHARGE
RESISTANCE
HIGH-
VOLTAGE
DC
SOURCE
Cs
100pF
STORAGE
CAPACITOR
DEVICE
UNDER
TEST
Figure 1a. Human Body ESD Test Models
IP 100%
90%
AMPERES
36.8%
10%
0
0 tRL
Ir
PEAK-TO-PEAK RINGING
(NOT DRAWN TO SCALE)
TIME
tDL
CURRENT WAVEFORM
Figure 1b. Human Body Model Current Waveform
RC
50MΩ TO 100MΩ
RD
330Ω
CHARGE-CURRENT-
LIMIT RESISTOR
DISCHARGE
RESISTANCE
HIGH-
VOLTAGE
DC
SOURCE
Cs
150pF
STORAGE
CAPACITOR
DEVICE
UNDER
TEST
Figure 1c. IEC 1000-4-2 ESD Test Model
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.
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