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MAX3341E

±15kV ESD-Protected USB Level Translator in UCSP with USB Detect

Maxim Integrated 

±15kV ESD-Protected USB Level Translator in

UCSP with USB Detect

Device Control

D+ and D-

D+ and D- are the USB side transmitter I/O connec-

tions, and are ESD protected to ±15kV using the

Human Body Model, ±15kV using IEC 1000-4-2 Air-

Gap Discharge, and ±8kV using IEC 1000-4-2 Contact

Discharge, making the MAX3341E ideal for applications

where a robust transmitter is required. A 23.7Ω resistor

is required on D+ and D- for normal operation (see

External Resistors).

The MAX3341E contains unique circuitry to ensure the

USB skew is independent of the input skew on VPO

and VMO. Input skews of up to 10ns are ignored and

do not show up on the output.

ENUM

USB specification 2.0 requires a 1.5kΩ pullup resistor

on D+ for full-speed (12Mbps) operation. Controlled by

enumerate (ENUM), the MAX3341E provides this inter-

nal 1.5kΩ resistor. Drive ENUM high to connect the

pullup resistor from D+ to VTRM. Drive ENUM low to

disconnect the pullup resistor from D+ to VTRM.

VPO/VMO, VPI/VMI, and OE

The MAX3341E system-side inputs are VPO and VMO.

Data from an ASIC comes into the MAX3341E through

VPO and VMO. VPO and VMO operate either differen-

tially with VPO as the positive terminal and VMO as the

negative terminal, or single ended with VPO as the data

input (see MODE section).

The MAX3341E system-side outputs are VPI, VMI, and

RCV. The MAX3341E sends data to an ASIC through

VPI, VMI, and RCV. VPI and VMI are outputs to the

single-ended receivers and RCV is the output of the dif-

ferential 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 MAX3341E. Drive MODE high to

select differential mode with VPO as the positive termi-

nal and VMO as the negative terminal. Drive MODE low

to select single-ended mode with VPO as the data input

(Table 1).

VTRM

VTRM is the 3.3V output of the internal linear voltage

regulator. VTRM powers the internal circuitry of the USB

side of the MAX3341E. Connect a 1µF (min) low-ESR

ceramic or plastic capacitor from VTRM to GND, as

close to VTRM as possible.

VCC

In most applications, VCC is derived from the USB 5V out-

put. If supplying VCC with an alternative power supply

such as a lithium-ion battery, the VCC input range is 4.0V

to 5.5V. If VCC drops below 4.0V, supply current drops

to 10µA avoiding excessive battery drain, and D+/D-

enter a high-impedance state allowing other devices to

drive the lines. Bypass VCC to GND with a 1µF ceramic

capacitor as close to the device as possible.

USB Detect

USB detect output (USB_DET) signals to the ASIC that

VCC is present. A high at USB_DET indicates that VCC

is present, while a low at USB_DET indicates that VCC

is not present.

SUSP

Suspend (SUSP) is a control input. Force SUSP high to

place the MAX3341E in a low-power state. In this state,

the quiescent supply current into VCC is less than 50µA

and RCV goes low.

In suspend mode, VPI and VMI remain active as

receive outputs and VTRM stays on. The MAX3341E

continues to receive data from the USB, allowing the µP

to sense activity on the D+/D- lines and wake up the

MAX3341E.

The MAX3341E can also transmit data to D+ and D-

while in suspend mode. This function is used to signal a

remote wakeup by driving a signal on D+ and D- for a

period of 1ms to 15ms. Slew rate control is not active

during suspend mode, and data can only be sent at

data rates up to 200kps.

Data Transfer

Receiving Data from the USB

Data received from the USB are output to VPI/VMI in

either of two ways, differentially or single ended. To

receive data from the USB, force OE high and SUSP

low. Differential data arriving at D+/D- appear as differ-

ential logic signals at VPI/VMI, and as a single-ended

logic signal at RCV. If both D+ and D- are low, then VPI

and VMI are low, signaling a single-ended zero condi-

tion on the bus; RCV is undefined (Table 1).

Transmitting Data to the USB

The MAX3341E outputs data to the USB differentially on

D+ and D-. The logic driving signals may be either dif-

ferential or single ended. For sending differential logic,

force MODE high, force OE and SUSP low, and apply

data to VPO and VMO. D+ then follows VPO, and D-

follows VMO. To send single-ended logic signals, force

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