NLSX4378FCT1G View Datasheet(PDF) - ON Semiconductor

Part Name

Description

Manufacturer

NLSX4378FCT1G

4-Bit 20 Mb/s Dual-Supply Level Translator

ON Semiconductor 

NLSX4378

APPLICATIONS INFORMATION

Level Translator Architecture

The NLSX4378 auto sense translator provides

bi−directional voltage level shifting to transfer data in

multiple supply voltage systems. This device has two

supply voltages, VL and VCC, which set the logic levels on

the input and output sides of the translator. When used to

transfer data from the VL to the VCC ports, input signals

referenced to the VL supply are translated to output signals

with a logic level matched to VCC. In a similar manner, the

VCC to VL translation shifts input signals with a logic level

compatible to VCC to an output signal matched to VL.

The NLSX4378 consists of two bi−directional channels

that independently determine the direction of the data flow

without requiring a directional pin. The one−shot circuits

are used to detect the rising or falling input signals. In

addition, the one shots decrease the rise and fall time of the

output signal for high−to−low and low−to−high transitions.

Each input/output channel has an internal 10 kW pull.

The magnitude of the pullup resistors can be reduced by

connecting external resistors in parallel to the internal

10 kW resistors.

Input Driver Requirements

The rise (tR) and fall (tF) timing parameters of the open

drain outputs depend on the magnitude of the pull−up

resistors. In addition, the propagation times (tPD), skew

(tPSKEW) and maximum data rate depend on the impedance

of the device that is connected to the translator. The timing

parameters listed in the data sheet assume that the output

impedance of the drivers connected to the translator is less

than 50 kW.

Enable Input (EN)

The NLSX4378 has an Enable pin (EN) that provides

tri−state operation at the I/O pins. Driving the Enable pin

to a low logic level minimizes the power consumption of

the device and drives the I/O VCC and I/O VL pins to a high

impedance state. Normal translation operation occurs

when the EN pin is equal to a logic high signal. The EN pin

is referenced to the VL supply and has Overvoltage

Tolerant (OVT) protection.

Power Supply Guidelines

During normal operation, supply voltage VL can be

greater than, less than or equal to VCC. The sequencing of

the power supplies will not damage the device during the

power up operation.

For optimal performance, 0.01 mF to 0.1 mF decoupling

capacitors should be used on the VL and VCC power supply

pins. Ceramic capacitors are a good design choice to filter

and bypass any noise signals on the voltage lines to the

ground plane of the PCB. The noise immunity will be

maximized by placing the capacitors as close as possible to

the supply and ground pins, along with minimizing the

PCB connection traces.

ORDERING INFORMATION

Device

Package

Shipping†

NLSX4378FCT1G

mBump12

(Pb−Free)

3000 / Tape & Reel

NLSX4378BFCT1G

mBump12

(Backside Laminate Coating)

(Pb−Free)

3000 / Tape & Reel

†For information on tape and reel specifications, including part orientation and tape sizes, please refer to our Tape and Reel Packaging

Specifications Brochure, BRD8011/D.

http://onsemi.com

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