1 Features

• Integrated gain: 40 kΩ

• Performance, CPD = 1 pF:

– Bandwidth: 240 MHz

– Input-referred noise: 50 nARMS

– Rise, fall time: 1.5 ns

• Integrated ambient light cancellation

• Integrated 100-mA protection clamp

• Quiescent current: 20 mA

• Low-power mode current: 1.5 mA

• Temperature range: –40°C to +125°C

2 Applications

• Mechanically scanning LIDAR

• Solid-state scanning LIDAR

• Laser distance meter

• Optical ToF position sensor

• Drone vision

• Industrial robot LIDAR

• Mobile robot LIDAR

• Vacuum robot LIDAR

3 Description

The LMH34400 is the industries' smallest, fixedgain,

single-ended transimpedance amplifier for light

detection and ranging (LIDAR) applications and laser

distance measurement systems. The LMH34400 can

produce 1.0 VPP of output swing and has an input

referred noise of 50 nARMS.

The LMH34400 has an integrated 100-mA clamp

that protects the amplifier and allows the device to

recover rapidly from an overloaded input condition.

The LMH34400 also features an integrated ambient

light cancellation (ALC) circuit that can be used

instead of AC coupling between the photodiode and

the amplifier to save board space and system cost.

The ALC loop should be disabled in cases where

frequency signal content less than 400 kHz needs to

be measured.

The LMH34400 can be placed in low-power mode

using the EN pin to conserve power when the

amplifier is not being used. This feature allows several

LMH34400 amplifiers to be multiplexed to the input of

the next stage of the receive signal chain with the EN

control pin serving as the multiplexer select function.

The LMH34400 offers single-ended output and is

optimized to be used with time-to-digital converter

(TDC) based LIDAR systems.