LMH32401IRGTR

Overview

The LMH32401IRGTR is a programmable-gain, single-ended input to differential output transimpedance amplifier. It features integrated ambient light cancellation and a 100-mA protection clamp for rapid recovery from overload. The device supports two gain settings: 2 kΩ with 450 MHz bandwidth and 250 nARMS noise, or 20 kΩ with 275 MHz bandwidth and 49 nARMS noise. It operates on a 3 V to 3.45 V supply, draws 30 mA quiescent current, and includes an output multiplexer for ADC sharing.

Feature Summary

• Integrated programmable gain selectable between 2 kΩ and 20 kΩ
• Built-in ambient light cancellation circuit replaces AC coupling
• Integrated 100-mA protection clamp for fast overload recovery
• Output multiplexer allows multiple amplifiers to share a single ADC

Applications

• Mechanically scanning LIDAR
• Solid-state scanning LIDAR
• Laser distance meter
• Optical ToF position sensor
• Drone vision systems

Procurement Notes

Verify the IRGTR suffix corresponds to the 16-pin VQFN package configuration. Confirm that the ordering quantity aligns with the manufacturer's standard reel packaging requirements. Ensure the application environment remains within the specified -40°C to +125°C operating temperature range. Validate power supply decoupling for VDD1 and VDD2 as recommended in the datasheet.

Selection Notes

Select this component when high-speed signal processing with configurable sensitivity is required. The dual gain options allow optimization for varying photodiode capacitance and signal levels. The integrated multiplexer simplifies system architecture by reducing external switching components. Verify that the 1.5 VPP output swing meets the input requirements of the downstream analog-to-digital converter.

Part Context

This device belongs to the LMH32401 series of high-speed transimpedance amplifiers designed for optical detection. It serves as a critical front-end interface for converting photocurrent into voltage signals. The family targets applications demanding precise timing and low noise performance in challenging lighting conditions.

Replacement Considerations

LMH32401-Q1

FAQ

How does the device handle ambient light interference?

The LMH32401IRGTR includes an integrated ambient light cancellation loop that can be enabled via the IDC_EN pin. This feature cancels DC currents from ambient light, eliminating the need for external AC coupling capacitors.

What is the function of the EN pin?

The EN pin controls the device state. Driving it logic low enables normal operation, while driving it logic high places the amplifier in a low-power shutdown mode with high-impedance outputs.