LMH32401YR

Overview

The LMH32401YR is a single-channel transimpedance amplifier with differential output, manufactured by Texas Instruments. It features integrated programmable gain selectable between 2 kΩ and 20 kΩ via the GAIN pin. The device operates on a single supply voltage ranging from 3 V to 3.45 V, consuming a typical quiescent current of 30 mA. Key electrical specifications include a small-signal bandwidth of 450 MHz at 2 kΩ gain and 275 MHz at 20 kΩ gain. The input-referred noise is 250 nARMS at 2 kΩ gain and 49 nARMS at 20 kΩ gain. The package options include a 16-pin VQFN and bare die.

Feature Summary

• Integrated programmable gain selection between 2 kΩ and 20 kΩ for flexible signal conditioning.
• Built-in ambient light cancellation circuit to reduce system cost and board space requirements.
• Internal 100-mA protection clamp ensures rapid recovery from overloaded input conditions.
• Differential output architecture designed to drive 100-ohm loads with wide output swing.

Applications

• Mechanically scanning LIDAR systems
• Solid-state scanning LIDAR applications
• Laser distance meters
• Optical Time-of-Flight (ToF) position sensors
• Drone vision systems

Procurement Notes

Verify the specific package variant required, as the LMH32401 family includes both packaged and bare die options. Confirm that the ordering suffix matches the intended physical form factor. Ensure power supply bypassing is implemented independently for VDD1 and VDD2 pins as specified in the datasheet. Check logic level compatibility for control pins such as EN, GAIN, and IDC_EN against the host microcontroller.

Selection Notes

Select this component when high-speed transimpedance amplification with differential outputs is required for optical sensing. The choice between 2 kΩ and 20 kΩ gain depends on the photodiode capacitance and desired bandwidth trade-off. Consider the integrated ambient light cancellation if AC coupling is undesirable. Verify thermal management requirements for the chosen package type under maximum operating temperatures.

Part Context

The LMH32401 belongs to Texas Instruments' high-performance transimpedance amplifier series designed specifically for LiDAR and laser ranging. It addresses the need for compact, low-power solutions in autonomous navigation and industrial robotics. The device integrates functions typically requiring external components, simplifying the design of optical front-end circuits.

Replacement Considerations

No direct public substitute part numbers are documented for this specific model.

FAQ

How is the gain configured?

The gain is set using the GAIN pin. A logic low selects 2 kΩ gain, while a logic high selects 20 kΩ gain.

What is the function of the IDC_EN pin?

The IDC_EN pin enables or disables the integrated ambient light cancellation loop. Logic low enables DC current cancellation, while logic high disables it.

Can multiple LMH32401 devices share a single ADC?

Yes, the EN pin can be used as a multiplexer select function to place unused amplifiers in a low-power shutdown mode with high-impedance outputs.