Analog Devices Inc./Maxim Integrated MAX3806GTC+

Overview

MAX3806GTC+ from Maxim Integrated is a single-channel, high-gain linear transimpedance preamplifier optimized for laser-based optical distance measurement systems. It converts photodiode current into a single-ended voltage with selectable 60kΩ or 30kΩ gain, 14dB programmable attenuation, and overload tolerance up to 2mAP - enabling robust operation in portable and industrial LIDAR receivers.

For engineers reviewing the MAX3806GTC+ datasheet, MAX3806GTC+ pinout, MAX3806GTC+ application, or MAX3806GTC+ equivalent, key selection criteria include input-referred noise (1.5pA/√Hz at 60kΩ), small-signal bandwidth (up to 98MHz), AC-coupled output drive capability, and configurable gain/attenuation/disabled-output logic for time-of-flight signal conditioning.

Technical Context

The MAX3806GTC+ implements a three-stage signal path: a CMOS/TTL-controlled transimpedance amplifier with two discrete gain settings (60kΩ or 30kΩ), followed by a 14dB attenuator selected via the ATT pin, and a buffered output stage with DIS-enabled high-impedance mode. All control inputs (GAIN, ATT, DIS) feature internal pull-up or pull-down resistors for default-state robustness.

Its functional architecture supports fast transient response (≤200ns disable settling), overload recovery from 2mAP pulses, and stable operation across -40°C to +105°C with supply rejection of -23dB (GAIN=0) at low-frequency noise. Input impedance varies with gain setting (800Ω at GAIN=1, 300Ω at GAIN=0), directly impacting photodiode interface design.

Key Specifications

Pinout & Package

The MAX3806GTC+ is housed in a 3mm × 3mm, 12-pin TQFN-EP package with exposed thermal pad (EP) requiring solder connection to PCB ground. The package supports high-density layout and efficient thermal dissipation in compact optical modules.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar transimpedance amplifier applications.

Compared with MAX3805GTC+, the MAX3806GTC+ adds critical configurability for LIDAR timing control; versus TZA1010IBK, it delivers lower noise and higher overload resilience essential for accurate time-of-flight calculation in variable-light environments.

Availability

MAX3806GTC+ is available at Aetrix Electronics and suitable for portable laser distance meters, industrial LIDAR sensors, automotive parking assist modules, and smart building occupancy detectors requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for MAX3806GTC+ includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Maxim Integrated, now part of Analog Devices, designs precision analog and mixed-signal ICs for demanding industrial, communications, and sensing applications.

The MAX3806GTC+ belongs to Maxim's optical receiver front-end product line, engineered specifically for high-speed, low-noise current-to-voltage conversion in laser time-of-flight distance measurement systems.

FAQ

What is the maximum input pulse width the MAX3806GTC+ can handle linearly?

The MAX3806GTC+ accepts single pulses or bursts with widths down to 30ns while maintaining linearity across its full input range (42nAP to 40μAP). Its 49MHz small-signal bandwidth (GAIN=1, ATT=0) supports pulse fidelity for time-of-flight measurements requiring sub-nanosecond timing resolution. Pulse width handling is not limited by upper bound - rather, it depends on photodiode capacitance and external AC-coupling network design.

Does the MAX3806GTC+ require external components for basic operation?

Yes, the MAX3806GTC+ requires external 0.01µF AC-coupling capacitors on both IN and OUT pins, plus local 0.01µF VCC bypass capacitors. The IN node also needs an external RC network (L and C) to set low-frequency cutoff per application. No external gain-setting resistors are needed - gain, attenuation, and output disable are controlled digitally via GAIN, ATT, and DIS pins.

Can the MAX3806GTC+ be used with DC-coupled photodiodes?

No - the MAX3806GTC+ input is strictly AC-coupled. Its IN pin accepts only current pulses from AC-coupled photodiodes; DC-coupled operation violates the device's biasing architecture and risks saturation or instability. The datasheet explicitly warns against DC coupling the output to ≤2kΩ loads, and the same constraint applies to input topology for optimal noise and bandwidth performance.

What is the purpose of the exposed pad (EP) on the MAX3806GTC+ package?

The exposed pad (EP) on the MAX3806GTC+ serves dual thermal and electrical functions: it provides a low-thermal-resistance path to dissipate heat and is internally connected to ground. Per Maxim's layout guidelines, the EP must be soldered to a solid PCB ground plane to ensure proper electrical performance, noise immunity, and thermal reliability - especially critical in continuous high-gain operation at +105°C.

How does the MAX3806GTC+ handle overload conditions above its linear range?

The MAX3806GTC+ withstands overload currents up to 2mAP without damage and recovers rapidly - typically within microseconds - due to internal transistor-level protection and fast saturation recovery design. While distortion occurs beyond 40μAP (GAIN=0) or 20μAP (GAIN=1), the device remains functional and resumes linear operation after the overload pulse ends, making it suitable for LIDAR systems encountering specular reflections or close-proximity targets.