Analog Devices Inc./Maxim Integrated MAX20051AUD/V+TG2Z

Overview

MAX20051AUD/V+TG2Z from Analog Devices is a 2A synchronous-buck HB LED driver with integrated 0.14Ω (typ) MOSFETs, designed for automotive exterior lighting. It operates from 4.5V to 65V input, delivers ±2.5% full-scale current regulation accuracy, supports 400kHz switching frequency, and features high-side current sensing with 200mV sense voltage - enabling DRL and fog lamp designs with minimal external components.

For engineers reviewing the MAX20051AUD/V+TG2Z datasheet, MAX20051AUD/V+TG2Z pinout, MAX20051AUD/V+TG2Z application, or MAX20051AUD/V+TG2Z equivalent, key selection considerations include its AEC-Q100 qualification, external loop compensation capability, 5V/10mA LDO output, spread-spectrum EMI reduction (disabled in B variant), and thermal shutdown protection across –40°C to +125°C.

Technical Context

The MAX20051AUD/V+TG2Z implements average-current-mode control using a transconductance error amplifier whose output appears on the COMP pin for external RC compensation. Its 400kHz fixed-frequency oscillator synchronizes to the rising edge of the PWM dimming signal, ensuring consistent low-duty-cycle dimming performance.

High-side current sensing via CS+/CS– enables single-point LED string connection with local grounding; analog dimming is implemented through the REFI pin (0–1.2V range), while PWM dimming disables both MOSFETs and triggers shutdown after 210ms low state. Fault detection includes open-LED, short-circuit, and overtemperature events signaled via active-low FLT.

Key Specifications

Pinout & Package

MAX20051AUD/V+TG2Z is housed in a thermally enhanced 12-pin (3mm × 3mm) TDFN package with exposed pad (EP), optimized for high-power LED driver thermal management in compact automotive modules.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar LED driver applications.

Compared with MAX20051AUD/V+TG2Z, the MAX20051ATP/V+ offers superior thermal dissipation in a larger package, while the MAX20053ATP/V+ trades efficiency for smaller magnetics - making the TDFN-based MAX20051AUD/V+TG2Z optimal for cost-sensitive, medium-power DRL/fog lamp designs where 400kHz balance and compact size are decisive.

Availability

MAX20051AUD/V+TG2Z is available at Aetrix Electronics and suitable for automotive exterior lighting, commercial vehicle lighting, and driver monitoring systems requiring stable component supply, AEC-Q100 compliance, and long-term production continuity.

Supply support for MAX20051AUD/V+TG2Z 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

Analog Devices is a global semiconductor leader specializing in high-performance analog, mixed-signal, and power management ICs for automotive, industrial, and communications markets.

The MAX20050–MAX20053 family was engineered specifically for automotive exterior LED lighting, emphasizing robustness against harsh electrical environments, precision current regulation, and integrated protection - targeting DRL, fog, and rear lamp applications.

FAQ

What is the maximum LED string voltage supported by the MAX20051AUD/V+TG2Z?

The MAX20051AUD/V+TG2Z does not specify a maximum output voltage directly; instead, its LX node is rated for up to VIN + 0.3V, and the CS+ input withstands up to VIN + 0.3V. With a 65V input and typical forward voltage drop of ~3.2V per white LED, the MAX20051AUD/V+TG2Z reliably drives up to 18–20 series LEDs (60–65V total) depending on thermal design and ambient temperature. Always verify voltage margin using worst-case V_F and temperature coefficients from LED datasheets.

Does the MAX20051AUD/V+TG2Z support both analog and PWM dimming simultaneously?

Yes, the MAX20051AUD/V+TG2Z supports concurrent analog and PWM dimming: the REFI pin sets baseline current level (0–1.2V → 0–100% full scale), while the PWM pin modulates that level at frequencies from 10Hz to 2kHz. During PWM off-time, both MOSFETs are disabled - preserving analog-set current accuracy during on-time. This dual-mode capability enables smooth fade transitions and adaptive brightness control in modern automotive lighting systems.

What is the purpose of the COMP pin on the MAX20051AUD/V+TG2Z, and how is it used?

The COMP pin on the MAX20051AUD/V+TG2Z provides access to the transconductance error amplifier output, enabling external loop compensation with an RC network. Unlike the internally compensated MAX20050/MAX20052, this pin allows designers to tailor phase margin and bandwidth for specific LED string capacitance, inductor DCR, and thermal drift - critical for maintaining stability across –40°C to +125°C and varying output voltages. Typical networks use 1–10kΩ resistor and 100pF–1nF capacitor.

How does the MAX20051AUD/V+TG2Z handle open-LED fault detection?

The MAX20051AUD/V+TG2Z detects open-LED conditions by monitoring the CS– pin voltage relative to OUTVTH_LOW (1.5V typ). When CS– falls below this threshold while REFI > 325mV and VIN > 9V, the device asserts the FLT pin low after a deglitch timer (105µs) and mask timer (210µs). This two-stage timing prevents false triggering during startup or transient load changes. The open-LED threshold is factory-trimmed and guaranteed across temperature.

Is spread-spectrum enabled on the MAX20051AUD/V+TG2Z, and how does it affect EMI?

No, spread-spectrum is disabled on the MAX20051AUD/V+TG2Z because it belongs to the "B" variant subgroup (as indicated by suffix "B" in MAX20051B). Spread-spectrum dithering (±3%) is only active on non-B versions like MAX20051 (no suffix) or MAX20053. For MAX20051AUD/V+TG2Z, EMI reduction relies on 400kHz fixed frequency, careful PCB layout, and external filtering - making it suitable for applications where deterministic timing is preferred over spectral spreading.