Analog Devices Inc./Maxim Integrated MAX6774BTALD3+

Overview

MAX6774BTALD3+ from Maxim Integrated is a micropower, high-voltage linear regulator with integrated watchdog timer and supervisor functionality. It operates from 4V to 72V input, delivers up to 100mA output at fixed 5.0V (L suffix), features active-low open-drain RESET with 50ms timeout (D3 suffix), and includes a 50ms watchdog timeout (B variant), making it suitable for automotive always-on modules requiring reliable power sequencing and microcontroller supervision.

For engineers reviewing the MAX6774BTALD3+ datasheet, MAX6774BTALD3+ pinout, MAX6774BTALD3+ application, or MAX6774BTALD3+ equivalent, key selection criteria include its AEC-Q100-qualified operation over –40°C to +125°C, 31µA quiescent current, 620mV dropout at 100mA/5V, watchdog input (WDI) compatibility, and TDFN-8 package thermal performance up to 1.951W.

Technical Context

The MAX6774BTALD3+ integrates a low-dropout linear regulator, precision reset supervisor with capacitor-adjustable timeout, and a dedicated watchdog timer with 50ms typical timeout - distinct from the 1.6s version in non-B variants. Its RESET output asserts when V_OUT falls below 4.625V (L threshold) and remains asserted for ≥50ms after recovery, synchronized to the TIMEOUT pin configuration.

This device uses an internal 1.233V reference for output regulation and reset threshold generation, supports external voltage adjustment via SET pin (though configured for fixed 5V here), and implements thermal shutdown at +160°C with 20°C hysteresis. The WDI input requires valid edges within 50ms to prevent reset assertion and cannot be disabled.

Key Specifications

Pinout & Package

MAX6774BTALD3+ is housed in an 8-pin, 3mm × 3mm thermally enhanced TDFN-EP package with exposed pad (EP) connected internally to GND. The package supports up to 1.951W continuous power dissipation at T_A ≤ +70°C and is RoHS-compliant (+ suffix).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar automotive supervisory regulator applications.

Compared with MAX6773BTALD3+, MAX6774BTALD3+ provides faster fault response for safety-critical code; compared with TPS7B8750QKVURQ1, it integrates watchdog supervision without external components, reducing design risk and layout complexity in space-constrained automotive ECUs.

Availability

MAX6774BTALD3+ is available at Aetrix Electronics and suitable for automotive body control, ADAS camera modules, commercial telematics gateways, and electric powertrain control units requiring stable component supply across extended temperature and high-reliability requirements.

Supply support for MAX6774BTALD3+ 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, mixed-signal, and power management ICs for automotive, industrial, and communications markets.

The MAX6765–MAX6774B family was engineered specifically for automotive always-on power domains, combining ultra-low quiescent current, high-voltage tolerance, and integrated supervision to replace discrete LDO + reset IC + watchdog solutions in ECUs.

FAQ

What is the watchdog timeout period for MAX6774BTALD3+?

The MAX6774BTALD3+ features a 50ms typical watchdog timeout period (40ms to 60ms over temperature), which is factory-configured and not user-adjustable. This value is distinct from the 1.6s timeout in non-B variants like MAX6773BTALD3+. The watchdog timer monitors the WDI pin and asserts RESET if no valid edge occurs within this window. MAX6774BTALD3+ relies on this fast timeout to meet ASIL-B timing requirements in driver assistance functions.

Does MAX6774BTALD3+ require external components to operate in fixed 5V mode?

No, MAX6774BTALD3+ operates in fixed 5V mode without external feedback components. The "L" suffix indicates factory-trimmed 5.0V output, and the SET pin is internally referenced to 1.233V and tied to GND internally for this configuration. Only two external capacitors are required: ≥0.1µF from IN to GND and ≥10µF from OUT to GND. No resistors or additional supervision circuitry are needed for basic operation of MAX6774BTALD3+.

Is MAX6774BTALD3+ AEC-Q100 qualified?

Yes, MAX6774BTALD3+ is AEC-Q100 qualified per Grade 0 (–40°C to +150°C junction temperature), including stress testing for high-temperature operating life, ESD, and latch-up. This qualification is explicitly listed in the datasheet for MAX6773B/MAX6774B variants. MAX6774BTALD3+ meets automotive reliability standards for deployment in engine bay, transmission, and chassis control modules where long-term robustness is mandatory.

What is the maximum continuous output current of MAX6774BTALD3+?

MAX6774BTALD3+ delivers up to 100mA of continuous output current, limited by both internal current limiting (150–250mA short-circuit limit) and package thermal dissipation. At 72V input and 5V output, power dissipation is (72V – 5V) × 100mA = 6.7W - exceeding the 1.951W TDFN-8 rating. Therefore, usable current depends on VIN–VOUT differential and ambient temperature; at 14V input, full 100mA is sustainable. Derating curves in the MAX6774BTALD3+ datasheet define safe operating area.

Can the RESET output of MAX6774BTALD3+ drive a microcontroller reset pin directly?

Yes, the open-drain RESET output of MAX6774BTALD3+ can directly drive standard microcontroller reset inputs when used with an external pull-up resistor (typically 10kΩ to V_CC). It sinks ≥3.2mA at 0.4V (V_OL) and supports voltages up to 12V on the RESET line. No level-shifter or buffer is required. However, ensure the µP's reset pin accepts open-drain signaling and that the pull-up voltage matches the µP's logic supply - MAX6774BTALD3+ does not provide push-pull RESET in this variant.