Analog Devices Inc./Maxim Integrated MAX6475TA15BD3+

Overview

MAX6475TA15BD3+ from Maxim Integrated is a 300mA low-dropout linear regulator with integrated microprocessor reset circuit, fixed 1.5V output voltage, -7.5% reset threshold, and 150ms (min) reset timeout. It features active-low push-pull RESET, shutdown control (SHDN), remote feedback (FB) for external NPN pass transistor support, and operates from 2.5V to 5.5V input. Designed for battery-powered portable equipment requiring precise power sequencing and brownout protection.

For engineers reviewing the MAX6475TA15BD3+ datasheet, MAX6475TA15BD3+ pinout, MAX6475TA15BD3+ application, or MAX6475TA15BD3+ equivalent, this device delivers verified ±2.0% output accuracy over temperature, 55mV dropout at 150mA, 82µA quiescent current, and integrated reset supervision - critical for reliable boot-up in handheld instruments, Bluetooth modules, and USB devices.

Technical Context

The MAX6475TA15BD3+ implements a dual-path LDO architecture with separate FB and OUT pins enabling remote sensing and external NPN transistor augmentation for higher-current applications. Its reset circuit shares the same reference as the regulator core and asserts active-low RESET when FB falls below 92.5% of nominal VOUT (i.e., 1.3875V for 1.5V output), with guaranteed 35µs response delay.

Shutdown is controlled via active-low SHDN, reducing supply current to 0.1µA (typ); the FB pin is internally disconnected from OUT and functions exclusively as a remote sense input - not a standard adjustable feedback node. The device uses an internal 1.229V SET reference (typ) but does not use the SET pin; instead, it routes FB directly to the error amplifier's inverting input for remote voltage monitoring.

Key Specifications

Pinout & Package

MAX6475TA15BD3+ is housed in an 8-pin TDFN-EP package (3mm × 3mm, 0.75mm height) with exposed paddle (EP) internally connected to GND. Thermal performance is optimized by soldering EP to PCB ground plane.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar LDO-with-reset applications.

Compared with TPS7A0515PDBVR and ADM7172ACPZ-1.5-R7, the MAX6475TA15BD3+ uniquely combines 300mA delivery, integrated -7.5% reset with 150ms timeout, remote FB sensing, and 0.1µA shutdown - enabling single-chip power sequencing in space-constrained portable systems where discrete supervisors increase BOM count and layout complexity.

Availability

MAX6475TA15BD3+ is available at Aetrix Electronics and suitable for handheld instruments, Bluetooth modules, and USB peripheral devices requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for MAX6475TA15BD3+ 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 demanding industrial, automotive, and portable applications.

The MAX6469–MAX6484 family was engineered specifically for battery-powered microprocessor systems needing tightly coupled regulation and reset supervision in minimal footprint - emphasizing low IQ, remote sensing, and robust fault protection.

FAQ

What is the exact output voltage tolerance of the MAX6475TA15BD3+ over temperature?

The MAX6475TA15BD3+ guarantees ±2.0% output voltage accuracy across the full -40°C to +85°C operating range. This specification applies to its fixed 1.5V output and is confirmed in the Electrical Characteristics table under "Output Voltage Accuracy (Fixed Output Voltage Operation)" for MAX6469–MAX6476 devices. At +25°C, typical accuracy is tighter at ±1.3%, but design margins must use the ±2.0% worst-case value.

Does the MAX6475TA15BD3+ support remote voltage sensing, and how is it implemented?

Yes, the MAX6475TA15BD3+ supports remote voltage sensing via its dedicated FB pin - distinct from the OUT pin. To implement, connect FB directly to the load's VCC point (e.g., µP VDD pin), not to the OUT pin. This compensates for PCB trace IR drop. The device's internal error amplifier compares FB voltage to its 1.229V reference, adjusting OUT to maintain 1.5V at the load. This feature is exclusive to MAX6475/MAX6476/MAX6483/MAX6484 variants.

What reset timeout period is configured in the MAX6475TA15BD3+?

Per the ordering suffix "D3", the MAX6475TA15BD3+ is configured with a 150ms minimum reset timeout period. This value is factory-trimmed and guaranteed across temperature. The reset pulse remains asserted for ≥150ms after VOUT rises above the 92.5% threshold (1.3875V), ensuring adequate time for clock oscillators and memory initialization before processor release.

Can the MAX6475TA15BD3+ be used with an external NPN transistor to increase output current?

Yes, the MAX6475TA15BD3+ is explicitly designed for external NPN transistor augmentation using its FB pin. Connect the NPN emitter to OUT, collector to load, and base via resistor network to FB. The regulator controls base drive to maintain 1.5V at the load (sensed at FB). Total current equals LDO current plus β×LDO current. Datasheet Figure 2 shows the validated circuit; transistor selection must meet beta, power dissipation, and collector current specs per application notes.

What is the shutdown current of the MAX6475TA15BD3+, and how is shutdown activated?

The MAX6475TA15BD3+ draws 0.1µA typical supply current in shutdown mode. Shutdown is activated by pulling the SHDN pin low (≤0.3×VIN); the device exits shutdown when SHDN rises above 0.7×VIN. During shutdown, the pass transistor, reference, and control circuitry are disabled. The RESET output remains asserted low until VOUT recovers and stabilizes post-shutdown, ensuring clean system reset on wake-up.