Analog Devices Inc./Maxim Integrated MAX38650AANT+T

Overview

MAX38650AANT+T from Maxim Integrated is a nanoPower synchronous buck DC-DC converter optimized for ultra-low-quiescent-current battery-powered systems. It operates from 1.8V to 5.5V input, delivers up to 100mA output current, achieves 95% peak efficiency, supports 100% duty cycle operation, and features 390nA quiescent current - enabling multi-year operation on coin-cell or single Li-ion batteries in wearables and NB-IoT sensors.

For engineers reviewing the MAX38650AANT+T datasheet, MAX38650AANT+T pinout, MAX38650AANT+T application, or MAX38650AANT+T equivalent, key selection criteria include its RSEL-programmable 1.2V–3.3V output, ±1.5% output accuracy, 5nA shutdown current, active discharge (85Ω), and WLP package compatibility with space-constrained PCB layouts.

Technical Context

The MAX38650AANT+T implements a proprietary adaptive control scheme that dynamically switches between low-power mode (LPM) and high-power mode (HPM) based on load demand. LPM enables 390nA IQ by over-regulating and leveraging COUT for transient response, while HPM activates switching for higher loads with 95% peak efficiency.

Its 100% duty cycle operation bridges input-to-output dropout seamlessly during battery discharge, maintaining regulation down to VIN ≈ VOUT via direct high-side conduction. The integrated active discharge resistor (85Ω typical) and reverse-current blocking at shutdown protect downstream circuitry without external components.

Key Specifications

Pinout & Package

MAX38650AANT+T is housed in a 1.58mm × 0.89mm, 6-pin wafer-level package (WLP) with 0.4mm pitch and 2×3 bump layout. The package is RoHS-compliant, moisture-sensitive level 1 (MSL1), and optimized for minimal board area in wearable and implantable designs.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar nanoPower buck converter applications.

Compared with TPS62840YKAR and ADP5302ACBZ-3-R7, the MAX38650AANT+T uniquely combines RSEL-based voltage configurability, true 100% duty cycle operation, and sub-1µA total shutdown current - making it optimal for cost-sensitive, space-constrained, and long-life battery applications requiring design reuse across multiple output voltages.

Availability

MAX38650AANT+T is available at Aetrix Electronics and suitable for portable medical diagnostics, wearable health sensors, BLE/NB-IoT endpoints, and industrial wireless nodes requiring stable component supply and long-term lifecycle support.

Supply support for MAX38650AANT+T 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, medical, and communications applications.

The MAX38650 series targets ultra-low-power battery-operated systems where nanoscale IQ, minimal solution size, and seamless battery-depletion handling are essential - especially in wearables, IoT edge nodes, and portable diagnostics.

FAQ

What is the maximum output current supported by the MAX38650AANT+T?

The MAX38650AANT+T delivers up to 100mA of continuous output current under typical conditions (VIN ≥ VOUT + 0.3V). Peak inductor current is limited to 310mA, and performance remains stable across the full -40°C to +125°C temperature range. This makes the MAX38650AANT+T suitable for powering low-power MCUs, BLE radios, and analog sensors without thermal derating in compact enclosures.

How does the RSEL pin configure the output voltage on the MAX38650AANT+T?

The MAX38650AANT+T uses the RSEL pin to detect an external resistor at startup, selecting both output voltage (1.2V–3.3V) and input UVLO threshold. For example, a 20kΩ resistor sets VOUT = 1.8V and UVLO rising threshold = 1.75V. The detection occurs once per power-up, drawing ≤200µA for ≤600µs - eliminating continuous divider current and preserving nanoPower operation.

Does the MAX38650AANT+T support 100% duty cycle operation, and what is its benefit?

Yes, the MAX38650AANT+T supports true 100% duty cycle operation: when VIN approaches VOUT, it stops switching and conducts continuously through the high-side FET and inductor. This eliminates dropout-related brownouts during battery discharge - critical for maintaining real-time sensor sampling or secure boot sequences in coin-cell-powered devices.

What is the purpose of the active discharge feature in the MAX38650AANT+T?

The MAX38650AANT+T integrates an 85Ω active discharge resistor between OUT and GND, activated automatically during shutdown. This rapidly discharges the output capacitor - reducing 22µF COUT voltage to <100mV in ~2ms - preventing false wake-ups, latch-up, or undefined states in downstream logic, especially in systems with multiple power domains.

Is the MAX38650AANT+T pin-compatible with other variants in the MAX38650 family?

Yes, the MAX38650AANT+T shares identical 6-pin WLP packaging, pinout, and footprint with MAX38650BANT+, enabling drop-in replacement where preprogrammed output voltage suffices. However, RSEL functionality is exclusive to MAX38650A variants; MAX38650B leaves RSEL floating and uses factory-set VOUT - so hardware design must match the selected variant's configuration method.