Analog Devices Inc. ADP1111ARZ-3.3

Overview

ADP1111ARZ-3.3 from Analog Devices is a micropower, fixed-output step-up/step-down switching regulator IC with internal 1 A power switch, 72 kHz oscillator, and 3.3 V ±5% output voltage. It operates from 2 V to 30 V input (step-down) or 2 V to 12.6 V (step-up), delivers up to 200 mA at 3.3 V in step-down mode from 12 V input, and supports low-battery detection via open-collector AO pin. Used in portable instrumentation and battery-backed peripherals.

For engineers reviewing the ADP1111ARZ-3.3 datasheet, ADP1111ARZ-3.3 pinout, ADP1111ARZ-3.3 application, or ADP1111ARZ-3.3 equivalent, key selection criteria include its dual-mode topology support, programmable current limit (400 mA typical), 300 μA quiescent current in shutdown, SO-8 package compatibility, and fixed 3.3 V output with 21–50 mV hysteresis - critical for stable operation in wide-input-voltage portable systems.

Technical Context

The ADP1111ARZ-3.3 implements a gated-oscillator control architecture with a 1.25 V internal reference and comparator-based feedback loop. Its dual-access power switch (SW1 collector, SW2 emitter) enables reconfigurable step-up, step-down, or inverting topologies using only three external components.

It integrates an uncommitted gain block (AO/SET pins) for auxiliary functions including low-battery detection, undervoltage lockout, or post-regulation error amplification. The ILIM pin allows resistor-programmable current limiting, and the FB pin connects directly to output for fixed-voltage versions - eliminating external resistors required in adjustable variants.

Key Specifications

Pinout & Package

ADP1111ARZ-3.3 is housed in an 8-lead SOIC (SO-8) package with exposed pad for thermal enhancement. Pin 1 is ILIM; pin 4 is GND; pin 5 is VIN; pin 6 is SW2; pin 7 is SW1; pin 8 is FB/SENSE. All pins are electrically validated per Analog Devices ADP1111 Rev. A datasheet.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS61040DRVR and LT1931ES5#TRMPBF, the ADP1111ARZ-3.3 uniquely supports step-up, step-down, and inverting configurations in a single SO-8 package with user-programmable current limit and auxiliary gain block - making it the only option among the three for dual-input-voltage-range battery backup systems requiring both 3.3 V generation and low-battery signaling.

Availability

ADP1111ARZ-3.3 is available at Aetrix Electronics and suitable for portable instrumentation, laptop peripheral regulation, flash memory VPP generation, and battery backup supplies requiring stable component supply with guaranteed long-term sourcing.

Supply support for ADP1111ARZ-3.3 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 leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, serving industrial, automotive, communications, and healthcare markets since 1965.

The ADP1111 product line was designed specifically for micropower, multimode DC/DC conversion in battery-powered portable equipment - emphasizing ultra-low quiescent current, topology flexibility, and minimal external component count.

FAQ

What is the maximum output current capability of the ADP1111ARZ-3.3 in step-down mode?

The ADP1111ARZ-3.3 delivers up to 200 mA at 3.3 V from a 12 V input in step-down mode, as confirmed in the "GENERAL DESCRIPTION" section of the Analog Devices datasheet. This assumes proper thermal management and use of recommended external components (e.g., 56 µH inductor, MBRS130T3 Schottky diode). Peak switch current is internally limited to 1.5 A absolute maximum, with 400 mA typical when ILIM is configured with a 220 Ω resistor.

Can the ADP1111ARZ-3.3 be used in step-up mode, and what is its minimum input voltage for that configuration?

Yes, the ADP1111ARZ-3.3 supports step-up (boost) operation with a minimum input voltage of 2.0 V, as specified in the "INPUT VOLTAGE" row of the Rev. A datasheet. It can generate 3.3 V from as low as 2 V input, delivering 100 mA at 3.3 V from a 3 V source - making it suitable for single-cell alkaline or LiFePO₄ battery applications where input voltage drops below nominal levels.

Does the ADP1111ARZ-3.3 require external feedback resistors to set its output voltage?

No, the ADP1111ARZ-3.3 does not require external feedback resistors. As a fixed-output variant, it integrates laser-trimmed internal resistors that set the output to 3.3 V ±5%. Per the "PIN DESCRIPTIONS" section, the FB/SENSE pin (Pin 8) connects directly to the regulated output - eliminating two external components and improving long-term accuracy versus adjustable versions.

How is low-battery detection implemented using the ADP1111ARZ-3.3?

Low-battery detection is implemented using the AO (Pin 1) and SET (Pin 2) pins. A resistor divider from VIN to GND applies a scaled voltage to SET; when this falls below the internal 1.25 V reference, the open-collector AO output pulls low (≤0.4 V at 300 µA sink). This signal can drive a microcontroller interrupt or enable/disable circuitry. The gain block's 1000–6000 V/V gain allows precise threshold setting independent of load conditions.

What package type and RoHS status does the ADP1111ARZ-3.3 use?

The ADP1111ARZ-3.3 uses an 8-lead SOIC (SO-8) package with gull-wing leads and is RoHS-compliant, as indicated by the "RZ" suffix per Analog Devices' packaging nomenclature. The "Z" denotes lead-free (Pb-free) finish, and the device meets JEDEC J-STD-020 moisture sensitivity level 3 requirements for standard surface-mount assembly processes.