Analog Devices Inc. ADP1111ANZ-3.3

Overview

ADP1111ANZ-3.3 from Analog Devices is a micropower, fixed-output step-up/step-down switching regulator 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 100 mA at 3.3 V from 3 V input in boost mode, and supports low-battery detection via open-collector AO pin. Used in portable instrumentation and battery-powered peripherals.

For engineers reviewing the ADP1111ANZ-3.3 datasheet, ADP1111ANZ-3.3 pinout, ADP1111ANZ-3.3 application, or ADP1111ANZ-3.3 equivalent, key selection factors include its dual-mode topology support, user-adjustable current limit via ILIM pin, fixed 3.3 V output with 21–50 mV hysteresis, 300–500 μA quiescent current, and compatibility with surface-mount inductors and Schottky diodes in compact DIP-8 or SO-8 packages.

Technical Context

The ADP1111ANZ-3.3 implements a gated-oscillator control architecture with internal 1.25 V reference and comparator-based regulation loop. Its dual-access power switch (SW1 collector, SW2 emitter) enables reconfigurable step-up, step-down, or inverting topologies using only three external components - inductor, diode, and output capacitor.

It integrates a programmable current-limit circuit (400 mA typical with 220 Ω ILIM-to-VIN resistor), an uncommitted gain block (AO/SET pins) for low-battery detection or post-regulation, and built-in hysteresis (8–12.5 mV comparator, 21–50 mV output) ensuring stable operation without external compensation.

Key Specifications

Pinout & Package

ADP1111ANZ-3.3 is housed in an 8-lead plastic DIP (N-8) package with 0.3-inch body width and standard 0.1-inch lead pitch. Pin 1 is marked by notch or dot; pin numbering follows counterclockwise convention from top-left when viewed from component side.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ADP1111ANZ-3.3, ADP1111ARZ-3.3 offers identical regulation performance in a surface-mount package ideal for high-volume production, while TPS61040DRVR trades programmability and diagnostic features for higher frequency and smaller passive components - making it suitable only when those trade-offs align with system priorities.

Availability

ADP1111ANZ-3.3 is available at Aetrix Electronics and suitable for portable instrumentation power, laptop peripheral regulation, flash memory VPP generation, and battery backup supplies requiring stable component supply across design, qualification, and production phases.

Supply support for ADP1111ANZ-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, headquartered in Norwood, MA, with design centers worldwide and ISO 9001-certified manufacturing.

The ADP1111 family was designed specifically for micropower, multi-topology DC/DC conversion in battery-operated and energy-sensitive applications - emphasizing wide input range, minimal external components, and integrated diagnostics like low-battery detection.

FAQ

What is the maximum input voltage for ADP1111ANZ-3.3 in step-down mode?

The ADP1111ANZ-3.3 supports up to 30 V input voltage in step-down mode, as specified in the Absolute Maximum Ratings table. This allows direct regulation from industrial 24 V rails or automotive 28 V systems. However, thermal limits and switch saturation voltage (1.1–1.5 V at 650 mA) require careful heatsinking above 15 V input with >100 mA load. Always verify junction temperature using θ_JA = 100°C/W for the N-8 package.

Does ADP1111ANZ-3.3 require external feedback resistors to set the 3.3 V output?

No, ADP1111ANZ-3.3 does not require external feedback resistors. It integrates laser-trimmed on-die resistors that fix the output at 3.3 V ±5%. The FB/SENSE pin connects directly to the output node - eliminating resistor matching errors, temperature drift, and PCB layout sensitivity. This differs from the adjustable ADP1111 variant, which requires external R1/R2.

Can ADP1111ANZ-3.3 operate in inverting (positive-to-negative) mode?

Yes, ADP1111ANZ-3.3 supports inverting mode using its dual-access switch (SW1 collector, SW2 emitter). Configure SW1 to ground and SW2 to inductor/diode to generate negative output voltages - e.g., –3.3 V from +3 V input. The datasheet Figure 22 shows this topology. Note that output current capability is reduced versus step-up/step-down due to higher conduction losses in the NPN emitter path.

What is the purpose of the AO and SET pins on ADP1111ANZ-3.3?

The AO (auxiliary output) and SET pins form an uncommitted gain block with internal 1.25 V reference. When configured as a comparator (e.g., resistor divider from VIN to GND feeding SET), AO asserts low when input drops below a user-defined threshold - enabling low-battery detection. AO is open-collector and sinks 300 μA; unused pins may be left floating per datasheet guidance.

Is ADP1111ANZ-3.3 pin-compatible with other ADP1111 variants like ADP1111-5 or ADP1111-12?

Yes, ADP1111ANZ-3.3 is pin-compatible with ADP1111-5 and ADP1111-12 - all share identical 8-pin DIP (N-8) or SO-8 footprints and pin functions. The only difference is internal laser-trimmed feedback resistors setting nominal outputs at 3.3 V, 5 V, or 12 V. No PCB redesign is needed when substituting between fixed-output versions; only output capacitor and inductor values may require adjustment for optimal ripple and transient response.