Analog Devices Inc. ADP2108ACBZ-1.1-R7

Overview

ADP2108ACBZ-1.1-R7 from Analog Devices is a fixed-output, 1.1 V synchronous step-down DC-DC converter delivering up to 600 mA from 2.3 V–5.5 V input, operating at 3 MHz with 95% peak efficiency and 18 μA quiescent current - deployed in portable media players, GPS units, and wireless handsets for battery-powered core logic rail regulation.

For engineers reviewing the ADP2108ACBZ-1.1-R7 datasheet, ADP2108ACBZ-1.1-R7 pinout, ADP2108ACBZ-1.1-R7 application, or ADP2108ACBZ-1.1-R7 equivalent, key selection considerations include its 5-ball WLCSP package, 100% duty-cycle low-dropout mode, internal soft start, power save mode transition at 80 mA, and thermal shutdown at 150°C.

Technical Context

The ADP2108ACBZ-1.1-R7 uses a high-speed current-mode PWM architecture with fixed 3 MHz switching frequency for fast line/load transient response and stable regulation across 2.3 V–5.5 V input. It integrates both PFET and NFET switches with on-resistances of 320 mΩ and 300 mΩ respectively in WLCSP.

It features dual-mode operation: PWM mode above 80 mA load for high efficiency and tight regulation, and hysteretic power save mode below 80 mA to reduce quiescent current to 18 μA - enabling extended battery life in always-on subsystems without sacrificing startup speed or output accuracy (±2% in PWM mode).

Key Specifications

Pinout & Package

ADP2108ACBZ-1.1-R7 is packaged in a 5-ball Wafer-Level Chip Scale Package (WLCSP) with 0.4 mm pitch, optimized for space-constrained portable designs. Ball layout follows standard A1–C2 grid with no exposed thermal pad.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar step-down DC-DC converter applications.

Compared with TPS62231DRYR and RT8059GJ6, ADP2108ACBZ-1.1-R7 offers the smallest total solution size (WLCSP + 0.7 µH + 4.7 µF), guaranteed 100% duty-cycle operation, and lowest thermal resistance (105°C/W), making it optimal for space- and thermal-limited portable systems where consistent low-VIN regulation is critical.

Availability

ADP2108ACBZ-1.1-R7 is available at Aetrix Electronics and suitable for portable media players, GPS navigation units, and wireless handsets requiring stable component supply, long-term lifecycle support, and guaranteed WLCSP packaging consistency.

Supply support for ADP2108ACBZ-1.1-R7 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, Inc. is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, headquartered in Norwood, MA, with R&D and manufacturing operations worldwide.

The ADP2108 product line delivers compact, high-efficiency step-down regulators targeting battery-powered portable electronics - designed specifically for minimal external component count, ultra-low quiescent current, and robust operation across wide input voltage and temperature ranges.

FAQ

What is the output voltage tolerance of the ADP2108ACBZ-1.1-R7 under varying load and temperature?

The ADP2108ACBZ-1.1-R7 guarantees ±2% output voltage accuracy in PWM mode across −40°C to +125°C junction temperature and full input range (2.3 V–5.5 V). At 25°C and 3.6 V input, typical deviation is ±0.5%; load regulation error remains within ±10 mV from 1 mA to 600 mA. This stability is achieved via internal trimming of the 1.1 V reference and current-mode control loop compensation.

Does the ADP2108ACBZ-1.1-R7 require external feedback resistors?

No, the ADP2108ACBZ-1.1-R7 does not require external feedback resistors. Its FB pin (C2) is internally connected to a precision 1.1 V reference, confirming fixed-output configuration. The part is factory-trimmed for 1.1 V output, eliminating resistor selection, placement, and tolerance errors - simplifying design and reducing BOM count.

How does the ADP2108ACBZ-1.1-R7 handle short-circuit conditions?

The ADP2108ACBZ-1.1-R7 employs frequency foldback protection: when FB voltage drops below 50% of target (i.e., <0.55 V), indicating possible output short, switching frequency halves from 3 MHz to ~1.5 MHz. This extends off-time, limits peak inductor current, and prevents thermal runaway while maintaining hiccup-like recovery behavior without latching off.

Can the ADP2108ACBZ-1.1-R7 operate with a 2.3 V input and still deliver 600 mA at 1.1 V?

Yes - the ADP2108ACBZ-1.1-R7 supports 600 mA output at 1.1 V with 2.3 V input by entering 100% duty-cycle mode. In this state, the PFET remains continuously on, minimizing dropout to ~200 mV. Efficiency drops to ~82% at full load, but regulation is maintained without reset or shutdown, unlike non-100% duty-cycle competitors.

What is the recommended PCB layout practice for the SW node on the ADP2108ACBZ-1.1-R7?

For the SW node (ball B), minimize trace length and loop area between the ADP2108ACBZ-1.1-R7 and the inductor. Use a solid copper pour tied directly to the SW ball via multiple microvias, avoid routing other signals underneath, and place the inductor within 2 mm. This reduces EMI, voltage spikes, and gate drive instability - critical for reliable 3 MHz operation in WLCSP layout.