Analog Devices Inc. ADP2108ACBZ-3.3-R7

Overview

ADP2108ACBZ-3.3-R7 from Analog Devices is a fixed-output, 3.3 V, 600 mA synchronous step-down DC-DC converter with 3 MHz switching frequency, 2.3 V to 5.5 V input range, and 95% peak efficiency. It integrates power switches, internal compensation, soft start, and operates in WLCSP-5 package for space-constrained portable power rails such as baseband processors in wireless handsets.

For engineers reviewing the ADP2108ACBZ-3.3-R7 datasheet, ADP2108ACBZ-3.3-R7 pinout, ADP2108ACBZ-3.3-R7 application, or ADP2108ACBZ-3.3-R7 equivalent, key selection criteria include light-load efficiency (18 μA quiescent current), 100% duty-cycle dropout mode, thermal shutdown (150°C), undervoltage lockout (2.15 V), and compatibility with tiny 1 µH inductors and 4.7 µF/10 µF ceramic capacitors.

Technical Context

The ADP2108ACBZ-3.3-R7 employs a high-speed current-mode PWM control architecture operating at a fixed 3 MHz frequency for fast line/load transient response. Its dual-mode operation-PWM at medium-to-heavy loads and hysteretic power-save mode below 80 mA-enables high efficiency across the full 0–600 mA load range.

It integrates a PFET high-side switch (320 mΩ typical in WLCSP) and NFET synchronous rectifier (300 mΩ), eliminating external diode losses. Internal soft start limits inrush current, while 100% duty-cycle operation maintains regulation during low-VIN or high-ILOAD conditions without output collapse.

Key Specifications

Pinout & Package

ADP2108ACBZ-3.3-R7 is packaged in a 5-ball Wafer-Level Chip Scale Package (WLCSP) with 0.4 mm pitch and 1.2 mm × 0.8 mm footprint. The package is lead-free, RoHS-compliant, and optimized for minimal board area in portable designs.

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 MAX17222ETA+, the ADP2108ACBZ-3.3-R7 offers superior thermal performance in its 1.2 mm × 0.8 mm WLCSP, guaranteed 600 mA delivery across full input range, and robust 100% duty-cycle operation - making it optimal for space- and battery-life-critical portable designs where input voltage may sag near battery end-of-discharge.

Availability

ADP2108ACBZ-3.3-R7 is available at Aetrix Electronics and suitable for wireless handset power management, portable media player audio subsystems, digital camera sensor biasing, and GPS navigation unit RF front-end regulation requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for ADP2108ACBZ-3.3-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 design centers worldwide and a focus on precision, power efficiency, and reliability.

The ADP2108 series was designed specifically for ultra-compact, high-efficiency power conversion in battery-powered portable electronics - emphasizing minimal external component count, low quiescent current, and seamless light-to-heavy load transitions.

FAQ

What is the output voltage tolerance of the ADP2108ACBZ-3.3-R7 under varying load and temperature?

The ADP2108ACBZ-3.3-R7 delivers a fixed 3.3 V output with ±2% accuracy in PWM mode across −40°C to +125°C junction temperature and full 2.3–5.5 V input range. Load regulation data (Figure 12) shows deviation ≤±12 mV from 3.3 V at 600 mA, confirming tight regulation for noise-sensitive analog circuits. This tolerance is guaranteed by internal trimming and does not require external feedback components.

Does the ADP2108ACBZ-3.3-R7 support 100% duty-cycle operation, and what is its practical benefit?

Yes, the ADP2108ACBZ-3.3-R7 supports true 100% duty-cycle operation: when input voltage drops or load increases to the point where PWM cannot sustain 3.3 V, the PFET remains continuously on. This prevents output collapse during battery brownout (e.g., Li+ cell discharging below 3.3 V), allowing continued system operation until cutoff - a critical feature for handheld devices requiring graceful shutdown.

How does the power-save mode of the ADP2108ACBZ-3.3-R7 differ from standard PWM mode, and at what load does it activate?

The ADP2108ACBZ-3.3-R7 transitions to power-save mode below 80 mA load current. In this mode, it operates hysteretically with higher output ripple (~1.5% above nominal) and periodic idle cycles to minimize switching losses. Unlike PWM mode (fixed 3 MHz), power-save mode dynamically adjusts frequency, achieving 18 μA quiescent current - ideal for standby functions like Bluetooth LE advertising or sensor wake-up timers.

What are the absolute maximum ratings for the EN pin of the ADP2108ACBZ-3.3-R7, and how should it be driven?

The EN pin of the ADP2108ACBZ-3.3-R7 has an absolute maximum rating of −0.4 V to +6.5 V. It is TTL-compatible with 1.2 V high threshold and 0.4 V low threshold. To ensure reliable enable/disable, drive EN with a clean logic signal referenced to GND; leakage current is ±1 μA. Pulling EN low reduces input current to ≤1 μA, making it suitable for direct connection to microcontroller GPIO without level-shifting.

Can the ADP2108ACBZ-3.3-R7 be used with ceramic output capacitors, and what are the recommended values and dielectrics?

Yes, the ADP2108ACBZ-3.3-R7 is optimized for ceramic output capacitors. Recommended values are ≥10 µF with X5R or X7R dielectric (6.3 V or 10 V rating) in 0603 case size. These dielectrics maintain ≥85% capacitance over −40°C to +125°C and under DC bias - critical for stability and low ripple. Y5V/Z5U types are explicitly discouraged due to excessive capacitance loss and temperature drift.