Analog Devices Inc. ADP2504ACPZ-4.2-R7

Overview

ADP2504ACPZ-4.2-R7 from Analog Devices is a 1000 mA, 2.5 MHz synchronous buck-boost DC-to-DC converter in a 3 mm × 3 mm LFCSP package, delivering fixed 4.2 V output from 2.3 V–5.5 V input, with 38 μA quiescent current and seamless mode transition-used in USB-powered portable audio players requiring stable single-cell Li-ion regulation.

For engineers reviewing the ADP2504ACPZ-4.2-R7 datasheet, ADP2504ACPZ-4.2-R7 pinout, ADP2504ACPZ-4.2-R7 application, or ADP2504ACPZ-4.2-R7 equivalent, this page delivers verified pin functions, real-world efficiency curves at 4.2 V output, load disconnect capability, thermal shutdown behavior at 150°C, and validated alternatives for battery-powered embedded systems.

Technical Context

The ADP2504ACPZ-4.2-R7 implements average current-mode control with internal compensation, enabling stable regulation across buck, boost, and buck-boost modes depending on VIN relative to VOUT. Its dual-switch architecture integrates both P-channel and N-channel MOSFETs (150 mΩ each) with reverse current limiting at 1.1 A and switch current limit of 1.3–2.0 A.

It supports three SYNC pin modes: power-save mode (PSM) below ~75 mA load, forced PWM at 2.5 MHz, and external clock synchronization between 2.2–2.8 MHz. Undervoltage lockout activates at 2.10–2.25 V, and soft start ramps VOUT in 200 μs with <600 mA inrush for 20 μF output capacitance.

Key Specifications

Pinout & Package

ADP2504ACPZ-4.2-R7 uses a 10-lead, 3 mm × 3 mm LFCSP (QFN) package with exposed pad thermally connected to PGND. The package enables low-profile (<1 mm height) integration into space-constrained handheld devices.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS63020DSJR and MAX77827CEFG+, the ADP2504ACPZ-4.2-R7 offers optimal trade-off of size, fixed-voltage simplicity, and guaranteed load disconnect - making it preferred for cost-sensitive, space-constrained USB peripherals where 4.2 V is the exact target and firmware control is unnecessary.

Availability

ADP2504ACPZ-4.2-R7 is available at Aetrix Electronics and suitable for wireless handsets, USB-powered audio players, and miniature hard disk power supplies requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for ADP2504ACPZ-4.2-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 is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, serving precision instrumentation, industrial automation, and communications markets since 1965.

The ADP2503/ADP2504 product line was designed specifically for ultra-compact, battery-operated portable electronics requiring efficient wide-input-range regulation without external compensation or complex layout tuning.

FAQ

What is the output voltage tolerance of the ADP2504ACPZ-4.2-R7 under full load and temperature range?

The ADP2504ACPZ-4.2-R7 has an output voltage initial accuracy of ±2% over temperature (−40°C to +125°C) and load (0–1000 mA) in forced PWM mode. Line regulation is 0.6% across 2.3–5.5 V input, and load regulation is 0.5% from 0–500 mA - meaning actual output remains within 4.116–4.284 V under worst-case conditions. This tolerance is confirmed in Table 1 of the Rev. F datasheet.

Does the ADP2504ACPZ-4.2-R7 require external feedback resistors to set its 4.2 V output?

No, the ADP2504ACPZ-4.2-R7 is a fixed-output variant - its 4.2 V regulation is implemented internally, and the FB pin is pre-connected to VOUT inside the IC. External resistors are unnecessary and must not be added; doing so would disrupt regulation. Only adjustable versions (e.g., ADP2504ACPZ-R7) require an external resistor divider between VOUT, FB, and GND.

Can the ADP2504ACPZ-4.2-R7 operate safely with a 1.0 µH inductor instead of the recommended 1.5 µH?

Yes, the ADP2504ACPZ-4.2-R7 supports inductors from 1.0 µH to 2.0 µH per the datasheet (Section "Inductor Selection"). A 1.0 µH inductor increases peak inductor current and output ripple but maintains stability if saturation current rating exceeds I_IN(MAX) + ΔI_LOAD/2. Recommended vendors include Toko (DE2810C, 1.0 µH, 1.8 A ISAT) and Murata (LQM2HP-G0, 1.0 µH, 1.6 A ISAT).

How does the ADP2504ACPZ-4.2-R7 handle input undervoltage conditions?

The ADP2504ACPZ-4.2-R7 features undervoltage lockout (UVLO) with rising threshold of 2.15–2.25 V and falling threshold of 2.10–2.20 V. When VIN drops below 2.10 V during operation, the device disables switching and draws <1 µA. It remains latched off until VIN rises above 2.25 V, preventing brown-out instability and deep battery discharge in Li-ion systems.

Is the exposed thermal pad on the ADP2504ACPZ-4.2-R7 electrically connected to any internal node?

Yes, the exposed pad (EP) on the ADP2504ACPZ-4.2-R7 is internally connected to PGND and must be soldered to a dedicated PGND plane using ≥4 thermal vias. It is not isolated or floating - incorrect connection (e.g., leaving unconnected or tying to AGND) degrades thermal performance and may cause premature thermal shutdown at <1 A load.