Analog Devices Inc. ADP2371ACPZ-3.3-R7

Overview

ADP2371ACPZ-3.3-R7 from Analog Devices is a high-efficiency, low-quiescent-current 800 mA synchronous buck regulator in a 3 mm × 3 mm LFCSP package, supporting 3.2 V to 15 V input and delivering fixed 3.3 V output with ±1% initial accuracy, 1.2 MHz/600 kHz selectable switching frequency, and integrated quick output discharge (QOD). It targets battery-powered portable equipment requiring long runtime and fast transient response.

For engineers reviewing the ADP2371ACPZ-3.3-R7 datasheet, ADP2371ACPZ-3.3-R7 pinout, ADP2371ACPZ-3.3-R7 application, or ADP2371ACPZ-3.3-R7 equivalent, key selection criteria include its <14 µA quiescent current in power-saving mode, 100% duty cycle capability for low-dropout operation, QOD function for controlled shutdown, and compatibility with compact 53 mm² total solution size using only three external components.

Technical Context

The ADP2371ACPZ-3.3-R7 employs a proprietary high-speed current-mode PWM control architecture with internal compensation and soft start, enabling excellent line/load transient response and stability without external loop compensation. Its synchronous rectifier eliminates the need for an external diode, reducing conduction losses and improving efficiency across load range.

It supports dual operating modes: forced PWM (FPWM) for noise-sensitive applications and automatic PWM/PSM mode for ultra-low quiescent current under light loads. The FSEL pin selects between 1.2 MHz and 600 kHz switching frequencies, while SYNC enables synchronization to an external clock within 400–800 kHz or 0.8–1.6 MHz ranges depending on FSEL state.

Key Specifications

Pinout & Package

ADP2371ACPZ-3.3-R7 uses an 8-lead, 0.75 mm × 3 mm × 3 mm LFCSP (QFN) package with exposed thermal pad electrically connected to PGND. The pad must be soldered to a PCB ground plane for thermal and electrical performance.

Key Features

Applications

Equivalent & Alternatives

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

Compared with TPS62840DRVR and MAX17503ATP+, the ADP2371ACPZ-3.3-R7 uniquely combines 3.3 V fixed output, integrated QOD, 100% duty cycle, and <14 µA quiescent current in a 3 mm × 3 mm package - making it optimal for space- and battery-limited 3.3 V systems where controlled shutdown and deep-discharge operation are critical.

Availability

ADP2371ACPZ-3.3-R7 is available at Aetrix Electronics and suitable for portable medical devices, smart metering nodes, and handheld POS terminals requiring stable component supply, long-term lifecycle support, and consistent parametric performance across production batches.

Supply support for ADP2371ACPZ-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, serving precision instrumentation, industrial automation, communications, and healthcare markets.

The ADP2371ACPZ-3.3-R7 belongs to Analog Devices' ADP237x family of high-efficiency, low-IQ buck regulators designed specifically for battery-powered portable and wireless sensor applications demanding extended runtime and compact power solutions.

FAQ

What is the maximum input voltage rating for the ADP2371ACPZ-3.3-R7?

The ADP2371ACPZ-3.3-R7 has an absolute maximum input voltage rating of +17 V relative to PGND, but its recommended operating input voltage range is 3.2 V to 15 V. Exceeding 15 V may trigger undervoltage lockout or cause reliability concerns despite surviving short-term transients. Always refer to Table 3 (Absolute Maximum Ratings) and Table 1 (Specifications) in the Rev. E datasheet for design margin guidance.

Does the ADP2371ACPZ-3.3-R7 require external feedback resistors to set the 3.3 V output?

No, the ADP2371ACPZ-3.3-R7 is a fixed-output variant with internal feedback network trimmed to 3.3 V ±1% at 25°C. Pin 5 (FB) is internally connected and not accessible for adjustment. This eliminates resistor tolerance errors, saves board space, and simplifies layout - unlike adjustable versions such as ADP2370/ADP2371-ADJ which require external resistive dividers.

How does the Quick Output Discharge (QOD) function work in the ADP2371ACPZ-3.3-R7?

The ADP2371ACPZ-3.3-R7 integrates a dedicated 260–400 Ω NMOS pull-down transistor between VOUT and PGND, activated automatically when EN is driven low. This discharges the output capacitor rapidly, ensuring VOUT falls below valid logic thresholds within milliseconds. QOD prevents unintended operation of downstream circuitry during power-down sequences - a feature absent in the pin-compatible ADP2370.

Can the ADP2371ACPZ-3.3-R7 operate with 100% duty cycle, and what is its practical benefit?

Yes, the ADP2371ACPZ-3.3-R7 supports true 100% duty cycle operation, meaning it can maintain regulation even when VIN approaches VOUT (e.g., 3.3 V input for 3.3 V output). This extends usable battery capacity in single-cell Li-ion or Li-poly systems, allowing operation down to ~3.3 V before dropout - critical for maximizing runtime in portable applications where every millivolt counts.

What thermal considerations apply to the ADP2371ACPZ-3.3-R7 in a 4-layer PCB design?

For the ADP2371ACPZ-3.3-R7 in a standard 4-layer board per JESD51-7, θJA is 36.7°C/W and ΨJB is 17.2°C/W. To keep junction temperature ≤125°C, ensure the exposed thermal pad is fully soldered to a solid ground plane with ≥4 thermal vias (0.3 mm diameter, spaced ≤1 mm apart). Power dissipation above 0.5 W requires careful copper pour sizing and airflow evaluation - especially at high ambient temperatures or full 800 mA load.