Analog Devices Inc. ADP3810AR-4.2

Overview

ADP3810AR-4.2 from Analog Devices is a precision Li-ion battery charger controller IC designed for secondary-side, isolated off-line charging systems. It integrates programmable current limiting (100 mA–1.2 A), fixed 4.2 V final battery voltage accuracy (±1.0%), 2.000 V precision reference, and optocoupler-driving output stage in an SO-8 package. It operates across 2.7 V to 16 V supply and supports shorted/open battery conditions.

For engineers reviewing the ADP3810AR-4.2 datasheet, ADP3810AR-4.2 pinout, ADP3810AR-4.2 application, or ADP3810AR-4.2 equivalent, key selection considerations include its ±1% battery voltage regulation at 4.2 V, 300 mV full-scale current sense threshold, UVLO trip at 2.7 V, SO-8 thermal performance, and compatibility with flyback/Buck DC-DC topologies requiring isolated feedback.

Technical Context

The ADP3810AR-4.2 implements dual-GM error amplifiers - GMI for constant-current control and GM2 for constant-voltage regulation - sharing a common COMP node for analog OR-mode switching between modes. Its internal thin-film resistor divider sets 4.2 V final voltage with ±1% total accuracy over −40°C to +85°C, including offset, bias, and reference errors.

It features a high-impedance VCTRL input (0–1.2 V, 10–40 nA bias) enabling PWM-filtered or DAC-based charge current programming, and drives optocouplers directly via its 4–6 mA current-output OUT pin with 0.1–0.4 V saturation voltage. The 2.000 V reference delivers ±0.25% load regulation and 35 µV_P-P (0.1–10 Hz) noise, stabilized by a mandatory 0.1 µF capacitor.

Key Specifications

Pinout & Package

ADP3810AR-4.2 is housed in an SO-8 (Small Outline-8) surface-mount package with standard 1.27 mm pitch, JEDEC MS-012AC compliant, and rated for 500 mW max power dissipation.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar battery charger controller applications.

Compared with ADP3810AR-4.2, ADP3811AR offers voltage flexibility at the cost of added BOM and reduced accuracy, while MAX1555 simplifies layout but sacrifices isolation support, programmability, and current scalability - making ADP3810AR-4.2 optimal for isolated, high-accuracy, multi-amp Li-ion systems.

Availability

ADP3810AR-4.2 is available at Aetrix Electronics and suitable for industrial battery chargers, medical device power supplies, and consumer portable electronics requiring stable component supply, long-term lifecycle assurance, and guaranteed parametric compliance.

Supply support for ADP3810AR-4.2 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 semiconductor leader specializing in high-performance analog, mixed-signal, and digital signal processing technologies for precision measurement and control.

The ADP3810 product line delivers isolated secondary-side battery charger controllers optimized for Li-ion safety, accuracy, and system-level integration in offline AC/DC adapters and industrial power supplies.

FAQ

What is the guaranteed accuracy of the 4.2 V battery voltage regulation in ADP3810AR-4.2?

The ADP3810AR-4.2 guarantees ±1.0% final battery voltage accuracy across −40°C to +85°C, inclusive of all error sources: reference voltage drift, internal resistor divider tolerance, amplifier offset voltage, and bias current effects - verified per SQC methods and explicitly stated in the datasheet for the 4.2 V option.

Can ADP3810AR-4.2 operate with a supply voltage lower than the battery voltage it regulates?

Yes. ADP3810AR-4.2 operates from 2.7 V to 16 V and regulates 4.2 V batteries even when VCC is as low as 2.7 V. Its internal voltage divider scales the 4.2 V battery sense signal to 2.000 V, ensuring GM2 input stays within safe operating range regardless of VCC level.

Does ADP3810AR-4.2 support charge termination for Li-ion batteries?

ADP3810AR-4.2 provides precise 4.2 V endpoint regulation essential for Li-ion charge termination, but does not implement dV/dt or timer-based cutoff. Termination is achieved by holding voltage at 4.2 V ±1% until current naturally tapers - consistent with CC/CV protocol - and requires external monitoring only if additional safety layers (e.g., timeout) are mandated.

What is the purpose of the COMP pin on ADP3810AR-4.2, and how is it used?

The COMP pin is the shared compensation node for both GMI (current loop) and GM2 (voltage loop) amplifiers. A single RC network from COMP to GND provides dominant-pole compensation for the voltage loop and influences current-loop stability. Internal 200 Ω resistance differentiates zero placement between loops, and optional second-stage RC may be added for higher-frequency current-loop tuning.

Is a capacitor required on the VREF pin of ADP3810AR-4.2, and why?

Yes - a 0.1 µF ceramic capacitor is mandatory between VREF and GND. It stabilizes the internal bandgap reference by providing local charge reservoir and phase compensation; omission causes reference oscillation or dropout instability, directly degrading battery voltage accuracy and system reliability.