Allegro MicroSystems A3904EEWTR-P

Overview

A3904EEWTR-P from Allegro MicroSystems is a discontinued low-voltage voice coil motor (VCM) driver IC with I²C-compatible serial interface, designed for camera autofocus and zoom actuation in portable devices. It delivers programmable sink output current up to 127.5 mA in 500 µA steps, operates from 2.4 V to 5.5 V, and features thermal shutdown, undervoltage lockout, and <0.5 µA sleep-mode supply current.

For engineers reviewing the A3904EEWTR-P datasheet, A3904EEWTR-P pinout, A3904EEWTR-P application, or A3904EEWTR-P equivalent, key selection criteria include its 6-ball WLCSP package, fixed-threshold I²C logic independent of VDD, 8-bit DAC resolution, 400 kHz I²C clock support, and integrated clamp diode for inductive load protection.

Technical Context

The A3904EEWTR-P implements a linear current-sink architecture using an internal 8-bit DAC referenced to a bandgap voltage, driving a MOSFET output stage. Its I²C slave interface supports four configurable addresses (0x18, 0x1A, 0x1C, 0x1E) and requires no external components for basic operation.

Logic inputs (SDA, SCL, SLEEPZ) use fixed voltage thresholds (~0.84 V low, ~1.26 V high), enabling interoperability with 1.8 V or 3.3 V microcontrollers regardless of VDD. The device enters ultra-low-power sleep mode (<100 nA typical) when SLEEPZ is pulled low, disabling the output MOSFET and internal bias circuitry.

Key Specifications

Pinout & Package

The A3904EEWTR-P is housed in a 6-ball wafer-level chip-scale package (WLCSP), measuring 1.1 mm × 0.7 mm × 0.5 mm max height, with bump-side orientation mark. This ultra-compact footprint targets space-constrained camera modules.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar voice coil motor driver applications.

Compared with A3904EEWTR-P, the DRV2605L prioritizes haptic waveform generation over optical precision, while the BD7301KV offers improved resolution and output but demands external protection and occupies more PCB area - making A3904EEWTR-P uniquely optimized for ultra-compact, low-voltage autofocus in legacy mobile platforms.

Availability

A3904EEWTR-P is available at Aetrix Electronics and suitable for smartphone camera modules, digital still camera zoom mechanisms, and portable medical endoscopes requiring stable component supply despite end-of-life status.

Supply support for A3904EEWTR-P 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

Allegro MicroSystems is a U.S.-based designer and manufacturer of high-performance magnetic sensing and power ICs, headquartered in Worcester, Massachusetts.

The A3904 product line was developed specifically for miniaturized optical actuation in mobile imaging systems, emphasizing ultra-low power, I²C configurability, and wafer-level packaging for camera module integration.

FAQ

Is the A3904EEWTR-P still in production?

No, the A3904EEWTR-P is a discontinued product. Allegro MicroSystems ceased production as of March 4, 2013. It is not recommended for new design applications, and samples are no longer available. Aetrix Electronics maintains limited legacy stock for existing production continuity support.

What is the package type and size of the A3904EEWTR-P?

The A3904EEWTR-P uses a 6-ball wafer-level chip-scale package (WLCSP) with dimensions of 1.1 mm × 0.7 mm and maximum height of 0.5 mm. The bump-side orientation mark identifies pin A1, and the package is Pb-free and RoHS compliant per the CG suffix designation.

Does the A3904EEWTR-P require external components for basic operation?

No, the A3904EEWTR-P operates autonomously with only VDD, GND, SDA, SCL, SLEEPZ, and IOUT connections. It integrates a bandgap reference, 8-bit DAC, output MOSFET, clamp diode, and protection circuitry - eliminating need for external resistors, capacitors, or diodes in standard VCM drive configurations.

What I²C addresses does the A3904EEWTR-P support?

The A3904EEWTR-P supports four configurable 7-bit slave addresses: 0x18, 0x1A, 0x1C, and 0x1E. Address selection is determined by internal logic tied to package-specific bond options - no external pins or resistors are used for address setting.

How does the SLEEPZ pin function on the A3904EEWTR-P?

The SLEEPZ pin is an active-low control input. When held low, it disables the output MOSFET and reduces the A3904EEWTR-P's supply current to less than 100 nA. This state preserves battery energy during camera idle periods while allowing immediate wake-up upon SLEEPZ transition to high.