Features
- Fixed I2C logic thresholds
- 8-bit D-to-A converter
- 500 µA resolution
- Low voltage I2C serial interface
- Low current-draw sleep mode
- 2.4 to 5.5 V operation
- 2 mm × 1.5 mm, 0.38 mm nominal overall height DFN
- 1.1 mm × 0.7 mm, 0.5 mm maximum overall height WLCSP
- 1.1 mm × 0.7 mm, 0.33 mm nominal overall height bare die
Description
The A3904 is a voice coil motor (VCM) driver, with an I2C-compatible serial interface. Designed for camera autofocus and zoom applications, this high accuracy digital IC is provided in small packages ideal for portable devices. Its operating voltage range is 2.4 to 5.5 V, and its maximum output current is 127 mA.
Output current is programmed via the I2C interface, in 500 µA increments, with clock rates up to 400 kHz. I2C inputs set the internal D-to-A converter output voltage that is the reference for linear current control via a MOSFET output sink transistor. To conserve battery power, a logic low signal on the SLEEPZ input disables the output MOSFET and reduces the supply current to <0.5 µA.
A3904 internal protection features include thermal shutdown and undervoltage lockout. Logic input levels are independent of the supply voltage. The operating temperature range is –40°C to 85°C.
The A3904 is available at three packaging levels: bare die on wafer (suffix CW); bumped wafer level chip scale package (WLCSP) (suffix CG); and complete thin profile (0.38 mm nominal overall height) DFN package, with NiAuPd leadframe plating and an exposed tab for enhanced thermal dissipation (suffix EW).
Functional Block Diagram
