Integrated auto focus controller for smartphone camera modules

July 18, 2014 // By Graham Prophet
ON Semiconductor’s LC898214XC Auto Focus Controller for camera modules in smartphones is an integrated solution designed to provide high performance auto focusing as well as lower power consumption.

The IC features a digital loop filter and provides fast, accurate auto focus convergence with temperature compensation, while consuming minimal power. The integrated constant current driver provides lower electro interference noise than competing solutions. In addition, the space-saving design enables thinner and lighter smartphones.

LC898214XC integrates all functions for the closed auto focus driver, including digital logic as a closed auto focus control, Hall device as a positioning sensor, EEPROM for the storage of filter parameters and compensation data, and a constant current driver as an actuator driver. The closed auto focus system provides for more accurate auto focus control, while also lowering power consumption compared with open loop systems. The loop filter coefficients are adjustable via an I2C interface, allowing the device to be programmed for optimal convergence time when paired with various different actuators. These integrated features support a closed auto focus system, and can provide higher auto focus performance from one integrated circuit.

In a WLCSP-8 package the part is priced at $0.88 (4,000).

ON Semiconductor; www.onsemi.com