Ordering number : ENA2118A
AF Control LSI
The AF control device, LC898212XA (LC898212XA-MH), provides an ideal way to implement the reduced power
consumption and the improved autofocus precision and speed (reduced convergence time) required in high-pixel-
count camera modules for use in smartphones.
The LC898212XA integrates on a single chip an equalizer circuit employing digital calculation, and it can be
combined with position sensors to build a closed-loop actuator control system. Since closed-loop control provides
better ability to maintain the control object than conventional open-loop systems and is not affected by position
differences, the LC898212XA is ideal for use in AF systems used in a wide variety of cameras. A closed-loop system
uses position sensors for position control, and power consumption is lower than with conventional open-loop control,
which uses current values for position control.
In addition, a new PWM drive system employed suppresses noise that could affect image quality while achieving
reduced power consumption, making this IC ideal for use in mobile devices such as smartphones. The filter
coefficients of the equalizer circuit can be adjusted to any values desired by making register settings via I2C
communication. This makes it possible to build a control circuit optimized to the various types of actuators and
thereby achieve faster autofocus (reduced convergence time) performance.
The integrated ADC provides up to 10-bit precision for highly accurate AF position control. Also integrated on-chip
are a constant current supply DAC for drive and an op-amp with adjustable gain for use with the position sensors
indispensable for building a closed-loop control system.
* I2C Bus is a trademark of Philips Corporation.
Semiconductor Components Industries, LLC, 2013
91212HK/82912HKPC 20111107-S00001 No.A2118-1/5