New Industry Products

Maxim Announces Small Liquid Lens Driver For Tiny Autofocus Camera Modules

December 08, 2008 by Jeff Shepard

Maxim Integrated Products introduced the MAX14515, a dc-to-ac liquid lens driver for autofocus (AF) camera modules. The MAX14515 features a high-voltage differential output controlled through an I²C interface. It employs a charge-pump topology to reduce the number of external components typically used for autofocus drivers in camera modules. The I²C interface and the charge-pump topology are combined in a 2 x 1mm WLP, which the company states makes the MAX14515 the industry’s smallest liquid lens driver. The device is suitable for tiny cell-phone camera modules that use the newest autofocus technologies.

According to Maxim, the traditional liquid lens drivers available on the market require components typically found in boost topologies, which minimally include a large inductor, diode, and high-voltage capacitor. Meanwhile, it is claimed that other charge-pump-based drivers are large and require many capacitors. When the numerous other supporting discrete components are added to the design, the size of these discrete solutions requires a large footprint, one that can no longer be accommodated inside the shrinking autofocus camera modules.

The MAX14515 needs at most two small external capacitors: one low-voltage capacitor and a tiny bypass capacitor. The device integrates an 8-bit monotonic DAC with a single-differential high-voltage output controlled by a 2-wire I²C interface to set the amplitude. The high-voltage output delivers up to 42Vrms into a 200pF liquid lens load at 1.1kHz.With its 2mm² footprint, which is said to be at least 60% smaller than the market’s available drivers, the MAX14515 liquid lens driver easily fits inside the camera module. The combination of smallest footprint, I²C interface, and low shutdown current make the MAX14515 well suited for enabling today’s newest high-performance, autofocus camera modules.

The MAX14515 is fully specified over the -40 to +85°C extended temperature range. The device is priced at $1.50 (1000-up, FOB USA).