Product Overview

California Micro Devices introduces significant additions to its PhotonIC™ portfolio of white LED (WLED) drivers for wireless handset applications. The portfolio additions offer a compelling and differentiated family of fractional charge pump WLED drivers. With increased demand for brighter and larger resolution displays, powerful camera flash capabilities for multi megapixel sensor resolutions and various types of LEDs to support keypad backlight and multimedia capabilities, wireless handset designers become increasingly concerned with the efficiency of the LED driver sub system.

California Micro Devices’ PhotonIC™ product portfolio of white LED drivers now includes five current regulated fractional charge pump products (CM913x/CM914x) that can drive up to six WLEDs, as well as three voltage regulated products (CM915x). All these products feature a simple analog control interface as well as optimal efficiency in a compact footprint.

Current Regulated Products: CM913x/CM914x

The CM913x/CM914x family consists of five fractional charge pump products described in the following table:

 

Product	Driving Capabilities
CM9130	One group of 3 matched WLEDs
CM9132	One group of 3 matched WLEDs + One group of 2 matched WLEDs
CM9133	One group of 3 matched WLEDs + One group of 3 matched WLEDs
CM9140	One group of 4 matched WLEDs
CM9142	One group of 4 matched WLEDs + One group of 2 matched WLEDs

Products in the CM913x/4x family can operate with an input voltage ranging from 2.9V to 6V and in both 1x and 1.5x (fractional) modes in order to optimize efficiency. They are capable of driving up to 50mA on each output with 2 percent current matching and each output can be independently controlled through a PWM or analog interface. They require no external ballast resistor or inductor minimizing the footprint of the complete solution. Using this architecture also helps designers significantly reduce EMI (electromagnetic interference). They operate at a switching frequency of 500 kHz and feature over-temperature protection, overcurrent protection, a soft start feature to prevent excessive in rush current and low shutdown current. They are housed in a 4mm x 4mm QFP package. These products are ideal for driving display backlights as well as keypad or camera flash LEDs in the most efficient way in a compact footprint.

Voltage Regulated Products: CM915x
The CM915x family consists of three products described in the following table:

 

Product	Driving Capabilities
CM9153	Up to 6 WLEDs – 650 kHz – DFN8 or MSOP8 packages
CM9156A	Up to 6 WLEDs – 4 Selectable frequencies – DFN10 or MSOP10 packages
CM9156B	Up to 6 WLEDs – 2 Selectable frequencies – DFN10 or MSOP10 packages

This product family features a fixed output voltage of 4.5V with a low output ripple of less than 1percent and an accuracy of 2 percent. They can operate in both 1x and 1.5x (fractional) modes in order to optimize efficiency. The CM9156A and CM9156B offer selectable switching frequencies to allow further power savings reduction. The CM9153 is housed in compact DFN8 or MSOP8, and the CM9156A/B are offered in either DFN10 or MSOP10. They also feature OTP, OCP and a soft start. The CM9156 is pin to pin compatible with other solutions in the market but offers higher efficiency, and therefore gives designers the opportunity of improving their WLED sub-system efficiency.

Application & Deliverables
Both product families are a perfect fit to drive backlight, keypad and camera flash LED sub systems in the most efficient way in a compact footprint and at the lowest bill of materials. Reference design kits are available to customers to allow rapid evaluation of the advantages and benefits of this product portfolio.

Sampling, Pricing and Availability
All the products described are currently sampling and reference design kits are available. Pricing ranges from $0.60 to $1.20 in 1,000 units. Production is scheduled for Q2 2006.