Press Release
California Micro Devices
Announces Low Noise
Charge Pump/Linear Regulator LED Driver
CM4072 PhotonIC™ LED Driver
for Cost Sensitive Wireless Handset Applications
MILPITAS, Calif., -- Nov. 15, 2005
-- California
Micro Devices (NASDAQ: CAMD) today announced the CM4072, a single-chip
low noise charge pump/linear regulator LED (light emitting diode) driver
designed to power white LEDs to backlight TFT LCD displays in wireless
handsets, PDAs and LCD modules. The CM4072 is the latest addition to the
PhotonIC™ portfolio, a product family of highly integrated,
efficient, compact and cost optimized LED drivers. The CM4072 is housed
in a low profile, very small form factor 3mm x 3mm 10-lead TDFN package
which makes it optimal for mobile electronics where space is critical.
The CM4072 is an ideal solution for cost sensitive wireless handset platforms
where superior performance is required in a tiny footprint while meeting
strict cost targets.
High Performance in Compact Footprint
By integrating the charge pump and linear regulator into one chip, the
CM4072 is able to boost the input voltage via the charge pump circuitry
and then feed it to the linear regulator to provide a constant 5V output
and a continuous output current of 200mA. To control the brightness of
the white LEDs, a PWM (pulse width modulation) signal is sent from the
baseband processor to the enable pin of the CM4072. The charge pump operates
at 250kHz which is well below the clock, cellular and PCS frequencies
in wireless handsets.
The CM4072 features are the following
- Stable, low noise 5V output
- Wide input voltage range: 3V to 5V
- Up to 200mA of continuous output current
- Up to 83% efficiency
- 42dB PSRR over 100Hz to 30kHz frequency range
- Low operating current (180µA) for power saving
- Low shutdown modes to extend battery life
- Dual enable pins allow separate control of charge pump and LDO regulators for faster startup from sleep modes
- Over-current and over-temperature protection
- Stable with low ESR ceramic or tantalum capacitors – requires 2 external capacitors
- Very small 3mm x 3mm 10-lead TDFN package for portable applications
Applications
The CM4072 with an output voltage of 5V is able to support LEDs with forward
voltages ranging from 2.2V to 4.0V. Typical wireless handsets use about
3 to 4 white LEDs to backlight the main TFT LCD displays where each LED
has a maximum of 25mA applied to it. Since the CM4072 can deliver up to
200mA of current, it can easily support 5 WLEDs at 25mA each to backlight
higher resolution, larger size QVGA TFT LCD displays. It can also be used
in camera phones where a high brightness camera flash LED is used. The
CM4072 can either drive three white LEDs with a maximum current of 65mA
each or a single high brightness camera flash LED at 200mA. With the popularity
of camera phones, two CM4072 LED drivers can be used in designs where
one is in or near the LCD module and the other is placed near the camera
module.
Pricing and Availability
The CM4072 is available for sampling and are priced at $0.69 each in 1,000
units. Volume production is scheduled for December 2005.
About California Micro Devices Corporation
California Micro Devices Corporation is a leading supplier of application specific
analog semiconductor products for the mobile handset, personal computer and digital
consumer electronic markets. Key products include Application Specific Integrated
Passive™ (ASIP) devices and selected high value mixed
signal ICs. Detailed corporate and product information may be accessed at www.calmicro.com.
Application Specific Integrated Passive™
, ASIP™ and PhotonIC™ are trademarks of
California Micro Devices. All other trademarks are property of their respective
owners.
