CM9156B Datasheet, PDF (1/13 Pages) California Micro Devices Corp – Charge-Pump White LED Driver

Charge-Pump White LED Driver
PRELIMINARY
CM9156B
Features
• 3.0V to 6.5V input voltage range
• Dual mode operation; 1x and 1.5x
• Fixed 4.5V output with initial accuracy of ± 2%
• Supports up to 180mA (@4V) output
• High efficiency at both high and low input voltage
• Low external parts count, requires no inductor
• PWM brightness control via the ENA pin
• Selectable 262kHz or 650kHz switching frequency
• Low shutdown current of <1µA
• Soft start prevents excessive inrush current
• Over-temperature and over-current protection
• Low output ripple (<1%), low EMI
• Input protection provides superior ESD rating,
requiring only standard handling precautions
• TDFN-10 or MSOP-10 package
• Optional RoHS compliant lead free package
Applications
² Drive white LEDs to backlight color LCDs
² Drive white or RGB LEDs for camera flash
² Cellular phones
² MP3 players
• PDAs, GPS
Product Description
CM9156B is an efficient 1.5x switched capacitor
(charge pump) regulator ideal for white LED applica-
tions. It has a regulated 4.5V, 120mA output, capable
of driving up to six parallel white LEDs. With a typical
operating input voltage range from 3.0V to 6.0V, the
CM9156B can be operated from a single-cell Li-Ion
battery.
It features an efficient, 1.5x charge-pump circuit that
uses only two 1.0µF ceramic bucket capacitors and
two small capacitors for VIN and VOUT. The CM9156B
offers a selectable switching frequency of 262kHz or
650kHz. The LED brightness can be adjusted by apply-
ing a PWM signal on the ENA pin.
The CM9156B output voltage is regulated to 4.5V, ±
5% over the line and load ranges. Up 180mA of output
current is available. The proprietary design architec-
ture maintains high efficiency (> 80%), and at low V_IN
provides longer battery life. With a high V_IN, or when
the adapter is powered, it provides cool reliable opera-
tion. It offers low output voltage ripple, typically less
than 50mV. Internal over-temperature and over-current
management provide short circuit protection.
The CM9156B is packaged in either a space saving
10-Lead TDFN or 10-Lead MSOP package. It can
operate over the industrial temperature range of –
25-°C to 85-°C.
.
Typical Application
4.5V
1.0uF
V OUT
1.0uF
C 2P
3.0V to 6.0V
1.0uF
C 1P
C 1N
PhotonIC^TM
1.0uF
GND
V IN CM9156B
C 2N
CLK
ENA
© 2006 California Micro Devices Corp. All rights reserved.
04/26/06 490 N. McCarthy Blvd., Milpitas, CA 95035-5112 l Tel: [phone] l Fax: [phone] l www.cmd.com
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