CM9156B Datasheet, PDF (7/13 Pages) California Micro Devices Corp – Charge-Pump White LED Driver

Functional Block Diagram
PRELIMINARY
CM9156B
3.0V T O 6.0V
1.0uF
V IN
1.0uF
1.0uF
C 1P C 1N C 2P C 2N
ENA
L DO
Pre- R egulator
1.5x C harge Pump
OS C
CM9156B
C ounter
CLK
Dr iver
V OUT
4.5V
1.0uF
GND
Pin Descriptions
LEAD(s)
1
2
3
4
5
6
7
8
9
10
NAME
VOUT
C1P
VIN
CLK
NC
ENA
C2N
GND
C1N
C2P
PIN DESCRIPTIONS
DESCRIPTION
The regulated 4.5V output voltage pin. This pin requires a 1.0μF or larger ceramic
capacitor to ground. This pin connects to the anodes of the LEDs.
This pin is the plus side of charge-pump bucket capacitor C1. Connect a 1.0μF
ceramic capacitor with a voltage rating of 10V or greater between C1N and C1P.
Positive supply voltage input pin. This voltage should be between 3.0V and 6V.
This pin requires a 1.0μF or larger ceramic capacitor to ground.
Pin for setting switching frequency (see Table 1 on page 6)
Pin not connected.
Enable pin, active high. By applying a PWM signal to this pin, the LED brightness
can be controlled.
This pin is the minus side of charge-pump bucket capacitor C2. Connect a 1.0μF
ceramic capacitor between C2N and C2P.
Ground pin.
This pin is the minus side of charge-pump bucket capacitor C1. Connect a 1.0μF
ceramic capacitor between C1N and C1P.
This pin is the plus side of charge-pump bucket capacitor C2. Connect a 1.0μF
ceramic capacitor between C2N and C2P.
© 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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