CM9321 Datasheet, PDF (6/11 Pages) California Micro Devices Corp – Asymmetrical High Efficiency Three Channel Boost LED/OLED Driver

PRELIMINARY
CM9321
Functional Block Diagram
VIN
EN
VREF
ISET1
VSET2
ISET3
MODE
ENABLE
UVLO
BIAS
BG
OSC
PMW
LOGIC
OVP
D4
D1
Q1
CONTROL
D2
Q2
D3
CM9321
GND
VOUT
SW
Q4
R
LED1
LED2
LED3
Q3
Pin Descriptions
LEAD(s)
NAME
1
ISET1
2
LED1
3
VREF
4
VSET2
5
LED2
PIN DESCRIPTIONS
DESCRIPTION
Channel 1 LED current set pin. Between this pin and GND connect the R_SET1
resistor, calculated as follows:
R_SET1(kΩ)
=
-----------4---5---0-----------
I_LED1(mA)
where I_LED1 is the DC LED current in channel 1.
Pin to cathode of channel 1 LED string.
Reference voltage output pin, used to bias VSET2 node.
The voltage on this pin sets the VOLED as follows:
V_OLED = 20 × V_SET2
Pin to cathode of channel 2 LED string.
© 2006 California Micro Devices Corp. All rights reserved.
6 490 N. McCarthy Blvd., Milpitas, CA 95035-5112 l Tel: [phone] l Fax: [phone] l www.cmd.com
04/26/06