CAT4104V-GT3 Datasheet, PDF (7/14 Pages) ON Semiconductor – 700 mA Quad Channel Constant Current LED Driver

PIN DESCRIPTIONS
Name
LED1
LED2
LED3
LED4
GND
EN/PWM
VIN
RSET
Pin
SOIC 8-Lead
1
2
3
4
5
6
7
8
Pin
TDFN 8-Lead
1
2
3
4
5 and TAB
6
7
8
Function
LED1 cathode terminal
LED2 cathode terminal
LED3 cathode terminal
LED4 cathode terminal
Ground reference
Device enable input and PWM control
Device supply pin
LED current set pin for the LED channels
CAT4104
PIN FUNCTION
VIN is the supply pin for the device. A small 0.1 μF
ceramic bypass capacitor is optional for noisy
environments. Whenever the input supply falls below
the under-voltage threshold, all LED channels are
automatically disabled.
EN/PWM is the enable and one wire dimming input
for all LED channels. Guaranteed levels of logic high
and logic low are set at 1.3 V and 0.4 V respetively.
When EN/PWM is initially taken high, the device
becomes enabled and all LED currents are set at a
gain of 100 times the current in RSET. To place the
device into zero current shutdown mode, the
EN/PWM pin must be held low for 4 ms typical.
LED1 to LED4 provide individual regulated currents
for each of the LED cathodes. There pins enter a high
impedance zero current state whenver the device is
placed in shutdown mode.
RSET pin is connected to an external resistor to set
the LED channel current. The ground side of the
external resistor should be star connected to the
GND of the PCB. The pin source current mirrors the
current to the LED sinks. The voltage at this pin is
regulated to 1.2 V.
GND is the ground reference for the device. The pin
must be connected to the ground plane on the PCB.
TAB (TDFN 8-Lead Only) is the exposed pad
underneath the package. For best thermal
performance, the tab should be soldered to the PCB
and connected to the ground plane.
© 2009 SCILLC. All rights reserved.
7
Characteristics subject to change without notice
Doc. No. MD-5041 Rev. B