CAT3636 Datasheet, PDF (7/15 Pages) Catalyst Semiconductor – 6-Channel Quad-ModeTM Fractional LED Driver in TQFN3x3

PIN DESCRIPTION
Pin #
Name
1
LEDC2
2
LEDC1
3
LEDB2
4
LEDB1
5
LEDA2
6
LEDA1
7
VOUT
8
VIN
9
C1+
10
C1-
11
C2+
12
C2-
13/14
NC
15
GND
16
EN/SET
TAB
TAB
CAT3636
Function
LEDC2 cathode terminal
LEDC1 cathode terminal
LEDB2 cathode terminal
LEDB1 cathode terminal
LEDA2 cathode terminal
LEDA1 cathode terminal
Charge pump output, connect to LED anodes
Charge pump input, connect to battery or supply
Bucket capacitor 1, positive terminal
Bucket capacitor 1, negative terminal
Bucket capacitor 2, positive terminal
Bucket capacitor 2, negative terminal
No connect
Ground reference
Device enable (active high) and 1 wire control input
Connect to GND on the PCB
PIN FUNCTION
VIN is the supply pin for the charge pump. A small
1μF ceramic bypass capacitor is required between the
VIN pin and ground near the device. The operating
input voltage range is from 2.5V to 5.5V. Whenever
the input supply falls below the under-voltage
threshold (2V) all the LED channels will be
automatically disabled and the device register are
reset to default values.
EN/SET is the enable and one wire addressable
control logic input for all LED channels. Guaranteed
levels of logic high and logic low are set at 1.3V and
0.4V respectively. When EN/SET is initially taken
high, the device becomes enabled and all LED
currents remain at 0mA. To place the device into zero
current mode, the EN/SET pin must be held low for
more than 1.5ms.
VOUT is the charge pump output that is connected to
the LED anodes. A small 1μF ceramic bypass
capacitor is required between the VOUT pin and
ground near the device.
GND is the ground reference for the charge pump.
The pin must be connected to the ground plane on the
PCB.
C1+, C1- are connected to each side of the ceramic
bucket capacitor C1.
C2+, C2- are connected to each side of the
ceramic bucket capacitor C2.
LEDxx provide the internal regulated current for
each of the LED cathodes. These pins enter high-
impedance zero current state whenever the device
is placed in shutdown mode.
TAB 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.
© 2006 Catalyst Semiconductor, Inc.
7
Characteristics subject to change without notice
Doc. No. 5020 Rev. A