CAT3614HV2-T2 Datasheet, PDF (8/13 Pages) ON Semiconductor – 4-Channel 1-Wire LED Driver in 3 x 3mm Package

CAT3614
PIN DESCRIPTIONS
Pin #
1
2
3
4
5
6
7
8
9
10
11
12
TAB
Name
VIN
C1+
C1-
C2-
C2+
GND
LED1
LED2
LED3
LED4
EN/DIM
VOUT
TAB
Function
Supply voltage.
Bucket capacitor 1 terminal
Bucket capacitor 1 terminal
Bucket capacitor 2 terminal
Bucket capacitor 2 terminal
Ground reference
LED1 cathode terminal (if not used, connect to VOUT)⁽¹⁾
LED2 cathode terminal (if not used, connect to VOUT)⁽¹⁾
LED3 cathode terminal (if not used, connect to VOUT)⁽¹⁾
LED4 cathode terminal (if not used, connect to VOUT)⁽¹⁾
Device enable (active high) and dimming control input
Charge pump output connected to the LED anodes
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 2.2V to 5.5V. Whenever
the input supply falls below the undervoltage threshold
(2V) all LEDs channels will be automatically disabled.
EN/DIM is the enable and dimming 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/DIM is initially taken high,
the device becomes enabled and all LED currents
remain at 0mA. The falling edge of the first pulse
applied to EN/DIM sets all LED currents to their full
scale of 31mA.
On each consecutive falling edge of the pulse applied
to EN/DIM, the LED current is decreased by 1mA
step. On the 32nd pulse, the LED current is set to
zero. The next pulse on EN/DIM resets the current
back to their full scale of 31mA.
To place the device into zero current shutdown mode,
the EN/DIM pin must be held low for 1.5ms or more.
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 1µF
ceramic bucket capacitor C1.
C2+, C2- are connected to each side of the 1µF
ceramic bucket capacitor C2.
LED1 to LED4 provide the internal regulated current
for each of the LED cathodes. These pins enter a high
impedance zero current state whenever the device is
placed in shutdown mode. In applications using less
than four LEDs, all unused channels should be wired
directly to VOUT. This ensures the channel is
automatically disabled dissipating less than 200µA.
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.
Notes:
(1) LED1, LED2, LED3, LED4 pins should not be left floating. They should be connected to the LED cathode, or tied to VOUT pin if not used.
Doc. No. MD-5035, Rev. C
8
© 2008 SCILLC. All rights reserved.
Characteristics subject to change without notice