CAT3614 Datasheet, PDF (8/12 Pages) Catalyst Semiconductor – 4-Channel 1-Wire LED Driver in 3x3mm Package

CAT3614
Table 5. PIN DESCRIPTIONS
Pin #
Name
Function
1
VIN
Supply voltage.
2
C1+
Bucket capacitor 1 terminal
3
C1−
Bucket capacitor 1 terminal
4
C2−
Bucket capacitor 2 terminal
5
C2+
Bucket capacitor 2 terminal
6
GND
Ground reference
7
LED1
LED1 cathode terminal (if not used, connect to VOUT) (Note 3)
8
LED2
LED2 cathode terminal (if not used, connect to VOUT) (Note 3)
9
LED3
LED3 cathode terminal (if not used, connect to VOUT) (Note 3)
10
LED4
LED4 cathode terminal (if not used, connect to VOUT) (Note 3)
11
EN/DIM
Device enable (active high) and dimming control input
12
VOUT
Charge pump output connected to the LED anodes
TAB
TAB
Connect to GND on the PCB
3. 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.
Pin Function
VIN is the supply pin for the charge pump. A small 1 mF
ceramic bypass capacitor is required between the VIN pin
and ground near the device. The operating input voltage
range is from 2.2 V to 5.5 V. Whenever the input supply falls
below the undervoltage threshold (2 V) 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 1.3 V and 0.4 V respectively. When EN/DIM
is initially taken high, the device becomes enabled and all
LED currents remain at 0 mA. The falling edge of the first
pulse applied to EN/DIM sets all LED currents to their full
scale of 31 mA.
On each consecutive falling edge of the pulse applied to
EN/DIM, the LED current is decreased by 1 mA 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 31 mA.
To place the device into zero current shutdown mode, the
EN/DIM pin must be held low for 1.5 ms or more.
VOUT is the charge pump output that is connected to the
LED anodes. A small 1 mF 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 1 mF ceramic
bucket capacitor C1.
C2+, C2− are connected to each side of the 1 mF 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 200 mA.
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.
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