CAT3616_08 Datasheet, PDF (8/14 Pages) Catalyst Semiconductor – 6-Channel Charge Pump LED Driver with EZDimTM

CAT3616
PIN DESCRIPTIONS
Pin #
1
2
3
4
Name
MAIN1
E¯N¯M¯
E¯N¯¯S
EN
Function
MAIN1 LED cathode terminal (if not used, connect to VOUT)¹
Enable main LED (MAIN1 to MAIN4) input. Active low
Enable sub LED (SUB1, SUB2) input. Active low
Device enable input. Active high.
5
VOUT Charge pump output connected to the LED anodes
6
VIN Supply voltage.
7, 8 C1-, C1+ Bucket capacitor 1 terminal
9, 10 C2-, C2+ Bucket capacitor 2 terminal
11
GND Ground reference
12
SUB2 SUB2 LED cathode terminal (if not used, connect to VOUT)¹
13
SUB1 SUB1 LED cathode terminal (if not used, connect to VOUT)¹
14
MAIN4 MAIN4 LED cathode terminal (if not used, connect to VOUT)¹
15
MAIN3 MAIN3 LED cathode terminal (if not used, connect to VOUT)¹
16
MAIN2 MAIN2 LED cathode terminal (if not used, connect to VOUT)¹
TAB
TAB Connect to Ground on PCB
Note:
(1) MAIN1 to MAIN4, SUB1, SUB2 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
1μF ceramic bypass capacitor is required between the
VIN pin and ground near the device. The operating
input voltage range is up to 5.5V. When the input
supply falls below the undervoltage threshold (2V), all
LED channels are disabled.
EN is the enable logic input. Logic level for high and
low are set at 1.3V and 0.4V respectively. When EN is
initially taken high, the device becomes enabled and
all LED currents remain at 0mA. To place the device
into zero current shutdown mode, the EN pin must be
held low for 1.5ms or more.
E¯N¯M¯ , E¯N¯¯S are the active low enable/ dimming control
logic inputs for respectively main and sub LED
channels. The falling edge of the first pulse applied to
E¯N¯M¯ and E¯N¯¯S sets the current for respectively the
main and sub LED channels to their full scale of
31mA. On each consecutive falling edge of the pulse
applied to E¯N¯M¯ and E¯N¯¯S, the LED current is
decreased by 1mA step. On the 32^nd pulse, the LED
current is set to zero. The next pulse resets the
current back to the full scale of 31mA.
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.
MAIN1-4, SUB1-2 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 six LEDs, the 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.
Doc. No. MD-5018 Rev. C
8
© Catalyst Semiconductor, Inc.
Characteristics subject to change without notice