CAT3616 Datasheet, PDF (9/14 Pages) Catalyst Semiconductor – 6-Channel Charge Pump LED Driver with EZDimTM

CAT3616
Table 5. PIN DESCRIPTIONS
Pin #
Name
Function
1
MAIN1
MAIN1 LED cathode terminal (if not used, connect to VOUT) (Note 3)
2
ENM
Enable main LED (MAIN1 to MAIN4) input. Active low
3
ENS
Enable sub LED (SUB1, SUB2) input. Active low
4
EN
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) (Note 3)
13
SUB1
SUB1 LED cathode terminal (if not used, connect to VOUT) (Note 3)
14
MAIN4
MAIN4 LED cathode terminal (if not used, connect to VOUT) (Note 3)
15
MAIN3
MAIN3 LED cathode terminal (if not used, connect to VOUT) (Note 3)
16
MAIN2
MAIN2 LED cathode terminal (if not used, connect to VOUT) (Note 3)
TAB
TAB
Connect to Ground on PCB
3. 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 1 mF
ceramic bypass capacitor is required between the VIN pin
and ground near the device. The operating input voltage
range is up to 5.5 V. When the input supply falls below the
undervoltage threshold (2 V), all LED channels are disabled.
EN is the enable logic input. Logic level for high and low are
set at 1.3 V and 0.4 V respectively. When EN is initially
taken high, the device becomes enabled and all LED
currents remain at 0 mA. To place the device into zero
current shutdown mode, the EN pin must be held low for
1.5 ms or more.
ENM, ENS 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 ENM and ENS sets
the current for respectively the main and sub LED channels
to their full scale of 31 mA. On each consecutive falling edge
of the pulse applied to ENM and ENS, the LED current is
decreased by 1 mA 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 31 mA.
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.
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 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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