CAT3603 Datasheet, PDF (7/11 Pages) Catalyst Semiconductor – 3-Channel LED Driver in 3x3mm Package

CAT3603
TYPICAL CHARACTERISTICS
(VIN = 3.6 V, I_OUT = 60 mA (3 LEDs at 20 mA), C₁ = C₂ = C_IN = C_OUT = 1 mF, T_AMB = 25°C unless otherwise specified.)
5
4
1x Mode
3
2
1
0
0
100
200
300
400
500
OUTPUT CURRENT (mA)
Figure 20. Foldback Current Limit
Table 4. PIN DESCRIPTION
Pin #
Name
Function
1
LED1
LED1 cathode terminal (if not used, connect to VOUT) (Note 2)
2
LED2
LED2 cathode terminal (if not used, connect to VOUT) (Note 2)
3
LED3
LED3 cathode terminal (if not used, connect to VOUT) (Note 2)
4
RSET
The LED output current is set by the current sourced out of the RSET pin
5
EN
Device enable (active high)
6
VOUT
Charge pump output connected to the LED anodes
7
VIN
Supply voltage
8
C1+
Bucket capacitor 1 terminal
9
C1−
Bucket capacitor 1 terminal
10
C2−
Bucket capacitor 2 terminal
11
C2+
Bucket capacitor 2 terminal
12
GND
Ground Reference
TAB
Connect to GND on the PCB
2. LED1, LED2, LED3 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 3.0 V to 5.5 V.
EN is the enable 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.
RSET pin is regulated at 1.2 V. An external resistor RSET
connected from the RSET pin to GND sets the LED current.
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 LED3 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 three
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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