CAT3603
3-Channel LED Driver in 3x3mm Package
FEATURES
Drives up to 3 LEDs
Current setting resistor
Compatible with supply voltage of 3V to 5.5V
Power efficiency up to 91%
Output Current up to 30mA per LED
Fractional pump 1x/1.5x
Low noise input ripple
Fixed High Frequency Operation 1MHz
“Zero” Current Shutdown Mode
Soft start and current limiting
Short circuit protection
12-lead TDFN 3mm x 3mm package
DESCRIPTION
The CAT3603 is a charge pump LED driver
operating in either 1x (LDO) mode or 1.5x fractional
mode regulating current through each of the 3 LED
pins. Operation at a constant switching frequency of
1MHz allows the use of very small value ceramic
capacitors.
The CAT3603 drives 3 white LEDs in parallel and
provides tightly matched regulated current to achieve
uniform brightness in LCD backlighting applications.
An external resistor, RSET, controls the output
current level. The device can deliver up to 30mA over
an input voltage supply range from 3V to 5.5V,
making it ideal for battery-powered applications
LED dimming can be accomplished using several
methods; using a DC voltage to set the RSET pin
current, applying a PWM signal on the EN pin, or
adding a switched resistor in parallel with RSET. The
EN input pin allows the device to be placed in power-
down mode with “near-zero” quiescent current.
The device is available in the tiny 12-lead thin DFN
3mm x 3mm package with a max height of 0.8mm.
APPLICATION
LCD Display Backlight
Cellular Phones
Digital Still Cameras
Handheld Devices
ORDERING INFORMATION
Part
Number
Package
Quantity Package
per Reel Marking
2000
HABB
CAT3603HV2 TDFN-12 3x3
Green*
* Lead Finish Matte-Tin
For Ordering Information details, see page 11.
PIN CONFIGURATION
12-lead TDFN 3mm (Top view)
TYPICAL APPLICATION CIRCUIT
Note:
Unused LED channels must be connected to VOUT.
© 2006 Catalyst Semiconductor, Inc.
Characteristics subject to change without notice
1
Doc. No. 5017 Rev. C
CAT3603
ABSOLUTE MAXIMUM RATINGS
Parameter
VIN, VOUT, LEDx voltage
EN voltage
RSET voltage
Junction Temperature Range
Storage Temperature Range
Lead Temperature
ESD Ratings
Human Body Model (HBM)
Machine Model (MM)
Rating
-0.3 to 7.0
-0.3 to VIN
-0.3 to VIN
-40 to +150
-65 to +160
300
2000
200
Unit
V
V
V
°C
°C
°C
V
V
RECOMMENDED OPERATING CONDITIONS
Parameter
VIN
Ambient Temperature Range
Input, Output, Bucket Capacitors
I
LED
per LED pin
IOUT Total Output Current
Range
3 to 5.5
-40 to +85
1 ±20% typical
0 to 31
0 to 150
Unit
V
°C
µF
mA
mA
Typical application circuit with external components are shown on page 1.
ELECTRICAL OPERATING CHARACTERISTICS
VIN = 3.6V, EN = High, ambient temperature of 25ºC (over recommended operating conditions unless specified
otherwise).
Symbol
I
Q
V
RSET
I
LED
I
LED-ACC
I
LED-DEV
R
OUT
f
OSC
T
DROPOUT
I
EN
V
EN
I
SC
I
LIM
T
SD
T
HYS
V
UVLO
Parameter
Quiescent Current
Conditions
V
EN
= 0V, shutdown mode
1x Mode, No Load
1.5x Mode, No Load
I
RSET
= 5µA
I
RSET
= 37µA
I
RSET
= 78µA
0.5mA
≤
I
LED
≤
3mA
3mA
≤
I
LED
≤
30mA
(I
LED
– I
LEDAVG
) / I
LEDAVG
1x Mode
1.5x Mode, I
OUT
= 100mA
0.8
0.4
On Input EN
On Input EN
VOUT = GND
VOUT > 1V
0.4
30
200
Min
Typ
0.1
0.4
2.7
1.2
2.4
15.0
30.0
±15
±5
±3
1.4
6.5
1.0
0.6
Max
1
1
5
1.23
Unit
µA
mA
mA
V
mA
mA
mA
%
%
%
Ω
Ω
MHz
ms
µA
V
V
mA
mA
ºC
ºC
V
RSET Regulated Voltage
Programmed LED Current
LED Current Accuracy
LED Channel Matching
Output Resistance
(Open Loop)
Charge Pump Frequency
1x to 1.5x Mode Transition
Dropout Delay
Input Leakage Current
High Detect Threshold
Low Detect Threshold
Short Circuit Output Current
Maximum Input Current
Thermal Shutdown
Thermal Hysteresis
Undervoltage lock out (UVLO) threshold
1.17
2.5
10
1.3
0.9
1
1.3
60
600
0.8
0.7
45
400
150
20
2
Doc. No. 5017 Rev. C
2
©
2006 Catalyst Semiconductor, Inc.
Characteristics subject to change without notice
CAT3603
TYPICAL CHARACTERISTICS
VIN = 3.6V, I
OUT
= 60mA (3 LEDs at 20mA), C
1
= C
2
= C
IN
= C
OUT
= 1µF, T
AMB
= 25°C unless otherwise specified.
Efficiency vs. Input Voltage (3 LEDs on)
100
90
EFFICIENCY [%]
80
70
60
50
40
4.2
4.0 3.8 3.6 3.4 3.2
INPUT VOLTAGE [V]
3.0
20mA
per LED
15mA
per LED
1x Mode
1.5x Mode
Efficiency vs. Total LED Current (3 LEDs)
100
90
EFFICIENCY [%]
80
70
60
50
40
0
20
40
60
80
LED CURRENT [mA]
100
VIN = 3.2V (1.5x Mode)
VIN = 4V (1x Mode)
Quiescent Current vs. Input Voltage (1x Mode)
0.8
QUIESCENT CURRENT [mA]
0.6
0.4
0.2
LEDs Off
0.0
3.0
3.2 3.4 3.6 3.8 4.0
INPUT VOLTAGE [V]
4.2
Quiescent Current vs. Temperature (1x Mode)
0.8
QUIESCENT CURRENT [mA]
0.6
0.4
0.2
LEDs Off
0.0
-40
0
40
80
TEMPERATURE [°C]
120
Quiescent Current vs. Input Voltage (1.5x Mode)
6.0
5.0
4.0
3.0
2.0
1.0
LEDs Off
0.0
3.0
3.2 3.4 3.6 3.8 4.0
INPUT VOLTAGE [V]
4.2
QUIESCENT CURRENT [mA]
Quiescent Current vs. Temperature (1.5x Mode)
6.0
QUIESCENT CURRENT [mA]
5.0
4.0
3.0
2.0
1.0
0.0
-40
0
40
80
TEMPERATURE [°C]
120
LEDs Off
©
2006 Catalyst Semiconductor, Inc.
Characteristics subject to change without notice
3
Doc. No. 5017 Rev. C
CAT3603
TYPICAL CHARACTERISTICS
VIN = 3.6V, I
OUT
= 60mA (3 LEDs at 20mA), C
1
= C
2
= C
IN
= C
OUT
= 1µF, T
AMB
= 25°C unless otherwise specified.
LED Current Change vs. Input Voltage
5.0
4.0
3.0
2.0
1.0
0.0
-1.0
-2.0
-3.0
-4.0
-5.0
LED CURRENT CHANGE [%]
LED Current Change vs. Temperature
LED CURRENT CHANGE [%]
5.0
4.0
3.0
2.0
1.0
0.0
-1.0
-2.0
-3.0
-4.0
-5.0
-40
VIN = 4V
0
40
80
TEMPERATURE [°C]
120
1x Mode
1.5x Mode
3.0
3.2 3.4 3.6 3.8 4.0
INPUT VOLTAGE [V]
4.2
Switching Frequency vs. Input Voltage
SWITCHING FREQUENCY [MHz]
1.3
1.2
1.1
1.0
0.9
0.8
0.7
3.0
3.2 3.4 3.6 3.8 4.0
INPUT VOLTAGE [V]
4.2
Switching Frequency vs. Temperature
SWITCHING FREQUENCY [MHz]
1.3
1.2
1.1
1.0
0.9
0.8
0.7
-40
0
40
80
TEMPERATURE [°C]
120
Output Resistance vs. Input Voltage (1x Mode)
4
OUTPUT RESISTANCE [Ω] .
Output Resistance vs. Input Voltage(1.5x Mode)
10
OUTPUT RESISTANCE [Ω] .
8
3
2
1
6
4
2
3.0
3.2 3.4 3.6 3.8 4.0
INPUT VOLTAGE [V]
4.2
0
3.0
3.2 3.4 3.6 3.8 4.0
INPUT VOLTAGE [V]
4.2
Doc. No. 5017 Rev. C
4
©
2006 Catalyst Semiconductor, Inc.
Characteristics subject to change without notice
CAT3603
TYPICAL CHARACTERISTICS
VIN = 3.6V, I
OUT
= 60mA (3 LEDs at 20mA), C
1
= C
2
= C
IN
= C
OUT
= 1µF, T
AMB
= 25°C unless otherwise specified.
Switching Waveforms in 1.5x Mode
Operating Waveforms in 1x Mode
Power Up 3 LEDs at 20mA, VIN = 3.2V (1.5x Mode)
Power Up 3 LEDs at 20mA, VIN = 4V (1x Mode)
LED Current vs. R
SET
100
LED CURRENT [mA]
Line Transient Response in 1x Mode
10
1
10
100
RSET [kohm]
1000
©
2006 Catalyst Semiconductor, Inc.
Characteristics subject to change without notice
5
Doc. No. 5017 Rev. C
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