CAT3604
4-Channel Regulated
Charge Pump White LED
Driver
Description
The CAT3604 is a charge pump operating in either 1x (LDO) mode
or 1.5x fractional mode regulating current through each of the 4 LED
pins. Operation at a fixed high frequency of 1 MHz typical allows the
use of very small value ceramic capacitors.
The CAT3604 drives white light-emitting diodes (LEDs) connected
in parallel and provides tightly matched regulated current to achieve
uniformity of brightness in LCD backlighting applications. An
external resistor R
SET
controls the output current level. LED currents
of up to 30 mA are supported over a range of input supply voltages
from 3 V to 5.5 V, making the device ideal for battery-powered
applications.
LED dimming can be accomplished by several methods including
using a DC voltage to set the RSET pin current, applying a PWM
signal on the Control signals, or adding a switched resistor in parallel
with RSET. The Enable input pin allows the device to be placed in
power-down mode with “zero” quiescent current.
The CAT3604 features short circuit and overcurrent limiting
protection. The device is available in a 16−pad TQFN package with a
max height of 0.8 mm.
Features
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TQFN−16
HV4 SUFFIX
CASE 510AE
PIN CONNECTIONS
(Note 1)
LED1
LED2
LED3
LED4
EN
CTR0
CTR1
CTR2
1
GND
GND
C2+
C2−
C1−
VOUT
•
•
•
•
•
•
•
•
•
•
•
•
•
Drives Individually up to 4 LEDs
Output Current up to 30 mA per LED
Digital Control On/Off of Each LED
Compatible with Supply Voltage of 3 V to 5.5 V
Power Efficiency up to 93%
2 Modes of Operation 1x and 1.5x
Automatic Short Circuit Detect/Disable
High−frequency Operation at 1 MHz
Low Value Ceramic Capacitors
“604” Compatible Pinout
Soft Start and Current Limiting
TQFN 16−pad Package, 4 x 4 mm, 0.8 mm Max Height
These Devices are Pb−Free, Halogen Free/BFR Free and are RoHS
Compliant
Color LCD and Keypad Backlighting
Cellular Phones
Handheld Devices
Digital Cameras
PDAs
Portable MP3 Players
1
(4 x 4 mm) (Top View)
MARKING DIAGRAMS
G364
CDBA
G364 = CAT3604HV4−T2
CDBA = CAT3604HV4−GT2
ORDERING INFORMATION
Device
CAT3604HV4−T2
CAT3604HV4−GT2
Package
TQFN−16
(Note 2)
TQFN−16
(Note 3)
Shipping
2,000/
Tape & Reel
Applications
•
•
•
•
•
•
1. The package exposed pad is electrically connec-
ted inside the package to GND and to pin 12.
2. Matte−Tin Plated Finish (RoHS−compliant).
3. NiPdAu Plated Finish (RoHS−compliant).
RSET
©
Semiconductor Components Industries, LLC, 2010
February, 2010
−
Rev. 1
Publication Order Number:
CAT3604/D
C1+
VIN
CAT3604
1
μF
C1+
Battery +
−
V
IN
3 V to 4.2 V
VIN
C
IN
EN
EN
CTR0
CTR1
CTR2
RSET
GND
CAT3604
LED1
LED2
LED3
LED4
1
μF
Control 0
Control 1
Control 2
R
SET
24 kW
C1− C2+
1
μF
C2−
VOUT
V
OUT
C
OUT
1
μF
20 mA
Figure 1. Typical Application Circuit
Table 1. PIN DESCRIPTION
Pin #
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
Pad
Name
EN
CTR0
CTR1
CTR2
RSET
VOUT
VIN
C1+
C1
C2
C2+
GND
LED4
LED3
LED2
LED1
GND Pad
Enable input, active HIGH
Digital control input 0
Digital control input 1
Digital control input 2
The LED output current is set by the current sourced out of the RSET pin
Charge pump output connected to the LED anodes
Supply voltage
Bucket capacitor 1 terminal
Bucket capacitor 1 terminal
Bucket capacitor 2 terminal
Bucket capacitor 2 terminal
Ground reference
LED 4 cathode terminal
LED 3 cathode terminal
LED 2 cathode terminal
LED 1 cathode terminal
Ground reference
Function
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2
CAT3604
Table 2. ABSOLUTE MAXIMUM RATINGS
Parameter
VIN, VOUT, LEDx voltage
EN, CTRx voltage
RSET voltage
RSET current
Ambient Temperature Range
Storage Temperature Range
Lead Temperature
ESD Rating HBM (Human Body Model)
ESD Rating MM (Machine Model) (Note 4)
Rating
−0.3
to 7.0
−0.3
to VIN
−0.3
to VIN
±1
−40
to +85
−65
to +160
300
2,000
200
Unit
V
V
V
mA
_C
_C
_C
V
V
Stresses exceeding Maximum Ratings may damage the device. Maximum Ratings are stress ratings only. Functional operation above the
Recommended Operating Conditions is not implied. Extended exposure to stresses above the Recommended Operating Conditions may affect
device reliability.
4. Machine model is with 200 pF capacitor discharged directly into each pin.
Table 3. RECOMMENDED OPERATING CONDITIONS
Parameter
VIN
Ambient Temperature Range
Input/Output/Bucket Capacitors
I
LED
per LED pin
5. Typical application circuit with external components is shown on page 2.
Range
3.0 to 5.5
−40
to +85
1
±20%
typical
0 to 30
Unit
V
_C
mF
mA
Table 4. ELECTRICAL OPERATING CHARACTERISTICS
(
Limits over recommended operating conditions unless specified otherwise. Typical values at T
A
= 25°C, V
IN
= 3.5 V, I
RSET
= 5
mA)
Symbol
I
Q
Parameter
Quiescent Current
Conditions
V
EN
= 0 V, Shutdown Mode
1x Mode, No Load
1.5x Mode, No Load
1.17
I
RSET
= 5
mA
I
RSET
= 37
mA
I
RSET
= 78
mA
0.5 mA
≤
I
LED
≤
3 mA
3 mA
≤
I
LED
≤
30 mA
(I
LED
– I
LEDAVG
) / I
LEDAVG
1x Mode
1.5x Mode, I
OUT
= 100 mA
0.8
0.4
On Inputs EN, CTR0, 1 & 2
On Inputs EN, CTR0, 1 & 2
VOUT = GND
VOUT > 1 V
0.4
30
200
Min
Typ
0.05
0.3
2.6
1.2
2.4
15.0
30.0
±15
±5
±3
1.4
6.5
1.0
0.6
0.001
0.8
45
400
2.5
10
1.3
0.9
1
1.3
60
600
Max
1
1
5
1.23
Units
mA
mA
mA
V
mA
V
RSET
I
LED
RSET Regulated Voltage
Programmed LED Current
I
LED−ACC
I
LED−DEV
R
OUT
f
OSC
T
DROPOUT
I
EN−CTR
V
EN−CTR
I
SC
I
LIM
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
Input Current Limit
Maximum Input Current
%
%
W
MHz
ms
mA
V
mA
mA
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3
CAT3604
Block Diagram
1
μF
C1−
C1+ C2−
1
μF
C2+
VIN
Battery +
V
IN
−
3 V to 4.2 V
C
IN
1
μF
1x mode (LDO)
1.5x Charge Pump
V
OUT
C
OUT
1 MHz
Oscillator
Mode Control
LED1
LED2
1.2 V Ref
LED3
LED4
20 mA
1
μF
EN
RSET
R
SET
24 kW
CTR0
CTR1
CTR2
Current
Setting
4 Current
Sink Regulators
LED
Output
Select
GND
Figure 2. CAT3604 Functional Block Diagram
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4
CAT3604
Basic Operation
At power-up, the CAT3604 starts operation in 1x mode. If
it is able to drive the programmed LED current, it continues
in 1x mode. If the battery voltage drops to a level where the
LED current cannot be met, the driver automatically
switches into 1.5x mode. The 1.5x charge pump will boost
the output voltage accordingly to achieve the nominal LED
current.
The operating mode is reinitialized each and every time
the chip is powered up or is taken out of shutdown mode (via
EN pin). The use of the control pins (CTR0, CTR1, CTR2)
does not reconfigure the mode of operation.
LED Current Setting
Table 5. RSET Resistor Selection
LED Current (mA)
1
2
5
10
15
20
30
R
SET
(kW)
649
287
102
49.9
32.4
23.7
15.4
The LED current is set by the external resistor R
SET
connected between the RSET pin and ground. Table 5 lists
various LED currents and the associated R
SET
resistor value
for standard 1% precision surface mount resistors.
The digital control lines CTR0, CTR1 and CTR2 allow to
turn On or Off a combition of LEDs as shown in Table 6.
Short Circuit Detect/Disables
Table 6. LED Selection
Control Lines
CTR2
CTR1
CTR0
LED4
LED Outputs
LED3
LED2
LED1
0
0
0
0
1
1
1
1
NOTE:
0
0
1
1
0
0
1
1
0
1
0
1
0
1
0
1
–
–
–
ON
–
–
ON
–
–
–
ON
−
–
ON
ON
–
–
ON
–
–
ON
ON
ON
–
ON
–
–
–
ON
ON
ON
–
The unused LED channels can also be turned off by
connecting the respective LED pins to VOUT. In which
case, the corresponding LED driver is disabled and the
typical LED sink current is only about 20
mA.
When the
following equation is true on any channel, the driver turns
off the LED channel:
VOUT
*
V
LED
v
1 V (LED channel OFF)
Note:
The CAT3604 is designed to drive LEDs with forward
voltage greater than 1 V and is not compatible with resistive
loads.
1 = logic high (or VIN)
0 = logic low (or GND)
– = LED output OFF
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