CAT4004
4-Channel Constant Current
LED Driver with EZDimt
Description
The CAT4004 provides four matched low dropout current sources to
drive LEDs. An external resistor on RSET sets the current in the LED
channels. Each LED channel includes an individual control loop
allowing the device to handle a wide range of LED forward voltages
while still maintaining tight current matching.
The EN/DIM logic inputs supports device enable and a digital
dimming interface for current setting of all LEDs. Six different current
dimming ratios are available.
The device is aimed at “direct drive” battery applications. It is
required that the battery or voltage source have enough headroom to
drive the LED forward voltage and current sink (>150 mV).
The device is available in a tiny 8−lead TDFN 2 mm x 3 mm
package with a max height of 0.8 mm.
Features
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TDFN−8
VP2 SUFFIX
CASE 511AK
PIN CONNECTIONS
EN/DIM
GND
LED1
LED2
(Top View)
1
VIN
RSET
LED4
LED3
•
•
•
•
•
•
•
•
•
Four LED Current Sinks with Tight Matching
Low Dropout Driver 130 mV at 30 mA
No Switching Noise
Shutdown Current < 1
mA
LED Current set by External Resistor
Dimming via 1−wire EZDimt Interface
Thermal Shutdown Protection
8−lead 2 mm x 3 mm TDFN Package
These Devices are Pb−Free, Halogen Free/BFR Free and are RoHS
Compliant
LCD Display Backlight
Cellular Phones
Digital Still Cameras
Handheld Devices
V
IN
2.4 V
to
5.5 V
C
IN
1
mF
LED1
VIN
One wire
programming
RSET
3.8 kW
EN/DIM
RSET
GND
CAT4004
LED2 LED3 LED4
20 mA
MARKING DIAGRAMS
FXA
XXX
YM
HAA
XXX
YM
Applications
•
•
•
•
FX = CAT4004VP2−T3
HA = CAT4004VP2−GT3
A = Assembly Location
XXX = Last Three Digits of Assembly Lot Number
Y = Production Year (Last Digit)
M = Production Month (1−9, A, B, C)
ORDERING INFORMATION
Device
CAT4004VP2−T3
(Note 1)
CAT4004VP2−GT3
(Note 2)
Package
TDFN−8
(Pb−Free)
TDFN−8
(Pb−Free)
Shipping
3,000/
Tape & Reel
3,000/
Tape & Reel
1. Matte−Tin Plated Finish (RoHS−compliant).
2. NiPdAu Plated Finish (RoHS−compliant).
Figure 1. Typical Application Circuit
©
Semiconductor Components Industries, LLC, 2010
March, 2010
−
Rev. 2
1
Publication Order Number:
CAT4004/D
CAT4004
Table 1. ABSOLUTE MAXIMUM RATINGS
Parameter
VIN, LEDx, RSET
EN/DIM Voltage
Storage Temperature Range
Junction Temperature Range
Lead Temperature
Rating
6
V
IN
+ 0.7
−65
to +160
−40
to +150
300
Unit
V
V
°C
°C
°C
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.
Table 2. RECOMMENDED OPERATING CONDITIONS
Parameter
V
IN
Ambient Temperature Range
I
LED
per LED pin
NOTE: Typical application circuit with external components is shown on page 1.
Rating
2.4 to 5.5
−40
to +85
0 to 40
Unit
V
°C
mA
Table 3. ELECTRICAL OPERATING CHARACTERISTICS
Symbol
I
Q
I
QSHDN
I
LED−ACC
I
LED−DEV
V
DOUT
R
EN/DIM
V
HI
V
LO
T
SD
T
HYS
V
UVLO
Quiescent Current
Shutdown Current
LED Current Accuracy
LED Channel Matching
Name
(over recommended operating conditions unless specified otherwise) V
IN
= 4.0 V, EN = High, T
AMB
= 25°C
Conditions
No load, RSET = Float
No load, RSET = 4.8 kW
V
EN
= 0 V
1 mA
≤
I
LED
≤
40 mA
I
LED
*
I
LEDAVG
I
LED
I
LED
= 30 mA
−5
±1
±1
130
100
1.3
0.4
150
20
1.8
+5
Min
Typ
0.6
1.0
1
Max
Units
mA
mA
%
%
Dropout Voltage
EN/DIM Pin
−
Internal pull−down resistor
−
Logic High Level
−
Logic Low Level
Thermal Shutdown
Thermal Hysteresis
Undervoltage lockout (UVLO) threshold
mV
kW
V
V
°C
°C
V
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2
CAT4004
Table 4. RECOMMENDED EN/DIM TIMING
Symbol
T
SETUP
T
LO
T
HI
T
PWRDWN
T
LED
Name
EN/DIM setup from shutdown
EN/DIM program low time
EN/DIM program high time
EN/DIM low time to shutdown
LED current settling time
T
SETUP
T
HI
(For 2.4
≤
V
IN
≤
5.5 V, over full ambient temperature range
−40°C
to +85°C.)
Conditions
Min
10
0.2
0.2
1.5
40
T
PWRDWN
100
Typ
Max
Units
ms
ms
ms
ms
ms
EN/DIM
T
LED
100%
50%
LED
Current
Shutdown
25%
12.5% 6.25%
3.12%
T
LO
100%
Shutdown
Figure 2. EN/DIM Dimming Timing Diagram
EN/DIM
Number of Pulses
(Note 3)
LOW
Transitions HIGH
1
st
2
nd
3
rd
4
th
5
th
6
th
x
th
R
SET
Gain
Shutdown mode
132
66
33
16.5
8.25
4.125
132
Device will keep cycling through gain selection
LED Current
Zero
132 x 0.6 V/R
SET
66 x 0.6 V/R
SET
33 x 0.6 V/R
SET
16.5 x 0.6 V/R
SET
8.25 x 0.6 V/R
SET
4.125 x 0.6 V/R
SET
132 x 0.6 V/R
SET
GAIN x 0.6 V/R
SET
3. The gain is changed on the rising edges of the EN/DIM input.
LED Current Selection
At power−up, the initial LED current is set to full scale
(100% brightness) by the external resistor RSET as follows:
LED current
+
132
0.6 V
R
SET
The EN/DIM pin has two primary functions. One function
enables and disables the device. The other function is LED
current dimming with six different levels by pulsing the
input signal, as shown on Figure 2. On each consecutive
pulse rising edge, the LED current is divided by half to 50%,
then 25%, 12.5%, 6.25% and 3.125% dimming levels.
Pulses faster than the minimum T
LO
may be ignored and
filtered by the device. Pulses longer than the maximum T
LO
may shutdown the device.
The LED driver enters a “zero current” shutdown mode if
EN/DIM is held low for 1.5 ms or more.
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3
CAT4004
TYPICAL PERFORMANCE CHARACTERISTICS
(V
IN
= 4 V, V
F
= 3.3 V, I
OUT
= 80 mA (4 LEDs at 20 mA), C
IN
= 1
mF,
T
AMB
= 25°C unless otherwise specified.)
1.4
QUIESCENT CURRENT (mA)
QUIESCENT CURRENT (mA)
1.4
1.2
1.2
1.0
1.0
0.8
0.8
0.6
2.5
3.0
3.5
4.0
4.5
5.0
5.5
0.6
−40
0
40
TEMPERATURE (°C)
80
120
INPUT VOLTAGE (V)
Figure 3. Quiescent Current vs. Input Voltage
1.0
LED CURRENT CHANGE (%)
0.6
0.4
0.2
0
−0.2
−0.4
−0.6
−0.8
−1.0
LED CURRENT CHANGE (%)
0.8
10
8
6
4
2
0
−2
−4
−6
Figure 4. Quiescent Current vs. Temperature
3.0
3.5
4.0
4.5
5.0
5.5
−8
−10
−40
0
40
TEMPERATURE (°C)
80
120
INPUT VOLTAGE (V)
Figure 5. LED Current Change vs. Input
Voltage
40
Figure 6. LED Current Change vs.
Temperature
LED CURRENT (mA)
30
20
10
0
0
5
10
RSET (kW)
15
20
Figure 7. LED Current vs. RSET Resistor
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4
CAT4004
TYPICAL PERFORMANCE CHARACTERISTICS
(V
IN
= 4 V, V
F
= 3.3 V, I
OUT
= 80 mA (4 LEDs at 20 mA), C
IN
= 1
mF,
T
AMB
= 25°C unless otherwise specified.)
0.7
0.6
RSET VOLTAGE (V)
0.5
0.4
0.3
0.2
RSET VOLTAGE (V)
2.0
2.5
3.0
3.5
4.0
4.5
5.0
5.5
0.7
0.6
0.5
0.4
0.3
0.2
−40
0
40
TEMPERATURE (°C)
80
120
INPUT VOLTAGE (V)
Figure 8. RSET Pin Voltage vs. Input Voltage
40
40
Figure 9. RSET Pin Voltage vs. Temperature
LED CURRENT (mA)
LED CURRENT (mA)
30
30
20
20
10
10
0
0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
0
0
50
100
150
200
250
300
LED PIN VOLTAGE (V)
LED PIN VOLTAGE (mV)
Figure 10. LED Current vs. LED Pin Voltage
100
90
EFFICIENCY (%)
80
70
60
50
Figure 11. Dropout Characteristics
5.0
4.5
4.0
3.5
3.0
2.5
2.0
INPUT VOLTAGE (V)
Figure 12. Efficiency vs. Input Voltage
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