CAT4002A D

CAT4002A, CAT4004A
Constant Current LED
Driver with 32 Dimming
Levels and Rset
Description
The CAT4002A and CAT4004A provide respectively two and four
matched low dropout current sources to drive LEDs. The CAT400XA
uses an external resistor RSET to set 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 setting the LED channel current with 32 linear
dimming levels.
LEDs can be powered directly from a Lithium−ion battery due to the
low dropout (50 mV at 20 mA) current sinks. The device is available
in the tiny 8−pad UDFN 2 mm x 2 mm package with a max height of
0.55 mm, as well as the 6−lead TSOT−23 and SC−70.
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UDFN−8
HU2G SUFFIX
CASE 517AW
SC70−6
SD SUFFIX
CASE 419AD
Features
•
•
•
•
•
•
•
•
•
•
2 and 4 LED Current Sinks with Tight Matching
32 Dimming Levels
Low Dropout Driver 50 mV at 20 mA
No Switching Noise
Shutdown Current less than 1 mA
LED Current set by External Resistor
Dimming via 1−wire EZDimt Interface
Thermal Shutdown Protection
6−lead TSOT−23, SC−70, and 8−pad UDFN 2 mm x 2 mm Packages
These Devices are Pb−Free, Halogen Free/BFR Free and are RoHS
Compliant
Applications
• LCD Display Backlight
• Cellular Phones
• Digital Still Cameras
• Handheld Devices
PIN CONNECTIONS
1
20 mA
CIN
LED2
CAT4004A
UDFN−8
1
EN/DIM
LED1
GND
RSET
VIN
LED2
CAT4002A
TSOT23−6
EN/DIM
1 mF
LED1 LED2 LED3 LED4
VIN
One wire
programming
EN/DIM
LED1
RSET
GND
VIN
LED2
(Top Views)
GND
ORDERING INFORMATION
See detailed ordering and shipping information in the package
dimensions section on page 11 of this data sheet.
Figure 1. Typical Application Circuit
© Semiconductor Components Industries, LLC, 2011
June, 2011 − Rev. 2
1
CAT4002A
SC70−6
CAT4004A
RSET
RSET
3.74 kW
VIN
RSET
LED4
LED3
EN/DIM
GND
LED1
VIN
2.4 V
to
5.5 V
TSOT23−6
TD SUFFIX
CASE 419AF
1
Publication Order Number:
CAT4002A/D
CAT4002A, CAT4004A
MARKING DIAGRAMS
BG
A
Y
M
BGA
YM
VLYM
VJA
UDFN8 (2 x 2 mm)
TSOT23−6
SC70−6
= CAT4004A Device Code
= Assembly Location Code
= Production Year (last digit)
= Production Month: 1 − 9, A, B, C
VL
Y
M
= CAT4002A Device Code
= Production Year (last digit)
= Production Month: 1 − 9, A, B, C
VJ
A
= CAT4002A Device Code
= Assembly Location Code
Table 1. ABSOLUTE MAXIMUM RATINGS
Parameter
VIN, LEDx, RSET
EN/DIM Voltage
Rating
Unit
6
V
6
V
Storage Temperature Range
−65 to +160
°C
Junction Temperature Range
−40 to +125
°C
300
°C
Lead Temperature
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. ELECTRICAL OPERATING CHARACTERISTICS (Min and Max values are over recommended operating conditions
unless specified otherwise. Typical values are at VIN = 4.0 V, EN/DIM = High, and TAMB = 25°C.)
Symbol
Name
Conditions
IQ
Quiescent Current
No load, RSET = Float
No load, RSET = 4.8 kW
IQSHDN
Shutdown Current
VEN/DIM = 0 V
ILED
LED Current Setting
ILED−ACC
LED Current Accuracy
ILED−DEV
LED Channel Matching (Note 1)
Min
Typ
25
RSET = 4.99 kW
15
1 mA ≤ ILED ≤ 40 mA
Units
mA
1
RSET = 3.0 kW
I LED * I LEDAVG
Max
0.2
0.5
mA
mA
%
±1
−5
±1
+5
%
0.57
0.6
0.63
V
I LEDAVG
VRSET
RSET pin regulated voltage
VDOUT
Dropout Voltage
(90% of nominal LED current)
REN/DIM
VHI
VLO
ILED = 20 mA
ILED = 1 mA
EN/DIM Pin
− Internal pull−down resistor
− Logic High Level
− Logic Low Level
50
25
mV
200
kW
V
V
1.3
0.4
TSD
Thermal Shutdown
150
°C
THYS
Thermal Hysteresis
20
°C
VUVLO
Undervoltage lockout (UVLO) threshold
2.0
V
1. For CAT4004A, ILEDAVG = (ILED,CH1 + ILED,CH2 + ILED,CH3 + ILED,CH4) / 4
For CAT4002A, ILEDAVG = (ILED,CH1 + ILED,CH2) / 2
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2
CAT4002A, CAT4004A
Table 3. RECOMMENDED OPERATING CONDITIONS
Parameter
Rating
Unit
VIN
2.4 to 5.5
V
Ambient Temperature Range
−40 to +85
°C
0 to 40
mA
ILED per LED pin
NOTE:
Typical application circuit with external components is shown on page 1.
Table 4. RECOMMENDED EN/DIM TIMING (For 2.4 V ≤ VIN ≤ 5.5 V, over full ambient temperature range −40°C to +85°C.)
Symbol
Name
Conditions
Min
TLO
EN/DIM program low time
0.2
THI
EN/DIM program high time
0.2
TLED
TPWRDWN
Typ
Max
Units
100
ms
ms
LED current settling time
10
EN/DIM low time to shutdown
3
ms
5
THI
EN/DIM
TLO
TPWRDWN
TLED
100%
LED
Current
100%
97% 94%
32 Levels
Shutdown
3%
Shutdown
0%
Figure 2. CAT400XA EN/DIM Dimming Timing Diagram
LED Current Setting
Table 5. RSET RESISTOR AND LED CURRENT
On the CAT400XA, the full scale LED current is set by the
external resistor connected between the RSET pin and
ground. Table 5 lists standard resistor values for several
LED current settings.
When the EN/DIM is initially taken high, the CAT400XA
becomes enabled and the LED channel current is set to the
full scale current according to the resistor RSET.
LED current ≅ 125 x VRSET / RSET
Full Scale
LED Current [mA]
RSET [kW]
2
40.2
5
15.4
10
7.68
15
4.99
20
3.74
25
3.00
30
2.49
40
1.87
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3
ms
CAT4002A, CAT4004A
TYPICAL PERFORMANCE CHARACTERISTICS
(CAT4002A, VIN = 4 V, VF = 3.3 V, IOUT = 50 mA (2 LEDs at 25 mA), CIN = 1 mF, TAMB = 25°C unless otherwise specified.)
QUIESCENT CURRENT (mA)
1.6
1.2
0.8
0.4
0
LED CURRENT CHANGE (%)
1.4
0
20
40
1.0
0.8
3.5
4.0
4.5
5.0
5.5
Figure 3. Quiescent Current vs. RSET Input
Voltage
Figure 4. Quiescent Current vs. Input Voltage
(Full Load)
1.0
10
8
0.6
0.4
0.2
0
−0.2
−0.4
−0.6
2.5
3.0
3.5
4.0
4.5
5.0
5.5
6
4
2
0
−2
−4
−6
−8
−10
−40
0
40
80
INPUT VOLTAGE (V)
TEMPERATURE (°C)
Figure 5. LED Current Change vs. Input
Voltage
Figure 6. LED Current Change vs.
Temperature
120
40
25°C
1.0
0.8
LED CURRENT (mA)
1.2
−40°C
80°C
0.6
0.4
3.0
INPUT VOLTAGE (V)
0.8
−0.8
−1.0
2.5
RSET (kW)
1.4
ENABLE HIGH THRESHOLD (V)
1.2
0.6
60
LED CURRENT CHANGE (%)
QUIESCENT CURRENT (mA)
2.0
2.0
2.5
3.0
3.5
4.0
4.5
5.0
30
20
10
0
5.5
1
10
INPUT VOLTAGE (V)
RSET (kW)
Figure 7. EN/DIM High Threshold vs. Input
Voltage
Figure 8. LED Current vs. RSET Resistor
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4
100
CAT4002A, CAT4004A
TYPICAL PERFORMANCE CHARACTERISTICS
(CAT4002A, VIN = 4 V, VF = 3.3 V, IOUT = 50 mA (2 LEDs at 25 mA), CIN = 1 mF, TAMB = 25°C unless otherwise specified.)
30
100
25 mA
90
EFFICIENCY (%)
LED CURRENT (mA)
25
20
15
10
70
60
5
0
80
1 mA
0
50
100
150
200
250
50
300
5.5
5.0
4.5
4.0
3.5
3.0
2.5
LED PIN VOLTAGE (mV)
INPUT VOLTAGE (V)
Figure 9. Dropout Characteristics
Figure 10. Efficiency vs. Input Voltage
Figure 11. Power Up Waveform
Figure 12. Power Down Waveform
Figure 13. Line Transient Waveform
Figure 14. Dimming Levels
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5
2.0
CAT4002A, CAT4004A
Table 6. PIN DESCRIPTIONS
Name
EN/DIM
Function
Device enable (active high) and dimming control
GND
Ground reference
LED1
LED1 cathode terminal
LED2
LED2 cathode terminal
LED3
LED3 cathode terminal (CAT4004A only)
LED4
LED4 cathode terminal (CAT4004A only)
RSET
Connect external RSET resistor to set the LED current
VIN
Device supply input, connect to battery or supply
TAB
Connect to GND on the PCB (CAT4004A only)
Pin Function
LED1 to LED4 provide the internal regulated current for
each of the LED cathodes. There pins enter a high
impedance zero current state whenver the device is placed
in shutdown mode.
RSET is connected to the resistor (RSET) to set the full scale
current for the LEDs. The voltage at this pin is regulated to
0.6 V. The ground side of the external resistor should be star
connected back to the GND of the PCB. In shutdown mode,
the RSET input becomes high impedance.
GND is the ground reference for the device. The pin must be
connected to the ground plane on the PCB.
TAB (CAT4004A only) 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.
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 2.5 V to 5.5 V. Whenever the input supply falls
below the under−voltage threshold (2.0 V), all the LED
channels are disabled and the device enters shutdown mode.
EN/DIM is the enable and one wire dimming input for all
LED channels. Levels of logic high and logic low are set at
1.3 V and 0.4 V respectively. When EN/DIM is initially
taken high, the CAT400XA becomes enabled and the LED
channel current is set to the full scale according to the
resistor RSET. To place the device into “zero current”
shutdown mode, the EN/DIM pin must be held low for 3 ms
typical.
Block Diagram
LED4
LED3
Undervoltage
Lockout
LED2
VIN
LED1
VIN
Reference
Voltage
RSET
EN/DIM
Current
Setting DAC
Serial
Interface
Register
4 Current Sink
Regulators
100 kW
GND
Figure 15. CAT4004A Functional Block Diagram
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6
CAT4002A, CAT4004A
Basic Operation
Table 7. DIMMING LEVELS
The CAT400XA uses tightly matched current sinks to
accurately regulate LED current in each channel
proportional to the current sourced from the RSET pin.
There are 32 different settings for LED brightness that can
be programmed through the EN/DIM pin. Tight current
regulation for all channels is possible over a wide range of
input and LED voltages due to independent current sensing
circuitry on each channel.
Each LED channel needs a minimum of 50 mV headroom
to sink a constant regulated current of 20 mA. If the input
supply falls below 2.0 V typical, the under−voltage lockout
circuit disables all LED channels and resets the circuit to
default values. Any unused LED channels should be left
open.
Full Scale (Current in %)
Dimming Pulses [n]
100
0
97
1
94
2
90
3
87
4
84
5
81
6
77
7
74
8
LED Current Selection
0.6 V
R SET
10
11
61
12
58
13
55
14
52
15
48
16
45
17
42
18
39
19
35
20
32
21
29
22
26
23
23
24
19
25
16
26
13
27
10
28
6
29
3
30
0
31
100
32
ǒ3131* nǓ
The full scale current is calculated from the above formula
with n equal to zero.
The EN/DIM pin has two primary functions. One function
enables and disables the device. The other function is LED
current dimming with 32 different levels by pulsing the input
signal, as shown on Figure 16. On each consecutive pulse
rising edge, the LED current is decreased by about 3.2%
(1/31th of the full scale value). After 30 pulses, the LED
current is 3.2% of the full scale current. On the 31st pulse, the
current drops to zero, and then goes back to full scale on the
following pulse.
Each pulse width should be between 200 ns and 100 ms.
Pulses faster than the minimum TLO may be ignored and
filtered by the device. Pulses longer than the maximum TLO
may shutdown the device. By pulsing the EN/DIM signal at
high frequency, the LED current can quickly be set to zero.
The LED driver enters a “zero current” shutdown mode if
EN/DIM is held low for 3 ms typical.
The dimming level is set by the number of pulses on the
EN/DIM after the power−up, as shown in Table 7.
9
68
65
After power−up, the LED current is set by the external
resistor (RSET) value and the number of pulses (n) on the
EN/DIM input as follows:
LED current + 125
71
THI
EN/DIM
TLO
TPWRDWN
TLED
100%
LED
Current
Shutdown
100%
97% 94%
32 Levels
3%
0%
Figure 16. EN/DIM Digital Dimming Timing Diagram
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7
Shutdown
CAT4002A, CAT4004A
PACKAGE DIMENSIONS
UDFN8, 2x2
CASE 517AW−01
ISSUE O
D
A
D2
DETAIL A
E
E2
PIN #1
IDENTIFICATION
A1
PIN #1 INDEX AREA
TOP VIEW
SIDE VIEW
SYMBOL
MIN
NOM
MAX
A
0.45
0.50
0.55
A1
0.00
0.02
0.05
b
0.18
0.25
0.30
D
1.90
2.00
2.10
D2
1.50
1.60
1.70
E
1.90
2.00
2.10
E2
0.80
0.90
1.00
e
L
BOTTOM VIEW
b
L
e
0.50 BSC
0.20
0.30
DETAIL A
0.45
Notes:
(1) All dimensions are in millimeters.
(2) Complies with JEDEC MO-229.
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8
CAT4002A, CAT4004A
PACKAGE DIMENSIONS
SC−70, 6 Lead, 1.25x2
CASE 419AD−01
ISSUE O
D
e
e
E1 E
SYMBOL
MIN
A
0.80
MAX
1.10
A1
0.00
0.10
A2
0.80
1.00
b
0.15
0.30
c
0.10
0.18
D
1.80
2.00
2.20
E
1.80
2.10
2.40
E1
1.15
1.25
1.35
e
L
0.65 BSC
0.26
0.36
0.46
0.42 REF
L1
L2
TOP VIEW
NOM
0.15 BSC
θ
0º
8º
θ1
4º
10º
q1
A2 A
q
q1
b
L
L1
A1
SIDE VIEW
c
END VIEW
Notes:
(1) All dimensions are in millimeters. Angles in degrees.
(2) Complies with JEDEC MO-203.
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9
L2
CAT4002A, CAT4004A
PACKAGE DIMENSIONS
TSOT−23, 6 LEAD
CASE 419AF−01
ISSUE O
SYMBOL
D
MIN
NOM
A
e
E1
MAX
1.00
A1
0.01
0.05
0.10
A2
0.80
0.87
0.90
b
0.30
c
0.12
0.45
0.15
D
2.90 BSC
E
2.80 BSC
E1
1.60 BSC
E
e
0.20
0.95 TYP
L
0.30
0.40
L1
0.60 REF
L2
0.25 BSC
0º
θ
0.50
8º
TOP VIEW
A2 A
b
q
L
A1
c
L1
SIDE VIEW
END VIEW
Notes:
(1) All dimensions are in millimeters. Angles in degrees.
(2) Complies with JEDEC MO-193.
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10
L2
CAT4002A, CAT4004A
Example of Ordering Information (Note 4)
Prefix
Device #
Suffix
CAT
4004A
HU2
−G
T3
Package
Lead Finish
G: NiPdAu
Tape & Reel (Note 6)
T: Tape & Reel
3: 3,000 Units / Reel
Company ID
(Optional)
Product Number
4002A
4004A
HU2: UDFN
TD: TSOT
SD: SC70
Table 8. ORDERING INFORMATION
Part Number
Package
Quantity per Reel
CAT4002ASD−GT3
SC70−6
3,000
CAT4002ATD−GT3
TSOT−23
3,000
UDFN−8 (2 x 2 mm)
3,000
CAT4004AHU2−GT3
2.
3.
4.
5.
6.
All packages are RoHS−compliant (Lead−free, Halogen−free).
The standard lead finish is NiPdAu.
The device used in the above example is a CAT4004AHU2−GT3 (UDFN, NiPdAu, Tape & Reel, 3,000/Reel).
For additional package and temperature options, please contact your nearest ON Semiconductor Sales office.
For information on tape and reel specifications, including part orientation and tape sizes, please refer to our Tape and Reel Packaging
Specifications Brochure, BRD8011/D.
ON Semiconductor and
are registered trademarks of Semiconductor Components Industries, LLC (SCILLC). SCILLC reserves the right to make changes without further notice
to any products herein. SCILLC makes no warranty, representation or guarantee regarding the suitability of its products for any particular purpose, nor does SCILLC assume any liability
arising out of the application or use of any product or circuit, and specifically disclaims any and all liability, including without limitation special, consequential or incidental damages.
“Typical” parameters which may be provided in SCILLC data sheets and/or specifications can and do vary in different applications and actual performance may vary over time. All
operating parameters, including “Typicals” must be validated for each customer application by customer’s technical experts. SCILLC does not convey any license under its patent rights
nor the rights of others. SCILLC products are not designed, intended, or authorized for use as components in systems intended for surgical implant into the body, or other applications
intended to support or sustain life, or for any other application in which the failure of the SCILLC product could create a situation where personal injury or death may occur. Should
Buyer purchase or use SCILLC products for any such unintended or unauthorized application, Buyer shall indemnify and hold SCILLC and its officers, employees, subsidiaries, affiliates,
and distributors harmless against all claims, costs, damages, and expenses, and reasonable attorney fees arising out of, directly or indirectly, any claim of personal injury or death
associated with such unintended or unauthorized use, even if such claim alleges that SCILLC was negligent regarding the design or manufacture of the part. SCILLC is an Equal
Opportunity/Affirmative Action Employer. This literature is subject to all applicable copyright laws and is not for resale in any manner.
PUBLICATION ORDERING INFORMATION
LITERATURE FULFILLMENT:
Literature Distribution Center for ON Semiconductor
P.O. Box 5163, Denver, Colorado 80217 USA
Phone: 303−675−2175 or 800−344−3860 Toll Free USA/Canada
Fax: 303−675−2176 or 800−344−3867 Toll Free USA/Canada
Email: [email protected]
N. American Technical Support: 800−282−9855 Toll Free
USA/Canada
Europe, Middle East and Africa Technical Support:
Phone: 421 33 790 2910
Japan Customer Focus Center
Phone: 81−3−5773−3850
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ON Semiconductor Website: www.onsemi.com
Order Literature: http://www.onsemi.com/orderlit
For additional information, please contact your local
Sales Representative
CAT4002A/D
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