ONSEMI CAT3612

CAT3612
Programmable 300 mA
Camera Flash LED Driver
Description
The CAT3612 is a high−efficiency 1x/1.5x fractional charge pump
with programmable current in two LED channels. Each channel
delivers accurate regulated current up to 150 mA and make CAT3612
ideal for driving one or two flash LEDs.
Low noise operation is achieved by operating at a constant
switching frequency of 1 MHz which allows the use of small external
ceramic capacitors. The 1x/1.5x fractional charge pump supports a
wide range of input voltages from 3 V to 5.5 V with efficiency up to
90%, and is ideal for Li−Ion battery powered devices.
The EN/DIM logic input provides a 1−wire EZDimt interface for
dimming control of the LEDs. When enabled, pulsing the EN/DIM
reduces the LED current on each negative edge in 31 linear steps from
150 mA down to zero current.
The device is available in the tiny 12−lead thin DFN 3 mm x 3 mm
package with a max height of 0.8 mm.
C1+
N/C
Features
C1−
EN/DIM
C2−
N/C
GND
C2+
LED1
LED2
•
•
•
•
•
•
•
•
•
•
•
•
•
•
Dual Matched Regulated LED Channels
300 mA Output Current (150 mA per Channel)
1−wire EZDimt Programmable LED Current
32 Accurate Dimming Levels
Power Efficiency up to 90%
Fractional Pump 1x/1.5x
Low Noise Input Ripple
Fixed High Frequency Operation 1 MHz
“Zero” Current Shutdown Mode
Soft Start and Current Limiting
Short Circuit Protection
Thermal Shutdown Protection
12−lead TDFN 3 mm x 3 mm Package
These Devices are Pb−Free, Halogen Free/BFR Free and are RoHS
Compliant
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TDFN−12
HV2 SUFFIX
CASE 511AN
PIN CONNECTIONS
1
VIN
VOUT
(Top View)
MARKING DIAGRAM
HAAD
AXXX
YWW
HAAF
AXXX
YWW
HAAD = CAT3612HV2-T2
HAAF = CAT3612HV2-GT2
A = Assembly Location
XXX = Last Three Digits of Assembly Lot Number
Y = Production Year (Last Digit)
WW = Production Week (Two Digit)
ORDERING INFORMATION
Applications
Device
• Camera Flash
• Cellular Phones
• Digital Still Cameras
Package
Shipping
CAT3612HV2−T2
(Note 1)
TDFN−12
(Pb−Free)
2,000/
Tape & Reel
CAT3612HV2−GT2
(Note 2)
TDFN−12
(Pb−Free)
2,000/
Tape & Reel
1. Matte−Tin Plated Finish (RoHS−compliant).
2. NiPdAu Plated Finish (RoHS−compliant).
© Semiconductor Components Industries, LLC, 2010
April, 2010 − Rev. 2
1
Publication Order Number:
CAT3612/D
CAT3612
1 mF
C1+
VIN
3 V to
5.5 V
CIN
1 mF
C1− C2+
C2−
VOUT
VIN
2.2 mF
CAT3612
2.2 mF
COUT
LED1
ENABLE/
DIMMING
EN/DIM
Flash
LED
300 mA
LED2
GND
Figure 1. Typical Application Circuit
NOTE:
Unused LED channel must be connected to VOUT
Table 1. ABSOLUTE MAXIMUM RATINGS
Parameter
Rating
Unit
VIN, LED1, LED2 voltage
6
V
VOUT, C1±, C2± voltage
7
V
EN/DIM voltage
VIN + 0.7 V
V
Storage Temperature Range
−65 to +160
°C
Junction Temperature Range
−40 to +150
°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. RECOMMENDED OPERATING CONDITIONS
Parameter
Range
Unit
3 to 5.5
V
−40 to +85
°C
ILED per LED pin
0 to 150
mA
Total Output Current
0 to 300
mA
VIN
Ambient Temperature Range
NOTE:
Typical application circuit with external components is shown above.
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CAT3612
Table 3. ELECTRICAL OPERATING CHARACTERISTICS
(over recommended operating conditions unless specified otherwise) VIN = 3.6 V, EN = High, ambient temperature of 25°C.
Symbol
Parameter
IQ
Quiescent Current
IQSHDN
Shutdown Current
Conditions
Min
Typ
1x mode, no load
1.5x mode, no load
Max
0.5
3
VEN = 0 V
Unit
mA
1
mA
ILED−ACC
LED Current Accuracy
5 mA ≤ ILED ≤ 150 mA
±3
%
ILED−DEV
LED Channel Matching
(ILED − ILEDAVG) / ILEDAVG
±3
%
ROUT
Output Resistance (open loop)
1x mode, IOUT = 100 mA
1.5x mode, IOUT = 100 mA
0.4
2.6
W
FOSC
Charge Pump Frequency
0.8
ISC_MAX
Output short circuit Current Limit
IIN_MAX
Input Current Limit
IEN/DIM
VHI
VLO
EN/DIM Pin
− Input Leakage
− Logic High Level
− Logic Low Level
1
1.3
MHz
VOUT < 0.5 V
60
mA
1x mode, VOUT > 1 V
350
mA
−1
1.3
1
0.4
mA
V
V
TSD
Thermal Shutdown
165
°C
THYS
Thermal Hysteresis
20
°C
VUVLO
Undervoltage lock out (UVLO) Threshold
2
V
Table 4. RECOMMENDED EN/DIM TIMING
(For 3 V ≤ VIN ≤ 5.5 V, over full ambient temperature range −40°C to +85°C.)
Symbol
TSETP
Parameter
Conditions
Min
EN/DIM setup from shutdown
10
TLO
EN/DIM program low time
0.3
THI
EN/DIM program high time
0.3
EN/DIM low time to shutdown
1.5
TOFF
TD
TDEC
Typ
Max
Unit
ms
200
ms
ms
ms
LED current enable
40
ms
LED current decrement
0.1
ms
TSETP
THI
TOFF
EN/DIM
TLO
TD
TDEC
150 mA
150mA 145 mA
140 mA
LED
Current
Shutdown
5 mA
0 mA
Figure 2. LED Dimming Timing Diagram
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3
Shutdown
CAT3612
TYPICAL CHARACTERISTICS
(VIN = 3.6 V, IOUT = 100 mA, CIN = COUT = 2.2 mF, C1 = C2 = 1 mF, TAMB = 25°C unless otherwise specified.)
100
100
VIN = 4.2 V (1x Mode)
90
EFFICIENCY (%)
90
EFFICIENCY (%)
VF = 3 V
VF = 3.4 V
80
70
60
IOUT = 250 mA
80
70
60
VIN = 3.2 V (1.5x Mode)
50
50
IOUT = 100 mA
40
4.2
4.0
3.8
3.6
3.4
3.2
40
3.0
250
Figure 4. Efficiency vs. LED Current
300
0.8
QUIESCENT CURRENT (mA)
QUIESCENT CURRENT (mA)
200
Figure 3. Efficiency vs. Input Voltage
0.4
0.2
LED Off
3.0
3.2
3.4
3.6
3.8
4.0
0.6
0.4
0.2
LED Off
0
−40
4.2
0
40
80
120
INPUT VOLTAGE (V)
TEMPERATURE (°C)
Figure 5. Quiescent Current vs. Input Voltage
(1x Mode)
Figure 6. Quiescent Current vs. Temperature
(1x Mode)
6
QUIESCENT CURRENT (mA)
6
QUIESCENT CURRENT (mA)
150
LED CURRENT (mA)
0.6
5
4
3
2
1
0
100
INPUT VOLTAGE (V)
0.8
0
50
3.2
3.4
3.6
4
3
2
1
LED Off
LED Off
3.0
5
3.8
4.0
0
−40
4.2
0
40
80
120
INPUT VOLTAGE (V)
TEMPERATURE (°C)
Figure 7. Quiescent Current vs. Input Voltage
(1.5x Mode)
Figure 8. Quiescent Current vs. Temperature
(1.5x Mode)
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CAT3612
TYPICAL CHARACTERISTICS
5
4
4
LED CURRENT CHANGE (%)
5
3
2
1x Mode
1
0
−1
−2
1.5x Mode
−3
−4
−5
3.0
3.2
3.4
3.6
3.8
4.0
1
0
−1
−2
−3
−4
80
120
Figure 9. LED Current Change vs. Input
Voltage
Figure 10. LED Current Change vs.
Temperature
1.2
1.2
1.1
1.0
0.9
0.8
3.2
3.4
3.6
3.8
1.1
1.0
0.9
0.8
0.7
−40
4.0
0
40
80
120
INPUT VOLTAGE (V)
TEMPERATURE (°C)
Figure 11. Oscillator Frequency vs. Input
Voltage
Figure 12. Oscillator Frequency vs.
Temperature
1.0
OUTPUT RESISTANCE (W)
4.0
0.8
0.6
0.4
0.2
0
40
TEMPERATURE (°C)
1.3
3.0
0
INPUT VOLTAGE (V)
1.3
0.7
OUTPUT RESISTANCE (W)
3
2
−5
−40
4.2
CLOCK FREQUENCY (MHz)
CLOCK FREQUENCY (MHz)
LED CURRENT CHANGE (%)
(VIN = 3.6 V, IOUT = 100 mA, CIN = COUT = 2.2 mF, C1 = C2 = 1 mF, TAMB = 25°C unless otherwise specified.)
3.0
3.2
3.4
3.6
3.8
4.0
3.5
3.0
2.5
2.0
1.5
1.0
4.2
3.0
3.2
3.4
3.6
3.8
4.0
4.2
INPUT VOLTAGE (V)
INPUT VOLTAGE (V)
Figure 13. Output Resistance vs. Input Voltage
(1x Mode)
Figure 14. Output Resistance vs. Input Voltage
(1.5x Mode)
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CAT3612
TYPICAL CHARACTERISTICS
(VIN = 3.6 V, IOUT = 100 mA, CIN = COUT = 2.2 mF, C1 = C2 = 1 mF, TAMB = 25°C unless otherwise specified.)
Figure 15. Power Up with 1 LED at 100 mA
(1x Mode)
Figure 16. Power Up with 1 LED at 100 mA
(1.5x Mode)
Figure 17. Enable Power Down Delay
(1x Mode)
Figure 18. Enable Power Down Delay
(1.5x Mode)
Figure 19. Switching Waveforms in 1.5x Mode
Figure 20. Operating Waveforms in 1x Mode
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CAT3612
TYPICAL CHARACTERISTICS
(VIN = 3.6 V, IOUT = 100 mA, CIN = COUT = 2.2 mF, C1 = C2 = 1 mF, TAMB = 25°C unless otherwise specified.)
Figure 21. Enable and Output Current
Dimming Waveforms
Figure 22. Line Transient Response
(3.6 V to 5.5 V) 1x Mode
200
200
VIN = 3.5 V
160
MINIMUM TIME (nS)
MINIMUM TIME (nS)
160
VIN = 3.5 V
120
80
VIN = 4.2 V
40
0
−40
0
40
80
80
0
−40
120
0
40
80
TEMPERATURE (°C)
TEMPERATURE (°C)
Figure 23. Enable High Minimum Program
Time vs. Temperature
Figure 24. Enable Low Minimum Program
Time vs. Temperature
120
4.0
3.5
OUTPUT VOLTAGE (V)
1.0
ENABLE VOLTAGE (V)
VIN = 4.2 V
40
1.2
0.8
0.6
0.4
0.2
0
−40
120
3.0
1x Mode
LED Off
2.5
2.0
1.5
1.0
0.5
0
40
80
0
120
0
100
200
300
400
TEMPERATURE (°C)
OUTPUT CURRENT (mA)
Figure 25. Enable Voltage Threshold vs.
Temperature
Figure 26. Foldback Current Limit
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500
CAT3612
Table 5. PIN DESCRIPTIONS
Pin #
Name
Function
1
VIN
Supply voltage.
2
C1+
Bucket capacitor 1 terminal
3
C1−
Bucket capacitor 1 terminal
4
C2−
Bucket capacitor 2 terminal
5
GND
Ground reference
6
LED1
LED1 cathode terminal (if not used, connect to VOUT) (Note 3)
7
LED2
LED2 cathode terminal (if not used, connect to VOUT) (Note 3)
8
C2+
9
−
10
EN/DIM
11
−
12
VOUT
TAB
TAB
Bucket capacitor 2 terminal
Not connected
Device enable (active high) and dimming control input.
Not connected
Charge pump output connected to the LED anodes.
Connect to GND on the PCB.
3. LED1, LED2 pins should not be left floating. They should be connected to the LED cathode, or tied to the VOUT pin if not used.
Pin Function
VIN is the supply pin for the device. A small 1 mF ceramic
bypass capacitor is required between the VIN pin and
ground near the device. The operating input voltage range is
up to 5.5 V. When the input supply falls below the
undervoltage threshold (2 V), all LEDs channels are
disabled.
EN/DIM is the enable and dimming 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. When EN/DIM
is initially taken high, the device becomes enabled and the
LED currents remain at 0 mA. The falling edge of the first
pulse on EN/DIM sets the LED currents to the full scale
150 mA.
On each consecutive falling edge of the pulse on EN/DIM,
the LED current decreases by 150/31 mA. On the 32nd pulse,
the LED current is set to zero. The next pulse on EN/DIM
resets the current back to full scale 150 mA.
To place the device into zero current shutdown mode, the
EN/DIM pin must be held low for 1.5 ms or more.
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, LED2 provide the internal regulated current for each
of the LED cathodes. These pins enter a high impedance
zero current state whenever the device is in shutdown mode.
In applications using only one LED channel, the unused
channel should be tied directly to VOUT. The disabled
channel only draws about 0.5 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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CAT3612
Block Diagram
C1−
VIN
C1+
C2−
C2+
VOUT
1x mode (LDO)
1.5x Charge Pump
Mode Control
1 MHz
Oscillator
EN/DIM
LED1
Reference
Voltage
LED2
Current
Setting DAC
LED Channel
Current Regulators
Serial
Interface
Registers
GND
Figure 27. CAT3612 Functional Block Diagram
Basic Operation
At power−up, the CAT3612 starts operating in 1x mode
where the output will be approximately equal to the input
supply voltage (less any internal voltage losses). If the
output voltage is sufficient to regulate all LEDs currents the
device remains in 1x operating mode.
If the input voltage is insufficient or falls to a level where
the regulated currents cannot be maintained, the device
automatically switches (after a fixed of 400 ms) into 1.5x
mode.
In 1.5x mode, the output is approximately equal to 1.5
times the input supply voltage (less any internal voltage
losses).
The above sequence is repeated each and every time the
chip is powered−up or is taken out of shutdown mode (via
EN/DIM pin).
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CAT3612
LED Current Setting
Table 6. SELECTION OF LED CURRENT
PER CHANNEL
Figure 2 shows the EN/DIM input timing diagram for
setting the LED currents. The EN/DIM set−up time requires
the signal to be held high for 10 ms or longer to ensure the
initialization of the driver at power−up. Each subsequent
pulse on the EN/DIM (300 ns to 200 ms pulse duration) steps
down the LED current from full scale of 150 mA to zero with
nearly 5 mA resolution. The selection of the LED current per
channel is shown in Table 6. Consecutive pulses should be
separated by 300 ns or longer. Pulsing beyond the 0 mA level
restores the current level back to full scale and the cycle
repeats. Pulsing frequencies from 5 kHz up to 1 MHz can be
supported during dimming operations. When the EN/DIM
is held low for 1.5 ms or more, the CAT3612 enters the
shutdown mode and draws “zero” current.
For applications with 2 LEDs, each LED connected to one
LED pin, refer to Figure 28.
1 mF
VIN
3 V to
5.5 V
CIN
2.2 mF
LED Current (mA)
1
150
2
145
1 mF
C1+ C1− C2+ C2−
VOUT
VIN
CAT3612
COUT
2.2 mF
LED1
ENABLE/
DIMMING
Number of Pulses on EN/DIM
EN/DIM
Flash
LED
150 mA
LED2
GND
Figure 28. Application with 2 LEDs
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3
140
4
135.5
5
131
6
126
7
121
8
116
9
111
10
106.5
11
101.5
12
97
13
92
14
87
15
82
16
77.5
17
72.5
18
68
19
63
20
58
21
53
22
48.5
23
43.5
24
39
25
34
26
29
27
24
28
19
29
14.5
30
10
31
5
32
0
CAT3612
Protection Mode
Recommended Layout
If an LED becomes open−circuit, the output voltage
VOUT is internally limited to about 5.5 V. This is to prevent
the output pin from exceeding its absolute maximum rating.
The driver enters a thermal shutdown mode as soon as the
die temperature exceeds about +165°C. When the device
temperature drops down by about 20°C, the device resumes
normal operation.
In 1.5x charge pump mode, the driver switches internally
at a high frequency of 1 MHz. It is recommended to
minimize trace length to all four capacitors. A ground plane
should cover the area under the driver IC as well as the
bypass capacitors. Short connection to ground on capacitors
Cin and Cout can be implemented with the use of multiple
via. A copper area matching the TDFN exposed pad (GND)
must be connected to the ground plane underneath. The use
of multiple via improves the package heat dissipation.
External Components
The driver requires a total of four external 1 mF ceramic
capacitors: two for decoupling input and output, and two for
the charge pump. Both capacitor types X5R and X7R are
recommended for the LED driver application. In the 1.5x
charge pump mode, the input current ripple is kept very low
by design, and an input bypass capacitor of 1 mF is sufficient.
In 1x mode, the device operating in linear mode does not
introduce switching noise back onto the supply.
Figure 29. Recommended Layout
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CAT3612
PACKAGE DIMENSIONS
TDFN12, 3x3
CASE 511AN−01
ISSUE A
D
A
e
b
L
E
E2
PIN#1 ID
PIN#1 INDEX AREA
A1
SIDE VIEW
TOP VIEW
SYMBOL
MIN
NOM
MAX
A
0.70
0.75
0.80
A1
0.00
0.02
0.05
A3
0.178
0.203
0.228
b
0.18
0.23
0.30
D
2.90
3.00
3.10
D2
2.30
2.40
2.50
E
2.90
3.00
3.10
E2
1.55
1.70
1.75
e
BOTTOM VIEW
A
A3
A1
FRONT VIEW
RECOMMENDED LAND PATTERN
R
e
M
0.45 BSC
L
0.30
0.40
0.50
M
0.25
0.30
0.35
N
0.60
0.70
0.80
P
2.70
3.00
3.10
R
D2
N
P
E2
2.25 TYP
Notes:
(1) All dimensions are in millimeters.
(2) Complies with JEDEC MO-229.
D2
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CAT3612
Example of Ordering Information (Note 6)
4.
5.
6.
7.
8.
Prefix
Device #
Suffix
CAT
3612
HV2
−G
T2
Company ID
(Optional)
Product Number
3612
Package
HV2: TDFN 3 x 3 mm
Lead Finish
Blank: Matte−Tin (Note 7)
G: NiPdAu
Tape & Reel (Note 8)
T: Tape & Reel
2: 2,000 / Reel
All packages are RoHS−compliant (Lead−free, Halogen−free).
The standard lead finish is NiPdAu.
The device used in the above example is a CAT3612HV2−GT2 (TDFN, NiPdAu Plated Finish, Tape & Reel, 2,000/Reel).
For Matte−Tin package option, 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.
EZDim is a trademark of Semiconductor Components Industries, LLC.
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
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Phone: 303−675−2175 or 800−344−3860 Toll Free USA/Canada
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For additional information, please contact your local
Sales Representative
CAT3612/D