CATALYST CAT3614HV2-GT2

CAT3614
4-Channel 1-Wire LED Driver in 3 x 3mm Package
FEATURES
DESCRIPTION
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The CAT3614 is a high efficiency 1x/1.5x fractional
charge pump with programmable dimming current in
four LED channels. To ensure uniform brightness in
LCD backlight applications, each LED channel
delivers an accurate regulated current.
Drives up to 4 LED channels
1-wire EZDimTM Programmable LED Current
Accurate 1mA Dimming Level
Power efficiency up to 91%
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
Thermal shutdown protection
TDFN 12-pad 3mm x 3mm package
Low noise and input ripple is achieved by operating
at a constant switching frequency of 1MHz which
allows the use of small external ceramic capacitors.
The 1x/1.5x fractional charge pump supports a wide
range of input voltages from 3V to 5.5V with
efficiency up to 91%, and is ideal for Li-Ion battery
powered devices.
TM
The EN/DIM logic input provides a 1-wire EZDim
interface for dimming control of the LEDs. When
enabled, a series of clock pulses reduces the LED
brightness in 1mA steps on each negative going
edge. Currents from 0mA to 31mA are supported.
APPLICATIONS
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LCD Display Backlight
Cellular Phones
Digital Still Cameras
Handheld Devices
The device is available in the tiny 12-pad TDFN
3 x 3mm package with a max height of 0.8mm.
ORDERING INFORMATION
Quantity
Part Number
Package per Reel
CAT3614HV2-T2 TDFN-12 (1)
2000
(2)
CAT3614HV2-GT2 TDFN-12
2000
Package
Marking
HAAA
HAAC
For Ordering Information details, see page 12.
Notes: (1) Matte-Tin Plated Finish (RoHS-compliant).
(2) NiPdAu Plated Finish (RoHS-compliant).
PIN CONFIGURATION
TYPICAL APPLICATION CIRCUIT
TDFN 12-Pad 3 x 3mm
(Top View)
VIN
1
12 VOUT
C1+
2
11 EN/DIM
C1-
3
10 LED4
C2-
4
9 LED3
C2+
5
8 LED2
GND
6
7 LED1
1µF
VIN
3V to CIN
5.5V
1µF
C1+
C1- C2+
VIN
1µF
C2VOUT
VOUT
COUT
1µF
CAT3614
LED1
LED2
ENABLE/
DIMMING
20mA
LED3
EN/DIM
GND
LED4
Note: Unused LED channels must be connected to VOUT.
© Catalyst Semiconductor, Inc.
Characteristics subject to change without notice
1
Doc. No. MD-5035, Rev.B
CAT3614
ABSOLUTE MAXIMUM RATINGS
Parameter
Rating
Unit
VIN, LEDx voltage
6
V
VOUT, C1±, C2± voltage
7
V
EN/DIM voltage
VIN + 0.7V
V
Storage Temperature Range
-65 to +160
°C
Junction Temperature Range
-40 to +150
°C
300
°C
Lead Temperature
RECOMMENDED OPERATING CONDITIONS
Parameter
Range
Unit
VIN
3 to 5.5
V
-40 to +85
°C
ILED per LED pin
0 to 31
mA
Total Output Current
0 to 124
mA
Ambient Temperature Range
Typical application circuit with external components is shown on page 1.
ELECTRICAL OPERATING CHARACTERISTICS
VIN = 3.6V, EN = High, ambient temperature of 25ºC (over recommended operating conditions unless
specified otherwise).
Symbol Parameter
Conditions
Min
Typ
Max
Unit
0.3
1
0.5
3
1
8
mA
mA
1
µA
IQ
Quiescent Current
1x mode, no load
1.5x mode, no load
IQSHDN
Shutdown Current
VEN = 0V
ILED-ACC
LED Current Accuracy
1mA ≤ ILED ≤ 31mA
±3
±8
%
ILED-DEV
LED Channel Matching
(ILED - ILEDAVG) / ILEDAVG
±3
±7
%
ROUT
Output Resistance (open loop)
1x mode, IOUT = 100mA
1.5x mode, IOUT = 100mA
0.4
2.6
1
7
Ω
Ω
FOSC
Charge Pump Frequency
0.8
1
1.3
MHz
ISC_MAX
Output short circuit Current Limit
VOUT < 0.5V
30
60
100
mA
IIN_MAX
Input Current Limit
1x mode, VOUT > 1V
200
300
600
mA
IEN/DIM
VHI
VLO
1
0.4
µA
V
V
TSD
EN/DIM Pin
• Input Leakage
• Logic High Level
• Logic Low Level
Thermal Shutdown
145
165
175
ºC
THYS
Thermal Hysteresis
10
20
30
ºC
VUVLO
Undervoltage lock out (UVLO)
threshold
1.7
2
2.4
V
Doc. No. MD-5035, Rev.B
-1
1.3
2
© Catalyst Semiconductor, Inc.
Characteristics subject to change without notice
CAT3614
RECOMMENDED EN/DIM TIMING
For 3V ≤ VIN ≤ 5.5V, over full ambient temperature range -40 to +85ºC.
Symbol Parameter
TSETP
Conditions
Min
Typ
Max
Unit
EN/DIM setup from shutdown
10
TLO
EN/DIM program low time
0.3
THI
EN/DIM program high time
0.3
µs
EN/DIM low time to shutdown
1.5
ms
TOFF
TD
TDEC
µs
200
µs
LED current enable
40
µs
LED current decrement
0.1
µs
TSETP
THI
TOFF
EN/DIM
TD
TLO
TDEC
31mA
31mA
30mA 29mA
LED
Current
Shutdown
1mA
0mA
Shutdown
Figure 1. LED Dimming Timing Diagram
© Catalyst Semiconductor, Inc.
Characteristics subject to change without notice
3
Doc. No. MD-5035, Rev.B
CAT3614
TYPICAL CHARACTERISTICS
VIN = 3.6V, IOUT = 80mA (4 LEDs at 20mA), C1 = C2 = CIN = COUT = 1μF, TAMB = 25°C unless otherwise specified.
Efficiency vs. Total LED Current (4 LEDs)
Efficiency vs. Input Voltage (4 LEDs)
100
100
20mA per LED
90
1x mode
EFFICIENCY [%]
EFFICIENCY [%]
90
80
70
10mA per LED
60
50
70
60
VIN = 3.2V (1.5x mode)
40
4.2
4.0
3.8
3.6
3.4
3.2
INPUT VOLTAGE [V]
0
3.0
25
50
75
100
125
TOTAL LED CURRENT [mA]
Quiescent Current vs. Temperature (1x mode)
Quiescent Current vs. Input Voltage (1x mode)
0.8
QUIESCENT CURRENT [mA]
0.8
QUIESCENT CURRENT [mA] .
80
50
1.5x mode
40
0.6
0.4
4 LEDs OFF
0.2
0.6
0.4
4 LEDs OFF
0.2
0.0
0.0
3.0
3.2
3.4
3.6
3.8
4.0
INPUT VOLTAGE [V]
-40
4.2
0
40
80
TEMPERATURE [°C]
120
Quiescent Current vs. Temperature (1.5x mode)
Quiescent Current vs. Input Voltage (1.5x mode)
6.0
6.0
QUIESCENT CURRENT [mA]
QUIESCENT CURRENT [mA] .
VIN = 4V (1x mode)
5.0
4.0
3.0
2.0
4 LEDs OFF
1.0
0.0
3.0
3.2
3.4
3.6
3.8
4.0
4.0
3.0
2.0
4 LEDs OFF
1.0
0.0
4.2
-40
INPUT VOLTAGE [V]
Doc. No. 8755 Rev. A
5.0
4
0
40
80
TEMPERATURE [°C]
120
© 2005 Catalyst Semiconductor, Inc.
Characteristics subject to change without notice
CAT3614
TYPICAL CHARACTERISTICS
VIN = 3.6V, IOUT = 80mA (4 LEDs at 20mA), C1 = C2 = CIN = COUT = 1μF, TAMB = 25°C unless otherwise specified.
LED Current Change vs. Temperature
5.0
5.0
4.0
3.0
4.0
2.0
1.0
LED CURRENT CHANGE [%]
LED CURRENT CHANGE [%] .
LED Current Change vs. Input Voltage
1x Mode
0.0
-1.0
-2.0
1.5x Mode
-3.0
-4.0
3.0
2.0
1.0
0.0
-1.0
-2.0
-3.0
-4.0
-5.0
-5.0
3.0
3.2
3.4
3.6
3.8
4.0
4.2
-40
INPUT VOLTAGE [V]
Oscillator Frequency vs. Input Voltage
80
1.3
CLOCK FREQUENCY [MHz]
CLOCK FREQUENCY [MHz]
0
20
40
60
TEMPERATURE [°C]
Oscillator Frequency vs. Temperature
1.3
1.2
1.1
1.0
4 LEDs at 20mA
0.9
0.8
0.7
1.2
1.1
1.0
0.9
0.8
0.7
3.0
3.2
3.4
3.6
3.8
INPUT VOLTAGE [V]
4.0
-40
0
40
80
TEMPERATURE [°C]
120
Output Resistance vs. Input Voltage (1.5x mode)
4.0
Output Resistance vs. Input Voltage (1x mode)
OUTPUT RESISTANCE [Ω] .
1.0
OUTPUT RESISTANCE [Ω] .
-20
0.8
0.6
0.4
0.2
3.5
3.0
2.5
2.0
1.5
1.0
0.0
3.0
3.2 3.4 3.6 3.8 4.0
INPUT VOLTAGE [V]
© 2005 Catalyst Semiconductor, Inc.
Characteristics subject to change without notice
3.0
4.2
5
3.2 3.4 3.6 3.8 4.0
INPUT VOLTAGE [V]
4.2
Doc. No. 8755 Rev. A
CAT3614
TYPICAL CHARACTERISTICS
VIN = 3.6V, IOUT = 80mA (4 LEDs at 20mA), C1 = C2 = CIN = COUT = 1μF, TAMB = 25°C unless otherwise specified.
Power Up with 4 LEDs at 15mA (1x Mode)
Power Up with 4 LEDs at 15mA (1.5x Mode)
Enable Power Down Delay (1x Mode)
Enable Power Down Delay (1.5x Mode)
Switching Waveforms in 1.5x Mode
Operating Waveforms in 1x Mode
Doc. No. 8755 Rev. A
6
© 2005 Catalyst Semiconductor, Inc.
Characteristics subject to change without notice
CAT3614
TYPICAL CHARACTERISTICS
VIN = 3.6V, IOUT = 80mA (4 LEDs at 20mA), C1 = C2 = CIN = COUT = 1μF, TAMB = 25°C unless otherwise specified.
Enable and Output Current Dimming Waveforms
Line Transient Response (3.6V to 5.5V) 1x Mode
Enable High Minimum Program Time
vs. Temperature
Enable Low Minimum Program Time vs.
Temperature
200
200
MINIMUM TIME [nS] .
MINIMUM TIME [nS] .
VIN = 3.5V
160
VIN = 3.5V
120
80
VIN = 4.2V
40
160
120
VIN = 4.2V
80
40
0
0
-40
0
40
80
TEMPERATURE [°C]
-40
120
0
80
120
TEMPERATURE [°C]
Foldback Current Limit
Enable Voltage Threshold vs. Temperature
4.0
1.2
1.0
OUTPUT VOLTAGE [V]
ENABLE VOLTAGE [V]
40
0.8
0.6
0.4
0.2
0.0
3.5
3.0
1x Mode
2.5
VIN = 3.5V
2.0
1.5
1.0
0.5
0.0
-40
0
40
80
120
0
TEMPERATURE [°C]
© 2005 Catalyst Semiconductor, Inc.
Characteristics subject to change without notice
7
100
200
300
OUTPUT CURRENT [mA]
400
Doc. No. 8755 Rev. A
CAT3614
PIN DESCRIPTIONS
Pin #
1
2
3
4
5
6
7
8
9
10
11
12
TAB
Name
VIN
C1+
C1C2C2+
GND
LED1
LED2
LED3
LED4
EN/DIM
VOUT
TAB
Function
Supply voltage.
Bucket capacitor 1 terminal
Bucket capacitor 1 terminal
Bucket capacitor 2 terminal
Bucket capacitor 2 terminal
Ground reference
LED1 cathode terminal (if not used, connect to VOUT) (1)
LED2 cathode terminal (if not used, connect to VOUT)(1)
LED3 cathode terminal (if not used, connect to VOUT)(1)
LED4 cathode terminal (if not used, connect to VOUT)(1)
Device enable (active high) and dimming control input
Charge pump output connected to the LED anodes
Connect to GND on the PCB
PIN FUNCTION
VIN is the supply pin for the charge pump. A small
1µF ceramic bypass capacitor is required between the
VIN pin and ground near the device. The operating
input voltage range is from 2.2V to 5.5V. Whenever
the input supply falls below the undervoltage threshold
(2V) all LEDs channels will be automatically disabled.
VOUT is the charge pump output that is connected to
the LED anodes. A small 1µF 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.
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 1.3V and 0.4V
respectively. When EN/DIM is initially taken high,
the device becomes enabled and all LED currents
remain at 0mA. The falling edge of the first pulse
applied to EN/DIM sets all LED currents to their full
scale of 31mA.
C1+, C1- are connected to each side of the 1µF
ceramic bucket capacitor C1.
C2+, C2- are connected to each side of the 1µF
ceramic bucket capacitor C2.
LED1 to LED4 provide the internal regulated current
for each of the LED cathodes. These pins enter a high
impedance zero current state whenever the device is
placed in shutdown mode. In applications using less
than four LEDs, all unused channels should be wired
directly to VOUT. This ensures the channel is
automatically disabled dissipating less than 200µA.
On each consecutive falling edge of the pulse applied
to EN/DIM, the LED current is decreased by 1mA
step. On the 32nd pulse, the LED current is set to
zero. The next pulse on EN/DIM resets the current
back to their full scale of 31mA.
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.
To place the device into zero current shutdown mode,
the EN/DIM pin must be held low for 1.5ms or more.
Notes:
(1) LED1, LED2, LED3, LED4 pins should not be left floating. They should be connected to the LED cathode, or tied to VOUT pin if not used.
Doc. No. MD-5035, Rev.B
8
© Catalyst Semiconductor, Inc.
Characteristics subject to change without notice
CAT3614
BLOCK DIAGRAM
1µF
C1-
VIN
C1+
C2-
1µF
C2+
VOUT
1x mode (LDO)
1.5x Charge Pump
CIN
1µF
Mode Control
1MHz
Oscillator
EN/DIM
LED1
LED2
Reference
Voltage
LED3
LED4
Current
Setting DAC
LED Channel
Current Regulators
Serial
Interface
Registers
GND
Figure 2. CAT3614 Functional Block Diagram
BASIC OPERATION
At power-up, the CAT3614 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 LED
currents the device remains in 1x operating 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).
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 delay
of 400µs) into 1.5x mode.
© Catalyst Semiconductor, Inc.
Characteristics subject to change without notice
9
Doc. No. MD-5035, Rev.B
CAT3614
The driver enters a thermal shutdown mode as soon
as the die temperature exceeds about +165ºC. When
the device temperature drops down by about 20ºC,
the device resumes normal operation.
LED Current Setting
Figure 1 shows the timing diagram necessary at the
EN/DIM input for setting the LED currents.
The EN/DIM set up time requires the signal to be held
high for 10µs or longer to ensure the initialization of
the driver at power-up. Each subsequent pulse on the
EN/DIM (300ns to 200µs pulse duration) steps down
the LED current from full scale of 31mA to zero with a
1mA resolution. Consecutive pulses should be
separated by 300ns or longer. Pulsing beyond the
0mA level restores the current level back to full scale
and the cycle repeats. Pulsing frequencies from 5kHz
up to 1MHz can be supported during dimming
operations. When the EN/DIM is held low for 1.5ms or
more, the CAT3614 enters the shutdown mode and
draws “zero” current.
External Components
The driver requires a total of four external 1µF
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 1µF is sufficient. In 1x mode,
the device operating in linear mode does not introduce
switching noise back onto the supply.
Recommended Layout
In 1.5x charge pump mode, the driver switches
internally at a high frequency of 1MHz. 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
vias. A copper area matching the TDFN exposed pad
(GND) must be connected to the ground plane
underneath. The use of multiple vias improves the
package heat dissipation.
For applications with three LEDs or less, any unused
LED pins should be tied to VOUT, as shown on Figure 3.
Protection Mode
If an LED becomes open-circuit, the output voltage
VOUT is internally limited to about 5.5V. This is to
prevent the output pin from exceeding its absolute
maximum rating.
1µF
VIN
3V to CIN
5.5V
1µF
C1+
C1- C2+
VIN
C2-
COUT
CAT3614
C1+
VIN
VOUT
LED1
ENABLE/
DIMMING
1µF
1µF
1µF
3V to CIN
5.5V
1µF
1µF
C1- C2+
VIN
VOUT
LED1
ENABLE/
DIMMING
LED3
GND
LED4
Flash
LED
120mA
LED2
EN/DIM
LED3
GND
Figure 3. Three LED Application
Doc. No. MD-5035, Rev.B
COUT
1µF
CAT3614
LED2
EN/DIM
C2-
LED4
Figure 4. Single Flash LED Application
10
© Catalyst Semiconductor, Inc.
Characteristics subject to change without notice
CAT3614
PACKAGE OUTLINE DRAWING
TDFN 12-Pad 3 x 3mm (HV2) (1)(2)
D
A
e
b
L
E
E2
PIN#1 ID
PIN#1 INDEX AREA
A1
D2
SIDE VIEW
TOP VIEW
BOTTOM VIEW
A
A3
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
A1
FRONT VIEW
RECOMMENDED LAND PATTERN
R
e
M
N
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
P
E2
2.25 TYP
D2
Notes:
(1) All dimensions in millimeters.
(2) Compiles with JEDEC MO-229.
© Catalyst Semiconductor, Inc.
Characteristics subject to change without notice
11
Doc. No. MD-5035, Rev.B
CAT3614
EXAMPLE OF ORDERING INFORMATION (1)
Prefix
CAT
Device #
3614
Suffix
HV2
–
Product Number
3614
Optional
Company ID
G
T2
Lead Finish
G: NiPdAu
Blank: Matte-Tin(4)
Tape & Reel
T: Tape & Reel
2: 2000/Reel
Package
HV2: TDFN 3 x 3mm
Notes:
(1) All packages are RoHS-compliant (Lead-free, Halogen-free).
(2) The standard lead finish is NiPdAu.
(3) The device used in the above example is a CAT3614HV2-GT2 (TDFN, NiPdAu Plated Finish,Tape & Reel 2000).
(4) For additional package, please contact your nearest Catalyst Semiconductor Sales office.
Doc. No. MD-5035, Rev.B
12
© Catalyst Semiconductor, Inc.
Characteristics subject to change without notice
REVISION HISTORY
Date
Rev.
02/09/2006
00
07/21/2006
01
01/07/08
B
Reason
Initial Release
Update Typical Application Circuit
Update Pin Descriptions
Update Electrical Operating Characteristics
Add NiPdAu lead finish.
Add Extended Temperature Range.
Update Package Outline Drawing.
Add Example of Ordering Information.
Change document number from 25095 to MD-5035.
Copyrights, Trademarks and Patents
© Catalyst Semiconductor, Inc.
Trademarks and registered trademarks of Catalyst Semiconductor include each of the following:
Adaptive Analog™, Beyond Memory™, DPP™, EZDim™, LDD™, MiniPot™, Quad-Mode™ and Quantum Charge Programmable™
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applications intended to support or sustain life, or for any other application in which the failure of the Catalyst Semiconductor product could create a situation where
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Catalyst Semiconductor reserves the right to make changes to or discontinue any product or service described herein without notice. Products with data sheets labeled
"Advance Information" or "Preliminary" and other products described herein may not be in production or offered for sale.
Catalyst Semiconductor advises customers to obtain the current version of the relevant product information before placing orders. Circuit diagrams illustrate typical
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Santa Clara, CA 95054
Phone: 408.542.1000
Fax:
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0Hwww.catsemi.com
Document No: MD-5035
Revision:
B
Issue date:
01/07/08