Catalyst CAT3644 0710 4-channel ultra high efficiency quad-modeâ ¢ led driver Datasheet

CAT3644
4-Channel Ultra High Efficiency Quad-Mode™
LED Driver
DESCRIPTION
FEATURES
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The CAT3644 is a high efficiency Quad-ModeTM
fractional charge pump that can drive up to four LEDs
programmable by a one wire digital interface. The
inclusion of a 1.33x fractional charge pump mode
increases device efficiency by up to 10% over tradi–
tional 1.5x charge pumps with no added external
capacitors.
High efficiency 1.33x charge pump
Quad-mode charge pump: 1x, 1.33x, 1.5x, 2x
Drives up to 4 LEDs at 25mA each
1-wire EZDim™ LED current programming
Power efficiency up to 92%
Low noise input ripple in all modes
“Zero” current shutdown mode
Soft start and current limiting
Short circuit protection
Thermal shutdown protection
3mm x 3mm, 16-pad TQFN package
Low noise input ripple is achieved by operating at a
constant switching frequency which allows the use of
small external ceramic capacitors. The multi-fractional
charge pump supports a wide range of input voltages
from 2.5V to 5.5V.
The EN/DIM logic input functions as a chip enable and
a digital dimming interface for current setting of all
LEDs. Six different current ratios are available via the
interface.
APPLICATION
„
„
„
„
LCD Display Backlight
Cellular Phones
Digital Still Cameras
Handheld Devices
The device is available in the tiny 16-pad TQFN
3mm x 3mm package with a max height of 0.8mm.
TM
Catalyst Semiconductor’s Quad-Mode 1.33x charge
pump switching architecture is patented.
ORDERING INFORMATION
Part Number
Qty per Reel
Marking
(1)
2000
2000 (2)
CAT3644HV3-T2
CAT3644HV3-GT2
JAAG
JAAH
For Ordering Information details, see page 13.
Notes: (1) Matte-Tin Plated Finish (RoHS-compliant)
(2) NiPdAu Plated Finish (RoHS-compliant)
PIN CONFIGURATION
TYPICAL APPLICATION CIRCUIT
Top View
LED1
GND
NC
NC
1µF
16
15
14
13
LED2
1
12 C2-
LED3
2
11 C2+
LED4
RSET
3
10 C1-
4
C1+
VIN
2.4V
to
5.5V
CIN
9 C1+
5
6
7
8
EN/DIM
VOUT
NC
VIN
© Catalyst Semiconductor, Inc.
Characteristics subject to change without notice
4.02kΩ
1
VIN
1µF
1-Wire
EZDimTM
Programming
C1- C2+
1µF
C2VOUT
CAT3644
VOUT
COUT
1µF
LED1
EN/DIM
LED2
RSET
LED3
GND
20mA
LED4
Doc. No. MD-5023, Rev. E
CAT3644
ABSOLUTE MAXIMUM RATINGS
Parameter
VIN, LEDx, C1±, C2±, EN/DIM voltage
VOUT voltage
Storage Temperature Range
Junction Temperature Range
Rating
6
7
-65 to +160
-40 to +150
Unit
V
V
°C
°C
Rating
2.5 to 5.5
-40 to +85
up to 30
1.3 to 4.3
Unit
V
°C
mA
V
RECOMMENDED OPERATING CONDITIONS
Parameter
VIN
Ambient Temperature Range
ILED per LED pin
LED Forward Voltage Range
Typical application circuit with external components is shown on page 1.
ELECTRICAL OPERATING CHARACTERISTICS
(over recommended operating conditions unless specified otherwise) VIN = 3.6V, EN = High, TAMB = 25°C
Symbol
Name
Conditions
1x mode, no load
1.33 x mode, no load
1.5x mode, no load
2x mode, no load
VEN = 0V
IQ
Quiescent Current
IQSHDN
Shutdown Current
ILED-ACC
LED Current Accuracy
(ILEDAVG – INOMINAL) / INOMINAL
RSET = 5kΩ
ILED-DEV
LED Channel Matching
(ILED - ILEDAVG) / ILEDAVG
VRSET
RSET Regulated Voltage
ROUT
Output Resistance (open loop)
FOSC
Charge Pump Frequency
ISC_MAX
Output short circuit Current Limit
IIN_MAX
VHYS
Input Current Limit
1x to 1.33x or 1.33x to 1.5x or 1.5x to 2x
Transition Thresholds at any LED pin
1x Mode Transition Hysteresis
TDF
Transition Filter Delay
LEDTH
REN/DIM
VHI
VLO
Min
0.8
1
VOUT > 1V
EN/DIM Pin
• Internal Pull-down Resistor
• Logic High Level
• Logic Low Level
Max
1
0.58
1x mode
1.33x mode, VIN = 3V
1.5x mode, VIN = 2.7V
2x mode, VIN = 2.4V
1.33x and 2x mode
1.5x mode
VOUT < 0.5V
Typ
1.0
1.7
2.2
2.4
Units
mA
mA
mA
mA
µA
±2
%
±1.5
%
0.6
0.8
5
5
10
1
1.3
50
0.62
1.3
1.6
V
Ω
Ω
Ω
Ω
MHz
MHz
mA
250
mA
130
mV
400
mV
500
µs
100
kΩ
V
V
1.3
0.4
TSD
Thermal Shutdown
150
°C
THYS
Thermal Hysteresis
20
°C
VUVLO
Undervoltage lockout (UVLO) threshold
Doc. No. MD-5023, Rev. E
1.6
2
1.8
2.0
V
© Catalyst Semiconductor, Inc.
Characteristics subject to change without notice
CAT3644
RECOMMENDED EN/DIM TIMING
For 2.4V ≤ VIN ≤ 5.5V, over full ambient temperature range -40ºC to +85ºC.
Symbol
Name
Conditions
TSETUP
EN/DIM setup from shutdown
10
TLO
EN/DIM program low time
0.2
THI
EN/DIM program high time
0.2
μs
TPWRDWN
EN/DIM low time to shutdown
1.5
ms
TLED
LED current settling time
TSETUP
Min
Typ
Max
Units
μs
100
40
μs
μs
TPWRDWN
THI
EN/DIM
TLED
TLO
100%
100%
50%
LED
Current
25%
Shutdown
12.5% 6.25%
3.12%
Shutdown
Figure 1. EN/DIM Digital Dimming Timing Diagram
LED Current Setting
The nominal LED current is set by the external
resistor connected between the RSET pin and
ground. Table 1 lists standard resistor values for
several LED current settings.
LED current (mA)
RSET (kΩ)
2
40.0
5
15.8
10
7.87
15
5.23
20
4.02
25
3.16
30
2.67
Table 1. Resistor RSET and LED current
© Catalyst Semiconductor, Inc.
Characteristics subject to change without notice
3
Doc. No. MD-5023, Rev. E
CAT3644
TYPICAL PERFORMANCE CHARACTERISTICS
VIN = 3.6V, IOUT = 80mA (4 LEDs at 20mA), CIN = COUT = C1 = C2 = 1μF, TAMB = 25°C unless otherwise specified.
Efficiency vs. Input Voltage
100
VF = 3.3V
100
1.33x
1.5x
90
1x
80
2x
70
60
40
4.2
2.0
4.0 3.8 3.6 3.4 3.2
INPUT VOLTAGE [V]
3.0
Quiescent Current vs. Temperature
4.0
4.0
VF = 3.3V
QUIESCENT CURRENT [mA]
QUIESCENT CURRENT [mA]
60
40
Quiescent Current vs. Input Voltage
3.0
2.0
1.0
LEDs Off
0.0
2x
2.0
1.0
1x
0.0
0
40
80
TEMPERATURE [°C]
120
LED Current Change vs. Temperature
LED CURRENT VARIATION [%] .
VF = 3.3V
10
8
6
4
2
VF = 3.3V
0
-2
-4
-6
-8
-10
-40
2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5
INPUT VOLTAGE [V]
Doc. No. MD-5023, Rev. E
1.33x
-40
LED Current Change vs. Input Voltage
10
8
6
4
2
0
-2
-4
-6
-8
-10
1.5x
3.0
5.5 5.0 4.5 4.0 3.5 3.0 2.5 2.0
INPUT VOLTAGE [V]
LED CURRENT VARIATION [%] .
1.33x
70
50
4.0
3.5
3.0
2.5
INPUT VOLTAGE [V]
1x
80
50
4.5
VF = 3.3V
90
EFFICIENCY [%]
EFFICIENCY [%]
Efficiency vs. Li-Ion Voltage
4
0
40
80
TEMPERATURE [°C]
120
© Catalyst Semiconductor, Inc.
Characteristics subject to change without notice
CAT3644
TYPICAL PERFORMANCE CHARACTERISTICS
VIN = 3.6V, IOUT = 80mA (4 LEDs at 20mA), CIN = COUT = C1 = C2 = 1μF, TAMB = 25°C unless otherwise specified.
Output Resistance vs. Input Voltage
12
1.3
1.2
OUTPUT RESISTANCE [Ω] .
SWITCHING FREQUENCY [MHz]
Switching Frequency vs. Temperature
1.5x Mode
1.1
1.0
0.9
1.33x, 2x Mode
0.8
0.7
-40
0
40
80
TEMPERATURE [°C]
2x
10
8
6
4
2
1.33x
1.5x
1x
0
2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5
INPUT VOLTAGE [V]
120
Power Up in 1x Mode
Power Up in 1.33x Mode
Power Up in 1.5x Mode
Power Up in 2x Mode
© Catalyst Semiconductor, Inc.
Characteristics subject to change without notice
5
Doc. No. MD-5023, Rev. E
CAT3644
TYPICAL PERFORMANCE CHARACTERISTICS
VIN = 3.6V, IOUT = 80mA (4 LEDs at 20mA), CIN = COUT = C1 = C2 = 1μF, TAMB = 25°C unless otherwise specified.
Power Up Delay (1x Mode)
Power Down Delay (1x Mode)
Operating Waveforms in 1x Mode
Switching Waveforms in 1.33x Mode
Switching Waveforms in 1.5x Mode
Switching Waveforms in 2x Mode
Doc. No. MD-5023, Rev. E
6
© Catalyst Semiconductor, Inc.
Characteristics subject to change without notice
CAT3644
TYPICAL PERFORMANCE CHARACTERISTICS
VIN = 3.6V, IOUT = 80mA (4 LEDs at 20mA), CIN = COUT = C1 = C2 = 1μF, TAMB = 25°C unless otherwise specified.
LED Current vs. LED Pin Voltage
Foldback Current Limit
40
1x Mode
3.5
LED CURRENT [mA]
OUTPUT VOLTAGE [V]
4.0
3.0
2.5
2.0
1.5
1.0
0.5
0.0
30
20
10
0
0
100
200
300
OUTPUT CURRENT [mA]
400
0
Dimming Waveform
50 100 150 200 250
LED PIN VOLTAGE [mV]
300
LED Current vs. RSET
LED CURRENT [mA]
50
40
30
20
10
0
1
© Catalyst Semiconductor, Inc.
Characteristics subject to change without notice
7
10
RSET RESISTANCE [kΩ]
100
Doc. No. MD-5023, Rev. E
CAT3644
PIN DESCRIPTION
Pin #
Name
Function
1
LED2
LED2 cathode terminal.
2
LED3
LED3 cathode terminal.
3
LED4
LED4 cathode terminal.
4
RSET
Connect resistor RSET to set the LED current.
5
EN/DIM
6
VOUT
7
NC
Not connected inside the package.
8
VIN
Charge pump input, connect to battery or supply.
9
C1+
Bucket capacitor 1 Positive terminal
10
C1-
Bucket capacitor 1 Negative terminal
11
C2+
Bucket capacitor 2 Positive terminal
12
C2-
Bucket capacitor 2 Negative terminal
13
NC
Not connected inside the package.
14
NC
Not connected inside the package.
15
GND
Ground Reference
16
LED1
LED1 cathode terminal.
TAB
GND
Connect to GND on the PCB.
Device enable (active high) and Dimming Control.
Charge pump output connected to the LED anodes.
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 2.5V to 5.5V. Whenever
the input supply falls below the under-voltage
threshold (1.8V), all the LED channels are disabled
and the device enters shutdown mode.
C1+, C1- are connected to each side of the ceramic
bucket capacitor C1.
C2+, C2- are connected to each side of the ceramic
bucket capacitor C2.
LED1 to LED4 provide the internal regulated current
source for each of the LED cathodes. These pins
enter high-impedance zero current state whenever the
device is placed in 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 1.3V and 0.4V respectively. When EN/DIM
is initially taken high, the device becomes enabled
and all LED currents are 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 at least 1.5ms.
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.
RSET is connected to the resistor (RSET) to set the full
scale current for the LEDs. The voltage at this pin
regulated to 0.6V. The ground side of the external
resistor should be star connected back to the GND of
the PCB. In shutdown mode, RSET beomes high
impedance.
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.
Doc. No. MD-5023, Rev. E
8
© Catalyst Semiconductor, Inc.
Characteristics subject to change without notice
CAT3644
BLOCK DIAGRAM
C1-
VIN
C1+
C2-
C2+
VOUT
1x mode (LDO)
4/3x, 3/2x, 2x Charge Pump
Mode Control
1, 1.3MHz
Oscillator
EN/DIM
LED1
100kΩ
LED2
Serial
Interface
Reference
Voltage
Registers
Current
Setting DAC
LED3
LED4
LED Channel
Current Regulators
RSET
GND
Figure 2. CAT3644 Functional Block Diagram
BASIC OPERATION
At power-up, the CAT3644 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.
This sequence repeats in the 1.33x and 1.5x mode until
the driver enters the 2x mode. In 1.5x mode, the output
voltage is approximately equal to 1.5 times the input
supply voltage. While in 2x mode, the output is
approximately equal to 2 times the input supply voltage.
If the device detects a sufficient input voltage is present
to drive all LED currents in 1x mode, it will change
automatically back to 1x mode. This only applies for
changing back to the 1x mode. The difference between
the input voltage when exiting 1x mode and returning to
1x mode is called the 1x mode transition hysteresis
(VHYS) and is about 500mV.
If the input voltage is insufficient or falls to a level
where the regulated currents cannot be maintained,
the device automatically switches into 1.33x mode
(after a fixed delay time of about 400μs). In 1.33x
mode, the output voltage is approximately equal to
1.33 times the input supply voltage (less any internal
voltage losses).
© Catalyst Semiconductor, Inc.
Characteristics subject to change without notice
9
Doc. No. MD-5023, Rev. E
CAT3644
LED Current Selection
At power-up, the initial LED current is set to full scale
(100% brightness) by the external resistor RSET as
follows:
0 .6 V
LED current = 132 ×
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
TSETUP
levels by pulsing the input signal, as shown on Figure 3.
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 TLO may be ignored and filtered by the device.
Pulses longer than the maximum TLO may shutdown the
device.
The LED driver enters a “zero current” shutdown mode
if EN/DIM is held low for 1.5ms or more.
TPWRDWN
THI
EN/DIM
TLED
TLO
100%
100%
50%
LED
Current
25%
Shutdown
12.5% 6.25%
3.12%
Shutdown
Figure 3. EN/DIM Digital Dimming Timing Diagram
Table 1. LED Current Dimming Levels
EN/DIM
# of pulses *
RSET Gain
LED Current
EN = High
132
132 × 0.6 V R SET
st
66
66 × 0.6 V R SET
nd
1
33
33 × 0.6 V R SET
rd
16.5
16.5 × 0.6 V R SET
4
th
8.25
8.25 × 0.6 V R SET
5
th
4.125
4.125 × 0.6 V R SET
6
th
132
132 × 0.6 V R SET
th
Device cycling through gain selection
GAIN × 0.6 V R SET
2
3
x
* The gain is changed on the rising edges of the EN/DIM input.
Doc. No. MD-5023, Rev. E
10
© Catalyst Semiconductor, Inc.
Characteristics subject to change without notice
CAT3644
Unused LED Channels
External Components
For applications not requiring all the channels, it is
recommended the unused LED pins be tied directly to
VOUT (see Figure 4).
The driver requires four external 1μF ceramic capacitors for decoupling input, output, and for the charge
pump. Both capacitors type X5R and X7R are
recommended for the LED driver application. In all
charge pump modes, the input current ripple is kept
very low by design and an input bypass capacitor of
1μF is sufficient.
1µF
C1+
VIN
CIN
C2VOUT
COUT
1µF
ENABLE
DIMMING
C1- C2+
VIN
1µF
CAT3644
LED1
EN/DIM
LED2
RSET
LED3
GND
RSET
1µF
In 1x mode, the device operates in linear mode and
does not introduce switching noise back onto the
supply.
Recommended Layout
LED4
In charge pump mode, the driver switches internally at
a high frequency. 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 TQFN
exposed pad (TAB) must be connected to the ground
plane underneath. The use of multiple via improves
the package heat dissipation.
Figure 4. Application with 3 LEDs
Protection Mode
If an LED is disconnected, the driver senses that and
automatically ignores that channel. When all LEDs are
disconnected, the driver goes to 1x mode where the
output is equal to the input voltage.
GND
As soon as the output exceeds about 6V, the driver
resets itself and reevaluate the mode.
If the die temperature exceeds +150°C, the driver will
enter a thermal protection shutdown mode. When the
device temperature drops by about 20°C, the device
will resume normal operation.
Pin1
C2
LED Selection
LEDs with forward voltages (VF) ranging from 1.3V to
4.3V may be used. Selecting LEDs with lower VF is
recommended in order to improve the efficiency by
keeping the driver in 1x mode longer as the battery
voltage decreases.
EN/DIM
VIN
GND
For example, if a white LED with a VF of 3.3V is
selected over one with VF of 3.5V, the driver will stay
in 1x mode for lower supply voltage of 0.2V. This
helps improve the efficiency and extends battery life.
© Catalyst Semiconductor, Inc.
Characteristics subject to change without notice
C1
RSET
COUT
CIN
GND
Figure 5. Recommended Layout
11
Doc. No. MD-5023, Rev. E
CAT3644
PACKAGE OUTLINE DRAWING
TQFN 16-Pad 3 x 3mm (HS3, HV3) (1)(2)
A
D
e
b
L
E
E2
PIN#1 ID
PIN#1 INDEX AREA
A1
TOP VIEW
SIDE 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
1.40
–
1.80
E
2.90
3.00
3.10
E2
1.40
–
1.80
e
L
D2
BOTTOM VIEW
A
A1
A3
FRONT VIEW
0.50 BSC
0.30
0.40
0.50
For current Tape and Reel information, download the PDF file from:
http://www.catsemi.com/documents/tapeandreel.pdf.
Notes:
(1) All dimensions are in millimeters.
(2) Complies with JEDEC standard MO-229.
Doc. No. MD-5023, Rev. E
12
© Catalyst Semiconductor, Inc.
Characteristics subject to change without notice
CAT3644
EXAMPLE OF ORDERING INFORMATION
Prefix
CAT
Device #
3644
(1)
Suffix
HV3
-G
Product Number
Optional
Company ID
Package
HV3: TQFN
T2
Lead Finish
Blank: Matte-Tin
G: NiPdAu
Tape & Reel
T: Tape & Reel
2: 2000/Reel
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 CAT3644HV3-GT2 (TQFN, NiPdAu, Tape & Reel).
(4) For additional package and temperature options, please contact your nearest Catalyst Semiconductor Sales office.
© Catalyst Semiconductor, Inc.
Characteristics subject to change without notice
13
Doc. No. MD-5023, Rev. E
REVISION HISTORY
Date
01/29/2007
Rev.
A
02/26/2007
B
06/15/2007
C
07/25/2007
D
10/16/2007
E
Reason
Initial Release
Electrical Operating Characteristics – Add the pull-down resistor value 100kΩ
Block Diagram – Add a 100kΩ pull-down resistor
Updated Example of Ordering Information
Added MD- to document number
Added RSET in Absolute Maximum Ratings table
Updated Recommended Operating Condition table
Updated Electrical Operating Characteristics table
Added LED Current section
Updated Package Outline Drawing
Update Description
Update Absolute Maximum Ratings
Update Updated Package Outline Drawing
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™
Catalyst Semiconductor has been issued U.S. and foreign patents and has patent applications pending that protect its products.
CATALYST SEMICONDUCTOR MAKES NO WARRANTY, REPRESENTATION OR GUARANTEE, EXPRESS OR IMPLIED, REGARDING THE SUITABILITY OF ITS
PRODUCTS FOR ANY PARTICULAR PURPOSE, NOR THAT THE USE OF ITS PRODUCTS WILL NOT INFRINGE ITS INTELLECTUAL PROPERTY RIGHTS OR THE
RIGHTS OF THIRD PARTIES WITH RESPECT TO ANY PARTICULAR USE OR APPLICATION AND SPECIFICALLY DISCLAIMS ANY AND ALL LIABILITY ARISING
OUT OF ANY SUCH USE OR APPLICATION, INCLUDING BUT NOT LIMITED TO, CONSEQUENTIAL OR INCIDENTAL DAMAGES.
Catalyst Semiconductor 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 Catalyst Semiconductor product could create a situation where personal
injury or death may occur.
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
semiconductor applications and may not be complete.
Catalyst Semiconductor, Inc.
Corporate Headquarters
2975 Stender Way
Santa Clara, CA 95054
Phone: 408.542.1000
Fax:
408.542.1200
www.catsemi.com
Document No: MD-5023
Revision:
E
Issue date:
10/16/07
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