CAT3616
6-Channel Charge Pump LED Driver with EZDimTM
FEATURES
6 LED channels with tight matching Independent Main and Sub 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 RoHS-compliant 16-pad TQFN 4mm x 4mm package
DESCRIPTION
The CAT3616 is a high efficiency 1x/1.5x fractional charge pump with programmable dimming current in six LED channels. To ensure uniform brightness in LCD backlight applications, each LED channel delivers an accurate regulated current. 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. Two groups of LEDs, main (MAIN1 to MAIN4) and sub (SUB1 and SUB2) are programmable through the ¯¯¯ ¯¯¯ ENM (active low) and ENS inputs. Independent current from 1mA to 31mA with a 1mA step are set by ¯¯¯ ¯¯¯ toggling the ENM and ENS inputs. The enable EN input pin allows to shutdown the device with zero quiescent current. The device is available in a 16-pad TQFN package with a max height of 0.8mm.
APPLICATION
Main and sub-display backlight Color LCD and keypad Backlighting Cellular Phones Handheld Devices Digital Cameras
ORDERING INFORMATION
Quantity Package Part Number Package per Reel Marking CAT3616HV4-T2 TQFN-16 (1) 2000 G616 (2) CAT3616HV4-GT2 TQFN-16 2000 CDAH
Notes: (1) Matte-Tin Plated Finish (RoHS-compliant). (2) NiPdAu Plated Finish (RoHS-compliant).
For Ordering Information details, see page 13.
PIN CONFIGURATION
TQFN 16-pad 4 x 4mm (Top view)
TYPICAL APPLICATION CIRCUIT
Note: Unused LED channels must be connected to VOUT.
© Catalyst Semiconductor, Inc. Characteristics subject to change without notice
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Doc. No. MD-5018 Rev. C
CAT3616
ABSOLUTE MAXIMUM RATINGS
Parameter VIN, LEDxx voltage VOUT, C1±, C2± voltage EN, ENM, ENS voltage ¯¯¯ ¯¯¯ Storage Temperature Range Junction Temperature Range Lead Temperature Rating 6 7 VIN + 0.7V -65 to +160 -40 to +150 300 Unit V V V ºC ºC ºC
RECOMMENDED OPERATING CONDITIONS
Parameter VIN Ambient Temperature Range ILED per LED pin IOUT Total Output Current Range 3 to 5.5 -40 to +85 0 to 31 0 to 150 Unit V ºC mA mA
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 IQ Quiescent Current Conditions 1x mode, all LEDs Off 1x mode, all LEDs On 1.5x mode, all LEDs Off VEN = 0V 1mA ≤ ILED ≤ 31mA (ILED - ILEDAVG) / ILEDAVG 1x mode, IOUT = 120mA 1.5x mode, IOUT = 120mA 0.8 VOUT < 0.5V 1x mode, VOUT > 1V -1 1.3 165 20 2 Min Typ 0.5 2.2 3.5 0 ±3 ±3 0.5 2.2 1 60 300 1.3 Max Unit mA mA mA µA mA % % Ω Ω MHz mA mA µA V V ºC ºC V
IQSHDN ILED ILED-ACC ILED-DEV ROUT FOSC ISC_MAX IIN_MAX IEN/DIM VHI VLO TSD THYS VUVLO
Shutdown Current LED Current Range with 6 LEDs LED Current Accuracy LED Channel Matching Output Resistance (open loop) Charge Pump Frequency Output short circuit Current Limit Input Current Limit EN/DIM Pin • Input Leakage • Logic High Level • Logic Low Level Thermal Shutdown Thermal Hysteresis Undervoltage lock out (UVLO) threshold
0
1 31
1 0.4
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© Catalyst Semiconductor, Inc. Characteristics subject to change without notice
CAT3616
¯¯¯¯ RECOMMENDED EN, ENM AND ¯¯¯¯ TIMING ENS
For 3V ≤ VIN ≤ 5.5V, over full ambient temperature range -40 to +125°C. Symbol TSETP TLO THI TOFF TD TDEC Parameter EN setup from shutdown Conditions Min 10 0.3 0.3 1.5 Typ Max 200 Unit µs µs µs ms µs µs
¯¯¯ ¯¯¯ ENM, ENS program low time ¯¯¯ ¯¯¯ ENM, ENS program high time EN low time to shutdown LED current enable LED current decrement
40 0.1
Figure 1. Enable LED Timing Diagram
© Catalyst Semiconductor, Inc.
Characteristics subject to change without notice
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Doc. No. MD-5018 Rev. C
CAT3616
TYPICAL CHARACTERISTICS VIN = 3.6V, IOUT = 90mA (6 LEDs at 15mA), EN = VIN, ENM = ENS = GND, CIN = C1 = C2 = COUT = 1µF, ¯¯¯ ¯¯¯ TAMB = 25ºC, unless otherwise specified. Efficiency vs. Input Voltage (6 LEDs on)
100 90 EFFICIENCY [%]
EFFICIENCY [%]
Efficiency vs. Total LED Current (6 LEDs)
100 90 80 70 60 50 40 VIN = 3.2V (1.5x mode) VIN = 4V (1x mode)
1x Mode
15mA per LED
80 70 60 50 40 4.2 4.0 3.8 3.6 3.4 3.2 INPUT VOLTAGE [V] 3.0 20mA per LED 1.5x Mode
0
50 100 150 200 TOTAL LED CURRENT [mA]
Quiescent Current vs. Input Voltage (1x Mode)
QUIESCENT CURRENT [mA] 0.8 0.6 0.4 0.2 6 LEDs OFF 0 3.0 3.2 3.4 3.6 3.8 4.0 INPUT VOLTAGE [V] 4.2
Quiescent Current vs. Temperature (1x Mode)
QUIESCENT CURRENT [mA]. 0.8 0.6 0.4 0.2 6 LEDs OFF 0.0 -40 0 40 80 TEMPERATURE [°C] 120
Quiescent Current vs. Input Voltage (1.5x Mode)
QUIESCENT CURRENT [mA]. 5 4 3 2 1 6 LEDs OFF 0 3.0 3.2 3.4 3.6 3.8 4.0 INPUT VOLTAGE [V] 4.2
Quiescent Current vs. Temperature (1.5x Mode)
QUIESCENT CURRENT [mA]. 5 4 3 2 1 0 -40 0 40 80 TEMPERATURE [°C] 120 6 LEDs OFF
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© Catalyst Semiconductor, Inc. Characteristics subject to change without notice
CAT3616
TYPICAL CHARACTERISTICS VIN = 3.6V, IOUT = 90mA (6 LEDs at 15mA), EN = VIN, ENM = ENS = GND, CIN = C1 = C2 = COUT = 1µF, ¯¯¯ ¯¯¯ TAMB = 25ºC, unless otherwise specified. LED Current Change vs. Input Voltage
5.0 4.0 3.0 2.0 1.0 0.0 -1.0 -2.0 -3.0 -4.0 -5.0 LED CURRENT CHANGE [%] .
LED Current Change vs. Temperature
5.0 4.0 3.0 2.0 1.0 0.0 -1.0 -2.0 -3.0 -4.0 -5.0 -40 -20 0 20 40 60 TEMPERATURE [°C] 80 LED CURRENT CHANGE [%]
1x Mode
1.5x Mode
3.0
3.2 3.4 3.6 3.8 4.0 INPUT VOLTAGE [V]
4.2
Oscillator Frequency vs. Input Voltage
CLOCK FREQUENCY [MHz] . 1.3 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
Oscillator Frequency vs. Temperature
CLOCK FREQUENCY [MHz] . 1.3 1.2 1.1 1.0 0.9 0.8 0.7 -40 0 40 80 TEMPERATURE [°C] 120
Output Resistance vs. Input Voltage (1x Mode)
OUTPUT RESISTANCE [Ω] . 1.0
Output Resistance vs. Input Voltage(1.5x Mode)
4.0 OUTPUT RESISTANCE [Ω] . 3.5 3.0 2.5 2.0 1.5 1.0 3.0 3.2 3.4 3.6 3.8 4.0 INPUT VOLTAGE [V] 4.2
0.8 0.6 0.4 0.2 0.0 3.0 3.2 3.4 3.6 3.8 4.0 4.2 INPUT VOLTAGE [V]
© Catalyst Semiconductor, Inc.
Characteristics subject to change without notice
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Doc. No. MD-5018 Rev. C
CAT3616
TYPICAL CHARACTERISTICS VIN = 3.6V, IOUT = 90mA (6 LEDs at 15mA), EN = VIN, ENM = ENS = GND, CIN = C1 = C2 = COUT = 1µF, ¯¯¯ ¯¯¯ TAMB = 25ºC, unless otherwise specified. Power Up with 6 LEDs at 15mA (1x Mode) Power Up with 6 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
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© Catalyst Semiconductor, Inc. Characteristics subject to change without notice
CAT3616
TYPICAL CHARACTERISTICS VIN = 3.6V, IOUT = 90mA (6 LEDs at 15mA), EN = VIN, ENM = ENS = GND, CIN = C1 = C2 = COUT = 1µF, TAMB ¯¯¯ ¯¯¯ = 25ºC, unless otherwise specified. ENM, ENS and Output Current Dimming ¯¯¯ ¯¯¯ Line Transient Response (3.6V to 5.5V) 1x Mode
Foldback Current Limit
4.0 OUTPUT VOLTAGE [V] 3.5 3.0 2.5 2.0 1.5 1.0 0.5 0.0 0 100 200 300 OUTPUT CURRENT [mA] 400 1x Mode
© Catalyst Semiconductor, Inc.
Characteristics subject to change without notice
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Doc. No. MD-5018 Rev. C
CAT3616
PIN DESCRIPTIONS
Pin # 1 2 3 4 5 6 7, 8 9, 10 11 12 13 14 15 16 TAB Name MAIN1 Function MAIN1 LED cathode terminal (if not used, connect to VOUT)1 Enable main LED (MAIN1 to MAIN4) input. Active low Enable sub LED (SUB1, SUB2) input. Active low Device enable input. Active high. Charge pump output connected to the LED anodes Supply voltage. Bucket capacitor 1 terminal Bucket capacitor 2 terminal Ground reference SUB2 LED cathode terminal (if not used, connect to VOUT)1 SUB1 LED cathode terminal (if not used, connect to VOUT)1 MAIN4 LED cathode terminal (if not used, connect to VOUT)1 MAIN3 LED cathode terminal (if not used, connect to VOUT)1 MAIN2 LED cathode terminal (if not used, connect to VOUT)1 Connect to Ground on PCB
¯¯¯ ENM ¯¯¯ ENS EN VOUT VIN C1-, C1+ C2-, C2+ GND SUB2 SUB1 MAIN4 MAIN3 MAIN2 TAB
Note: (1) MAIN1 to MAIN4, SUB1, SUB2 pins should not be left floating. They should be connected to the LED cathode, or tied to VOUT pin if not used.
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 up to 5.5V. When the input supply falls below the undervoltage threshold (2V), all LED channels are disabled. EN is the enable logic input. Logic level for high and low are set at 1.3V and 0.4V respectively. When EN is initially taken high, the device becomes enabled and all LED currents remain at 0mA. To place the device into zero current shutdown mode, the EN pin must be held low for 1.5ms or more. 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 1μF ceramic bucket capacitor C1. C2+, C2- are connected to each side of the 1μF ceramic bucket capacitor C2. MAIN1-4, SUB1-2 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 six LEDs, the unused channels should be wired directly to VOUT. This ensures the channel is automatically disabled dissipating less than 200µA. 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.
¯¯¯ ¯¯¯ ENM, ENS are the active low enable/ dimming control logic inputs for respectively main and sub LED channels. The falling edge of the first pulse applied to ¯¯¯ ¯¯¯ ENM and ENS sets the current for respectively the main and sub LED channels to their full scale of 31mA. On each consecutive falling edge of the pulse ¯¯¯ ¯¯¯ applied to ENM and ENS, the LED current is decreased by 1mA step. On the 32nd pulse, the LED current is set to zero. The next pulse resets the current back to the full scale of 31mA.
VOUT is the charge pump output that is connected to the LED anodes. A small 1μF ceramic bypass capacitor
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© Catalyst Semiconductor, Inc. Characteristics subject to change without notice
CAT3616
BLOCK DIAGRAM
Figure 2. CAT3616 Functional Block Diagram
BASIC OPERATION
At power-up, the CAT3616 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. If the input voltage is insufficient or falls to a level where the regulated currents cannot be maintained, the device automatically switches (after 400µs) 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 pin).
© Catalyst Semiconductor, Inc.
Characteristics subject to change without notice
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Doc. No. MD-5018 Rev. C
CAT3616
LED CURRENT SETTING
The LED current is controlled by toggling the input ¯¯¯ ¯¯¯ ¯¯¯ signals ENM and ENS. ENM controls the four LED ¯¯¯ channels MAIN1 to MAIN4. ENS controls the two LED ¯¯¯ ¯¯¯ lines SUB1 and SUB2. ENM and ENS work the same way. The chip must first be enabled by setting the ¯¯¯ ¯¯¯ enable input EN high. On the first ENM or ENS transition from high to low, the LED current in the associated LEDs is set to the full scale 31mA. On ¯¯¯ ¯¯¯ each consecutive falling edge of ENM or ENS, the LED current is decreased by 1mA. On the 32nd pulse, the LED channel is turned off and the current drops to ¯¯¯ ¯¯¯ 0mA. One additional ENM or ENS pulse resets the full current to 31mA, as shown on Figure 1. Consecutive pulses should be separated by 300ns or more. Pulsing frequencies from 5kHz up to 1MHz are supported during dimming operations. When the EN is held low for 1.5ms or more, the CAT3616 enters the shutdown mode and draws “zero” current. When the ¯¯¯ ¯¯¯ enable EN input is low, toggling ENM or ENS has no effect. Unused LED channels can be disabled independently by connecting the corresponding main or sub LED pin to VOUT. 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. 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. 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 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.
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© Catalyst Semiconductor, Inc. Characteristics subject to change without notice
CAT3616
APPLICATION INFORMATION
Single wire Dimming Application The dimming control can be achieved through a single wire interface by connecting together all three logic ¯¯¯ ¯¯¯ input signals EN, ENM and ENS as shown on Figure 3. The common enable signal is set high to enable the driver. On the first negative going pulse, the LEDs turn full on. The pulse low state duration (between the falling and rising edges) must be shorter than 0.5msec. Any consecutives pulses reduce the LED current by 1mA. The enable signal is kept low for more than 1.5msec to turn off all the LED channels and set the driver in shutdown mode, as shown on Figures 4.
Figure 3. Single Wire Dimming Control
Figure 4. Single Enable Timing Diagram
© Catalyst Semiconductor, Inc.
Characteristics subject to change without notice
11
Doc. No. MD-5018 Rev. C
CAT3616
PACKAGE OUTLINE DRAWING
TQFN 16-Pad 4 x 4mm (HV4)
(1)(2)
D
A DETAIL A
E
E2
PIN#1 ID D2
PIN#1 INDEX AREA
A1 SIDE VIEW
TOP VIEW
BOTTOM VIEW
SYMBOL
MIN
NOM
MAX
b
e
A A1 A3 b D D2 E E2 e L
0.70 0.00 0.25 3.90 2.00 3.90 2.00 0.45
0.75 0.02 0.20 REF 0.30 4.00 – 4.00 – 0.65 BSC –
0.80 0.05 0.35 4.10 2.25 4.10 2.25 0.65
A1 FRONT VIEW A3 A L DETAIL A
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-220.
Doc. No. MD-5018 Rev. C
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© Catalyst Semiconductor, Inc. Characteristics subject to change without notice
CAT3616
EXAMPLE OF ORDERING INFORMATION 1
Prefix CAT
Device # 3616
Suffix HV4 – G T2
Product Number 3616 Optional Company ID Package HV4: TQFN 4 x 4mm
Lead Finish G: NiPdAu Blank: Matte-Tin(4)
Tape & Reel T: Tape & Reel 2: 2,000/Reel
For Product Top Mark Codes, click here: http://www.catsemi.com/techsupport/producttopmark.asp
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 CAT3616HV4-GT2 (TQFN, NiPdAu Plated Finish, Tape & Reel, 2,000/Reel). (4) For Matte-Tin package option, please contact your nearest Catalyst Semiconductor Sales office.
© Catalyst Semiconductor, Inc.
Characteristics subject to change without notice
13
Doc. No. MD-5018 Rev. C
REVISION HISTORY
Date 20-July-06 07-Jan-08 Rev. A B Reason Initial Issue Add NiPdAu lead finish Add Extended Temperature range Update Package Outline Drawing Update Example of Ordering Information Add “MD-” to Document Number Update Package Outline Drawing Add Top Mark Code Link
30-May-08
C
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Document No: MD-5018 Revision: C Issue date: 05/30/2008