CAT3616 6-Channel Charge Pump LED Driver with EZDimTM DESCRIPTION FEATURES 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. 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-lead Thin QFN 4mm x 4mm 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. Two groups of LEDs, main (MAIN1 to MAIN4) and sub (SUB1 and SUB2) are programmable through the ¯¯¯ (active low) and ENS ¯¯¯ inputs. Independent ENM current from 1mA to 31mA with a 1mA step are set by ¯¯¯ and ENS ¯¯¯ inputs. The enable EN toggling the ENM input pin allows to shutdown the device with zero quiescent current. APPLICATION Main and sub-display backlight Color LCD and keypad Backlighting Cellular Phones Handheld Devices Digital Cameras The device is available in a 16-lead thin QFN package with a max height of 0.8mm. ORDERING INFORMATION Part Number Package CAT3616HV4 Thin QFN-16 Green* Quantity per Reel 2000 Package Marking G616 *Lead Finish Matte-Tin For Ordering Information details, see page 13. PIN CONFIGURATION TYPICAL APPLICATION CIRCUIT TQFN 16-lead 4x4mm (Top view) Note: Unused LED channels must be connected to VOUT. © 2006 Catalyst Semiconductor, Inc. Characteristics subject to change without notice 1 Doc. No. 5018 Rev. A 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 +125 300 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 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 Doc. No. 5018 Rev. A Conditions 1x mode, all LEDs Off 1x mode, all LEDs On 1.5x mode, all LEDs Off VEN = 0V Min Typ 0.5 2.2 3.5 0 1mA ≤ ILED ≤ 31mA (ILED - ILEDAVG) / ILEDAVG ±3 ±3 Unit mA mA mA µA mA % % 1x mode, IOUT = 120mA 1.5x mode, IOUT = 120mA 0.5 2.2 1 60 300 Ω Ω MHz mA mA 0 0.8 VOUT < 0.5V 1x mode, VOUT > 1V -1 1.3 Max 1 31 1.3 1 0.4 165 20 2 2 µA V V ºC ºC V © 2006 Catalyst Semiconductor, Inc. Characteristics subject to change without notice CAT3616 ¯¯¯¯ AND ¯¯¯¯ RECOMMENDED EN, ENM ENS TIMING 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 ¯¯¯ , ENS ¯¯¯ program low time ENM ¯¯¯ , ENS ¯¯¯ program high time ENM EN low time to shutdown LED current enable LED current decrement Min 10 0.3 0.3 1.5 Typ Max 200 40 0.1 Unit µs µs µs ms µs µs Figure 1. Enable LED Timing Diagram © 2006 Catalyst Semiconductor, Inc. Characteristics subject to change without notice 3 Doc. No. 5018 Rev. A 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. Total LED Current (6 LEDs) Efficiency vs. Input Voltage (6 LEDs on) 100 1x Mode 100 15mA per LED EFFICIENCY [%] EFFICIENCY [%] 80 70 60 1.5x Mode 50 80 70 60 40 4.2 4.0 3.8 3.6 3.4 3.2 INPUT VOLTAGE [V] 3.0 0 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] 0.4 0.2 6 LEDs OFF 0.0 0 40 80 TEMPERATURE [°C] 120 Quiescent Current vs. Temperature (1.5x Mode) QUIESCENT CURRENT [mA]. 4 3 2 1 6 LEDs OFF 0 Doc. No. 5018 Rev. A 0.6 -40 5 3.2 3.4 3.6 3.8 4.0 INPUT VOLTAGE [V] 0.8 4.2 Quiescent Current vs. Input Voltage (1.5x Mode) 3.0 50 100 150 200 TOTAL LED CURRENT [mA] Quiescent Current vs. Temperature (1x Mode) Quiescent Current vs. Input Voltage (1x Mode) QUIESCENT CURRENT [mA] VIN = 3.2V (1.5x mode) 50 20mA per LED 40 QUIESCENT CURRENT [mA]. VIN = 4V (1x mode) 90 90 5 4 3 2 1 6 LEDs OFF 0 -40 4.2 4 0 40 80 TEMPERATURE [°C] 120 © 2006 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. Temperature 5.0 4.0 3.0 2.0 1.0 0.0 -1.0 -2.0 -3.0 -4.0 -5.0 1x Mode 1.5x Mode 3.0 3.2 3.4 3.6 3.8 4.0 INPUT VOLTAGE [V] -40 4.2 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] -20 0 20 40 60 TEMPERATURE [°C] 80 Oscillator Frequency vs. Temperature CLOCK FREQUENCY [MHz] . CLOCK FREQUENCY [MHz] . Oscillator Frequency vs. Input Voltage 1.3 1.2 1.1 1.0 0.9 0.8 0.7 -40 4.0 0 40 80 TEMPERATURE [°C] 120 Output Resistance vs. Input Voltage(1.5x Mode) Output Resistance vs. Input Voltage (1x Mode) 4.0 1.0 OUTPUT RESISTANCE [Ω] . OUTPUT RESISTANCE [Ω] . 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 [%] . LED Current Change vs. Input Voltage 0.8 0.6 0.4 0.2 0.0 Characteristics subject to change without notice 3.0 2.5 2.0 1.5 1.0 3.0 3.0 3.2 3.4 3.6 3.8 4.0 4.2 INPUT VOLTAGE [V] © 2006 Catalyst Semiconductor, Inc. 3.5 5 3.2 3.4 3.6 3.8 4.0 INPUT VOLTAGE [V] 4.2 Doc. No. 5018 Rev. A 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 Doc. No. 5018 Rev. A 6 © 2006 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. Line Transient Response (3.6V to 5.5V) 1x Mode ENM ¯¯¯ , ENS ¯¯¯ and Output Current Dimming Foldback Current Limit OUTPUT VOLTAGE [V] 4.0 3.5 3.0 2.5 1x Mode 2.0 1.5 1.0 0.5 0.0 0 100 200 300 OUTPUT CURRENT [mA] © 2006 Catalyst Semiconductor, Inc. Characteristics subject to change without notice 400 7 Doc. No. 5018 Rev. A CAT3616 PIN DESCRIPTIONS Pin # 1 2 3 4 5 6 7, 8 9, 10 11 12 13 14 15 16 TAB Name MAIN1 ¯¯¯ ENM ¯¯¯ ENS EN VOUT VIN C1-, C1+ C2-, C2+ GND SUB2 SUB1 MAIN4 MAIN3 MAIN2 TAB 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 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. is required between the VOUT pin and ground near the device. 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. C1+, C1- are connected to each side of the 1µF ceramic bucket capacitor C1. GND is the ground reference for the charge pump. The pin must be connected to the ground plane on the PCB. 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. ¯¯¯ , ENS ¯¯¯ are the active low enable/ dimming control ENM logic inputs for respectively main and sub LED channels. The falling edge of the first pulse applied to ¯¯¯ and ENS ¯¯¯ sets the current for respectively the ENM main and sub LED channels to their full scale of 31mA. On each consecutive falling edge of the pulse ¯¯¯ and ENS ¯¯¯ , the LED current is applied to ENM 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. 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. VOUT is the charge pump output that is connected to the LED anodes. A small 1µF ceramic bypass capacitor Doc. No. 5018 Rev. A 8 © 2006 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. 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). 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. © 2006 Catalyst Semiconductor, Inc. Characteristics subject to change without notice 9 Doc. No. 5018 Rev. A CAT3616 LED CURRENT SETTING The LED current is controlled by toggling the input ¯¯¯ and ENS ¯¯¯ . ENM ¯¯¯ controls the four LED signals ENM ¯¯¯ controls the two LED channels MAIN1 to MAIN4. ENS ¯¯¯ and ENS ¯¯¯ work the same lines SUB1 and SUB2. ENM way. The chip must first be enabled by setting the ¯¯¯ or ENS ¯¯¯ enable input EN high. On the first ENM transition from high to low, the LED current in the associated LEDs is set to the full scale 31mA. On ¯¯¯ or ENS ¯¯¯ , the each consecutive falling edge of ENM LED current is decreased by 1mA. On the 32nd pulse, the LED channel is turned off and the current drops to ¯¯¯ or ENS ¯¯¯ pulse resets the full 0mA. One additional ENM current to 31mA, as shown on Figure 1. 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. 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 ¯¯¯ or ENS ¯¯¯ has no enable EN input is low, toggling ENM effect. 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. 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. Doc. No. 5018 Rev. A 10 © 2006 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 ¯¯¯ and ENS ¯¯¯ as shown on Figure 3. input signals EN, ENM 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 © 2006 Catalyst Semiconductor, Inc. Characteristics subject to change without notice 11 Doc. No. 5018 Rev. A CAT3616 PACKAGE DRAWING AND DIMENSIONS Thin QFN 16-Lead 4mm x 4mm D2 C PIN 1 ID D E2 b L A1 E A SYMBOL MIN NOM MAX A 0.70 0.75 0.80 A1 0.00 0.02 0.05 b 0.25 0.30 0.35 C e 3xe 0.20 REF D 3.95 4.00 4.05 D2 2.15 2.20 2.25 e 0.65 BSC E 3.95 4.00 4.05 E2 2.15 2.20 2.25 L 0.50 0.55 0.60 Notes: (1) All dimensions are in millimeters. (2) Complies with JEDEC specification MO-229. For current Tape and Reel information, download the PDF file from: http://www.catsemi.com/documents/TapeandReel.pdf Doc. No. 5018 Rev. A 12 © 2006 Catalyst Semiconductor, Inc. Characteristics subject to change without notice CAT3616 EXAMPLE OF ORDERING INFORMATION Prefix Device # Suffix CAT 3616 HV4 Company ID Product Number 3616 Package HV4: TQFN – T2 T: Tape & Reel 2: 2000/Reel Notes: (1) All packages are RoHS-compliant (Lead-free, Halogen-free). (2) The standard lead finish is Matte-Tin. (3) The device used in the above example is a CAT3616HV4-T2 (TQFN, Tape & Reel). (4) For additional package and temperature options, please contact your nearest Catalyst Semiconductor Sales office. © 2006 Catalyst Semiconductor, Inc. Characteristics subject to change without notice 13 Doc. No. 5018 Rev. A REVISION HISTORY Date 07/20/2006 Rev. 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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: 5018 Revision: A Issue date: 07/20/2006