CAT4004 4-Channel Constant Current LED Driver with EZDim™ FEATURES DESCRIPTION Four LED current sinks with tight matching Low Dropout Driver 130mV at 30mA No switching noise Shutdown current < 1μA LED current set by external resistor Dimming via 1-wire EZDimTM interface Thermal shutdown protection RoHS Compliant 8-lead 2mm x 3mm TDFN package The EN/DIM logic inputs supports device enable and a digital dimming interface for current setting of all LEDs. Six different current dimming ratios are available. The device is aimed at “direct drive” battery applications. It is required that the battery or voltage source have enough headroom to drive the LED forward voltage and current sink (>150mV). APPLICATIONS The CAT4004 provides four matched low dropout current sources to drive LEDs. An external resistor on RSET sets the current in the LED channels. Each LED channel includes an individual control loop allowing the device to handle a wide range of LED forward voltages while still maintaining tight current matching. LCD Display Backlight Cellular Phones Digital Still Cameras Handheld Devices The device is available in a tiny 8-lead TDFN 2mm x 3mm package with a max height of 0.8mm. ORDERING INFORMATION Part Number Package Quantity per Reel Package Marking (1) 3000 FT CAT4004VP2-GT3 TDFN-8 (2) 3000 HA CAT4004VP2-T3 TDFN-8 For Ordering Information details, see page 10. Notes: (1) Matte-Tin Plated Finish (RoHS-compliant). (2) NiPdAu Plated Finish (RoHS-compliant). PIN CONFIGURATION TYPICAL APPLICATION CIRCUIT VIN 8-lead TDFN Package 2.4V to 5.5V (Top View) EN/DIM 1 GND 2 LED1 3 8 VIN CAT4004 LED2 4 20mA CIN 1µF 7 RSET LED1 LED2 LED3 LED4 6 LED4 VIN 5 LED3 One wire programming EN/DIM CAT4004 RSET RSET 3.8kΩ © Catalyst Semiconductor, Inc. Characteristics subject to change without notice 1 GND Doc. No. MD-5024 Rev. B CAT4004 ABSOLUTE MAXIMUM RATINGS Parameter Rating Unit 6 V VIN + 0.7 V Storage Temperature Range -65 to +160 °C Junction Temperature Range -40 to +150 °C 300 °C VIN, LEDx, RSET EN/DIM Voltage Lead Temperature RECOMMENDED OPERATING CONDITIONS Parameter Rating (1) Unit VIN 2.4 to 5.5 Ambient Temperature Range -40 to +85 °C 0 to 40 mA ILED per LED pin V Typical application circuit with external components is shown on page 1. ELECTRICAL OPERATING CHARACTERISTICS (over recommended operating conditions unless specified otherwise) VIN = 4.0V, EN = High, TAMB = 25°C Symbol IQ Name Quiescent Current IQSHDN ILED-ACC Shutdown Current LED Current Accuracy ILED-DEV LED Channel Matching VDOUT Dropout Voltage REN/DIM VHI VLO EN/DIM Pin • Internal pull-down resistor • Logic High Level • Logic Low Level Conditions No load, RSET = Float No load, RSET = 4.8kΩ VEN = 0V 1mA ≤ ILED ≤ 40mA ILED − ILEDAVG ILED Min Typ Max 0.6 1.0 1 ±1 -5 ILED = 30mA ±1 +5 Units mA mA µA % % 130 mV 100 kΩ V V 1.3 0.4 TSD Thermal Shutdown 150 °C THYS Thermal Hysteresis 20 °C VUVLO Undervoltage lockout (UVLO) threshold 1.8 V Doc. No. MD-5024 Rev. B 2 © Catalyst Semiconductor, Inc. Characteristics subject to change without notice CAT4004 RECOMMENDED EN/DIM TIMING For 2.4 ≤ VIN ≤ 5.5V, over full ambient temperature range -40ºC to +85ºC. Symbol Name TSETUP Conditions Min Typ Max Units EN/DIM setup from shutdown 10 TLO EN/DIM program low time 0.2 THI EN/DIM program high time 0.2 μs EN/DIM low time to shutdown 1.5 ms TPWRDWN TLED LED current settling time TSETUP μs 100 40 μs μs TPWRDWN THI EN/DIM TLO TLED 100% 100% 50% LED Current 25% Shutdown 12.5% 6.25% 3.12% Shutdown Figure 1. EN/DIM Dimming Timing Diagram EN/DIM number of pulses * RSET Gain LED Current LOW Shutdown mode Zero Transitions HIGH 132 132 x 0.6V/RSET st 66 66 x 0.6V/RSET nd 33 33 x 0.6V/RSET rd 16.5 16.5 x 0.6V/RSET 1 2 3 4 th 8.25 8.25 x 0.6V/RSET 5th 4.125 4.125 x 0.6V/RSET 6th 132 132 x 0.6V/RSET th x Device will keep cycling through gain selection GAIN x 0.6V/RSET * The gain is changed on the rising edges of the EN/DIM input. 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 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 EN/DIM pin has two primary functions. One function enables and disables the device. The other function is LED current dimming with six different © Catalyst Semiconductor, Inc. Characteristics subject to change without notice The LED driver enters a “zero current” shutdown mode if EN/DIM is held low for 1.5ms or more. 3 Doc. No. MD-5024 Rev. B CAT4004 TYPICAL PERFORMANCE CHARACTERISTICS VIN = 4V, VF = 3.3V, IOUT = 80mA (4 LEDs at 20mA), CIN = 1μF, TAMB = 25°C unless otherwise specified. Quiescent Current vs. Temperature Quiescent Current vs. Input Voltage 1.4 QUIESCENT CURRENT [mA] QUIESCENT CURRENT [mA] 1.4 1.2 1.0 0.8 0.6 2.5 3.0 3.5 4.0 4.5 5.0 INPUT VOLTAGE [V] 0.6 0 40 80 TEMPERATURE [°C] 120 LED Current Change vs. Temperature LED CURRENT CHANGE [%] LED CURRENT CHANGE [%] 0.8 -40 1.0 0.8 0.6 0.4 0.2 0.0 -0.2 -0.4 -0.6 -0.8 -1.0 3.5 4.0 4.5 5.0 INPUT VOLTAGE [V] 1.0 5.5 LED Current Change vs. Input Voltage 3.0 1.2 10 8 6 4 2 0 -2 -4 -6 -8 -10 -40 5.5 0 40 80 TEMPERATURE [°C] 120 LED Current vs. RSET Resistor LED CURRENT [mA] 40 30 20 10 0 0 5 10 RSET [kΩ] © Catalyst Semiconductor, Inc. Characteristics subject to change without notice 15 20 4 Doc. No. MD-5024 Rev. B CAT4004 TYPICAL PERFORMANCE CHARACTERISTICS VIN = 4V, VF = 3.3V, IOUT = 80mA (4 LEDs at 20mA), CIN = 1μF, TAMB = 25°C unless otherwise specified. RSET Pin Voltage vs. Temperature 0.7 0.7 0.6 0.6 RSET VOLTAGE [V] RSET VOLTAGE [V] RSET Pin Voltage vs. Input Voltage 0.5 0.4 0.3 0.5 0.4 0.3 0.2 0.2 -40 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 INPUT VOLTAGE [V] 120 Dropout Characteristics LED Current vs. LED Pin Voltage 40 LED CURRENT [mA] 40 LED CURRENT [mA] 0 40 80 TEMPERATURE [°C] 30 20 10 30 20 10 0 0 0 0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 LED PIN VOLTAGE [V] 50 100 150 200 250 LED PIN VOLTAGE [mV] 300 Efficiency vs. Input Voltage 100 EFFICIENCY [%] 90 80 70 60 50 5.0 4.5 4.0 3.5 3.0 2.5 INPUT VOLTAGE [V] © Catalyst Semiconductor, Inc. Characteristics subject to change without notice 2.0 5 Doc. No. MD-5024 Rev. B CAT4004 TYPICAL PERFORMANCE CHARACTERISTICS VIN = 4V, VF = 3.3V, IOUT = 80mA (4 LEDs at 20mA), CIN = 1μF, TAMB = 25°C unless otherwise specified. Power Up Waveform Power Down Waveform Line Transient Waveform 4V to 5.5V Dimming Waveform 80mA to 40mA Doc. No. MD-5024 Rev. B 6 © Catalyst Semiconductor, Inc. Characteristics subject to change without notice CAT4004 PIN DESCRIPTIONS Pin # Name Function 1 EN/DIM 2 GND Ground reference 3 LED1 LED1 cathode terminal 4 LED2 LED2 cathode terminal 5 LED3 LED3 cathode terminal 6 LED4 LED4 cathode terminal 7 RSET RSET external LED mirror gain 128 8 VIN Device supply input, connect to battery or supply TAB TAB Connect to GND on the PCB Device enable (active high) and dimming control PIN FUNCTION VIN is the supply pin for the device logic. 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. impedance zero current state whenver the device is placed in shutdown mode. RSET is connected to the resistor (RSET) to set the full scale current for the LEDs. The voltage at this pin is 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. 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. GND is the ground reference for the device. The pin must be connected to the ground plane on the PCB. 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. LED1 to LED4 provide the internal regulated current for each of the LED cathodes. There pins enter a high © Catalyst Semiconductor, Inc. Characteristics subject to change without notice 7 Doc. No. MD-5024 Rev. B CAT4004 BLOCK DIAGRAM LED4 LED3 Undervoltage Lockout LED2 VIN LED1 VIN Reference Voltage RSET Current Setting DAC Serial Interface EN/DIM Register 4 Current Sink Regulators 100kΩ GND Figure 2. CAT4004 Functional Block Diagram BASIC OPERATION The CAT4004 uses four tightly matched current sinks to accurately regulate LED current in each channel proportional to the current sourced from the RSET pin. ILED = GAIN × Each LED channel needs a minimum of 150mV headroom to sink constant regulated current. If the input supply falls below 1.8V, the under-voltage lockout circuit disables all LED channels and resets the circuit to default values. Any unused LED channels should be left open. 0.6 V R SET There are six different gain settings for LED brightness that can be set through the EN/DIM pin. The default gain on power-up is 132. Tight current regulation for all channels is possible over a wide range of input and LED voltages due to independent current sensing circuitry on each channel. Doc. No. MD-5024 Rev. B 8 © Catalyst Semiconductor, Inc. Characteristics subject to change without notice CAT4004 PACKAGE OUTLINE DRAWING TDFN 8-Pad 2 x 3mm (VP2) (1)(2) A D e b E2 E PIN#1 IDENTIFICATION A1 PIN#1 INDEX AREA D2 TOP VIEW SIDE VIEW SYMBOL MIN NOM MAX A 0.70 0.75 0.80 A1 0.00 0.02 0.05 A2 0.45 0.55 0.65 A3 b 0.25 A2 A3 D 1.90 2.00 2.10 1.30 1.40 1.50 E 2.90 3.00 3.10 E2 1.20 1.30 1.40 e FRONT VIEW 0.30 D2 L BOTTOM VIEW 0.20 REF 0.20 L 050 TYP 0.20 0.30 0.40 For current Tape & 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. © Catalyst Semiconductor, Inc. Characteristics subject to change without notice 9 Doc. No. MD-5024 Rev. B CAT4004 EXAMPLE OF ORDERING INFORMATION 1 Prefix CAT Device # 4004 Suffix VP2 Product Number 4004 Optional Company ID – G T2 Lead Finish G: NiPdAu Blank: Matte-Tin(4) Tape & Reel T: Tape & Reel 3: 3000/Reel Package VP2: TDFN 2 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 CAT4004VP2-GT3 (TDFN, NiPdAu Plated Finish, Tape & Reel 3000). (4) For Matte-Tin package option, please contact your nearest Catalyst Semiconductor Sales office. Doc. No. MD-5024 Rev. B 10 © Catalyst Semiconductor, Inc. Characteristics subject to change without notice REVISION HISTORY Date Rev. 03/15/2007 A 01/07/2008 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 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 2Hwww.catsemi.com Document No: MD-5024 Revision: B Issue date: 01/07/08