CAT4008 8-Channel Constant Current LED Driver FEATURES DESCRIPTION 8 Constant current-sink channels The CAT4008 is an 8 channel constant current driver for LED billboard and other general display applications. LED channel currents are programmed together via an external RSET resistor. Low output voltage operation on the LED channels as low as 0.4V (for 2 to 100mA LED current) allows for more power efficient designs. Serial interface up to 25MHz clock frequency 3V to 5.5V logic supply LED current range from 2mA to 100mA LED current set by external RSET resistor 300mV LED dropout at 30mA A high-speed 4-wire serial interface of up to 25MHz clock frequency controls each individual channel using a shift register and latch configuration. A serial output data pin (SOUT) allows multiple devices to be cascaded and programmed via one serial interface. The device also includes a blanking control pin (BLANK) that can be used to disable all channels independently of the interface. Thermal shutdown protection Available in RoHS-compliant 16-lead SOIC (150 and 300mil wide), and TSSOP packages APPLICATIONS Billboard Display Marquee Display Instrument Display Thermal shutdown protection is incorporated in the device to disable the LED outputs if the die temperature exceeds a set limit. General Purpose Display The device is available in the 16-lead SOIC (narrow and wide), and TSSOP packages. For Ordering Information details, see page 13. TYPICAL APPLICATION CIRCUIT VIN 3V to 5.5V VDD CONTROLLER 20mA 1µF LED1 LED2 LED8 BLANK LATCH CAT4008 SIN SOUT to next device RSET CLK GND © Catalyst Semiconductor, Inc. Characteristics subject to change without notice 3.09kΩ 1 Doc. No. MD-5034 Rev. A CAT4008 ORDERING INFORMATION Part Number CAT4008W-T2 CAT4008V-T1 CAT4008Y-T2 Package Quantity per Reel Package Marking (1) 2000 CAT4008W (1)(2) 1000 CAT4008V 2000 CAT4008Y SOIC16 (N) SOIC16 (W) TSSOP16 (1)(2) PIN CONFIGURATION 16-Lead SOIC (W, V), TSSOP (Y) GND 1 16 VDD SIN 2 15 RSET SCLK 3 14 SOUT XLAT 4 13 BLANK LED1 5 12 LED8 LED2 6 11 LED7 LED3 7 10 LED6 LED4 8 9 LED5 Notes: (1) (2) Matte-Tin Plated Finish (RoHS-compliant). Contact factory for package availability. Doc. No. MD-5034 Rev. A 2 © Catalyst Semiconductor, Inc. Characteristics subject to change without notice CAT4008 ABSOLUTE MAXIMUM RATINGS Parameter VDD Supply Voltage Logic input/output voltage (SIN, SOUT, CLK, BLANK, LATCH) Rating Units 6 -0.3V to VDD+0.3V V V 6 150 -55 to +160 -40 to +150 300 V mA °C °C °C Range Units 3.0 to 5.5 0.4 to 5.5 up to 100 -40 to +85 V V mA °C LEDn voltage DC output current on LED1 to LED8 Storage Temperature Range Junction Temperature Range Lead Soldering Temperature (10sec.) RECOMMENDED OPERATING CONDITIONS Parameter VDD Voltage applied to LED1 to LED8 LED current RSET control range Ambient Temperature Range ELECTRICAL OPERATING CHARACTERISTICS DC CHARACTERISTICS VDD = 5.0V, TAMB = 25 ºC, over recommended operating conditions unless specified otherwise. Symbol Name ILED-ACC LED Current (any channel) ILED-MAT LED Current Matching (ILED - ILEDAVR) / ILEDAVR ΔIVDD LED current regulation vs. VDD ΔIVLED LED current regulation vs. VLED IDDOFF Supply Current (all outputs off) IDDON Supply Current (all outputs on) ILKG RLATCH RBLANK LEDn output Leakage LATCH Pull-down Resistance BLANK Pull-up Resistance VIH VIL VHYS IIL VOH VOL VRSET TSD THYST Conditions VLED = 1V, RSET = 3.08kΩ VLED = 1V, RSET = 1.54kΩ VLED = 1V, RSET = 769Ω VLED = 1V, RSET = 3.08kΩ VLED = 1V, RSET = 1.54kΩ VLED = 1V, RSET = 769Ω VDD within 4.5V and 5.5V LED current 30mA VLED within 1V and 3V LED current 30mA RSET = 3.08kΩ RSET = 769Ω Min Typ Max Units 18 36 20 40 80 ±1.5 ±1.5 ±2.0 22 44 mA +6.0 % -6.0 RSET = 3.08kΩ RSET = 769Ω VLED = 5V, outputs off Logic high input voltage Logic low input voltage %/V ±0.05 %/V 2 5.5 8 mA mA 2.5 9 mA 6.2 -1 100 100 180 180 0.7xVDD Logic input hysteresis voltage mA 1 300 300 µA kΩ kΩ 0.3xVDD V V 0.1xVDD Logic Input leakage current (CLK, SIN) VI = VDD or GND SOUT logic high output voltage SOUT logic low output voltage IOH = -1mA IOL = 1mA RSET Regulated Voltage Thermal Shutdown Thermal Hysteresis BLANK high, outputs off © Catalyst Semiconductor, Inc. Characteristics subject to change without notice ±0.1 3 -5 0 VCC-0.3V 1.17 V 5 0.3 1.20 160 20 1.23 µA V V ºC ºC Doc. No. MD-5034 Rev. A CAT4008 TIMING CHARACTERISTICS For 3.0V ≤ VDD ≤ 5.5V, TAMB = 25 ºC, unless specified otherwise. Symbol Name Min (1) Conditions Typ (2) Max (1) Units 25 MHz CLK fclk CLK Clock Frequency tcwh CLK Pulse Width High 20 ns tcwl CLK Pulse Width Low 20 ns tssu Setup time SIN to CLK 4 ns tsh Hold time SIN to CLK 4 ns tlwh LATCH Pulse width 20 ns Tlh Hold time LATCH to CLK 4 ns Tlsu Setup time LATCH to CLK Channel Stagger Delay 400 ns tld LED1 Propagation delay LATCH to LED1 off/on 40 300 ns tls LED Propagation delay stagger LED(n) to LED(n+1) 17 40 ns tlst LED Propagation delay stagger total LED1 to LED8 120 tbd BLANK Propagation delay BLANK to LED(n) off/on 60 300 ns tlr LED rise time (10% to 90%) Pull-up resistor = 50Ω to 3.0V 40 200 ns tlf LED fall time (90% to 10%) Pull-up resistor = 50Ω to 3.0V 30 250 ns SIN LATCH LEDn ns SOUT tor SOUT rise time (10% to 90%) CL = 15pF 5 ns tof SOUT fall time (90% to 10%) CL = 15pF 5 ns tod Propagation delay time SOUT CLK to SOUT 8 15 25 ns TEST CIRCUIT FOR AC CHARACTERISTICS 1µF VDD VDD CONTROLLER LED1 Rp 50Ω Rp 50Ω BLANK LATCH CAT4008 LED8 SIN SOUT CLK RSET GND V1 Cl 3V 15pF RSET Notes: (1) All min and max values are guaranteed by design. (2) VDD = 5V, LED current 30mA. Doc. No. MD-5034 Rev. A 4 © Catalyst Semiconductor, Inc. Characteristics subject to change without notice CAT4008 1/fclk CLK tssu tsh tcwl tcwh SIN tod SOUT tlh tlsu LATCH tlwh Figure 1. Serial Input Timing Diagram tld LATCH tbd BLANK tls LED1 LED2 tlst = 7 tls LED8 Figure 2. LED Output Timing Diagram © Catalyst Semiconductor, Inc. Characteristics subject to change without notice 5 Doc. No. MD-5034 Rev. A CAT4008 TYPICAL PERFORMANCE CHARACTERISTICS VDD = 5.0V, LED current 30mA, all LEDs On, TAMB = 25°C unless otherwise specified. Supply Current vs. VDD Pin Voltage LED Current vs. LED Pin Voltage 4.0 SUPPLY CURRENT [mA] LED CURRENT [mA] 70 60 50 40 30 20 10 0 All LED's ON 3.5 3.0 2.5 2.0 1.5 All LED's OFF 1.0 0.0 0.3 0.6 0.9 LED PIN [V] 1.2 1.5 3.0 8 SUPPLY CURRENT [mA] 31.5 31.0 LED CURRENT [mA] 4.0 4.5 VDD [V] 5.0 5.5 Supply Current vs. RSET Current LED Current vs. VDD Pin Voltage 30.5 30.0 29.5 29.0 28.5 All LED's ON 7 6 5 4 3 2 All LED's OFF 1 0 3.0 3.5 4.0 4.5 VDD [V] 5.0 5.5 0.0 RSET Voltage vs. VDD Pin Voltage 0.5 1.0 1.5 RSET CURRENT [mA] 2.0 LED Current vs. RSET Resistor 1.30 100 LED CURRENT [mA] RSET PIN [V] 3.5 1.25 1.20 1.15 1.10 3.0 Doc. No. MD-5034 Rev. A 3.5 4.0 4.5 VDD [V] 5.0 80 60 40 20 0 5.5 0.1 6 1.0 10.0 RSET [kΩ] 100.0 © Catalyst Semiconductor, Inc. Characteristics subject to change without notice CAT4008 TYPICAL PERFORMANCE CHARACTERISTICS VDD = 5.0V, LED current 30mA, all LEDs On, TAMB = 25°C unless otherwise specified. LED Current vs. Temperature RSET Voltage vs. Temperature 1.30 31.5 31.0 LED CURRENT [mA] RSET PIN [V] 1.25 1.20 1.15 30.5 30.0 29.5 29.0 1.10 28.5 -50 0 50 100 TEMPERATURE [°C] 150 -50 150 Internal Pull-Up Current (BLANK pin) Internal Pull-Down Current (LATCH pin) 30 PULL-UP CURRENT [μA] . 30 PULL-DOWN CURRENT [μA] . 0 50 100 TEMPERATURE [°C] 25 20 15 10 5 25 20 15 10 5 0 0 0 1 2 3 4 LATCH VOLTAGE [V] 0 5 1 2 3 4 BLANK VOLTAGE [V] 5 BLANK Transient Response PWM Dimming on BLANK pin (f = 10kHz) 100 DUTY CYCLE [%] 80 60 40 20 0 0 5 10 15 20 25 LED CURRENT [mA] © Catalyst Semiconductor, Inc. Characteristics subject to change without notice 30 7 Doc. No. MD-5034 Rev. A CAT4008 PIN DESCRIPTION Name Function GND Ground SIN Serial data input pin CLK Serial clock input pin LATCH Latch serial data to output registers LED1-LED8 LED channel 1 to 8 cathode terminals BLANK Enable / disable all channels SOUT Serial data output pin. RSET LED current set pin VDD Positive supply Voltage PIN FUNCTION GND is the ground reference pin for the device. This pin must be connected to the ground plane on the PCB. BLANK is the LED channel enable and disable input pin. When low, LEDs are enabled according to the output latch register content. When high, all LEDs are off, while preserving the data in the output latch register. SIN is the serial data input. Data is loaded into the internal register on each rising edge of CLK. CLK is the serial clock input. On each rising CLK edge, data is transferred from SIN to the internal 8-bit serial shift register. SOUT is the serial data output of the 8-bit serial shift register. This pin is used to cascade several devices on the serial bus. The SOUT pin is then connected to the SIN input of the next device on the serial bus to cascade. LATCH is the latch data input. On the rising edge of LATCH, data is loaded from the 8-bit serial shift register into the output register latch. On the falling edge, this data is latched in the output register and isolated from the state of the serial shift register. RSET is the LED current setting pin. A resistor is connected between this pin and ground. Each LED channel current is set to about 51 times the current pulled out of the pin. The RSET pin voltage is regulated to 1.2V. LED1 – LED8 are the LED current sink channels. These pins are connected to the LED cathodes. The current sinks drive the LEDs with a current equal to about 51 times RSET pin current. For the LED sink to operate correctly, the voltage on the LED pin must be above 0.4V. VDD is the positive supply pin voltage for the entire device. A small 1µF ceramic is recommended close to pin. CURRENT SETTING RESISTOR Table 1 lists standard resistor values for various LED current settings. Table 1. LED Current and RSET resistor values LED Current [mA] RSET [kΩ] 10 20 30 40 60 80 6.19 3.09 2.05 1.54 1.02 0.768 Doc. No. MD-5034 Rev. A 8 © Catalyst Semiconductor, Inc. Characteristics subject to change without notice CAT4008 BLOCK DIAGRAM LED1 LED2 LED3 LED8 VDD + VIN + CURRENT SINKS Current Setting BLANK RSET 1.2V Ref GND LATCH L1 SIN S1 L2 S2 L3 S3 LATCHES SHIFT REGISTER L8 S8 SOUT CLK Figure 2. CAT4008 Functional Block Diagram BASIC OPERATION The CAT4008 uses 8 tightly matched current sinks to accurately regulate the LED current in each channel. The external resistor, RSET, is used to set the LED Pull-up and pull-down resistors are internally provided to set the state of the BLANK and LATCH pins to the off-state when not externally driven. 1.2 R SET channel current to about 51 times the current in RSET. SERIAL INTERFACE LED current ≅ 51× A high-speed serial 4-wire interface is provided to program the state of each LED on or off. The interface contains an 8-bit serial to parallel shift register (S1-S8) and an 8-bit latch (L1-L8). Programming the serial to parallel register is accomplished via SIN and CLK input pins. On each rising edge of the CLK signal, the data from SIN is moved through the shift register serially. Data is also moved out of SOUT which can be connected to a next device if programming more then one device on the same interface. 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. The LED channels have a maximum dropout of 0.4V for most current and supply voltage conditions. This helps improve the heat dissipation and efficiency of the LED driver. Upon power-up, an under-voltage lockout circuit clears all latches and shift registers and sets all outputs to off. Once the under-voltage lockout threshold has been reached the device can be programmed. On the rising edge of LATCH, the data contents of the serial to parallel shift register is reflected in the latches. On the falling edge of LATCH, the state of the serial to parallel register at that particular time is saved in the latches and does not change irrespective of the contents of the serial to parallel register. The driver delays the activation of each consecutive LED output channel by 17ns (typical). Relative to LED1, LED2 is delayed by 17ns, LED3 by 34ns and LED8 by 120ns typical. The delay is introduced when LATCH is activated. The delay minimizes the inrush current on the LED supply by staggering the turn on and off current spikes over a period of time and therefore allowing usage of smaller bypass capacitors. © Catalyst Semiconductor, Inc. Characteristics subject to change without notice BLANK is used to disable all LEDs (turn off) simultaneously while maintaining the same data in the latch register. When low, the LED outputs reflect the data in the latches. When high, all outputs are high impedance (zero current). 9 Doc. No. MD-5034 Rev. A CAT4008 PACKAGE OUTLINE DRAWINGS SOIC 16-Lead Narrow Body 150mils (W) (1)(2) E1 SYMBOL MIN A 1.35 1.75 A1 0.10 0.25 E MAX b 0.33 0.51 c 0.19 0.25 D 9.80 9.90 10.00 E 5.80 6.00 6.20 E1 3.80 3.90 4.00 e PIN#1 IDENTIFICATION NOM 1.27 BSC h 0.25 0.50 L 0.40 1.27 θ 0º 8º TOP VIEW D h θ A e b A1 SIDE VIEW c L END VIEW For current Tape and Reel information, download the PDF file from: http://www.catsemi.com/documents/tapeandreel.pdf. Notes: (1) All dimensions in millimeters. Angle in degrees. (2) Compiles with JEDEC MS-012 Doc. No. MD-5034 Rev. A 10 © Catalyst Semiconductor, Inc. Characteristics subject to change without notice CAT4008 SOIC 16-Lead Wide Body 300mils (V) (1)(2) D SYMBOL MIN NOM MAX A 2.36 2.49 2.64 0.41 0.51 E1 E A1 0.10 b 0.33 0.30 c 0.18 0.23 0.28 D 10.08 10.31 10.49 E 10.01 10.31 10.64 E1 7.39 7.49 7.59 e 1.27 BSC h 0.25 L 0.38 θ 0º 0.75 0.81 1.27 8º PIN #1 IDENTIFICATION TOP VIEW h A b e c θ L A1 SIDE VIEW END VIEW For current Tape and Reel information, download the PDF file from: http://www.catsemi.com/documents/tapeandreel.pdf. Notes: (1) All dimensions in millimeters. Angle in degrees. (2) Compiles with JEDEC MS-013. © Catalyst Semiconductor, Inc. Characteristics subject to change without notice 11 Doc. No. MD-5034 Rev. A CAT4008 TSSOP 16-Lead 4.4mm (Y) (1)(2) b SYMBOL MIN NOM A E1 E MAX 1.10 A1 0.05 0.15 A2 0.85 0.95 b 0.19 0.30 c 0.13 0.20 D 4.90 5.10 E 6.30 6.50 E1 4.30 4.50 e 0.65 BSC L 1.00 REF L1 0.45 0.75 θ1 0° 8° e PIN#1 IDENTIFICATION TOP VIEW D A2 A c θ1 A1 L1 L SIDE VIEW END VIEW For current Tape and Reel information, download the PDF file from: http://www.catsemi.com/documents/tapeandreel.pdf. Notes: (1) All dimensions in millimeters. Angle in degrees. (2) Compiles with JEDEC MO-153. Doc. No. MD-5034 Rev. A 12 © Catalyst Semiconductor, Inc. Characteristics subject to change without notice CAT4008 EXAMPLE OF ORDERING INFORMATION Prefix Device # Suffix CAT 4008 W – Optional Company ID Product Number 4008 Package W: SOIC, 150mils V: SOIC, 300mils (4) Y: TSSOP (4) T2 Tape & Reel T: Tape & Reel 1: 1000/Reel 2: 2000/Reel (1) 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 CAT4008W–T2 (SOIC 16-Lead 150 mils, Matte-Tin, Tape & Reel 2000). (4) Contact factory for package availability. (5) 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-5034 Rev. A REVISION HISTORY Date 01/10/2008 Rev. A Reason Initial Issue 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-5034 Revision: A Issue date: 01/10/08