CAT3636 6-Channel Quad-ModeTM Fractional LED Driver in TQFN3x3 FEATURES DESCRIPTION The CAT3636 is a high efficiency quad-mode fractional charge pump that can drive up to six 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 traditional 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 6 LEDs at 32mA each 1-wire EZDimTM 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 Tiny 3mm x 3mm, 16-lead TQFN package APPLICATIONS LCD Display Backlight Color RGB LEDs Cellular Phones Digital Still Cameras Handheld Devices The EN/SET logic input functions as a chip enable and a “1-wire” addressable interface for control and current setting of all LEDs. Three groups of two LEDs can be configured with independent LED currents between 0.25mA and 32mA. The device is available in a tiny 16-lead TQFN 3mm x 3mm package with a max height of 0.8mm. ORDERING INFORMATION Part Package Number CAT3636 TQFN-16 HV3-T2 3x3 Green 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. Quantity per Reel Package Marking 2000 JAAA The 1.33x charge pump with two fly capacitors is a patent pending architecture exclusive to Catalyst Semiconductor. * Matte Tin Lead Finish For Ordering Information details, see page 14. PIN CONFIGURATION TYPICAL APPLICATION CIRCUIT © 2006 Catalyst Semiconductor, Inc. Characteristics subject to change without notice 1 Doc. No. 5020 Rev. A CAT3636 ABSOLUTE MAXIMUM RATINGS Parameter VIN, LEDx, C1±, C2± voltage VOUT voltage EN/SET 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 °C °C °C RECOMMENDED OPERATING CONDITIONS Parameter VIN Ambient Temperature Range ILED per LED pin Total Output Current Rating 2.5 to 5.5 -40 to +85 0 to 32 0 to 192 Unit V °C mA mA 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 IQ Name Quiescent Current IQSHDN ILED-ACC Shutdown Current LED Current Accuracy ILED-DEV LED Channel Matching ROUT Output Resistance (open loop) FOSC Charge Pump Frequency ISC_MAX LEDTH VHYS TDF IIN_MAX IEN/DIM VHI VLO TSD THYS VUVLO Doc. No. 5020 Rev. A Output short circuit Current Limit 1x to 1.33x or 1.33x to 1.5x or 1.5x to 2x Transition Thresholds at any LEDxx pin 1.33x to 1x Transition Hysteresis Transition Filter Delay Input Current Limit EN/DIM Pin • Input Leakage • Logic High Level • Logic Low Level Thermal Shutdown Thermal Hysteresis Undervoltage lockout (UVLO) threshold Conditions 1x mode, no load 1.33 x mode, no load 1.5x mode, no load 2x mode, no load VEN = 0V 1mA ≤ ILED ≤ 31mA ILED − ILEDAVG ILED 1x mode, IOUT = 100mA 1.33x mode, IOUT = 100mA 1.5x mode, IOUT = 100mA 2x mode, IOUT = 100mA 1.33x and 2x mode 1.5x mode VOUT < 0.5V Min Typ 0.5 3.5 3 2.5 1 ±3 0.6 0.8 VOUT > 1V Units mA mA mA mA µA % ±1 % 0.5 4.5 3.5 6 0.8 1.1 80 Ω Ω Ω Ω MHz MHz mA 1.1 1.4 150 mV 400 500 450 mV µs mA 1 150 20 µA V V °C °C 2 V -1 1.3 2 Max 0.4 © 2006 Catalyst Semiconductor, Inc. Characteristics subject to change without notice CAT3636 RECOMMENDED EN/SET TIMING For 2.5 ≤ VIN ≤ 5.5V, over full ambient temperature range -40 to +85ºC. Symbol TSETUP TLO THI TOFF TDATADELAY TRESETDELAY Name EN/SET setup from shutdown EN/SET program low time EN/SET program high time EN/SET low time to shutdown EN/SET Delay to DATA EN/SET Delay High to ADDRESS Conditions Min 10 0.2 0.2 1.5 500 2 Typ Max 100 100 1000 Units μs μs μs ms μs ms Figure 1. EN/SET One Wire Addressable Timing Diagram © 2006 Catalyst Semiconductor, Inc. Characteristics subject to change without notice 3 Doc. No. 5020 Rev. A CAT3636 TYPICAL PERFORMANCE CHARACTERISTICS VIN = 3.6V, IOUT = 120mA (6 LEDs at 20mA), CIN = COUT = C1 = C2 = 1μF, TAMB = 25°C unless otherwise specified. Efficiency vs. Input Voltage Efficiency vs. Li-Ion Voltage 100 100 VF = 3.3V 1.33x 1.5x 1x 80 2x 70 60 IOUT = 40mA 4.0 3.5 3.0 2.5 INPUT VOLTAGE [V] 60 QUIESCENT CURRENT [mA] 3.0 2.0 1.0 0.0 2x 5.0 4.0 1.5x 3.0 1.33x 2.0 1x 1.0 0.0 -40 5.5 5.0 4.5 4.0 3.5 3.0 2.5 2.0 INPUT VOLTAGE [V] -20 0 20 40 60 TEMPERATURE [°C] 80 LED Current Change vs. Temperature LED Current Change vs. Input Voltage 10 LED CURRENT VARIATION [%] . LED CURRENT VARIATION [%] . 3.0 6.0 VF = 3.3V 4.0 VF = 3.3V 4 2 0 -2 -4 -6 -8 -10 10 8 6 4 2 0 -2 -4 -6 -8 -10 -40 5.5 5.0 4.5 4.0 3.5 3.0 2.5 2.0 INPUT VOLTAGE [V] Doc. No. 5020 Rev. A 4.0 3.8 3.6 3.4 3.2 INPUT VOLTAGE [V] Quiescent Current vs. Temperature 6.0 8 6 Traditional 1.5x Charge Pump 4.2 2.0 Quiescent Current vs. Input Voltage QUIESCENT CURRENT [mA] 70 40 40 4.5 VF = 3.0V 80 50 50 5.0 VF = 3.3V 90 EFFICIENCY [%] EFFICIENCY [%] 90 4 -20 0 20 40 60 TEMPERATURE [°C] 80 © 2006 Catalyst Semiconductor, Inc. Characteristics subject to change without notice CAT3636 TYPICAL PERFORMANCE CHARACTERISTICS VIN = 3.6V, IOUT = 120mA (6 LEDs at 20mA), CIN = COUT = C1 = C2 = 1μF, TAMB = 25°C unless otherwise specified. Output Resistance vs. Input Voltage 10 1.2 OUTPUT RESISTANCE [Ω] . SWITCHING FREQUENCY [MHz] Switching Frequency vs. Temperature 1.1 1.5x Mode 1.0 0.9 0.8 1.33x, 2x Mode 0.7 VF = 3.3V 8 2x 6 1.33x 1.5x 4 2 1x 0 0.6 -40 -20 0 20 40 60 TEMPERATURE [°C] 5.5 5.0 4.5 4.0 3.5 3.0 2.5 2.0 INPUT VOLTAGE [V] 80 Power Up in 1x Mode Power Up in 1.33x Mode Power Up in 1.5x Mode Power Up in 2x Mode © 2006 Catalyst Semiconductor, Inc. Characteristics subject to change without notice 5 Doc. No. 5020 Rev. A CAT3636 TYPICAL PERFORMANCE CHARACTERISTICS VIN = 3.6V, IOUT = 120mA (6 LEDs at 20mA), CIN = COUT = C1 = C2 = 1μF, TAMB = 25°C unless otherwise specified. Foldback Current Limit Power Down Delay (1x Mode) OUTPUT VOLTAGE [V] 4.0 3.5 3.0 2.5 2.0 1x Mode 1.5 1.0 0.5 0.0 0 100 200 300 400 OUTPUT CURRENT [mA] 500 Operating Waveforms in 1x Mode Switching Waveforms in 1.33x Mode Switching Waveforms in 1.5x Mode Switching Waveforms in 2x Mode Doc. No. 5020 Rev. A 6 © 2006 Catalyst Semiconductor, Inc. Characteristics subject to change without notice CAT3636 PIN DESCRIPTION Pin # 1 2 3 4 5 6 7 8 9 10 11 12 13/14 15 16 TAB Name LEDC2 LEDC1 LEDB2 LEDB1 LEDA2 LEDA1 VOUT VIN C1+ C1C2+ C2NC GND EN/SET TAB Function LEDC2 cathode terminal LEDC1 cathode terminal LEDB2 cathode terminal LEDB1 cathode terminal LEDA2 cathode terminal LEDA1 cathode terminal Charge pump output, connect to LED anodes Charge pump input, connect to battery or supply Bucket capacitor 1, positive terminal Bucket capacitor 1, negative terminal Bucket capacitor 2, positive terminal Bucket capacitor 2, negative terminal No connect Ground reference Device enable (active high) and 1 wire control input Connect to GND on the PCB 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 (2V) all the LED channels will be automatically disabled and the device register are reset to default values. 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 ceramic bucket capacitor C1. C2+, C2- are connected to each side of the ceramic bucket capacitor C2. EN/SET is the enable and one wire addressable control logic input for all LED channels. Guaranteed levels of logic high and logic low are set at 1.3V and 0.4V respectively. When EN/SET is initially taken high, the device becomes enabled and all LED currents remain at 0mA. To place the device into zero current mode, the EN/SET pin must be held low for more than 1.5ms. LEDxx provide the internal regulated current for each of the LED cathodes. These pins enter highimpedance zero current state whenever the device is placed in shutdown mode. 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 is required between the VOUT pin and ground near the device. © 2006 Catalyst Semiconductor, Inc. Characteristics subject to change without notice 7 Doc. No. 5020 Rev. A CAT3636 BLOCK DIAGRAM Figure 2. CAT3636 Functional Block Diagram BASIC OPERATION At power-up, the CAT3636 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. 400μs). In 1.5x mode, the output is approximately equal to 1.5 times the input supply voltage (less any internal voltage losses). If the input voltage fails more or is still insufficient to drive the LEDs, it will automatically switch again into 2x mode where the output is approximately equal to 2 times the input supply voltage (less any internal voltage losses). 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). 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. If the input voltage is insufficient again or falls to a level where the regulated currents cannot be maintained, the device will automatically switch to the 1.5x boost mode (after a fixed delay time of about Doc. No. 5020 Rev. A 8 © 2006 Catalyst Semiconductor, Inc. Characteristics subject to change without notice CAT3636 LED Current Setting The current in each of the six LED channels is programmed through the 1-wire EN/SET digital control input. By pulsing this signal according to a specific protocol, a set of internal registers can be addressed and written into allowing to configure each bank of LEDs with the desired current. There are six registers: the first five are 4 bits long and the sixth is 1 bit long. The registers are programmed by first selecting the register address and then programming data into that register. Data in a register is reset once it is selected by the address pointer. If a register is selected but no data is programmed, then the register value is reset back to its initial default value with all data bits to 0. Once the final rising edge of the data pulses is programmed, the user must wait 1.5ms before programming another address. If programming fails or is interrupted, the user must wait TRESETDELAY 2ms from the last rising edge before reprogramming can commence. An internal counter records the number of falling edges to identify the address and data. The address is serially programmed adhering to low and high duration time delays. One down pulse corresponds to register 1 being selected. Two down pulses correspond to register 2 being selected and so on up to register 6. TLO and THI must be within 200ns to 100μs. Anything below 200ns may be ignored. Upon power-up, the device automatically starts looking for an address. If no falling edge is detected within 100μs of power-up, then the user must wait 2ms before trying to program the device again. The device requires a minimum 10μs delay to ensure the initialization of the internal logic at power-up. After this time delay, the device registers may be programmed adhering to the timing constraints shown in Figure 1. Once the final rising edge of the address pointer is programmed, the user must wait 500μs to 1000μs before programming the first data pulse falling edge. If the falling edge of the data is not received within 1000μs, the device will revert back to waiting for an address. To power-down the device and turn-off all current sources, the EN/SET input should be kept low for a duration TOFF of 1.5ms or more. The driver typically powers-down with a delay of about 1ms. All register data are lost. Figure 3. EN/SET One Wire Addressable Timing Diagram © 2006 Catalyst Semiconductor, Inc. Characteristics subject to change without notice 9 Doc. No. 5020 Rev. A CAT3636 REGISTER CONFIGURATION AND PROGRAMMING Table 1. Register Address and Data Register Address Pulses Description Bits REG1 REG2 REG3 REG4 REG5 REG6 1 2 3 4 5 6 Bank Enable and IMODE Global Current Setting Bank A Current Setting Bank B Current Setting Bank C Current Setting Return Lockout 4 4 4 4 4 1 0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 REG1-6 Value (binary) 0000 1111 1110 1101 1100 1011 1010 1001 1000 0111 0110 0101 0100 0011 0010 0001 0000 LED Current IMODE = 0 LED Current IMODE = 1 0.0mA 3.75mA 3.5mA 3.25mA 3mA 2.75mA 2.5mA 2.25mA 2mA 1.75mA 1.5mA 1.25mA 1mA 0.75mA 0.5mA 0.25mA 0.0mA 2mA 32mA 30mA 28mA 26mA 24mA 22mA 20mA 18mA 16mA 14mA 12mA 10mA 8mA 6mA 4mA 2mA Bit 0 ENC See Table 2 for values RTLKO REG6 contains the return lockout (RTLKO) bit. This stops the charge pump returning to 1x mode. One pulse sets it to 1. Two pulses or no pulses set RTLKO to 0. When RTLKO is set to 1, the charge pump cannot automatically return to 1x mode when in one of the charge pump modes. The device can however move from 1x to 1.33x to 1.5x to 2x if the input voltage is not sufficient to drive the programmed LED currents. REG6 also triggers a charge pump reset as soon as it is addressed. This forces the charge pump to start from 1x mode and reassess the correct mode it should be in to drive the LEDs most efficiently. If the input voltage has risen or the device has been reprogrammed to other LED values, it is recommended to trigger this reset allowing the charge pump to run in the most efficient mode. The CAT3636 enters a “zero current” shutdown mode if EN/SET is held low for 1.5ms or more. All registers are reset back to zero when the device is placed in shutdown. Register REG1 allows to set the mode and select the pairs of LEDs to be turned on. A low LED current mode exists to allow for very low current operation under 4mA per channel. If IMODE equals 1, the high current range is selected up to 32mA. If IMODE is set to 0, all currents are divided by 8. Each bank of LEDs (A, B or C) can be turned on independently by setting the respective bit ENA, ENB, ENC to 1. Doc. No. 5020 Rev. A DATA pattern Bit 2 Bit 1 ENA ENB Register REG2 allows to set the same current for all 6 channels. REG3, REG4, REG5 allow to set the current respectively in banks A, B and C. The three banks can be programmed with independent current values. Table 2. REG2-5 Current Setting Registers Data Pulses Bit 3 IMODE 10 © 2006 Catalyst Semiconductor, Inc. Characteristics subject to change without notice CAT3636 Programming 6 LEDs to 32mA Programming 6 LEDs to 1mA Programming 6 LEDs to 20mA PROGRAMMING EXAMPLES © 2006 Catalyst Semiconductor, Inc. Characteristics subject to change without notice 11 Doc. No. 5020 Rev. A CAT3636 Unused LED Channels External Components For applications with only four or two LEDs, unused LED banks can be disabled via the enable register internally and left to float. The driver requires two 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. For applications with 5 LEDs or less, unused LEDs can also be disabled by connecting the LED pin directly to VOUT, as shown on Figure 4. If LED pin voltage is within 1V of VOUT, then the channel is switched off and a 200μA test current is placed in the channel to sense when the channel moves below VOUT – 1V. In 1x mode, the device operates in linear mode and does not introduce switching noise back onto the supply. Recommended Layout 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. Five LED Application Protection Mode If an LED is disconnected, the output voltage VOUT automatically limits at about 5.5V. This is to prevent the output pin from exceeding its absolute maximum rating. 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. LED Selection LEDs with forward voltages (VF) ranging from 1.3V to 5.0V may be used with the CAT3636. 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. Figure 5. Recommended Layout For example, if a white LED with a VF of 3.3V is selected over one with VF of 3.5V, the CAT3636 will stay in 1x mode for lower supply voltage of 0.2V. This helps improve the efficiency and extends battery life. Doc. No. 5020 Rev. A 12 © 2006 Catalyst Semiconductor, Inc. Characteristics subject to change without notice CAT3636 PACKAGE OUTLINES 16 Lead TQFN (HV3) Notes: (1) All dimensions are in millimeters, angles in degrees. (2) Complies with JEDEC Standard MO-220. For current Tape & Reel information, download the pdf file from: http://www.catsemi.com/documents/tapeandreel.pdf © 2006 Catalyst Semiconductor, Inc. Characteristics subject to change without notice 13 Doc. No. 5020 Rev. A CAT3636 EXAMPLE OF ORDERING INFORMATION Prefix CAT Device # 3636 Suffix HV3 – T2 T: Tape & Reel 2: 2000/Reel Product Number Optional Company ID Package HV3: TQFN 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 CAT3636HV3–T2 (TQFN, Tape & Reel). (4) For additional package and temperature options, please contact your nearest Catalyst Semiconductor Sales office. Doc. No. 5020 Rev. A 14 © 2006 Catalyst Semiconductor, Inc. Characteristics subject to change without notice REVISION HISTORY Date 09/08/06 Rev. A Reason Initial Issue Copyrights, Trademarks and Patents Trademarks and registered trademarks of Catalyst Semiconductor include each of the following: DPP ™ AE2 ™ Quad-Mode ™ 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: 5020 Revision: A Issue date: 09/08/06