XRP7620IHTR-F

XRP7620 4-Channel Adjustable Current I2C Controlled LED Driver June 2012 Rev. 1.1.0 GENERAL DESCRIPTION APPLICATIONS The XRP7620 is a multi purpose 4-channel independently adjustable current sink driver. Optimized for LED backlighting and RGBW/RGBA color mixing applications, the XRP7620 can also be used as a generic software programmable current sink I/O expander.  LCD Display & Keypad Backlighting  Color Coded Indicator Lighting  RGBW/RGBA Color Mixing  Cell Phones & Handheld Devices  Generic Current Sink I/O Expander 2 Supporting an industry standard 2-wire I C serial interface, the XRP7620 provides full independent control of each channel and can be programmed up to a current of 31.5mA in steps of 0.5mA. Uniform display brightness is ensured through better than 3% channel to channel current matching. Five internal registers are provided to set operational configuration and individual channel current programmation. A specific shutdown mode allows the device to retain the previously loaded configuration – operational and current programming – in order to be reused upon the next enabling. The XRP7620 is designed to operate from a single cell lithium-ion battery or fixed 3.3V or 5.0V power rails and is available in a RoHS compliant, “green”/halogen free space saving 8-pin 2mmx3mm DFN package. FEATURES  4-Channel LED Current Sink Driver  Individual Channel Current Control  Up to 31.5mA per channel / 0.5mA Steps  100mV Channel Dropout Voltage  I2C Serial Interface  2.7V - 5.5V Input Voltage Range  3% Channel Current Matching  Register Retention in Shutdown  Shutdown Current 6mA 150 2/11 • ILED=20mA; The voltage where LED current decreases 3% from nominal value at V LED = 1V. VIN=2.7 to 5.5V Rev. 1.1.0 XRP7620 4-Channel Adjustable Current I2C Controlled LED Driver Parameter Min. Typ. Thermal Shutdown Hysteresis Max. Units 15 SDA, SCL Input Logic Low Voltage 0.4 SDA, SCL Input Logic High Voltage 1.6 SDA, SCL Timeout for Shutdown Conditions °C 90 150 Regulator turns on V • V • ms I2C SPECIFICATION S XRP7620 Address R/W 7-bit 1/0 A Status Data A LED1 Data 8-bit A LED2 Data 8-bit A LED3 Data 8-bit LED4 Data A 8-bit A SP 8-bit Start Condition Stop Condition Acknowledgement - sent by the slave when R/W=0 - sent by master when R/W=1 Acknowledgement sent by the slave Fig. 2: Data Input Format I2C TIMING CHARACTERISTICS Unless otherwise indicated, V IN = 2.7V to 4.6V, C IN = 1µF, TA= –40°C Parameter Symbol Min. Typ. to 85°C, TJ = –40°C to 100°C. Max. Units 400 KHz Serial Clock Frequency fSCL Bus Free Time between a STOP and a START tBUF 1.3 µs tHD_STA 0.6 µs Hold Time, Repeated START Condition STOP Condition Setup Time tSU,STO 0.6 Data Hold Time tHD,DAT(OUT) 225 900 ns Input Data Hold Time tHD, DAT(IN) 0 900 ns tSU, DAT 100 ns SCL Clock Low Period tLOW 1.3 ms SCL Clock High Period ms Data Setup Time Conditions ms tHIGH 0.6 Rise Time of Both SDA and SCL Signals, receiving tR 20+0.1Cb 300 ns Note 4,5 Fall Time of Both SDA and SCL Signals, Receiving tF 20+0.1Cb 300 ns Note 4,5 Fall Time of SDA Transmitting tF.TX 20+0.1Cb 250 ns Note 4,5, 6 Pulse Width of Spike Suppressed tSP 0 50 ns Note 7 Capacitive Load for each Bus Line Cb 400 pF Note 4 I2C Startup Time after UVLO clears tSRT 1 µs Note 4 Note 1: All parameters tested at TA=25 °C. Specifications over temperature are guaranteed by design. Note 2: LED current matching is calculated by this equation: I LED  I AVG  100% Where IAVG is the average current of 4 channels. I AVG © 2012 Exar Corporation 3/11 Rev. 1.1.0 XRP7620 4-Channel Adjustable Current I2C Controlled LED Driver Note 3: Ling regulation is calculated by this equation: I 2  I1 1 Where I1 and I2 is the current at different V IN.   100% I AVG V Note Note Note Note 4: 5: 6: 7: Guaranteed by design. Cb = total capacitance of one bus line in pF. tR and tF measured between 0.3 x V DD and 0.7 x VDD. ISINK ≤6mA. Cb =total capacitance of one bus line in pF. t R and tF measured between 0.3 x V DD and 0.7 VDD. Input filters on the SDA and SCL inputs suppress noise spikes less than 50ns. BLOCK DIAGRAM Fig. 3: XRP7620 Block Diagram PIN ASSIGNMENT 2mm x 3mm VIN SDA SCL GND 1 8 2 7 3 6 4 5 LED1 LED2 LED3 LED4 DFN-8L Fig. 4: XRP7620 Pin Assignment © 2012 Exar Corporation 4/11 Rev. 1.1.0 XRP7620 4-Channel Adjustable Current I2C Controlled LED Driver PIN DESCRIPTION Name Pin Number VIN 1 Connect a 1µF decoupling capacitor between this pin and the ground pin (pin 4). Description SDA 2 I2C Interface Serial Data Input-Output. SCL 3 I2C Interface Serial Clock Input. GND 4 Ground Signal. LED4 5 LED 4 Input. Connect a LED between this pin and VIN. Current Value is set by the serial interface. LED3 6 LED 3 Input. Connect a LED between this pin and VIN. Current Value is set by the serial interface. LED2 7 LED 2 Input. Connect a LED between this pin and VIN. Current Value is set by the serial interface. LED1 8 LED 1 Input. Connect a LED between this pin and VIN. Current Value is set by the serial interface. GND Exp. Pad Ground Signal. ORDERING INFORMATION Temperature Range Marking Package Packing Quantity XRP7620IH-F -40°C≤TJ≤+100°C 7620I YYWWFX DFN-8L Bulk Green Halogen Free 0x70 XRP7620IHTR-F -40°C≤TJ≤+100°C 7620I YYWWFX DFN-8L 3K/Tape & Reel Green Halogen Free 0x70 Part Number XRP7620EVB Note 1 I2C Address XRP7620 Evaluation Board “YY” = Year – “WW” = Work Week – “F”= Green/Halogen Free Package - “X” = Lot Number XRP7620 may be ordered with alternative I2C addresses – Contact your Exar Sales Representative for further information. © 2012 Exar Corporation 5/11 Rev. 1.1.0 XRP7620 4-Channel Adjustable Current I2C Controlled LED Driver Typical Performance Characteristics All data taken at V IN = 2.7V to 5.5V, TJ = TA = 25°C, unless otherwise specified - Schematic and BOM from Application Information/Theory of Operation section of this datasheet. CH1 = SDA, CH2 = SCL, CH 4 = ILED = 20mA/div Fig. 5: LED Current Change Settling Time From 0.5mA to 31.5mA Fig. 6: LED Current Change Settling Time From 0mA to 31.5mA Fig. 7: SDA, SCL Timeout for Shutdown Fig. 8: LED Current Change Settling Time From DAC 31.5mA to 0mA Fig. 9: Line Regulation DAC = 101000 (20mA) Fig. 10: Line Regulation LED1 DAC = 101000 (20mA) © 2012 Exar Corporation 6/11 Rev. 1.1.0 XRP7620 4-Channel Adjustable Current I2C Controlled LED Driver Fig. 11: Line Regulation @ TA = 25oC DAC = 111100 (30mA) Fig. 12: Line Regulation @ TA = -40oC DAC = 111100 (30mA) Fig. 13: Line Regulation @ TA = 85oC DAC = 111100 (30mA) Fig. 14: Line Regulation @ TA = 25oC DAC = 001010 (5mA) Fig. 15: Line Regulation @ TA = -40oC DAC = 001010 (5mA) Fig. 16: Line Regulation @ TA = 85oC DAC = 001010 (5mA) © 2012 Exar Corporation 7/11 Rev. 1.1.0 XRP7620 4-Channel Adjustable Current I2C Controlled LED Driver THEORY OF OPERATION LED Registers (x4) LED register bits B7-B2 I2C SERIAL INTERFACE In LED registers bits B7, B6, B5, B4, B3 and B2 represent the DAC codes D5-D0 used to set the LED current in the four LEDs, and B1 and B0 are not used. The following table lists the DAC codes and the corresponding current for each channel in mA: The XRP7620 has five data registers which can be programmed serially through the I²C interface. The first register is a status register which has two bits used for shutdown/power up options, 4 bits used for individual LED ON/OFF control, one bit for over-temperature readback and one bit for undervoltage lockout readback. The next four registers are used to set the brightness levels of the four LEDs. B7 Status WZ B6 WP B5 B4 B3 B2 LED4 LED3 LED2 LED1 B7-B2 Current mA B7-B2 Current mA 000000 0 100000 16.0 000001 0.5 100001 16.5 000010 1.0 100010 17.0 000011 1.5 100011 17.5 B0 000100 2.0 100100 18.0 UVL 000101 2.5 100101 18.5 3.0 100110 19.0 B1 OVT LED1 D5 D4 D3 D2 D1 D0 - - 000110 LED2 D5 D4 D3 D2 D1 D0 - - 000111 3.5 100111 19.5 LED3 D5 D4 D3 D2 D1 D0 - - 001000 4.0 101000 20.0 LED4 D5 D4 D3 D2 D1 D0 - - 001001 4.5 101001 20.5 001010 5.0 101010 21.0 001011 5.5 101011 21.5 Status Register 001100 6.0 101100 22.0 Status register bits B7 and B6 001101 6.5 101101 22.5 001110 7.0 101110 23.0 001111 7.5 101111 23.5 010000 8.0 110000 24.0 010001 8.5 110001 24.5 010010 9.0 110010 25.0 010011 9.5 110011 25.5 010100 10.0 110100 26.0 010101 10.5 110101 26.5 010110 11.0 110110 27.0 010111 11.5 110111 27.5 011000 12.0 111000 28.0 011001 12.5 111001 28.5 011010 13.0 111010 29.0 011011 13.5 111011 29.5 011100 14.0 111100 30.0 011101 14.5 111101 30.5 011110 15.0 111110 31.0 011111 15.5 111111 31.5 2 Table 1: XRP7620 I C Register Bit Map The following table defines the states for bits B7 and B6 of the STATUS register. They are used to put the XRP7620 into shutdown, standby, or active mode. WZ 0 0 1 1 WP State IQ 0 Shutdown and reset registers to 00000000 1 Shutdown Keeps registers contents 0µA Standby Keeps registers contents 30µA Active Active 0 1 0µA LED Driver Off Off Off On Table 2: XRP7620 Status Register Bits B7 and B6 Status register bits B5-B2 These bits are to control the LED On/Off individually. Putting 1 (logic high) will enable the driver and putting 0 (logic low) will disable the driver. Table 3: LED Current DAC Settings Status register bits B1 and B0 These bits are the readback bits. Their values are 0 for normal operations. If overtemperature is detected, B1=1, and If undervoltage is detected, B0=1. The UVL threshold is approximately 2.4V. © 2012 Exar Corporation 8/11 Rev. 1.1.0 XRP7620 4-Channel Adjustable Current I2C Controlled LED Driver Addressing and Writing Data SHORTED LEDS To write data to the XRP7620 one of the following two cycles must be followed: If an LED shorts to the extent that the LED pin comes within 0.7V of VIN the LED channel may turn off because the drive circuitry effectively is in a dropout condition. The exact voltage will vary with programmed LED current. Easy shutdown/startup sequence [Slave Address with write bit][Data for Status] PARALELLING CURRENT SINKS Full shutdown/startup sequence The maximum programmable current per LED pin is 31.5mA. If a higher current is desired, 2, 3, or all 4 LED pins may be connected to share current. Although it is technically possible to program the channels to different values to add up to the desired total, it is recommended that paralleled channels be programmed to the same value. [Slave Address with write bit][Data for Status][Data for LED1][Data for LED2][Data for LED3][Data for LED4] Addressing and Reading Data To read data from the XRP7620 the following data cycle must be obeyed: [Slave Address with read bit][Data for Status][Data for LED1][Data for LED2][Data for LED3][Data for LED4] SHUTDOWN OPTIONS The XRP7620 can be placed in shutdown mode by holding both the SDA and SCL lines low for a minimum of typically 90ms. This puts a zero in bit 7 and bit 6 of the status register, which in turn will reset all bits of all registers. After any shutdown, the part can only be restarted through the I2C bus. © 2012 Exar Corporation 9/11 Rev. 1.1.0 XRP7620 4-Channel Adjustable Current I2C Controlled LED Driver PACKAGE SPECIFICATION 8-PIN DFN © 2012 Exar Corporation 10/11 Rev. 1.1.0 XRP7620 4-Channel Adjustable Current I2C Controlled LED Driver REVISION HISTORY Revision Date 1.0.0 06/04/2009 Initial release of datasheet Description 1.1.0 06/12/2012 Added Exposed Pad description in Pin Assignment table FOR FURTHER ASSISTANCE Email: customersupport@exar.com Exar Technical Documentation: http://www.exar.com/TechDoc/default.aspx? EXAR CORPORATION HEADQUARTERS AND SALES OFFICES 48720 Kato Road Fremont, CA 94538 – USA Tel.: +1 (510) 668-7000 Fax: +1 (510) 668-7030 www.exar.com NOTICE EXAR Corporation reserves the right to make changes to the products contained in this publication in order to improve design, performance or reliability. EXAR Corporation assumes no responsibility for the use of any circuits described herein, conveys no license under any patent or other right, and makes no representation that the circuits are free of patent infringement. Charts and schedules contained here in are only for illustration purposes and may vary depending upon a user’s specific application. While the information in this publication has been carefully checked; no responsibility, however, is assumed for inaccuracies. EXAR Corporation does not recommend the use of any of its products in life support applications where the failure malfunction of the product can reasonably be expected to cause failure of the life support system or to significantly affect safety or effectiveness. Products are not authorized for use in such applications unless EXAR Corporation receive s, writing, assurances to its satisfaction that: (a) the risk of injury or damage has been minimized; (b) the user assumes such risks; (c) potential liability of EXAR Corporation is adequately protected under the circumstances. or its in all Reproduction, in part or whole, without the prior written consent of EXAR Corporation is prohibited. © 2012 Exar Corporation 11/11 Rev. 1.1.0