Document
XRP7620
4-Channel Adjustable Current I2C Controlled LED Driver
June 2009 Rev. 1.0.0
GENERAL DESCRIPTION
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. 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.
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APPLICATIONS
• LCD Display & Keypad Backlighting • Color Coded Indicator Lighting • RGBW/RGBA Color Mixing • Cell Phones & Handheld Devices • Generic Current Sink I/O Expander
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 <1µA • Thermal and UVLO Built-in Protection • RoHS Compliant, “Green”/Halogen Free 2x3mm 8-Pin DFN package
TYPICAL APPLICATION DIAGRAM
Fig. 1: XRP7620 Application Diagram
Exar Corporation 48720 Kato Road, Fremont CA 94538, USA
www.exar.com Tel. +1 510 668-7000 – Fax. +1 510 668-7001
XRP7620
4-Channel Adjustable Current I2C Controlled LED Driver ABSOLUTE MAXIMUM RATINGS
These are stress ratings only and functional operation of the device at these ratings or any other above those indicated in the operation sections of the specifications below is not implied. Exposure to absolute maximum rating conditions for extended periods of time may affect reliability. VIN, SDA, SCL, LEDx .................................. -0.3V to 6.0V Storage Temperature .............................. -65°C to 150°C Power Dissipation ................... Internally Limited (Note 1) Lead Temperature (Soldering, 10 sec) ................... 300°C ESD Rating (Human Body Model) ............................. 2kV
OPERATING RATINGS
Input Voltage Range VIN ...............................2.7V to 5.5V Junction Temperature Range ....................-40°C to 100°C Thermal Resistance θJA ...................................... 59°C/W
ELECTRICAL SPECIFICATIONS
Specifications with standard type are for an Operating Junction Temperature of TJ = 25°C only; limits applying over the full Operating Junction Temperature range are denoted by a “•”. Minimum and Maximum limits are guaranteed through test, design, or statistical correlation. Typical values represent the most likely parametric norm at TJ = 25°C, and are provided for reference purposes only. Unless otherwise indicated, VIN = 2.7V to 4.6V, CIN = 1µF, TA= –40°C to 85°C, TJ = –40°C to 100°C. Parameter Operating Input Voltage Range Operating Input Current DAC=000000 Operating Input Current LED Current accuracy (includes Line Regulation) -0.3 -5 -8 LED Current Matching Line Regulation -3 Min. 2.7 30 450 Typ. Max. 5.5 50 600 0.3 5 8 3 1 6 2 0.35 30.50 0.50 31.75 0.65 33.00 Units V µA µA mA % % % %/V Bit µA mA mA • Applies to all LEDs Applies to all LEDs Applies to all LEDs For changes between any DAC code 000001 and higher. Current must change within this time after the last bit of LED data. VIN=2.7 to 5.5V Applies to changes between DAC code 000000 and higher or change from 0 to 1 for STATUS bits B5-B2 (channel enable). Current must change within this time after the last bit of LED data. VIN=2.7 to 5.5V • ILED=20mA; The voltage where LED current decreases 3% from nominal value at VLED = 1V. VIN=2.7 to 5.5V VIN=4.2V VIN=4.2V, TA=85°C Regulator turns off • • • • • • • ILEDX=0, VIN=4.2V ILED1=ILED2=ILED3=ILED4=10mA, VIN=4.2V VLED = 0.2V to 2.7V ILEDX ≤ 6mA VLED = 0.2V to 2.7V ILEDX > 6mA For same DAC setting VLED = 0.2V to 2.7V, Note 2 Measured as ΔIOUT /IOUT_AVG /ΔV VLED = 0.2V to 2.7V, Note 3 Conditions
www.DataSheet4U.com Current DAC Resolution
Current for DAC=000000 Current for DAC=000001 Maximum LED Current DAC=111111
2 Maximum Current Change Settling Time 60 150
µs
•
µs
Current Source Dropout Voltage Shutdown Supply Current Shutdown Supply Current Thermal Shutdown Die Temperature 125
0.1 0.01 150
0.15 1 5 175
V µA µA °C
© 2009 Exar Corporation
2/11
Rev. 1.0.0
XRP7620
4-Channel Adjustable Current I2C Controlled LED Driver
Parameter Thermal Shutdown Hysteresis SDA, SCL Input Logic.