 |
|
| If you can't view the Datasheet, Please click here to try to view without PDF Reader . |
|
|
|
| If you can't view the Datasheet, Please click here to try to view without PDF Reader . |
|
|
| Datasheet File OCR Text: |
| www.fairchildsemi.com FAN5610 LED Driver for White, Blue or any Color LED Features * LED Driver for 4 Parallel-connected LEDs * Low Voltage Drop (<350mV) to Support Direct Li-ion Applications with Low VF LEDs * Independent Control Loop for Each LED * Regulated, Matched Constant Current in LEDs * No External Components * No EMI, No Switching Noise * Built-in DAC for Digital and PWM Brightness Control * Up to 91% Maximum Efficiency * Up to 84mA (21mA/LED) Bias Current * 2.7V to 5.5V Input Voltage Range * ICC < 1A in Shutdown Mode * 3mmX3mm MLP-8 Package Description The FAN5610 generates matched current source drives for a maximum of four LEDs. Since each LED current source has its own self-regulating loop, precise current matching is maintained even if there is a substantial forward voltage spread among the LEDs. LED pre-selection therefore is not required. In order to minimize voltage drop, and maximize efficiency, the value of the internal current sense resistors connected in series with the LEDs is very low (10). This is an important consideration for direct DC-driven white LEDs in battery-powered systems. The LEDs' current can be set to 0mA (OFF Mode), 7mA, 14mA, and 21mA with a built-in two-bit digital-to-analog converter. Customized current settings can also be used. When the control bits are set to zero, the internal circuitry is disabled and the quiescent current drops below 1A. Both digital input lines (A, B) can be pulse-width-modulated (PWM). Using PWM, any value of average LED current can be obtained within the 1 to 20 mA range. The FAN5610 is available in an 8-lead 3X3 MLP package. Applications * * * * * * Cell Phones Handheld Computers PDA, DSC, MP3 Players LCD Display Modules Keyboard Backlight LED Displays Typical Application VIN VIN D4 D3 D2 D1 D A C IN A FAN5610 IN B GND REV. 1.0.2 10/28/03 FAN5610 PRODUCT SPECIFICATION Pin Assignment D1 D2 IN B IN A GND FAN5610 D4 D3 VIN 3x3mm 8-LEAD MLP PACKAGE Pin Descriptions Pin Name D1 D2 IN B IN A VIN D3 D4 GND Pin Function Description Cathode of Diode No.1 Cathode of Diode No. 2 DAC Input B, Active High DAC Input A, Active High Input Voltage Cathode of Diode No. 3 Cathode of Diode No. 4 Ground 2 REV. 1.0.2 10/28/03 PRODUCT SPECIFICATION FAN5610 Absolute Maximum Ratings Parameter VIN, IN A/IN B Voltage to GND Lead Soldering Temperature (10 seconds) Operating Junction Temperature Range Storage Temperature Electrostatic Discharge Protection Level (Note1) HBM CDM -55 4 2 Min. -0.3 Max. 6.0 300 150 150 Unit V C C C kV Recommended Operating Conditions Parameter Input Voltage Range, VIN (Note2) Operating Ambient Temperature Range Min. 2.7 -40 25 Typ. Max. 5.5 85 Unit V C DC Electrical Characteristics (VIN =3.3V to 5.5V, TA = 25 C, unless otherwise noted. Boldface values indicate specifications over the ambient operating temperature range.) Parameter Conditions Min. Typ. Max. Units Supply Current, OFF Mode Output Current Accuracy LED to LED Current Matching DAC Input Voltage Threshold Peak Efficiency IN A = 0 IN B = 0 VD > 0.3V IN A = 1, IN B = 1 VIN = 3.6V IN A = 1, IN B = 1 LOW HIGH LED VF =3V at 20mA 14.8 -7.5 0 0.6 x VIN <1 21 2 26 7.5 0.3 x VIN VIN A mA % V % 91 Notes: 1. Using Mil Std. 883E, method 3015.7(Human Body Model) and EIA/JESD22C101-A (Charge Device Model). 2. The minimum operating voltage depends on the LED's operating voltage, as shown in the "Application Information" section. REV. 1.0.2 10/28/03 3 FAN5610 PRODUCT SPECIFICATION Block Diagram VIN D1 D2 D3 + Error Ampl. + Error Ampl. - Bandgap Reference 2-bit DAC 10 10 D4 + + Error Ampl. - IN A IN B Error Ampl. - 10 10 GND 4 REV. 1.0.2 10/28/03 PRODUCT SPECIFICATION FAN5610 Typical Performance Characteristics Unless otherwise specified, TA = 25 C, using Fairchild QTLP670IW Super Bright LED. LED Current vs. Input Voltage (Low VF - White LED) 25 25 LED Current vs. Cathode Voltage A = 1, B = 1 20 20 A = 1, B = 1 LED Current (mA) LED Current (mA) A = 0, B = 1 15 A=0,B= 1 15 10 A = 1, B = 0 10 A = 1, B = 0 5 5 0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 0 0.0 0.5 1.0 1.5 2.0 2.5 Input Voltage (V) Cathode Voltage (V) LED Current vs. Temperature Input Voltage (V) (1V/div) 25 Line Transient Response V IN = 5V A = 1, B = 1 LED Current (mA) 20 A = 0, B = 1 15 10 A=1,B= 0 5 -40 -20 0 20 40 60 80 LED Current (AC) (1mA/div) V IN = 4 V Temperature (C) Ti me (2 s/div) DAC Transient Response Voltage at DAC Inputs (2V/div) A = 1, B = 1 LED Current (10mV/div) ILE D = 0m A A = 0, B = 0 I LED = 21 m A Time (50s/div) REV. 1.0.2 10/28/03 5 FAN5610 PRODUCT SPECIFICATION Digital LED Brightness Control 1. Digital Control A digital to analog converter selects the following modes of operation: OFF, 7mA, 14mA, 21mA per diode. In addition, by turning the "IN B" pin ON and OFF , the current can be modulated between 8 to 20mA to achieve any Iaverage value. A B ILED 0 0 OFF 1 0 7mA 0 1 14mA 1 1 21mA 2. Digital Control with PWM Any pin can be modulated by a variable duty cycle () pulse train. Care should be taken not to use too low frequency, otherwise a flickering effect can be seen.The minimum range is between 100Hz to 5KHz. For a maximum range of LED current, both A and B can be modulated at the same time. Digital Control with PWM A is PWM and B is Low. ILED (Average) = x 7mA where is Duty Cycle. (Note 3) A Input (PWM) 30% Duty Cycle ss 70% Duty Cycle 1KHz B Input (0) 1KHz ILED (Average) = 0.7 x 7mA = 4.9mA ILED (Average) = 0.3 x 7mA = 2.1mA ILED 0mA ss OFF A is High and B is PWM. ILED (Average) = 7mA + x 14mA where is Duty Cycle. (Note 4, 5) A Input B Input (PWM) 30% Duty Cycle 1KHz ss 70% Duty Cycle 1KHz ILED (Average) = 7mA + 0.7 x 14mA = 16.8mA ILED (Average) = 7mA + 0.3 x 14mA = 11.2mA ILED 0mA ss OFF Notes: 3. Proportionally select the duty cycle to achieve a typical LED current between 1mA to 6mA. 4. If either input A or B is high continuously, the other input can be modulated at a maximum rate of 30kHz. If this is not the case, the maximum rate of modulation should be limited to 1kHz. 5. Proportionally select the duty cycle to achieve a typical LED current between 8mA to 20mA. 6 REV. 1.0.2 10/28/03 PRODUCT SPECIFICATION FAN5610 Digital Control with PWM (Continued) A and B are PWM. ILED (Average) = x 21mA where is Duty Cycle. (Note 6) A Input (PWM) 30% Duty Cycle 1KHz ss 70% Duty Cycle 1KHz B Input (PWM) 30% Duty Cycle ss 70% Duty Cycle ILED (Average) = 0.7 x 21mA = 14.7mA ILED (Average) = 0.3 x 21mA = 6.3mA ILED 0mA ss OFF Note: 6. Proportionally select the duty cycle to achieve the desired value of typical LED current between 1mA to 20mA. Application Information As seen in the block diagram, the FAN5610 includes four independent current regulators able to maintain a programmable constant current through LEDs, regardless of their forward voltage. This is true over a wide range of input voltage starting from VF_max + 0.35V, where VF_max is the highest forward voltage among the LEDs driven by FAN5610. The independence of current (LED current changes less than 1%) with change in VIN and VF for VIN > VF (MAX) + 0.35V, is shown in the graph below. Program the LED's brightness by applying a continuous voltage level or a PWM signal at the inputs of the built-in digital to analog converter (DAC). When a PWM signal is utilized to drive the DAC inputs, the current through the LEDs is switched between two levels with the PWM signal frequency. Consequently, the average current changes with the duty cycle. The LED current waveform tracks the PWM signal, so the LEDs brightness depends on the duty cycle. For white LEDs the spectral composition is optimal at a current level specified by the manufacturer. The DAC inputs should be programmed to set the current required to achieve white LED spectrum and PWM used for dimming. To maintain the "purest" white, the current through the LEDs should be switched between zero and a specified current level (usually around 20mA) corresponding to the white light chromaticity coordinate. Conversion errors are minimized and the best LED to LED matching is achieved over the entire range of average current settings, when PWM brightness control is used to modulate the LED current between zero and the maximum value (A=1, B=1). Current Regulation Performance 25 V F1 = 3.3 V 20 LED Current (mA) V IN > V F ( M A X) + 0.3 5V 15 10 V F2 =3 .6V 5 0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 Input Voltage (V) REV. 1.0.2 10/28/03 7 FAN5610 PRODUCT SPECIFICATION Application Examples: Example 1: Drive low VF white or blue LEDs directly from single cell Li-ion When using white or blue low VF LEDs, and utilizing the driver's low voltage drop, only 3.45V in VIN is needed for the full 20mA LED current. Usually at 3.1V, there is still 5mA current available for the LEDs. The single cell Li-ion is utilized in most applications like cell phones or digital still cameras. In most cases, the Li-ion battery voltage level only goes down to 3.0V voltage level, and not down to the full discharge level (2.7V) before requesting the charger. - VDROP ~ 0.35V - VF (at 20mA) = 3.3V to 4.0V (High VF) - VIN(at 20mA) VDROP + VF = 4.35V(max) Where VIN = Existing bus = 5V VIN(System Bus) D4 VIN D3 D2 D1 VIN(Li-Ion) Microprocessor I/O IN A IN B FAN5610 GND D4 VIN IN A Micro-Controller IN B D3 D2 D1 FAN5610 GND Key advantages: * No boost circuit needed for LCD or keyboard backlight * Driver utilizes the existing bus * Low voltage drop provides the full 20mA LED current at the lowest possible voltage level. - - - - VDROP ~ 0.35V VF (at 20mA) < 3.1V (Low VF) VIN (at 20mA) =VDROP + VF = 3.45V VIN (at 5mA Typical) ~ 3.1V Where VIN = Single cell Li-ion Voltage Key advantages: * No boost circuit needed for the LCD or keyboard backlight * Driver directly connected to a Li-ion battery * No EMI, no switching noise, no boost efficiency lost, no capacitor, and no inductor. Example 2: Drive high VF white or blue LEDs from existing bus from 4.0V to 5.5V High VF white or blue LEDs have forward-voltage drop in the range of 3.3V to 4.0V. To drive these LEDs with the maximum current of 20mA for maximum brightness, usually requires a boost circuit for a single cell Li-ion voltage range. In some cases, there is already a voltage bus in the system, which can be utilized. Due to the low voltage drop of the FAN5610, VIN needs to be only 350mV higher than the voltage VF of LEDs connected to FAN5610. 8 REV. 1.0.2 10/28/03 PRODUCT SPECIFICATION FAN5610 Mechanical Dimensions 3mmX3mm 8-Lead MLP Package 2.37 4 B 1 0.15 C 2X 3.0 A 1.42 3.0 (0.65) 5 0.15 C 2X 0.65 TYP 8 1.99 3.30 0.47 TYP TOP VIEW 1.0 MAX 0.10 C (0.20) 0.08 C 0.05 0.00 SEATING PLANE 1 RECOMMENDED LAND PATTERN C SIDE VIEW 2.25 MAX 4 0.45 0.20 1.30 MAX. 8 0.65 1.95 5 0.25~0.35 O 0.10 M C A B O 0.05 M BOTTOM VIEW NOTES: A. CONFORMS TO JEDEC REGISTRATION MO-229, VARIATION VEEC, DATED 11/2001 B. DIMENSIONS ARE IN MILLIMETERS. C. DIMENSIONS AND TOLERANCES PER ASME Y14.5M, 1994 REV. 1.0.2 10/28/03 9 FAN5610 PRODUCT SPECIFICATION Ordering Information Product Number FAN5610 Package Type 3x3mm 8-Lead MLP Order Code FAN5610MPX DISCLAIMER FAIRCHILD SEMICONDUCTOR RESERVES THE RIGHT TO MAKE CHANGES WITHOUT FURTHER NOTICE TO ANY PRODUCTS HEREIN TO IMPROVE RELIABILITY, FUNCTION OR DESIGN. FAIRCHILD DOES NOT ASSUME ANY LIABILITY ARISING OUT OF THE APPLICATION OR USE OF ANY PRODUCT OR CIRCUIT DESCRIBED HEREIN; NEITHER DOES IT CONVEY ANY LICENSE UNDER ITS PATENT RIGHTS, NOR THE RIGHTS OF OTHERS. LIFE SUPPORT POLICY FAIRCHILD'S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT OF FAIRCHILD SEMICONDUCTOR CORPORATION. As used herein: 1. Life support devices or systems are devices or systems which, (a) are intended for surgical implant into the body, or (b) support or sustain life, and (c) whose failure to perform when properly used in accordance with instructions for use provided in the labeling, can be reasonably expected to result in a significant injury of the user. www.fairchildsemi.com 10/28/03 0.0m 005 Stock#DS30005609 2003 Fairchild Semiconductor Corporation 2. A critical component in any component of a life support device or system whose failure to perform can be reasonably expected to cause the failure of the life support device or system, or to affect its safety or effectiveness. |
Price & Availability of FAN5610
 |
|
|
|
|
All Rights Reserved © IC-ON-LINE 2003 - 2022 |
| [Add Bookmark] [Contact Us] [Link exchange] [Privacy policy] |
|
Mirror Sites : [www.datasheet.hk]
[www.maxim4u.com] [www.ic-on-line.cn]
[www.ic-on-line.com] [www.ic-on-line.net]
[www.alldatasheet.com.cn]
[www.gdcy.com]
[www.gdcy.net] |