FAN5612S7X

Low-Dropout LED Drivers for White, Blue, or any Color LED November 2006 tm FAN5611/FAN5612/FAN5613/FAN5614 Low-Dropout LED Drivers for White, Blue, or any Color LED Features ■ LED drivers for parallel-connected LEDs (2 to 4) ■ Ultra-low voltage drop (< 300mV) to support direct Description The FAN5611/12/13/14 low-dropout product family is designed to drive two to four parallel LEDs, providing matched current source bias for all color LEDs. The LED current is set by an external resistor, RSET. The FAN5611/13 supports four parallel LEDs with up to 160mA bias current (up to 40mA per output). The FAN5612 supports three LEDs with up to 120mA bias current (40mA per output). The FAN5614 drives two high-current LEDs (80mA per output). Pin I1 should always be connected to an LED to provide a matched current for any additional LEDs. The FAN5612/13 and 14 are selected using an ENABLE pin. When the chip is not selected (ENABLE pin is LOW), the supply current drops to less than 1µA. The FAN5611, FAN5612, and FAN5614 are available in an SC-70 package. The FAN5611 and FAN5613 are available in MLP packages. Li-ion applications ■ No EMI, no switching noise ■ No external components needed for current matching ■ Both analog and PWM brightness control ■ FAN5611, FAN5613 feature up to 160mA bias current (up to 40mA for each LED) ■ FAN5612 features up to 120mA bias current (up to 40mA for each LED) ■ FAN5614 features up to 160mA bias current (up to 80mA for each LED) ■ Enable/Shutdown control (FAN5612, FAN5613, FAN5614) ■ Shutdown current < 1μA ■ Small footprint SC-70 and MLP Applications ■ Cell Phones ■ PDA, DSC, MP3 Players ■ Handheld Computers ■ LCD Display Modules ■ Keyboard Backlight ■ LED Displays Ordering Information Product Number FAN5611 FAN5612 FAN5613 FAN5614 Table 1. Ordering Information Package Type 6-Lead SC-70 / 2x2mm 6-Lead MLP 6-Lead SC-70 2x2mm 8-Lead MLP 6-Lead SC-70 Order Code FAN5611S7X / FAN5611MPX FAN5612S7X FAN5613MPX FAN5614S7X © 2003 Fairchild Semiconductor Corporation FAN5611/FAN5612/FAN5613/FAN5614 Rev. 1.0.9 www.fairchildsemi.com FAN5611/FAN5612/FAN5613/FAN5614 Typical Applications VIN VIN VIN ISET VCONTROL (3V) RSET I4 CTRL I3 I2 I1 VCONTROL (3V) ISET RSET ENABLE I3 CTRL ON/OFF I2 I1 ISET VCONTROL (3V) RSET ENABLE I4 CTRL ON/OFF I3 I2 I1 FAN5611 GND FAN5612 GND FAN5613 GND Four Diode Control Three Diode Control with ON/OFF Four Diode Control With ON/OFF VIN ISET VCONTROL (3V) RSET CTRL ON/OFF I1/I2 I3/I4 FAN5614 GND ENABLE Two Diode Control with ON/OFF Figure 1. Typical Applications for FAN5611, FAN5612, FAN5613, FAN5614 Pin Assignments CTRL I2 I1 1 2 3 6 5 4 I3 I4 GND CTRL I2 I1 1 2 3 6 5 4 ON/OFF I3 GND CTRL I1/I2 N/C 1 2 3 6 5 4 ON/OFF I3/I4 GND FAN5611 FAN5612 FAN5614 6-LEAD SC-70 TOP VIEW D2 CTRL D3 GND D1 GND D4 ON/OFF I3 I4 GND TOP VIEW NC CTRL I2 I1 FAN5611 FAN5613 2x2mm 6-LEAD MPX 2x2mm 8-LEAD MLP Figure 2. Pin Assignments for FAN5611, FAN5612, FAN5613, FAN5614 © 2003 Fairchild Semiconductor Corporation FAN5611/FAN5612/FAN5613/FAN5614 Rev. 1.0.9 2 www.fairchildsemi.com FAN5611/FAN5612/FAN5613/FAN5614 Pin Descriptions Name Pin # 1 2 FAN5611 CTRL I2 FAN5612 CTRL FAN5613 ON/OFF FAN5614 CTRL Description Sets LED Current (see Operational Descripton) Chip ON/OFF/Disable Connect to Cathode of LED Connect to Cathode of LED I2 I3 I1/I2 3 I1 I1 I4 N/C Connect to Cathode of LED Connect to Cathode of LED No Connection Ground Connect to Cathode of LED Connect to Cathode of LED I1 I3/I4 Connect to Cathode of LED Connect to Cathode of LED Connect to Cathode of LED Chip ON/OFF/Disable Connect to Cathode of LED Sets LED Current (see Operational Descripton) No Connection GND 4 5 GND I4 GND I3 GND 6 I3 ON/OFF I2 ON/OFF CTRL NC 7 8 Table 2. Pin Descriptions Notes: 1. The DAP of FAN 5611MPX can be tied to the GND pin or left floating. For better power dissipation, tie to GND. © 2003 Fairchild Semiconductor Corporation FAN5611/FAN5612/FAN5613/FAN5614 Rev. 1.0.9 3 www.fairchildsemi.com FAN5611/FAN5612/FAN5613/FAN5614 Absolute Maximum Ratings The “Absolute Maximum Ratings” are those values beyond which the safety of the device cannot be guaranteed. The device should not be operated at these limits. The parametric values defined in the Electrical Characteristics tables are not guaranteed at the absolute maximum ratings. The “Recommended Operating Conditions” table defines the conditions for actual device operation. Parameter VI1, VI2, VI3, VI4 and ENABLE Voltage to GND CTRL Voltage to GND Power Dissipated by package at TA = 85°C I1, I2, I3, I4 Steady State Current I1/I2, I3/I4 Steady State Current Lead Temperature (Soldering 10 seconds) Junction Temperature Storage Temperature Electrostatic Discharge Protection (ESD) Level (1) HBM CDM Table 3. Absolute Maximum Ratings 6-Lead SC70 6, 8-Lead MLP FAN5611/12/13 FAN5614 Min. -0.3 -0.3 Max. 6.0 3.0 190 700 40 80 300 150 Unit V mW mA °C °C °C kV -55 4 1 150 Recommended Operating Conditions Parameter LED Cathode Voltage FAN5611, FAN5612, FAN5613 FAN5614 Ambient Temperature Table 4. Recommended Operating Conditions Notes: 2. Using Mil Std. 883E, method 3015.7 (Human Body Model) and EIA/JESD22C101-A (Charge Device Model). Min. 0.3 0.15 -40 Typ. 0.5 Max. 1.0 Unit V 25 85 °C © 2003 Fairchild Semiconductor Corporation FAN5611/FAN5612/FAN5613/FAN5614 Rev. 1.0.9 4 www.fairchildsemi.com FAN5611/FAN5612/FAN5613/FAN5614 DC Electrical Characteristics VIN = 3.3V to 5.5V, ENABLE = VIN, TA = 25°C unless otherwise noted. Parameter FAN5611/12/13 Current Gain FAN5614 FAN5611/12/13 FAN5614 Conditions ISET = 100µA VSAT = 300mV ISET = 100µA VSAT = 150mV VSAT = 300mV ISET = 100µA VSAT = 150mV ISET = 100µA VSAT = 300mV ISET = 100µA TA = -40°C to 85°C VSAT = 150mV ISET = 100µA TA = -40°C to 85°C VIN = 3V VEN = 0V ISET = 150µA (2) Min. Typ. Max. Units 140 200 260 LED Current (Per Diode) 20 mA FAN5611/12/13 LED to LED Current Matching FAN5614 Peak Efficiency Current in OFF Mode (ISET and II) Minimum ENABLE “ON Voltage” (FAN5612, FAN5613, FAN5614) -3 3 % 90 1 2.8 0.5 % µA V V Maximum ENABLE “OFF Voltage”(2) (FAN5612, FAN5613 FAN5614) Table 5. DC Electrical Characteristics Notes: 3. ENABLE “ON” is VEN where II1>20mA @ VI1=0.3V, while ENABLE “OFF” is VEN where II10.3V. © 2003 Fairchild Semiconductor Corporation FAN5611/FAN5612/FAN5613/FAN5614 Rev. 1.0.9 5 www.fairchildsemi.com FAN5611/FAN5612/FAN5613/FAN5614 Typical Performance Characteristics Figure 3. FAN5611/12/13 Output Current vs. Temerature Figure 4. ISET vs. VCTRL Figure 5. FAN5611/12/13 LED Current vs. LED Cathode Voltage Figure 6. FAN5614 LED Current vs. LED Cathode Voltage Figure 7. FAN5611/12/13 LED Current vs. Set Resistor Figure 8. FAN5614 LED Current vs. Set Resistor © 2003 Fairchild Semiconductor Corporation FAN5611/FAN5612/FAN5613/FAN5614 Rev. 1.0.9 6 www.fairchildsemi.com FAN5611/FAN5612/FAN5613/FAN5614 Typical Performance Characteristics (Continued) Figure 9. FAN5611/12/13/14 Control Voltage Transient Response Figure 10. FAN5612/13/14 Enable Voltage Transient Response © 2003 Fairchild Semiconductor Corporation FAN5611/FAN5612/FAN5613/FAN5614 Rev. 1.0.9 7 www.fairchildsemi.com FAN5611/FAN5612/FAN5613/FAN5614 Application Information Operational Descripton The regulated current through each LED is a multiplication of the ISET current. The ISET value is determined by the RSET value. The ISET value can be calculated as: ISET = ILED / Current Gain Reference Figure 4, the ISET vs. VCTRL graph, to estimate VCTRL. The value of RSET is calculated according to the formula: RSET = (VCONTROL - VCTRL) / ISET For example, with VCONTROL = 3V, a 10mA current limit through the LED results in ISET = 50µA. That translates to an approximate value of 1.2V for VCTRL, shown in Figure 4. The resulting RSET value that maintains 10mA regulation is 36kΩ. The LED intensity can be adjusted by varying the duty cycle of a square wave applied to the enable pin. Frequency greater than 100Hz is best to avoid a "flickering" effect. The maximum operation frequency is 10MHz. Efficiency Considerations The FAN561X driver’s low-dropout architecture can significantly improve the efficiency compared to using simple ballast resistors. The system efficiency, defined as the ratio between the LEDs’ power and the input supplied power, can be calculated as: Efficiency = ( V IN – V CATHODE ) ⁄ V IN The lower the VCATHODE, the higher the system efficiency. Efficiency can be further improved by using a higher VIN with more LEDs, as shown in Example 3. VCONTROL VIN ISET RSET I4 CTRL ON/OFF I3 I2 I1 FAN5613 GND ENABLE – – – – VDROP < 0.3V VF (at 20mA) < 3.1V (Low VF) VIN (at 20mA) =VDROP + VF = 3.4V VIN (at 5mA Typical) ~ 3.1V where VIN = Single cell Li-ion voltage. Key advantages: • No boost circuit is needed for the LCD or keyboard backlight. • Drivers are 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 3.2V to 4.0V. Driving 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 ultralow voltage drop of the FAN561X series of LED drivers to drive high-VF white or blue LEDs, the VIN needs to be only 300mV higher than the highest VF in the circuit. – – – – VDROP < 0.3V VF (at 20mA) < 3.3V to 4.0V (High VF) VIN (at 20mA) =VDROP + VF = 3.6V to 4.3V VIN (at 5mA Typical) ~ 3.3V Application Notes The ultra-low voltage drop across the FAN561X series of LED drivers allows the devices to drive white, blue, and other color LEDs in a wide range of input voltages. The driver can be used in many applications. Although only the FAN5613 is shown in all three examples, any of the FAN561X-series LED drivers can be used in the applications presented, due to their similar operation. 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 drivers low voltage drop, only 3.4V in VIN is needed for the full 20mA LED current. At 3.1V, there is 5mA typical current available for the LEDs. The single cell Li-ion is utilized in 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, not down to the full discharge level (2.7V) before requesting the charger. where VIN = existing bus = 3.3V to 4.3V. Key advantages: • No boost circuit is needed for LCD or keyboard backlight. • Driver utilizes the existing bus. • Ultra-low voltage drop provides the full 20mA LED current at the lowest possible voltage level. © 2003 Fairchild Semiconductor Corporation FAN5611/FAN5612/FAN5613/FAN5614 Rev. 1.0.9 8 www.fairchildsemi.com FAN5611/FAN5612/FAN5613/FAN5614 Example 3: Drive white, blue, red, amber LEDs string Assuming a boost circuit or existing voltage bus, the FAN561X series of LED drivers can be used to drive a whole string of LEDs with flexible brightness control via analog and/or PWM. . VIN – VDROP < 0.3V – VIN_MIN = N ¥ VF + VDROP – VIN _MAX = N ¥ VF + 5.5V where VIN = existing bus, boost voltage. Key advantage: • No need for current matching resistors and discrete transistor for brightness control. 'N' number of LEDs Per Branch ISET VCONTROL RSET ENABLE I4 CTRL I3 I2 I1 FAN5613 ON/OFF GND LED Brightness Control All of the FAN561X LED drivers feature analog and PWM controls to give designers flexible brightness control. These control methods can be applied to the circuit in two different ways to provide more flexibility than other solutions. To determine the value of RSET, use the ISET vs. VCTRL graph in Figure 4. 2. FAN5612 VIN ISET VCONTROL RSET ENABLE I3 CTRL ON/OFF I2 I1 FAN5612 GND 1. FAN5611 VIN ISET VCONTROL (3V) RSET I4 CTRL I3 I2 I1 - Analog Set VCONTROL and RSET for LED current using: - PWM - 1 200 × ( V CONTROL – V CTRL ) I LED = ------------------------------------------------------------------------R SET VCONTROL = PWM – Amplitude sets maximum LED current. – Pulse width controls between 0 and maximum. - PWM - 2 Set VCONTROL and RSET for maximum LED current using: I LED ∼ 200 × I SET ON/OFF = PWM – Amplitude has no effect on current. – Pulse width controls between 0 and maximum. FAN5611 GND - Analog Set VCONTROL and RSET for LED current using: 200 × ( V CONTROL – V CTRL ) I LED = ------------------------------------------------------------------------R SET - PWM VCONTROL = PWM – Amplitude sets maximum LED current. – Pulse width controls between 0 and maximum. © 2003 Fairchild Semiconductor Corporation FAN5611/FAN5612/FAN5613/FAN5614 Rev. 1.0.9 9 www.fairchildsemi.com FAN5611/FAN5612/FAN5613/FAN5614 3. FAN5613 VIN 4. FAN5614 VIN VCONTROL ISET RSET I4 CTRL ON/OFF I3 I2 I1 ISET VCONTROL RSET CTRL ON/OFF I1/I2 I3/I4 FAN5614 VSS FAN5613 VSS ENABLE ENABLE - Analog Set VCONTROL and RSET for LED current using: I LED 200 × ( V CONTROL – V CTRL ) = ------------------------------------------------------------------------R SET - Analog Set VCONTROL and RSET for LED current using: 200 × ( V CONTROL – V CTRL ) I LED = ------------------------------------------------------------------------R SET - PWM - 1 VCONTROL = PWM – Amplitude sets maximum LED current. – Pulse width controls between 0 and maximum. - PWM - 2 Set VCONTROL and RSET for maximum LED current using: I LED ∼ 200 × I SET 200 × ( V CONTROL – V CTRL ) I LED = ------------------------------------------------------------------------R SET ON/OFF = PWM – Amplitude has no effect on current. – Pulse width controls between 0 and maximum. - PWM - 1 VCONTROL = PWM – Amplitude sets maximum LED current. – Pulse width controls between 0 and maximum. - PWM - 2 Set VCONTROL and RSET for maximum LED current using: I LED ∼ 200 × I SET ON/OFF = PWM – Amplitude has no effect on current. – Pulse width controls between 0 and maximum. © 2003 Fairchild Semiconductor Corporation FAN5611/FAN5612/FAN5613/FAN5614 Rev. 1.0.9 10 www.fairchildsemi.com FAN5611/FAN5612/FAN5613/FAN5614 Mechanical Dimensions 2x2mm 6-Lead MLP © 2003 Fairchild Semiconductor Corporation FAN5611/FAN5612/FAN5613/FAN5614 Rev. 1.0.9 11 www.fairchildsemi.com FAN5611/FAN5612/FAN5613/FAN5614 Mechanical Dimensions 2x2mm 8-Lead MLP © 2003 Fairchild Semiconductor Corporation FAN5611/FAN5612/FAN5613/FAN5614 Rev. 1.0.9 12 www.fairchildsemi.com FAN5611/FAN5612/FAN5613/FAN5614 Mechanical Dimensions 6-Lead SC-70 Package © 2003 Fairchild Semiconductor Corporation FAN5611/FAN5612/FAN5613/FAN5614 Rev. 1.0.9 13 www.fairchildsemi.com FAN5611/FAN5612/FAN5613/FAN5614 © 2003 Fairchild Semiconductor Corporation FAN5611/FAN5612/FAN5613/FAN5614 Rev. 1.0.9 14 www.fairchildsemi.com