Advanced Power Electronics Corp. APE1612 1.9A FIXED FREQUENCY WHITE LED DRIVER FEATURES DESCRIPTION The APE1612 is a step-up converter designed for driving up to 8 series white LEDs for backlighting application. The APE1612 uses current mode, 1.2MHz fixed frequency architecture to regulate the LED current, which is set through an external current sense resistor. Its low 300mV feedback voltage reduces power loss and improves efficiency. The OV pin monitors the output voltage and turns off the converter if an over-voltage condition is present due to an open circuit condition. The APE1612 includes under-voltage lockout, current limiting and thermal shutdown protection preventing damage in the event of an output overload. The driver is available in TSOT-26 packages. 2.5V to 5.5 V Operating Input Voltage Rang Drives up to 8 Series White LEDs 1.2MHz Fixed Switching Frequency Wide Range for PWM Dimming (200Hz to 200KHz) Internal 1.9A Switching Current Limit Over Voltage Protection (OVP) Internal Soft-start Function Current Limit and Thermal Shutdown Protection Under Voltage Lockout Available in the TSOT-26 Packages TYPICAL APPLICATION 1. 8 series LED application VIN=5V L1 4.7uH D1 B240A U1 ON C1 4.7uF OFF VCC SW EN OV GND FB 8-WLEDs C2 1uF APE1612 R3 ILED= VFB/R3, VFB=300mV 2. LED Dimming application VIN=5V L1 4.7uH D1 B240A U1 C1 4.7uF Dimming 200~200KHz VCC SW EN OV GND FB 8-WLEDs C2 1uF APE1612 R3 ILED= VFB/R3, VFB=300mV Data and specifications subject to change without notice 1 201203211 Advanced Power Electronics Corp. APE1612 ABSOLUTE MAXIMUM RATINGS (at TA=25°C) VCC Pin Voltage (VCC) ------------------------------------ GND - 0.3 to GND + 6V EN, FB, OV Pin Voltage ----------------------------------- GND - 0.3 to VCC + 0.3V SW Pin Voltage (VSW ) ------------------------------------- 30V Power Dissipation(PD) ------------------------------------- ( TJ-TA ) / Rthja mW Storage Temperature Range(TST) ---------------------- -65°C To 150°C Operating Junction Temperature Range(TOP) ------- -40°C To 125°C Thermal Resistance from Junction to Case(RthJC) 180°C/W Thermal Resistance from Junction to Ambient(RthJA) 250°C/W 2 Note: RthJA is measured with the PCB copper area of approximately 1 in (Multi-layer) ORDERING / PACKAGE INFORMATION (Top View) APE1612 X SW 1 6 VCC Package Type GND 2 5 OV TY : TSOT-26 FB 3 4 EN TSOT-26 ELECTRICAL SPECIFICATIONS (VCC=5V, IOUT = 20mA, TA = 25oC, unless otherwise noted) Parameter SYM TEST CONDITION MIN TYP MAX UNITS Input Voltage Range VCC 2.5 - 5.5 V Step-Up Voltage Range VOUT 3 - 27 V OV Sense Voltage VOV 27.5 29 30.5 V Under Voltage Lockout UVLO - 2.25 2.45 V - 100 - mV VFB 285 300 315 mV Logic-High Voltage VIH 1.4 - - V Logic-Low Voltage VIL - - 0.4 V Rising UVLO Hysteresis Feedback Voltage EN Threshold EN Hysteresis Operating Quiescent Current Shutdown Current N-Channel MOSFET Current Limit (Note1) MOSFET On-resistance Maximum Duty Cycle (Note1) ICCQ IOUT= 0mA, VFB =0.5V - 200 170 - mV μA ISD VEN=0V, tEN > 20ms - - 1 μA ILIM Duty=50% - 1.9 - A VCC=3V, ISW =1A - 650 - VCC=5V, ISW =1A - 500 - 85 90 - RDS(on) DMAX VCC = 3V to 5V mΩ % - 1 - % Switching Frequency FOSC 0.9 1.2 1.5 MHz Dimming Clock Rate FDIM 0.2 - 200 KHz Line Regulation 2 Advanced Power Electronics Corp. APE1612 ELECTRICAL SPECIFICATIONS Parameter SYM FB Input Leakage Current IFB-LKG SW Leakage Current ISWL MIN TYP MAX UNITS VFB = 0.5V - 0.01 100 nA VLX = 27V, VFB =0.5V - - 1 µA TEST CONDITION IEN-LKG1 VEN= VCC - 1.5 3 μA IEN-LKG2 VEN= GND - 0.01 0.1 μA TSHDN - 10 - mS Thermal Shutdown TSD - 150 - Thermal Shutdown Hysteresis TSH - 30 - EN Input Leakage Current Shutdown Delay o C Note1 : Guaranteed by design. PIN DESCRIPTIONS PIN SYMBOL VCC PIN DESCRIPTION Power Input Pin EN Enable with dimming pin, Internal pull-high. FB Feedback Pin; Put a resistor to GND to setting the current Ground Pin GND OV OVP Sense Pin SW Switch Output Pin BLOCK DIAGRAM VCC UVLO EN Soft Start Reference 1.238V Enable Logic 10ms Shutdown Summing Comparator 300mV FB Error Amplifier OVP OV Thermal Shutdown SW Control and Driver Logic N-MOS Oscillator 1.2MHz Slope Compensation Current Sense GND 3 Advanced Power Electronics Corp. APE1612 APPLICATION INFORMATION Setting the ILED Current Application circuit item shows the basic application circuit with APE1612 adjustable output version. The external resistor sets the LED output current according to the following equation: ⎛ 0.3V ⎞ I LED = ⎜ ⎟ ⎝ R3 ⎠ I LED R3 20mA 15Ω 6mW 350mA 0.857Ω 105mW Over Voltage Protection OV measure the output voltage for open circuit protection. Connect OV pin to the output at the top of the LED string. If VOUT above 29V, the OVP protection is happened that stops the internal driver until VOUT below 29V. Under Voltage Lockout (UVLO) To avoid mis-operation of the device at low input voltages an under voltage lockout is included that disables the device, if the input voltage falls below (2.25V-100mV). Input Capacitor Selection The input capacitor reduces the surge current drawn from the input and switching noise from the device. The input capacitor impedance at the switching frequency shall be less than input source impedance to prevent high frequency switching current passing to the input. A low ESR input capacitor sized for maximum RMS current must be used. Ceramic capacitors with X5R or X7R dielectrics are highly recommended because of their low ESR and small temperature coefficients. A 4.7 µ F ceramic capacitor for most applications is sufficient. For a lower output power requirement application, this value can be decreased. Output Capacitor Selection The output capacitor is required to keep the output voltage ripple small and to ensure regulation loop stability. The output capacitor must have low impedance at the switching frequency. Ceramic capacitors with X5R or X7R dielectrics are recommended due to their low ESR and high ripple current. A 1uF ceramic capacitors works for most of the applications. Higher capacitor values can be used to improve the load transient response. 4 Advanced Power Electronics Corp. APE1612 TYPICAL PERFORMANCE CHARACTERISTICS Efficiency vs. Output Current Efficiency vs. Input Voltage Output Voltage vs. Output Current Quiescent Current vs. Input Voltage Frequency vs. Input Voltage Frequency vs. Temperature 5 Advanced Power Electronics Corp. APE1612 TYPICAL PERFORMANCE CHARACTERISTICS Reference Voltage vs. Input Voltage Reference Voltage vs. Temperature LED Current vs. Duty Enable Threshold vs. Input Voltage Power ON from VIN Power ON from EN 6 Advanced Power Electronics Corp. APE1612 TYPICAL PERFORMANCE CHARACTERISTICS Steady State Operation Normal Operation into OVP ( VOUT, IOUT: measured by AC coupled mode ) PWM Dimming from EN (200Hz) PWM Dimming from EN (20KHz) 7 Advanced Power Electronics Corp. APE1612 MARKING INFORMATION TSOT-26 JAYWS Part Number : JA Week: A~Z : 01~26 a~z : 27~52 ID Code : Internal Year : A = 2010 1 = 2011 ： ： 8 Advanced Power Electronics Corp. APE1612 PACKAGE OUTLINES TSOT-26 θ D L E1 E L1 R b e C L2 y A1 A A2 e1 Dimensions in Millimeters Min. Nom. Max. A 1.10 A1 0.00 0.10 A2 0.70 0.90 1.00 b 0.30 0.40 0.50 C 0.08 0.14 0.20 D 2.80 2.90 3.00 E 2.60 2.80 3.00 E1 1.50 1.60 1.70 e 0.95 BSC. e1 1.90 BSC. L 0.30 0.45 0.60 L1 0.60 REF. L2 0.25 BSC. y 0.10 R 0.10 o θ 0 8o JEDEC outline: MO-193 AA Symbol Dimensions in Inches Min. Nom. Max. 0.043 0 0.004 0.028 0.035 0.039 0.012 0.016 0.020 0.003 0.006 0.008 0.110 0.114 0.118 0.102 0.110 0.118 0.059 0.063 0.067 0.037 BSC. 0.075 BSC. 0.012 0.018 0.024 0.024 REF. 0.010 BSC. 0.004 0.004 o 0 8o