AME5142

AME, Inc. AME5142 n Pin Configuration SOT-25/TSOT-25 Top View 5 4 White LED Boost Converter In Tiny Package SOT-26/TSOT-26 Top View AME5142AEEV 1. SW 2. GND 6 5 4 AME5142AEEY 1. SW 2. GND AME5142 3. FB 4. EN 5. IN AME5142 3. FB 4. EN 5. OVP 1 2 3 1 2 3 6. IN * Die Attach: Conductive Epoxy * Die Attach: Conductive Epoxy n Pin Description AME5142AEEV Pin Number 1 Pin Name SW Pin Description Power Switch input. This is the drain of the internal NMOS power switch. Minimize the metal trace area connected to this pin to minimize EMI. Ground. Tie directly to ground plane. Output voltage feedback input. Connect the ground of the feedback network to an AGND (Analog Ground) plane which should be tied directly to the GND pin. Enable control input, active high. The enable pin is an active high control. Tie this pin above 1.5V to enable the device. Tie this pin below 0.4V to turn off the device. Analog and Power input. Input Supply Pin. Bypass this pin with a capacitor as close to the device as possible. 2 GND 3 FB 4 EN 5 IN Rev. A.01 3 AME, Inc. AME5142 n Pin Description AME5142AEEY White LED Boost Converter In Tiny Package Pin Number 1 Pin Name SW Pin Description Power Switch input. This is the drain of the internal NMOS power switch. Minimize the metal trace area connected to this pin to minimize EMI. Ground. Tie directly to ground plane. Output voltage feedback input. Connect the ground of the feedback network to an AGND(Analog Ground) plane which should be tied directly to the GND pin. Enable control input, active high. The enable pin is an active high control. Tie this pin above 1.5V to enable the device. Tie this pin below 0.4V to turn off the device. Over Voltage Protection. Analog and Power input. Input Supply Pin. Bypass this pin with a capacitor as close to the device as possible. 2 GND 3 FB 4 EN 5 OVP 6 IN 4 Rev. A.01 AME, Inc. AME5142 n Ordering Information AME5142 x x x x xxx x Special Feature Output Voltage Number of Pins Package Type Operating Ambient Temperature Range Pin Configuration Operating Ambient Temperature Range E: -40OC to 85OC Number of Pins V: 5 Y: 6 White LED Boost Converter In Tiny Package Pin Configuration A (SOT-25) (TSOT-25) Package Type E: SOT-2X Output Voltage Special Feature 1. SW 2. GND 3. FB 4. EN 5. IN 1. SW 2. GND 3. FB 4. EN 5. OVP 6. IN ADJ: Adjustable Y: Lead free & Low profile Z: Lead free A (SOT-26) (TSOT-26) n Ordering Information Part Number AME5142AEEYADJZ AME5142AEEYADJY AME5142AEEVADJZ AME5142AEEVADJY Marking* BJGww BJGww BJHww BJHww Output Voltage ADJ ADJ ADJ ADJ Package SOT-26 TSOT-26 SOT-25 TSOT-25 Operating Ambient Temperature Range -40OC to 85OC -40OC to 85OC -40OC to 85OC -40OC to 85OC Note: ww represents the date code and pls refer to Date Code Rule page on Package Dimension. * A line on top of the first letter represents lead free plating such as BJGww. Please consult AME sales office or authorized Rep./Distributor for the availability of package type. Rev. A.01 5 AME, Inc. AME5142 n Absolute Maximum Ratings Parameter Input Supply Voltage EN, FB Voltages SW, OVP Voltage ESD Classification White LED Boost Converter In Tiny Package Symbol VIN V EN ,VFB V SW,VOVP Maximum 6 VIN 30 B* Unit V V V Caution: Stress above the listed in absolute maximum ratings may cause permanent damage to the device. * HBM B: 2000V ~ 3999V n Recommended Operating Conditions Parameter Ambient Temperature Range Junction Temperature Range Storage Temperature Range Symbol TA TJ TSTG Rating -40 to 85 -40 to 125 -65 to 150 Unit o C n Thermal Information Parameter Thermal Resistance* (Junction to Case) Thermal Resistance (Junction to Ambient) Internal Power Dissipation Solder Iron (10Sec)** Package Die Attach Symbol θJC Maximum 81 Unit SOT-25 TSOT-25 SOT-26 TSOT-26 o C/W Conductive Epoxy θJA PD 260 400 350 mW o C * Measure θJC on center of molding compound if IC has no tab. ** MIL-STD-202G 210F 6 Rev. A.01 AME, Inc. AME5142 n Electrical Specifications VIN = 4.2V, EN = VIN, TA = 25oC, Unless otherwise noted. Parameter Input Voltage Quiescent Current Feedback Trip Point FB Pin Bias Current Switch Current Limit Switch On-Resistance SW Leakage Current Swich frequency Maximum Duty Cycle Shutdown Supply Current Over Temperature Protection TRS Over Voltage Protection Input Undervoltage Lockout EN Input Low EN Input High EN Input Current OVP UVP V EL VEH IEN EN = GND or VIN 1.5 0.1 2 µA Restore, temperature decreasing Rising edge VIN rising or falling 24 2.35 140 26 2.5 28 2.65 0.4 V V V Symbol V IN Switching, VFB = 0V IQ VFB IFB ICL RDSON ISW fSW Dmax ISD OTP ISW = 100mA, VFB = 0.2V VSW = 20V VFB = 0.1V VFB = 0V VEN = 0V Shutdown, temperature increasing 0.9 88 VFB = 0.2V 650 Not Switching, VFB = 0.2V 0.137 Test Condition Min 2.7 0.85 180 0.15 0.1 850 0.7 1 1.2 92 0.01 160 1 Typ Max 5.5 1 250 0.163 1 1000 1.4 10 1.5 Units V mA µA V µA mA Ω µA MHz % µA o White LED Boost Converter In Tiny Package C Rev. A.01 7 AME, Inc. AME5142 n Detailed Description The AME5142 is a constant frequency step-up converter with an internal switch. The operations of AME5142 can be understood from block diagram clearly figure.2. The oscillator triggers the SET input of SR latch to turn on the power switch MS at the start of each cycle. A current sense voltage sum with a stabilizing ramp is connected to the positive terminal of the PWM comparator. When this voltage exceeds the output voltage of the error amplifier, the SR latch is reset to turn off the power switch till next cycle starts. The output voltage of the error amplifier is amplified from the difference between the reference voltage 0.15V and the feedback voltage. In this manner, if the error amplifiers voltage increases, more current is delivered to the output; if it decreases, less current is delivered. A 26V Zener diode connects from OVP pin to FB pin internally to provide an optional protection function which prevents SW pin from over-voltage damage. Especially when the case of the feedback loop broken due to component wear-out or improper connection occurs. The behavior of OVP is to clamp the output voltage to 26V typically. This function is suitable for the applications while driving white LEDs less than 6 in series. Current Limit Protection The AME5142 has current limiting protection to prevent excessive stress on itself and external components during overload conditions. The internal current limit comparator will disable the NMOS power device at a typical switch peak current limit of 850mA. Output Over-Voltage Protection The AME5142 contains dedicated circuitry for monitoring the output voltage. In the event that the primary LED network is disconnected the output will increase and be limited to 26V (TYP), which will turn the NMOS off when the output voltage is at 26V (max.) until the output voltage reach 26V (TYP.) or lower. The 26V limit allows the use of 26V 1µF ceramic output capacitors creating an overall small solution for white LED applications. Under Voltage Protection The AME5142 has an UVP comparator to turn the NMOS power device off in case the input voltage or battery voltage is too low preventing an on state of the power device conducting large amounts of current. White LED Boost Converter In Tiny Package n Application Hints Inductor Selection The recommended value of inductor for AME5142 applications is 10µH. Small size and better efficiency are the major concerns for portable device, such as AME5142 used for dual panel mobile phone. The inductor should have low DCR for better efficiency. To avoid inductor saturation, current rating should be at least 1A. The input range is 2.7V to 5.5V. Capacitor Selection 4.7µF input capacitor can reduce input ripple. For better voltage stability, to increase the input capacitor value or using LC filter is feasible, especially in the Li-ion battery application. 1µF output capacitor is sufficient to reduce output voltage ripple. For better voltage filtering, ceramic capacitors with low ESR are recommended. X5R and X7R types are suitable because of their wider voltage and temperature ranges. Diode Selection Schottky diode is a good choice for AME5142 because of its lower forward voltage drop and faster reverse recovery. Using schottky diode can get better efficiency. The high speed rectification is also a good characteristic of schottky diode for high switching frequency. Current rating of the diode must meet the root mean square of the peak current and output average current multiplication. Duty Cycle The maximum duty cycle of the switching regulator determines the maximum boost ratio of output-toinput voltage that the converter can attain in mode of operation. The duty cycle for a given boost application is defined as: This applies for continuous mode operation. D= VOUT + VDIODE - VIN VOUT + VDIODE - VSW 8 Rev. A.01 AME, Inc. AME5142 n Application Hints Calculating Load Current The load current is related to the average inductor current by the relation: ILOAD = IIND (AVG) x (1 - D) Where “D” is the duty cycle of the application. The switch current can be found by: ISW = IIND (AVG) + 1 /2 (IRIPPLE) Inductor ripple current is dependent on inductance, duty cycle, input voltage and frequency: IRIPPLE = D x (VIN-VSW ) / (f x L) Combining all terms, we can develop an expression which allows the maximum available load current to be calculated: VIN 2.7V to 5.5V CIN 4.7µF White LED Boost Converter In Tiny Package Dimming Control A. Using a PWM Signal to EN Pin For controlling the LED brightness, the AME5142 can perform the dimming control by applying a PWM signal to EN pin. The average LED current is proportional to the PWM signal duty cycle. The magnitude of the PWM signal should be higher than the maximum enable voltage of EN pin, in order to let the dimming control perform correctly. L1 10µH VOUT SW COUT 1µF IN EN Dimming Control 25KHz to 100KHz AME5142 OVP ILOAD = ( 1-D ) x ( ISW (max) Thermal Considerations D ( VIN-VSW ) 2fL ) GND FB R1 7.5Ω At higher duty cycles, the increased ON time of the FET means the maximum output current will be determined by power dissipation within the AME5142 switch. The switch power dissipation from ON-state conduction is calculated by: P(SW) = D x IIND(AVE)2 x RDS(ON) There will be some switching losses as well, so some derating needs to be applied when calculating IC power dissipation. Shutdown Pin Operation The device is turned off by pulling the shutdown pin low. If this function is not going to be used, the pin should be tied directly to VIN. If the SHDN function will be needed, a pull-up resistor must be used to VIN (approximately 50k100k recommended). The EN pin must not be left unterminated. Figure 5. PWM Dimming Control Using the EN Pin Rev. A.01 9 AME, Inc. AME5142 n Application Hints Dimming Control B. Using a DC Voltage Using a variable DC voltage to adjust the brightness is a popular method in some applications. The dimming control using a DC voltage circuit is shown in Figure 6. According to the Superposition Theorem, as the DC voltage increases, the voltage contributed to VFB increases and the voltage drop on R2 decreases, i.e. the LED current decreases. For example, if the VDC range is from 0V to 3V, the selection of resistors in Figure 6 sets dimming control of LED current from 20mA to 0mA. L1 10µH White LED Boost Converter In Tiny Package C. Using a Filtered PWM Signal The filtered PWM signal can be considered as an adjustable DC voltage. It can be used to replace the variable DC voltage source in dimming control. The circuit is shown in Figure 7. L1 10µH VIN 2.7V to 5.5V CIN 4.7µF VOUT SW COUT 1µF IN EN AME5142 OVP R3 5.1K VIN 2.7V to 5.5V CIN 4.7µF VOUT SW COUT 1µF GND FB IN R4 91K RDC 10K 3V CDC 0.1µF EN AME5142 OVP R3 5.1K R2 7.5Ω GND FB R4 91K VDC Dimming 0V to 3V R2 7.5Ω 0V PWM Signal Figure 7. Dimming Control Using a Filtered PWM Signal Figure6. Dimming Control Using a DC Voltage 10 Rev. A.01 AME, Inc. AME5142 Max Duty Cycle vs. Temperature 92.0 91.8 91.6 91.4 91.2 91.0 90.8 90.6 90.4 90.2 90.0 89.8 89.6 89.4 89.2 89.0 88.8 88.6 88.4 88.2 88.0 -25 White LED Boost Converter In Tiny Package Oscillator Frequency vs. Temperature 1.50 1.45 1.40 1.35 1.30 1.25 1.20 1.15 1.10 1.05 1.00 0.95 0.90 -25 0 25 50 75 100 125 0 25 50 Temperature ( C) 75 o 100 125 Oscillator Frequency (MHz) Max Duty Cycle (%) Temperature (oC) Switch RDSON 1.80 1.60 Efficiency vs. Load Current Dirving 3 LEDs 100 90 1.40 1.20 1.00 0.80 0.60 0.40 0.20 2.7 TA = 25 C o TA = 85oC Efficiency (%) RDSON (Ω) 80 70 60 3.1 3.5 3.9 4.3 4.7 5.1 5.5 50 2.7 3.1 3.5 3.9 4.3 4.7 5.1 5.5 VIN (V) VIN (V) Efficiency vs. Load Current Dirving 4 LEDs 100 100 Efficiency vs. Load Current Dirving 6 LEDs 90 90 Efficiency (%) 80 Efficiency (%) 3.1 3.5 3.9 4.3 4.7 5.1 5.5 80 70 70 60 60 50 2.7 50 2.7 3.1 3.5 3.9 4.3 4.7 5.1 5.5 VIN (V) VIN (V) Rev. A.01 11 AME, Inc. AME5142 Current Limit vs. VIN 1000 White LED Boost Converter In Tiny Package VFB vs. Temperature 0.177 950 0.173 0.169 0.165 Current Limit (mA) 900 850 800 750 700 650 2.7 3.1 3.5 3.9 4.3 4.7 5.1 5.5 VFB (V) 0.161 0.157 0.153 0.149 0.145 0.141 0.137 -25 0 25 50 75 100 125 VIN (V) Temperature (oC) Dimming Control for Driving 6LEDs Dimming Control for Driving 6LEDs 2 2 3 3 1 1 1mS / div 1mS / div VIN = 2.7V; 6 LEDs IOUT = 20mA 2) EN = 1V / div, DC f = 200Hz 3) VOUT , 10V / div, DC 1) VSW = 10V / div, DC VIN = 5.5V; 6 LEDs IOUT = 20mA 2) EN = 1V / div, DC f = 200Hz 3) VOUT , 10V / div, DC 1) VSW = 10V / div, DC 12 Rev. A.01 AME, Inc. AME5142 Dimming Control for Driving 6LEDs White LED Boost Converter In Tiny Package Dimming Control for Driving 6LEDs 2 2 3 3 1 1 4µS / div 4µS / div VIN = 2.7V; 6 LEDs IOUT = 20mA 2) EN = 1V / div, DC f = 200KHz 3) VOUT , 10V / div, DC 1) VSW = 10V / div, DC Start-Up / Shutdown VIN = 5.5V; 6 LEDs IOUT = 20mA 2) EN = 1V / div, DC f = 200KHz 3) VOUT , 10V / div, DC 1) VSW = 10V / div, DC Start-Up / Shutdown 1 1 2 2 3 3 200µS / Div 200µS / div VIN = 2.7V; 1 LEDs IOUT = 20mA 1) EN = 2V/div, DC 2) Inductor Current, 100mA / div, DC 3) VOUT , 2V / div, DC VIN = 2.7V; 6 LEDs IOUT = 20mA 1) EN = 2V / div, DC 2) Inductor Current, 500mA / div, DC 3) VOUT , 10V / div, DC Rev. A.01 13 AME, Inc. AME5142 Start-Up / Shutdown White LED Boost Converter In Tiny Package Typical Switching Waveform 1 1 2 2 3 3 200µS / div 1µS / div VIN = 5.5V; 6 LEDs IOUT = 20mA 1) EN = 2V / div, DC 2) Inductor Current, 500mA / div, DC 3) VOUT , 10V / div, DC Typical Switching Waveform VIN = 2.7V; 6 LEDs IOUT = 20mA 1) VSW = 10V / div, DC 2) VOUT , 20mV / div, AC 3) Input Current, 100mA / div, DC Inductor = 10µH, COUT = 1µF 1 2 3 1µS / div VIN = 5.5V; 6 LEDs IOUT = 20mA 1) VSW = 10V / div, DC 2) VOUT , 20mV / div, AC 3) Input Current, 100mA / div, DC Inductor = 10µH, COUT = 1µF 14 Rev. A.01 AME, Inc. AME5142 n Date Code Rule Marking A A A A A A A A A A A A A A A A A A A A A A A A A A A A A A Date Code W W W W W W W W W W W W W W W W W W W W Year xxx0 xxx1 xxx2 xxx3 xxx4 xxx5 xxx6 xxx7 xxx8 xxx9 White LED Boost Converter In Tiny Package n Tape and Reel Dimension SOT-25 P W AME PIN 1 AME Carrier Tape, Number of Components Per Reel and Reel Size Package SOT-25 Carrier Width (W) 8.0±0.1 mm Pitch (P) 4.0±0.1 mm Part Per Full Reel 3000pcs Reel Size 180±1 mm Rev. A.01 15 AME, Inc. AME5142 n Tape and Reel Dimension TSOT-25 P White LED Boost Converter In Tiny Package W AME PIN 1 AME Carrier Tape, Number of Components Per Reel and Reel Size Package TSOT-25 Carrier Width (W) 8.0±0.1 mm Pitch (P) 4.0±0.1 mm Part Per Full Reel 3000pcs Reel Size 180±1 mm SOT-26 P W AME PIN 1 AME Carrier Tape, Number of Components Per Reel and Reel Size Package SOT-26 Carrier Width (W) 8.0±0.1 mm Pitch (P) 4.0±0.1 mm Part Per Full Reel 3000pcs Reel Size 180±1 mm 16 Rev. A.01 AME, Inc. AME5142 n Tape and Reel Dimension TSOT-26 P White LED Boost Converter In Tiny Package W AME PIN 1 AME Carrier Tape, Number of Components Per Reel and Reel Size Package TSOT-26 Carrier Width (W) 8.0±0.1 mm Pitch (P) 4.0±0.1 mm Part Per Full Reel 3000pcs Reel Size 180±1 mm Rev. A.01 17 AME, Inc. AME5142 n Package Dimension SOT-25 Top View D L White LED Boost Converter In Tiny Package Side View SYMBOLS A A1 MILLIMETERS MIN 0.00 0.30 2.70 1.40 INCHES MIN 0.0000 0.0118 0.1063 0.0551 MAX 0.15 0.55 3.10 1.80 MAX 0.0059 0.0217 0.1220 0.0709 1.20REF 0.0472REF E b D E S1 e θ1 H e H L θ1 1.90 BSC 2.60 3.00 0.07480 BSC 0.10236 0.11811 0.0146BSC o 0.37BSC 0 o Front View A 10 0o 10 o S1 0.95BSC 0.0374BSC b TSOT-25 Top View D L A1 Side View SYMBOLS A+A1 b MILLIMETERS MIN 0.90 0.30 0.09 2.70 1.40 INCHES MIN 0.0354 0.0118 0.0035 0.1063 0.0551 MAX 1.25 0.50 0.25 3.10 1.80 MAX 0.0492 0.0197 0.0098 0.1220 0.0709 E c D E S1 e θ1 H e H L θ1 S1 1.90 BSC 2.40 3.00 0.07480 BSC 0.09449 0.11811 0.0138BSC o 0.35BSC 0 o Front View A 10 0o 10 o 0.95BSC 0.0374BSC b A1 18 Rev. A.01 AME, Inc. AME5142 n Package Dimension SOT-26 Top View D e Side View White LED Boost Converter In Tiny Package SYMBOLS A A1 b MILLIMETERS MIN MAX 0.15 0.55 3.10 1.80 INCHES MIN 0.0000 0.0118 0.1063 0.0551 MAX 0.0059 0.0217 0.1220 0.0709 1.20REF 0.00 0.30 2.70 1.40 0.0472REF H E L D E θ1 S1 e H L θ1 1.90 BSC 2.60 3.00 0.0748 BSC 0.10236 0.11811 0.0146REF 0o 10 o 0.37REF 0o 10 o Front View A S1 0.95REF 0.0374REF b TSOT-26 Top View D e Side View A1 SYMBOLS L MILLIMETERS MIN MAX 1.25 0.50 3.10 1.80 INCHES MIN 0.0354 0.0118 0.1063 0.0551 MAX 0.0492 0.0197 0.1220 0.0709 A+A1 b H E 0.90 0.30 2.70 1.40 D E θ1 S1 e H L θ1 S1 1.90 BSC 2.40 3.00 0.07480 BSC 0.09449 0.11811 0.0138BSC 0o 10o 0.35BSC 0o 10o Front View A 0.95BSC 0.0374BSC b Rev. A.01 A1 19 www.ame.com.tw E-Mail: sales@ame.com.tw Life Support Policy: These products of AME, Inc. are not authorized for use as critical components in life-support devices or systems, without the express written approval of the president of AME, Inc. AME, Inc. reserves the right to make changes in the circuitry and specifications of its devices and advises its customers to obtain the latest version of relevant information. © AME, Inc. , July 2007 Document: 1229-DS5142-A.01 Corporate Headquarter AME, Inc. 2F, 302 Rui-Guang Road, Nei-Hu District Taipei 114, Taiwan. Tel: 886 2 2627-8687 Fax: 886 2 2659-2989 U.S.A. (Subsidiary) Analog Microelectronics, Inc. 3100 De La Cruz Blvd., Suite 201 Santa Clara, CA. 95054-2438 Tel : (408) 988-2388 Fax: (408) 988-2489