AP1522WA

AP1522 Step-Up DC/DC Converter Features - High Efficiency: 84% Typical - 36V High Output Voltage - Fast 1MHz Switching Frequency - Low Profile SOT23-5 Pb-Free Packaging General Description The AP1522 is a step-up DC/DC converter in a 5-Lead low profile SOT23-5 package. The AP1522 switches at 1MHz that allows the use of tiny external components. A low 1.25V feedback voltage minimizes power loss in the current setting resistor for better efficiency. Applications - Cellular Phones - PDAs, Handhelp Computers - Digital Cameras - LCD Bias Voltage, Battery Backup - Pin Assignments Top View VIN SHDN Pin Descriptions Name SW VSS FB SHDN Description Switch Pin. Connect inductor/diode here. Minimize trace area at this pin to reduce EMI. GND pin Feedback Pin. Reference voltage is 1.25V. Shutdown Pin. Tie to 0.6V or higher to enable device ； 0.5Vor less to disable device. Input Supply Pin. Must be locally bypassed. SW VSS FB SOT23-5L VIN Ordering Information AP1522 Package W: SOT23-5L XX Packing Blank : Tube A : Taping This datasheet contains new product information. Anachip Corp. reserves the rights to modify the product specification without notice. No liability is assumed as a result of the use of this product. No rights under any patent accompany the sale of the product. Rev. 1.0 May. 5, 2005 1/8 AP1522 Step-Up DC/DC Converter Block Diagram 1 SW Driver R S Q Q1 Comparator A2 + FB 3 VIN 5 VREF 1.25V A1 RC + CC Σ RAMP Generator SHDN 4 Shutdown 1MHz Oscillator 2 GND Absolute Maximum Ratings Symbol VIN VSW VFB VSHDN TJ TLEAD TOPR VIN Pin Voltage SW Voltage Feedback Pin Voltage SHDN Pin Voltage Maximum Junction Temperature Power Dissipation Operating Temperature Range Parameter Rating 10 36 10 10 125 300 -40 to +85 Unit V V V V o o o o + C C C TSTG Storage Temperature Range -40 to +125 C Caution The absolute maximum ratings are rated values exceeding which the product could suffer physical damage. These values must therefore not be exceeded under any conditions. Anachip Corp. www.anachip.com.tw 2/8 Rev. 1.0 May. 5, 2005 AP1522 Step-Up DC/DC Converter Electrical Characteristics (Ta=25°C, VIN = 5V, VSHDN = 5V, unless otherwise noted.) Symbol VIN VIN VFB IFB Parameter Minimum Operation Voltage Maximum Operation Voltage Feedback Pin Voltage Feedback Pin Bios Current Supply Current FSW Duty ISW VSAT VSHDN VSHDN ISHDN Switching frequency PWM Maximum Duty Cycle Switch Current Limit Switch VSAT Switch Leakage Current SHDN Pin Voltage High SHDN Pin Voltage Low SHDN Pin Bios Current Conditions Operation current VSHDN = 0V Min. 2.5 1.225 10 0.75 85 280 0.6 Typ. 1.25 45 2 0.1 1.0 90 320 350 0.1 10 Max. 10 1.275 100 3 1.0 1.25 360 5 0.5 Unit V V V nA mA µA MHz % mA mV µA V V µA ISW = 250mA VSW = 5V Enable Disable Typical Application Circuit Vout=10V C2 4.7uF R1 70K R2 10K D1 L1 10uH Vin=3.3V Option SW Vss FB SHDN Vin C1 4.7uF ON OFF VOUT=VFB (1+ R1 ) R2 1K < R2 < 50K Anachip Corp. www.anachip.com.tw 3/8 Rev. 1.0 May. 5, 2005 AP1522 Step-Up DC/DC Converter Typical Application Circuit (Continued) Step up DC-DC Regulator VIN 2.5V~3.3V L 22uH D VOUT 4.8V CIN 4.7uF VIN SHDN GND SW FB 57K 4.7pF AP1522 COUT 4.7uF 20K 1-Cell Li-lon to 3.3V SEPIC Converter VIN 2.5V to 4.2V 5 VIN C1 4.7uF 4 SHDN GND 2 20K AP1522 L1 10uH C3 1uF D1 3.3V 50mA L2 33K 10uH 3 4.7pF C2 10uF 1 SW FB 4-Cell to 5V SEPIC Converter VIN 3V to 6V 5 VIN C1 4.7uF 4 SHDN GND 2 10K AP1522 L1 10uH C3 1uF D1 5V 40mA L2 10uH 3 30K 4.7pF C2 10uF 1 SW FB Anachip Corp. www.anachip.com.tw 4/8 Rev. 1.0 May. 5, 2005 AP1522 Step-Up DC/DC Converter Typical Application Circuit (Continued) +20V Dual Output Converter with Output Disconnect D3 C4 1uF D2 C5 1uF D1 -20V 4mA C3 1uF 20V 4mA 150K 4.7pF C2 10uF 10K VIN 2.5V to 5V 5 VIN C1 4.7uF 4 L1 10uH 1 SW FB 3 AP1522 D4 SHDN GND 2 Applications Information Inductor Selection A 10µH inductor is recommended for most AP1522 applications. Although small size and high efficiency are major concerns, the inductor should have low core losses at 1MHz and low DCR (copper wire resistance). Capacitor Selection The small size of ceramic capacitors makes them ideal for AP1522 applications. X5R and X7R types are recommended because they retain their capacitance over wider voltage and temperature ranges than other types such as Y5V or Z5U. A 4.7µF input capacitor and a 4.7µF output capacitor are sufficient for most AP1522 applications. Diode Selection Schottky diodes, with their low forward voltage drop and fast reverse recovery, are the ideal choices for AP1522 applications. The forward voltage drop of a Schottky diode represents the conduction losses in the diode, while the diode capacitance (CT or CD) represents the switching losses. For diode selection, both forward voltage drop and diode capacitance need to be considered. Schottky diodes with higher current ratings usually have lower forward voltage drop and larger diode capacitance, which can cause significant switching losses at the 1MHz switching frequency of the AP1522. A Schottky diode rated at 100mA to 200mA is sufficient for most AP1522 applications. Anachip Corp. www.anachip.com.tw 5/8 Open-Circuit Protection In the cases of output open circuit, when the R1 are disconnected from the circuit, the feedback voltage will be zero. The AP1522 will then switch at a high duty cycle resulting in a high output voltage, which may cause the SW pin voltage to exceed its maximum 36V rating. A zener diode can be used at the output to limit the voltage on the SW pin (Figure 1). The zener voltage should be larger than the maximum forward voltage of the VOUT. The current rating of the zener should be larger than 0.1mA. V IN L 22uH D COUT 2uF 4.7pF C IN 1uF VIN SHDN GND SW R2 1K R3 14K AP1522 FB R1 200K Figure 1. With Open-Circuit Protection Rev. 1.0 May. 5, 2005 AP1522 Step-Up DC/DC Converter Typical Performance Characteristics Frequency v.s. Temperature Vin=5V; Vout=15V 1000 900 800 700 600 500 400 300 200 100 0 -40 10 60 o Feedback Voltage v.s. Temperature Vin=5V; Vout=15V 1.26 Feedback Voltage (V) 110 Frequency (KHz) 1.25 1.24 1.23 1.22 -40 10 60 o 110 Temperature ( C) Temperature ( C) Supply Current v.s. Temperature Vin=5V; Vout=15V; Iout=0A 3 Supply Current v.s. Supply Voltage Vout=15V; Iout=0A 3 2.5 Supply Current (mA) 2.5 Supply Current (mA) 2 1.5 1 0.5 0 -40 2 1.5 1 0.5 0 Temperature ( C) 10 o 60 110 0 5 10 15 Supply Voltage (V) Efficiency v.s. Output Current Vin=5V; Vout=15V 90 85 Efficiency v.s. Output Current Vin=3.3V; Vout=15V 85 Efficiency (%) 80 Efficiency (%) 75 65 75 70 0 55 Output Current (mA) 20 40 60 0 20 40 60 Output Current (mA) Anachip Corp. www.anachip.com.tw 6/8 Rev. 1.0 May. 5, 2005 AP1522 Step-Up DC/DC Converter Typical Performance Characteristics (Continued) Frequency v.s. Supply Voltage Vout=15V 1200 1000 Frequency (KHz) 800 600 400 200 0 0 2 Supply Voltage (V) 4 6 8 10 12 Marking Information 5 Identification code (See Appendix) 4 XX Y M 1 2 3 Appendix Part Number AP1522 Month: A~L Year: 0-9 7 Package SOT23-5 Identification Code FA Anachip Corp. www.anachip.com.tw 7/8 Rev. 1.0 May. 5, 2005 AP1522 Step-Up DC/DC Converter Package Information Package Type: SOT23-5L D e1 θ1(4x) 5 4 0.10 C 5x Seating Plane A1 θ 2(4x) E1 E A A2 1 e 2 3 b With Plating b1 C C1 Gauge Plane 0.25 mm θ Base Metal b L L1 Symbol A A1 A2 b b1 c c1 D E E1 L L1 e e1 θ θ1 θ2 Dimensions In Millimeters Min. 1.05 0.05 1.00 0.25 0.25 0.08 0.08 2.70 2.60 1.50 0.35 Nom. 1.20 0.10 1.10 0.40 0.11 2.85 2.80 1.60 0.45 0.60 Ref. 0.95 Bsc. 1.90 Bsc. 0o 3o 6o 5o 5o 8o 10o 7o 10o Max. 1.35 0.15 1.20 0.55 0.45 0.20 0.15 3.00 3.00 1.70 0.55 Dimensions In Inches Min. 0.041 0.002 0.039 0.010 0.010 0.003 0.003 0.106 0.102 0.059 0.014 Nom. 0.047 0.004 0.043 0.016 0.004 0.112 0.110 0.063 0.018 0.024 Ref. 0.037 Bsc. 0.075 Bsc. 0o 3o 6o 5o 5o 8o 10o 7o 10o Max. 0.053 0.006 0.047 0.022 0.018 0.008 0.006 0.118 0.118 0.067 0.022 Anachip Corp. www.anachip.com.tw 8/8 Rev. 1.0 May. 5, 2005