AP1621 PWM/PFM Dual Mode Step-down DC/DC Controller Features General Descriptions - Input voltage range:2.2V~8VVOUT type - Adjustable version2.5% - Oscillator frequency: 270KHz15% - High Efficiency: 92%typ . - Stand-by capability: ISTB2A.max . - Soft-start time set-up externally type possible - Output voltage type possibleFB - Package: SOT23-5 The AP1621 series are multi-functional step-down DC/DC converters with built-in speed, low ON resistance drivers. A more than 1A output current is possible using an externally connected transistor, coil, diode and capacitor. Output voltage is set-up by external resistor.2.5% accuracy. With a 270KHz switching frequency, the size of the external components can be reduced. Control switches from PWM to PFM during light loads with the AP1621PWM/PFM switchableand the series is highly efficient from light loads to large output currents. In relation to soft-start time external capacitor regulated types. During stand-by time CE pin "LOW",current consumption is reduced to less than 0.5A. With U.V.L.O internal, the external MOSFET. Will be forcibly switched off if used below the stipulated voltage. Applications Electronic Information Organizers Palmtops Cellular and portable phones Portable Audio Systems Various Multi-function Power Supplies Pin Assignment Pin Descriptions (Top View) FB CE VDD VOUT 5 4 5 4 AP1621B AP1621A 1 2 VOUT GND Pin No. A B 3 1 2 3 VDD CE GND FB Pin Name Function 1 4 V OUT External PMOSFET Connection 2 2 GND Ground 3 5 V DD Power Supply 4 1 CE Chip Enable Soft-start capacitor connection 5 3 FB Feedback pin SOT23-5 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.1.1 May.27, 2004 1/5 AP1621 PWM/PFM Dual Mode Step-down DC/DC Controller Ordering Information AP1621X X X X Version Package Packing Lead Free A : A version W : SOT23-5 B : B version Blank : Normal A : Taping L : Lead Free Package Block Diagrams FB VDD Phase Compensation + + - Vref with Soft Start CE CE - PWM/PFM Controller Buffer, Driver Vout PWM Comparator Ramp Wave Generator, OSC GND Absolute Maximum Ratings Ta=25C Parameter VIN Pin Voltage VOUT Pin Voltage FB Pin Voltage CE Pin Voltage VOUT Pin Current Continuous Total Power Dissipation Operating Ambient Temperature Storage Temperature Symbol Rating Unit VDD VOUT VFB VCE VOUT -0.3 ~ 8.5 -0.3 ~ VIN+0.3 -0.3 ~ VIN+0.3 -0.3 ~ VIN+0.3 100 V V V V mA Pd 250 mW Topr -30 ~ +80 C Tstg -40 ~ +125 C Anachip Corp. www.anachip.com.tw Rev.1.1 May.27, 2004 2/5 AP1621 PWM/PFM Dual Mode Step-down DC/DC Controller Electrical Characteristics AP1621 VOUT3.3V, FOSC270kHz Parameter Symbol FB Maximum Input Voltage UVLO Voltagemin. operating voltage VFB VIN VUVLO Supply Current IDD Stand-by Current ISTB Oscillator Frequency Fosc Ta=25C Conditions Min. Typ. Max. 1.17 8 Same as IDD, voltage required to maintain H at VOUT No external components, CE=VIN, VOUT=0V No external components, CE=VIN, VOUT=0V Measuring of EXT/waveform, VIN=output voltage+0.3V 1.2 35 230 270 Unit 1.23 V V 2.2 V 102 A 2 A 310 KHz Maximum Duty Ratio PFM Duty Ratio MAXDTY 100 % PFMDTY NO load (AP1621 only) 15 25 35 % NO external components, VFB=0V, apply 0.65V (min.) to CE, determine 0.5 CE"High" Voltage VCEH Vcc VOUT"Low" Same as VCEH, determine CE"Low" Voltage VCEL 0.20 V EXT/"High" Efficiency EFFI 92 % Soft-Start Time Tss Use a 33 nF Capacitor 5 15 msec Measuring conditions: Unless otherwise specified, connect external components. VIN=5.0V,LOUT=220mA Series Amendment: AP1621 External Components: Css 0.033F, Rss470k The Following Parameter Applies: Soft Start TimeTss:Connect Rss,CSS. CE, 0V3.0VWhen VIN<3.0V, VIN3.0V Anachip Corp. www.anachip.com.tw Rev.1.1 May.27, 2004 3/5 AP1621 PWM/PFM Dual Mode Step-down DC/DC Controller Typical Application Circuit AP1621 L PMOS RSS VIN VDD +CIN CFB VOUT SD CE VOUT RFB1 +CL FB GND CSS RFB2 RL Marking Information SOT23-5L 4 7 5 XX Y M X 1 2 3 XX : Identification code (See Appendix) Y : Year: 0-9 M : Month: A~L Appendix X : Blank: normal L: Lead Free Package Part Number Package AP1621A AP1621B SOT23-5 SOT23-5 Identification Code EX EU SOT23-5L Anachip Corp. www.anachip.com.tw Rev.1.1 May.27, 2004 4/5 AP1621 PWM/PFM Dual Mode Step-down DC/DC Controller Package Information Package Type: SOT23-5L D e1 1(4x) 4 5 E1 A E 0.10 C 5x A2 Seating Plane A1 1 2 2(4x) 3 b e With Plating b1 C C1 Gauge Plane 0.25 mm Base Metal L b Symbol L1 Dimensions In Millimeters Dimensions In Inches Min. Nom. Max. Min. Nom. Max. A 1.05 1.20 1.35 0.041 0.047 0.053 A1 0.05 0.10 0.15 0.002 0.004 0.006 A2 1.00 1.10 1.20 0.039 0.043 0.047 b 0.25 - 0.55 0.010 - 0.022 b1 0.25 0.40 0.45 0.010 0.016 0.018 c 0.08 - 0.20 0.003 - 0.008 c1 0.08 0.11 0.15 0.003 0.004 0.006 D 2.70 2.85 3.00 0.106 0.112 0.118 E 2.60 2.80 3.00 0.102 0.110 0.118 E1 1.50 1.60 1.70 0.059 0.063 0.067 L 0.35 0.45 0.55 0.014 0.018 0.022 L1 0.60 Ref. 0.024 Ref. e 0.95 Bsc. 0.037 Bsc. e1 1.90 Bsc. 0.075 Bsc. 0o 5o 10o 0o 5o 10o 1 3o 5o 7o 3o 5o 7o 2 o o o o 6 8 o 10 6 8 10o Anachip Corp. www.anachip.com.tw Rev.1.1 May.27, 2004 5/5