UNISONIC TECHNOLOGIES CO., LTD UC3655 Preliminary CMOS IC 500mA SYNCHRONOUS STEP-DOWN DC/DC CONVERTERS DESCRIPTION The UTC UC3655 is a synchronous-rectification type DC/DC converters with a built-in 0.6Ω P-channel driver transistor and 0.7Ω N-channel switching transistor, which designed to allow the use of ceramic capacitors. Using only a coil and two capacitors connected externally, the UC3655 enable a high efficiency, stable power supply with an output current of 500mA to be configured. Its operating voltage is 2.0V and the output voltage is programmable in a range from 0.9V to 4.0V in increments of 0.1V (accuracy: ±2.0%) internally. The oscillation frequency is 1.2MHz. For operation mode, it is PWM control in the UTC UC3655, the UTC UC3655 series is automatic PWM/PFM switching control, allowing fast response, low ripple and high efficiency over the full range of load. Internal soft start and current control functions are built in it. All circuits are shutdown to reduce current consumption to as low as 1.0μA or less during standby mode. With the built-in Under Voltage Lock Out (U.V.L.O.) function, when input voltage becomes 1.4V or lower the internal P channel driver transistor is forced OFF. FEATURES * Very High Efficiency 92% * Low Ripple Rejection Voltage 10mV * Output Current 500mA @VIN=3.0V, VOUT=1.8V * Oscillation Frequency is 1.2MHz * With PWM / PFM Automatic Switching Control * Maximum Duty Ratio is 100% * Ceramic Capacitor Available ORDERING INFORMATION Ordering Number Lead Free Halogen Free UC3655L-xx-AF5-R UC3655G-xx-AF5-R www.unisonic.com.tw Copyright © 2011 Unisonic Technologies Co., Ltd Package Packing SOT-25 Tape Reel 1 of 9 QW-R502-280.c UC3655 Preliminary CMOS IC MARKING PACKAGE VOLTAGE CODE SOT-25 12:1.2V 28:2.8V 33:3.3V 38:3.8V MARKING 4 5 Voltage Code UHXXG 1 2 G: Halogen Free L: Lead Free 3 PIN DESCRIPTION PIN NO 1 2 3 4 5 PIN NAME VIN VSS CE / MODE VOUT Lx DESCRIPTION Power Input Voltage Ground Switch Pin For Chip Enable Mode Output Voltage Sense Pin Output Of Switching UNISONIC TECHNOLOGIES CO., LTD www.unisonic.com.tw 2 of 9 QW-R502-280.c UC3655 Preliminary CMOS IC BLOCK DIAGRAM UNISONIC TECHNOLOGIES CO., LTD www.unisonic.com.tw 3 of 9 QW-R502-280.c UC3655 Preliminary CMOS IC ABSOLUTE MAXIMUM RATING (TA=25°C) PARAMETER VIN Pin Voltage SYMBOL RATINGS UNIT VIN - 0.3 ~ 6.5 V LX VLx - 0.3 ~ VIN + 0.3 Input/Output Pins VOUT VOUT -0.3 ~ 6.5 V CE/MODE VCE - 0.3 ~ VIN + 0.3 Lx Pin Current ILX ±1000 mA Power Dissipation PD 250 mW Operating Temperature TOPR - 40 ~ 85 °C Storage Temperature Range TSTG - 55 ~ 125 °C Note: Absolute maximum ratings are those values beyond which the device could be permanently damaged. Absolute maximum ratings are stress ratings only and functional device operation is not implied. ELECTRICAL CHARACTERISTICS (fOSC=1.2MHz, TA=25°C) UC3655-12 (VIN=3.6V, VOUT=1.2V) PARAMETER SYMBOL Operating Voltage Range VIN Output Voltage VOUT U.V.L.O. Voltage VUVLO ΔVOUT Output Voltage Temperature VOUT*ΔTOPR Characteristics Maximum Output Current IOUT(MAX) Supply Current IDD Stand-by Current ISTN-BY PFM Switch Current IPFM Current Limit ILIM Efficiency (Note 1) η OSCILLATOR Oscillation Frequency fOSC Maximum Duty Ratio DMAX Minimum Duty Ratio DMIN Soft-Start Time TSS Latch Time TLAT CE (PIN 3) CE "H" Voltage VCEH CE "L" Voltage VCEL CE "H" Current ICEH CE "L" Current ICEL LX (PIN 5) LX SW "H" ON Resistance RLXH LX SW "L" ON Resistance RLXL LX SW "H" Leak Current (Note 2) ILEAKH LX SW "L" Leak Current ILEAKL TEST CONDITIONS CE=VIN, IOUT=30mA CE=VIN, VOUT=0V, LX=L IOUT=30mA, -40°C ≤TOPR≤85°C VIN=4.5V VIN=CE=5.0V, VOUT=VOUT*1.1 VIN=5.0V, CE=0V, VOUT=VOUT*1.1 CE=VIN, IOUT=1mA VIN=CE=5.0V, VOUT=0V CE=VIN=4.5V, IOUT=100mA IOUT=100mA CE=VIN, VOUT=0V CE=VOUT=VIN IOUT=1mA VIN=CE=5.0V (Note 3) VIN=CE=5.5V, VOUT=0V VIN=5.5V, CE=0V, VOUT=0V CE=0.5VIN, VOUT=0V, ILX=100mA CE=0.5VIN, ILX=100mA VIN=VOUT=5.0V, CE=0V, LX=0V VIN=VOUT=5.0V, CE=0V, LX=5.0V UNISONIC TECHNOLOGIES CO., LTD www.unisonic.com.tw MIN 2.0 1.176 1.0 TYP 1.200 1.40 MAX 6.0 1.224 1.78 UNIT V V V ±100 ppm/°C 70 0 140 700 90 115 1.0 180 mA µA µA mA mA % 1020 100 1200 1380 0.5 1 1.0 0 3.0 20 kHz % % ms ms VIN 0.3 0.1 0.1 V V µA µA 1.0 1.0 Ω Ω µA µA 500 100 600 0.9 VSS -0.1 -0.1 0.6 0.7 0.01 0.01 4 of 9 QW-R502-280.c UC3655 Preliminary CMOS IC ELECTRICAL CHARACTERISTICS(Cont.) UC3655-28 (VIN=3.6V, VOUT=2.8V) PARAMETER SYMBOL Operating Voltage Range VIN Output Voltage VOUT U.V.L.O. Voltage VUVLO ΔVOUT Output Voltage Temperature VOUT*ΔTOPR Characteristics Maximum Output Current IOUT(MAX) Supply Current IDD Stand-by Current ISTN-BY PFM Switch Current IPFM Current Limit ILIM Efficiency (Note 1) η OSCILLATOR Oscillation Frequency fOSC Maximum Duty Ratio DMAX Minimum Duty Ratio DMIN Soft-Start Time TSS Latch Time TLAT CE (PIN 3) CE "H" Voltage VCEH CE "L" Voltage VCEL CE "H" Current ICEH CE "L" Current ICEL LX (PIN 5) LX SW "H" ON Resistance RLXH LX SW "L" ON Resistance RLXL LX SW "H" Leak Current ILEAKH LX SW "L" Leak Current ILEAKL UC3655-33 (VIN=5.0V, VOUT=3.3V) PARAMETER SYMBOL Operating Voltage Range VIN Output Voltage VOUT U.V.L.O. Voltage VUVLO ΔVOUT Output Voltage Temperature VOUT*ΔTOPR Characteristics Maximum Output Current IOUT(MAX) Supply Current IDD Stand-by Current ISTN-BY PFM Switch Current IPFM Current Limit ILIM Efficiency (Note 1) η OSCILLATOR Oscillation Frequency fOSC Maximum Duty Ratio DMAX Minimum Duty Ratio DMIN Soft-Start Time TSS Latch Time TLAT TEST CONDITIONS CE=VIN, IOUT=30mA CE=VIN, VOUT=0V, LX=L IOUT=30mA, -40°C ≤TOPR≤85°C VIN=4.5V VIN=CE=5.0V, VOUT=VOUT*1.1 VIN=5.0V, CE=0V, VOUT=VOUT*1.1 CE=VIN, IOUT=1mA VIN=CE=5.0V, VOUT=0V CE=VIN=4.5V, IOUT=100mA IOUT=100mA CE=VIN, VOUT=0V CE=VOUT=VIN IOUT=1mA VIN=CE=5.0V (Note 3) VIN=CE=5.5V, VOUT=0V VIN=5.5V, CE=0V, VOUT=0V TEST CONDITIONS CE=VIN, IOUT=30mA CE=VIN, VOUT=0V, LX=L IOUT=100mA CE=VIN, VOUT=0V CE=VOUT=VIN IOUT=1mA VIN=CE=5.0V (Note 3) 2.8 1.40 MAX 6.0 2.856 1.78 UNIT V V V ppm/°C 500 mA µA µA mA mA % 75 0 140 700 92 120 1.0 180 1020 100 1200 1380 0.5 1 1.0 0 3.0 20 kHz % % ms ms VIN 0.3 0.1 0.1 V V µA µA 100 600 0.9 VSS -0.1 -0.1 0.5 0.6 MIN 2.0 3.234 1.0 IOUT=30mA, -40℃≤TOPR≤85℃ VIN=4.5V VIN=CE=5.0V, VOUT=VOUT*1.1 VIN=5.0V, CE=0V, VOUT=VOUT*1.1 CE=VIN, IOUT=1mA VIN=CE=5.0V, VOUT=0V CE=VIN=4.5V, IOUT=100mA TYP ±100 CE=0.5VIN, VOUT=0V, ILX=100mA CE=0.5VIN, ILX=100mA VIN=VOUT=5.0V, CE=0V, LX=0V (Note 2) VIN=VOUT=5.0V, CE=0V, LX=5.0V UNISONIC TECHNOLOGIES CO., LTD www.unisonic.com.tw MIN 2.0 2.744 1.0 Ω Ω 0.01 1.0 µA 0.01 1.0 µA TYP MAX 6.0 3.366 1.78 UNIT V V V 3.300 1.40 ±100 ppm/°C 500 75 0 140 700 92 120 1.0 180 1020 100 1200 1380 0.5 1 1.0 0 3.0 20 100 600 mA µA µA mA mA % kHz % % ms ms 5 of 9 QW-R502-280.c UC3655 Preliminary CMOS IC ELECTRICAL CHARACTERISTICS(Cont.) PARAMETER CE (PIN 3) CE "H" Voltage CE "L" Voltage CE "H" Current CE "L" Current LX (PIN 5) LX SW "H" ON Resistance LX SW "L" ON Resistance LX SW "H" Leak Current (Note 2) LX SW "L" Leak Current SYMBOL TEST CONDITIONS MIN VCEH VCEL ICEH ICEL VIN=CE=5.5V, VOUT=0V VIN=5.5V, CE=0V, VOUT=0V 0.9 VSS -0.1 -0.1 RLXH RLXL ILEAKH ILEAKL CE=0.50VIN, VOUT=0V, ILX=100mA CE=0.5VIN, ILX=100mA VIN=VOUT=5.0V, CE=0V, LX=0V VIN=VOUT=5.0V, CE=0V, LX=5.0V TYP 0.5 0.6 0.01 0.01 MAX UNIT VIN 0.3 0.1 0.1 V V µA µA 1.0 1.0 Ω Ω µA µA UC3655-38 (VIN=5.0V, VOUT=3.8V) PARAMETER SYMBOL TEST CONDITIONS MIN TYP MAX UNIT Operating Voltage Range VIN 2.0 6.0 V Output Voltage VOUT CE=VIN, IOUT=30mA 3.724 3.800 3.876 V U.V.L.O. Voltage VUVLO CE=VIN, VOUT=0V, LX=L 1.0 1.40 1.78 V ΔVOUT Output Voltage Temperature ±100 ppm/°C VOUT*ΔTOPR IOUT=30mA, -40℃≤TOPR≤85℃ Characteristics Maximum Output Current IOUT(MAX) VIN=4.5V 500 mA Supply Current IDD VIN=CE=5.0V, VOUT=VOUT*1.1 75 120 µA I VIN=5.0V, CE=0V, VOUT=VOUT*1.1 Stand-by Current 0 1.0 µA STN-BY PFM Switch Current IPFM CE=VIN, IOUT=1mA 100 140 180 mA Current Limit ILIM VIN=CE=5.0V, VOUT=0V 600 700 mA Efficiency (Note 1) η CE=VIN=4.5V, IOUT=100mA 92 % OSCILLATOR Oscillation Frequency fOSC IOUT=100mA 1020 1200 1380 kHz Maximum Duty Ratio DMAX CE=VIN, VOUT=0V 100 % Minimum Duty Ratio DMIN CE=VOUT=VIN 0 % Soft-Start Time TSS IOUT=1mA 0.5 1.0 3.0 ms Latch Time TLAT VIN=CE=5.0V (Note 3) 1 20 ms CE (PIN 3) CE "H" Voltage VCEH 0.9 VIN V CE "L" Voltage VCEL VSS 0.3 V CE "H" Current ICEH VIN=CE=5.5V, VOUT=0V -0.1 0.1 µA CE "L" Current ICEL VIN=5.5V, CE=0V, VOUT=0V -0.1 0.1 µA LX (PIN 5) LX SW "H" ON Resistance RLXH CE=0.5VIN, VOUT=0V, ILX=100mA 0.5 Ω LX SW "L" ON Resistance RLXL CE=0.5VIN, ILX=100mA 0.6 Ω LX SW "H" Leak Current (Note 2) ILEAKH VIN=VOUT=5.0V, CE=0V, LX=0V 0.01 1.0 µA LX SW "L" Leak Current ILEAKL VIN=VOUT=5.0V, CE=0V, LX=5.0V 0.01 1.0 µA Note: 1. η= [(VOUT*IOUT)/(VIN*IIN)]*100 Note: 2. When temperature is high, a current of approximately 20μA (maximum) may leak. Note: 3. Time until it short-circuits DCOUT with GND through 1Ω of resistance from a state of operation and is set to DCOUT=0V from current limit pulse generating. UNISONIC TECHNOLOGIES CO., LTD www.unisonic.com.tw 6 of 9 QW-R502-280.c UC3655 Preliminary CMOS IC OPERATIONAL EXPLANATION CE / MODE Pin Function When a low level signal is input to the CE/MODE pin the operation of the UC3655 series will enter into the shut down mode. In this mode, the current consumption occurs only in the detector and is 0 μA (TYP.), with a state of high impedance at the Lx pin and VOUT pin. By inputting a high level signal to the CE/MODE pin the IC starts its operation. The input of the CE/MODE pin is a CMOS input and its sink current is 0 μA (TYP.). UC3655 series - Examples of how to use CE/MODE pin VIN VDD R1 CE/MODE SW_CE SW_CE ON OFF STATUS Stand-by Operation SW_CE ON OFF STATUS Stand-by Operation FUNCTIONS CE/MODE H Level M Level L Level VOLTAGE LEVEL VIN-0.3V≦H level≦VIN 0.9V≦M Level≦VIN-1.0V 0V≦L Level≦0.3V UNISONIC TECHNOLOGIES CO., LTD www.unisonic.com.tw OPERATION Synchronous PWM/PFM Automatic Switching Control Stand-by 7 of 9 QW-R502-280.c UC3655 Preliminary CMOS IC TEST CIRCUIT CI CL L UNISONIC TECHNOLOGIES CO., LTD www.unisonic.com.tw 4.7µF (Ceramic) 10µF (Ceramic) 3.3µH 8 of 9 QW-R502-280.c UC3655 Preliminary CMOS IC TYPICAL APPLICATION CIRCUIT VIN CI CE/MODE LX VIN CE/ MODE VSS CI CL L L VOUT (400mA) CL VOUT 4.7µF (Ceramic) 10µF (Ceramic) 3.3µH UTC assumes no responsibility for equipment failures that result from using products at values that exceed, even momentarily, rated values (such as maximum ratings, operating condition ranges, or other parameters) listed in products specifications of any and all UTC products described or contained herein. UTC products are not designed for use in life support appliances, devices or systems where malfunction of these products can be reasonably expected to result in personal injury. Reproduction in whole or in part is prohibited without the prior written consent of the copyright owner. The information presented in this document does not form part of any quotation or contract, is believed to be accurate and reliable and may be changed without notice. UNISONIC TECHNOLOGIES CO., LTD www.unisonic.com.tw 9 of 9 QW-R502-280.c