UNISONIC TECHNOLOGIES CO., LTD UC3550 CMOS IC PWM CONTROLLED， PWM/PFM SWITCHABLE STEP-UP DC-DC CONTROLLER 3 1 DESCRIPTION The UTC UC3550 series is a compact, high efficiency, step-up DC/DC controllers includes an error amplifier, oscillator, PWM comparator, skip cycle comparator, voltage reference, soft-start, and high speed lower ON-resistance driver for driving external power devices (NMOS or NPN) ,Additionally, a CE (chip enable) function that reduces power consumption during shut-down mode. That typically operated from a single-or dual-cell battery packs. It have a driver pin ,ext pin, for connecting to an external transistor(NMOS or NPN). a lower ON-resistance external transistor can obtain larger output current. With only external components, this series allow a simple means to accommodate high output current applications. The UTC UC3550 series goes automatically into skip switching cycles under light load condition to maintain high efficiency. 2 5 4 SOT-25 FEATURES * Input Voltage Range：0.9~8V * Output Voltage Range：1.8~6V Programmable in 0.1V with High Accuracy ± 2.5% * High Efficiency 88% (Typ.) * Low Start-up Voltage of 0.9V Typical at IOUT = 1.0mA * Oscillator Frequency: 300kHz.(±20%) * Chip Enable Pin with Pull-up Current Source * High Output Current up to 1000mA (VIN = 2.0V, VOUT =3.3V) ORDERING INFORMATION Order Number UC3550G-xx-AF5-R Package SOT-25 www.unisonic.com.tw Copyright © 2010 Unisonic Technologies Co., Ltd Packing Tape Reel 1 of 10 QW-R502-082,B UC3550 CMOS IC MARKING INFORMATION PACKAGE VOLTAGE CODE SOT-25 33:3.3V 50:5.0V PIN CONFIGURATION PIN DESCRIPTION PIN NO PIN NAME 1 CE 2 3 4 5 OUT NC GND EXT MARKING DESCRIPTION Chip Enable: The chip is enabled if a voltage equal to or greater than 1.0V or left floating is applied. The chip is disabled if a voltage less than 0.3V is applied. Output voltage monitor, IC internal power supply No connection Ground External transistor drive UNISONIC TECHNOLOGIES CO., LTD www.unisonic.com.tw 2 of 10 QW-R502-082,B UC3550 CMOS IC BLOCK DIAGRAM UNISONIC TECHNOLOGIES CO., LTD www.unisonic.com.tw 3 of 10 QW-R502-082,B UC3550 CMOS IC ABSOLUTE MAXIMUM RATING PARAMETER SYMBOL RATINGS UNIT Supply Voltage VOUT -0.3~8 V VEXT -0.3 ~ 8 V EXT Voltage EXT Sink/Source Current IEXT -150 ~ +150 mA CE Input Voltage Range VCE -0.3 ~ 12.0 V CE Input Current Range ICE -155 ~ 155 mA Power Dissipation (Ta=25°C) PD 500 mW Junction Temperature TJ +150 °C Operating Temperature TOPR -40 ~ +85 °C Storage Temperature TSTG -55 ~ +150 °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. THERMAL DATA PARAMETER Junction to Ambient SYMBOL θJA RATINGS 250 UNIT °C/W ELECTRICAL CHARACTERISTICS (Ta=25°C, fOSC＝300kHz, unless otherwise specified) UC3550-3.3V PARAMETER OSCILLATOR Frequency Frequency Temperature Coefficient Maximum PWM Duty Cycle Minimum Start-up Voltage Minimum Start-up Voltage Minimum Start-up Voltage Temperature Coefficient Minimum Operation Hold Voltage Soft-Start Time CE (PIN 1) CE Input Voltage : High State, Device Enabled Low State, Device Disabled CE Input Current : High State, Device Enabled Low State, Device Disabled EXT (PIN 5) EXT “H” ON Resistance EXT “L” TOTAL DEVICE Output Voltage Output Voltage temperature coefficient Operating Current Stand-by Current Off-State Current Efficiency SYMBOL fOSC △f DMAX VSTART1 VSTART2 TEST CONDITIONS VOUT=VSET×0.96 Ta=-40°C ~ 85°C VOUT=VSET×0.96 IOUT=0mA IOUT=1mA TYP MAX UNIT 240 300 0.10 80 800 900 360 kHz %/°C % mV mV 70 △VSTART Ta=-40°C ~ 85°C VOPR tSS IOUT=0mA VOUT=VSET VCEH VCEL VOUT=VSET×0.96 ICEH ICEL VOUT=VCE=5.0V VOUT=5.0V, VCE=0V REXTH REXTL 90 900 1000 -1.6 600 60 mV/°C 700 250 mV ms 680 mV mV 0 0.15 0.5 0.5 μA μA 11 8 15 12 Ω Ω 3.3 3.383 900 -0.5 0 VEXT=VOUT-0.4V VEXT=0.4V VOUT 3.218 V △VOUT Ta=-40 ~ 85°C 150 IDD ISTN-BY VOUT=VCE=VSET×0.96 VOUT=VCE=VSET+0.5V VOUT=5.0V, VCE=0V, Ta=-40 ~ +85°C IOUT = 200mA, VIN = 2.0V 103 15 160 38 μA μA 0.6 1.5 μA IOFF η UNISONIC TECHNOLOGIES CO., LTD www.unisonic.com.tw MIN 80 88 ppm/°C % 4 of 10 QW-R502-082,B UC3550 CMOS IC ELECTRICAL CHARACTERISTICS (Cont.) UC3550-5.0V PARAMETER OSCILLATOR Frequency Frequency Temperature Coefficient Maximum PWM Duty Cycle Minimum Start-up Voltage Minimum Start-up Voltage Minimum Start-up Voltage Temperature Coefficient Minimum Operation Hold Voltage Soft-Start Time CE (PIN 1) CE Input Voltage : High State, Device Enabled Low State, Device Disabled CE Input Current : High State, Device Enabled Low State, Device Disabled EXT (PIN 5) EXT “H” ON Resistance EXT “L” TOTAL DEVICE Output Voltage Output Voltage temperature coefficient Operating Current Stand-by Current Off-State Current Efficiency SYMBOL fOSC △f DMAX VSTART1 VSTART2 TEST CONDITIONS VOUT=VSET×0.96 Ta=-40°C ~ 85°C VOUT=VSET×0.96 IOUT=0mA IOUT=1mA TYP MAX UNIT 240 300 0.1 80 800 900 360 kHz %/°C % mV V 70 △VSTART Ta=-40°C ~ 85°C VOPR tSS IOUT=0mA VOUT=VSET VCEH VCEL VOUT=VSET×0.96 ICEH ICEL VOUT=VCE=5.0V VOUT=5.0V, VCE=0V REXTH REXTL VEXT=VOUT-0.4V VEXT=0.4V VOUT △VOUT IDD ISTN-BY IOFF η 90 900 1 -1.6 600 60 mV/°C 700 200 mV ms 680 mV mV 0 0.15 0.5 0.5 μA μA 6 6 10 10 Ω Ω 5 5.125 900 -0.5 0 4.875 V Ta=-40 ~ 85°C 150 VOUT=VCE=VSET×0.96 VOUT=VCE=VSET+0.5V VOUT=5.0V, VCE=0V, Ta=-40 ~ +85°C IOUT = 200mA, VIN = 3.0V 136 15 220 38 μA μA 0.6 1.5 μA UNISONIC TECHNOLOGIES CO., LTD www.unisonic.com.tw MIN 80 88 ppm/°C % 5 of 10 QW-R502-082,B UC3550 CMOS IC TYPICAL STEP-UP CONVERTER APPLICATION 10uH VIN VOUT 220uF EXT CE 1 5 OUT UTC UC3550 2 10uF NC 0.1µ 3 GND 4 Step-up Converter using external MOSFET 10uH VIN VOUT Cb 3000P 1 OUT 2 10uF NC 0.1µ 3 220uF EXT CE 5 Rb 560 UTC UC3550 GND 4 Step-up Converter using external NPN Recommended components Nmos tR ：XP161A0390PR/ (Torex) or NTGS3446T1(ON SEMI) L ：10Uh(Sunida CD54 fosc＝300kHz) SD ：MA737, or MBRM110L CIN ：10V 10uF (tantalum) CL ：16V220uF (tantalum) NPN tR type tR ：2SD1628(Sanyo)，MMJT9410 Rb ：500～1000Ω(Adjust according to load and Tr. hFE levels) Cb ：3000p(ceramic type) UNISONIC TECHNOLOGIES CO., LTD www.unisonic.com.tw 6 of 10 QW-R502-082,B UC3550 CMOS IC EXTERNAL COMPONENT SELECTION Inductor Selection An inductor value of 10uH performs well in most application. The UC3550 series also work with inductors in the 4.7uH to 12uH range. An inductor with higher peak inductor current tends a higher output voltage ripple(IPEAK x output filter capacitor ESR). The inductor’s DC resistance significantly affects efficiency. Output Capacitor Selection The output ripple voltage(IPEAK x output filter capacitor ESR)is the product of the peak inductor current and the output capacitor Equivalent Series Resistance (ESR). Best performances are obtained with good high frequency characteristics capacitors and low ESR. The best compromise for the value of the Output Capacitance is 220F Tantalum Capacitor. The output capacitor as close as possible to the device pins. Input Capacitor Selection The Input Capacitor is required to compensate, if present, the series impedance between the Supply Voltage Source and the Input Voltage of the Application. A value of 10 F is enough to guarantee stability for distances less than 2". In any case we suggest to connect both capacitors, The input capacitor as close as possible to the device pins. Diode Selection The Schottky diode with an high switching speed and a very low Forward Voltage (VF) is needed. Higher VF may cause lost power as heat in the diode, with a decrease of the Efficiency. Moreover, since the Output Voltage pin is also used as the device Supply Voltage, the Start-up Voltage (see related plots) is strictly due to the diode Forward Voltage at the rated Forward Current. External Component Selection An enhancement N-channel MOSFET or a bipolar NPN transistor can be used as the external switch transistor. since enhancement N-channel MOSFET is a voltage driven device, it is a more efficient switch than a BJT transistor. However, he MOSFET requires a higher voltage to turn on as compared with BJT transistor For enhancement N-channel MOSFET ( it is especially importance for RDS(ON),typically<0.1Ω, threshold voltage, VGS(TH) must be<VOUT, typically<1.5V. For bipolar NPN transistor, continuous collector current typically 1A to 4A and VCE(SAT)<0.2V. the driving capability is determined by the DC current gain, HFE, of the transistor and the base resistor, Rb. Moreover, a speed-up capacitor, Cb should be connected in paralled with Rb to reduce switch loss and improve efficiency. UNISONIC TECHNOLOGIES CO., LTD www.unisonic.com.tw 7 of 10 QW-R502-082,B UC3550 TYPICAL CHARACTERISTICS 1 VOUT=5.0V 0.1 VOUT=3.0V 2 3 4 Input Voltage, VIN (V) 10 1 0.1 0.01 1 5 VOUT=5.0V, Rb=560Ω VOUT=3.0V, Rb=560Ω 2 5 3 4 Input Voltage, VIN (V) 6 Maximum Duty Cycle, DMAX (%) 0.01 1 No Load Input Current vs. Input Voltage (Using BJT) 100 NO Load Input Current, IIN (mA) NO Load Input Current, IIN (mA) No Load Input Current vs. Input Voltage (Using MOSFET) 10 Output Voltage, VOUT (V) CMOS IC UNISONIC TECHNOLOGIES CO., LTD www.unisonic.com.tw 8 of 10 QW-R502-082,B UC3550 TYPICAL CHARACTERISTICS(Cont.) Efficiency vs Output Current (5.0V) Startup/Hold Voltage, Vstart/Vhold (V) 100 Efficiency (%) VIN=3.0V 80 VIN=2.0V 60 VIN=0.9V 40 20 0 0. 01 0.1 1 10 100 1000 Startup/Hold Voltage vs Output Current (Using MOSFET) Output Current (3.3V) 2.0 Vstart 1.6 1.2 0.8 Vnold 0.4 0.0 0 Output Current, IOUT (mA) EXT ON-Resistance vs Temperature 20 15 VOUT=5.0V×0.96 VEXT=VOUT-0.4V Open-Loop Test 10 VOUT=5.0V×0.96 VEXT=0.4V Open-Loop Test 5 0 -50 25 - 0 25 50 75 200 Ripple Voltage, VRIPPLE (mV) ON-Resistance, (Ω) 25 20 40 60 80 100 Output Current, IC (mA) Temperature℃ Ripple Voltage vs Output Current 180 160 VIN=2.0V 140 120 100 VIN=3.0V VIN=1.5V 80 60 VIN=4.5V 40 20 0 0 100 200 400 600 800 1000 Output Current, IOUT (mA) Oscilator Frequency, fosc (KHz) Oscilator Frequency, fosc (KHz) CMOS IC UNISONIC TECHNOLOGIES CO., LTD www.unisonic.com.tw 9 of 10 QW-R502-082,B UC3550 CMOS IC TYPICAL CHARACTERISTICS(Cont.) 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 10 of 10 QW-R502-082,B