UC3550_10

UNISONIC TECHNOLOGIES CO., LTD UC3550 PWM CONTROLLED， PWM/PFM SWITCHABLE STEP-UP DC-DC CONTROLLER 3 2 1 CMOS IC 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. 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 Packing Tape Reel www.unisonic.com.tw Copyright © 2010 Unisonic Technologies Co., Ltd 1 of 10 QW-R502-082,B UC3550 MARKING INFORMATION PACKAGE VOLTAGE CODE MARKING CMOS IC SOT-25 33:3.3V 50:5.0V PIN CONFIGURATION PIN DESCRIPTION PIN NO 1 2 3 4 5 PIN NAME CE OUT NC GND EXT 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 BLOCK DIAGRAM CMOS IC UNISONIC TECHNOLOGIES CO., LTD www.unisonic.com.tw 3 of 10 QW-R502-082,B UC3550 ABSOLUTE MAXIMUM RATING CMOS IC 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 MIN 240 70 TYP 300 0.10 80 800 900 -1.6 600 60 700 250 MAX 360 90 900 1000 UNIT kHz %/°C % mV mV mV/°C mV ms △VSTART Ta=-40°C ~ 85°C VOPR tSS IOUT=0mA VOUT=VSET VCEH VCEL ICEH ICEL REXTH REXTL VOUT △VOUT IDD ISTN-BY IOFF η VOUT=VSET×0.96 VOUT=VCE=5.0V VOUT=5.0V, VCE=0V VEXT=VOUT-0.4V VEXT=0.4V 900 680 -0.5 0 0 0.15 11 8 3.218 3.3 150 103 15 0.6 80 88 160 38 1.5 0.5 0.5 15 12 3.383 mV mV μA μA Ω Ω V ppm/°C μA μA μA % Ta=-40 ~ 85°C VOUT=VCE=VSET×0.96 VOUT=VCE=VSET+0.5V VOUT=5.0V, VCE=0V, Ta=-40 ~ +85°C IOUT = 200mA, VIN = 2.0V UNISONIC TECHNOLOGIES CO., LTD www.unisonic.com.tw 4 of 10 QW-R502-082,B UC3550 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 MIN 240 70 TYP 300 0.1 80 800 900 -1.6 600 60 CMOS IC MAX 360 90 900 1 UNIT kHz %/°C % mV V mV/°C △VSTART Ta=-40°C ~ 85°C VOPR tSS IOUT=0mA VOUT=VSET 700 200 mV ms VCEH VCEL ICEH ICEL REXTH REXTL VOUT △VOUT IDD ISTN-BY IOFF η VOUT=VSET×0.96 900 680 -0.5 0 0 0.15 6 6 4.875 5 150 136 15 0.6 80 88 220 38 1.5 0.5 0.5 10 10 5.125 mV mV μA μA Ω Ω V ppm/°C μA μA μA % VOUT=VCE=5.0V VOUT=5.0V, VCE=0V VEXT=VOUT-0.4V VEXT=0.4V Ta=-40 ~ 85°C VOUT=VCE=VSET×0.96 VOUT=VCE=VSET+0.5V VOUT=5.0V, VCE=0V, Ta=-40 ~ +85°C IOUT = 200mA, VIN = 3.0V UNISONIC TECHNOLOGIES CO., LTD www.unisonic.com.tw 5 of 10 QW-R502-082,B UC3550 TYPICAL STEP-UP CONVERTER APPLICATION CMOS IC 10uH VIN VOUT 220uF CE EXT 1 OUT 5 UTC UC3550 GND 2 10uF NC 0.1µ 3 4 Step-up Converter using external MOSFET 10uH VIN Cb 3000P CE EXT VOUT 220uF 1 OUT 5 UTC UC3550 GND 2 10uF NC Rb 560 4 0.1µ 3 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 EXTERNAL COMPONENT SELECTION CMOS IC 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