UNISONIC TECHNOLOGIES CO., LTD UC3552 CMOS IC PWM DC-DC CONVERTER WITH INTERNAL SWITCH AND SOFT-START DESCRIPTION The UTC UC3552 is a step-up PWM DC-DC converter with a internal switch which is 1.6A, 0.23Ω. UTC UC3552 offers users flexibility in determining loop dynamics and adjusting operating frequency cause it’s equipped with an external compensation pin ,and it also allows the use of small, low equivalent resistance (ESR) ceramic output capacitors. UTC UC3552 is capable of converting a standard input of 3.3V to multiple outputs of 8V, − 8V , and 23V. Otherwise, filtering and loop performance are enhanced and facilitated by a high switching frequency of either 640 kHz or1.3MHz. As a power-smart design in shutdown mode a soft-start with an external capacitor that sets the input current ramp rate, reduces the current consumption to 0.1µA. A mere 2.6V input yields an impressive output voltage to 12V when operating. *Pb-free plating product number: UC3552L FEATURES * 1.6A, 0.23Ω, internal switch * High efficiency: 90% * Adjustable output: VDD to 12V * Adjustable frequency: 640kHz or 1.3MHz * Wide input range: +2.6V ~ +5.5V * Low shutdown current: 0.1µA * Programmable soft-start ORDERING INFORMATION Ordering Number UC3552-S08-R UC3552L-S08-R UC3552-S08-T UC3552L-S08-T UC3552-SM1-R UC3552L-SM1-R UC3552-SM1-T UC3552L-SM1-T Package SOP-8 SOP-8 MSOP-8 MSOP-8 www.unisonic.com.tw Copyright © 2007 Unisonic Technologies Co., Ltd Packing Tape Reel Tube Tape Reel Tube 1 of 7 QW-R502-134.A UC3552 CMOS IC PIN CONFIGURATION PIN DESCRIPTION PIN NO. PIN NAME 1 EO 2 IN 3 SHDN 4 GND 5 SW 6 VDD I/O I I I O 7 FREQ I 8 SS I DESCRIPTION Compensation pin for Error Amplifier Feedback pin with a typical reference voltage of 1.24V Shutdown control pin. The device will turn off when SHDN is low Ground Switch pin Power supply pin Frequency select pin. Switch oscillator frequency to 640kHz when FREQ is low, and 1.3MHz when FREQ is high Soft-Start control pin. No soft-start when the pin is left open UNISONIC TECHNOLOGIES CO., LTD www.unisonic.com.tw 2 of 7 QW-R502-134.A UC3552 CMOS IC BLOCK DIAGRAM UNISONIC TECHNOLOGIES CO., LTD www.unisonic.com.tw 3 of 7 QW-R502-134.A UC3552 CMOS IC ABSOLUTE MAXIMUM RATINGS PARAMETER SW to GND IN, SHDN , VDD , FREQ to GND SS, EO to GND RMS SW Pin Current RATINGS UNIT -0.3 ~ +14 V -0.3 ~ +6 V -1.3V ~ (VDD+0.3V) V ISW 1.2 A SOP-8 350 mW Continuous Power Dissipation (TC = 70℃) PD MSOP-8 300 mW Junction Temperature TJ +125 ℃ Operating Temperature TOPR -20 ~ +85 ℃ Storage Temperature TSTG -45 ~ +125 ℃ 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. SYMBOL ELECTRICAL CHARACTERISTICS TC = +25 ℃, VDD =SHDN = 3V, FREQ = GND, unless otherwise specified.) PARAMETER SYMBOL TEST CONDITIONS MIN Input Supply Voltage VDD 2.6 When VDD is rising, typical hysteresis is 40mV; SW remains off below this 2.25 VDD Under Voltage Lockout UVLO level VDD = 1.3V, not switching Quiescent Current IDD VDD = 1.0V, switching Shutdown Current ISC SHDN = GND ERROR AMPLIFIER Feedback Voltage VIN Level to produce VEO = 1.24V 1.22 VDD Input Bias Current II(BIAS) VIN= 1.24V Level to produce VEO = 1.24V, Feedback-Voltage Line Regulation 2.6V < VDD < 5.5V Transconductance gm ∆I = 5µA 70 Voltage Gain GV OSCILLATOR FREQ = GND 540 Frequency fOSC 1100 FREQ = VDD FREQ = GND 79 Maximum Duty Cycle tDUTY FREQ = VDD N-CHANNEL SWITCH Current Limit ILIMIT VDD = 1V, Duty Cycle = 65% 1.2 On-Resistance RON ISW = 1.2A Leakage Current ILEAK VSW = 12V SOFT-START Reset Switch Resistance Charge Current VSS = 1.2V 1.5 CONTROL INPUTS Input Low Voltage VIL SHDN , FREQ; VDD = 2.6V ~ 5.5V Input High Voltage VIH SHDN , FREQ; VDD = 2.6V ~ 5.5V 0.7VDD Hysteresis SHDN , FREQ FREQ Pull-Down Current IFREQ 1.8 SHDN Input Current ISHDN UNISONIC TECHNOLOGIES CO., LTD www.unisonic.com.tw TYP MAX 5.5 UNIT V 2.38 2.52 V 0.21 1.2 0.1 0.35 5.0 10.0 1.240 0 1.258 40 V nA 0.05 0.15 %/V 105 1500 240 µA/V V/V 640 1320 85 85 740 1600 92 1.6 0.23 0.01 2.3 0.50 20.00 A Ω µA 4.0 300 7.0 Ω µA 0.3VDD V V V µA µA 0.1VDD 5.0 9.0 0.001 1.000 mA µA kHZ % 4 of 7 QW-R502-134.A UC3552 CMOS IC TYPICAL APPLICATION CIRCUIT L VDD 2.6V~5V 6.8µH VDD VOUT SW ON/OFF SHDN D1 COUT 33µF R1 C1 3.3µF 274kΩ IN C2 0.47µF UTC UC3552 SS CSS 27nF 1.2MHz R2 44.2kΩ GND FREQ EO CEO2 33pF 640KHz REO 47KΩ CEO 1.3nF UNISONIC TECHNOLOGIES CO., LTD www.unisonic.com.tw 5 of 7 QW-R502-134.A UC3552 CMOS IC IN A SEPIC CONFIGURATION UNISONIC TECHNOLOGIES CO., LTD www.unisonic.com.tw 6 of 7 QW-R502-134.A UC3552 CMOS IC MULTIPLE-OUTPUT TFT LCD POWER SUPPLY EO 150kΩ SHDN SS 27nF 18pF UTC UC3552 V1 274kΩ C5 C4 3.3µF 3.3µF C3 3.3µF IN FREQ GND VDD 44.2kΩ VDD C1 3.0V ~ 3.6V 3.3µF C2 0.47µF SW L1 D1 6.8µH V3 D2 1µF 3.3µF V2 D4 +26V 5mA 0.1µF 0.1µF 1µF D3 1µF 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 7 of 7 QW-R502-134.A