UC3552

UNISONIC TECHNOLOGIES CO., LTD UC3552 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. CMOS IC *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 Packing Tape Reel Tube Tape Reel Tube www.unisonic.com.tw Copyright © 2007 Unisonic Technologies Co., Ltd 1 of 7 QW-R502-134.A UC3552 PIN CONFIGURATION CMOS IC PIN DESCRIPTION PIN NO. PIN NAME 1 EO 2 IN 3 SHDN 4 GND 5 SW 6 VDD 7 8 FREQ SS I/O I I I O I 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 BLOCK DIAGRAM CMOS IC UNISONIC TECHNOLOGIES CO., LTD www.unisonic.com.tw 3 of 7 QW-R502-134.A UC3552 ABSOLUTE MAXIMUM RATINGS PARAMETER SW to GND IN, SHDN , VDD , FREQ to GND SS, EO to GND RMS SW Pin Current SYMBOL CMOS IC 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. 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 TYP MAX 5.5 2.52 0.35 5.0 10.0 1.258 40 0.15 240 UNIT V V mA µA V nA %/V µA/V V/V kHZ % A Ω µA Ω µA V V V µA µA 2.38 0.21 1.2 0.1 1.240 0 0.05 105 1500 640 1320 85 85 1.6 0.23 0.01 740 1600 92 2.3 0.50 20.00 300 7.0 0.3VDD 4.0 0.1VDD 5.0 9.0 0.001 1.000 UNISONIC TECHNOLOGIES CO., LTD www.unisonic.com.tw 4 of 7 QW-R502-134.A UC3552 TYPICAL APPLICATION CIRCUIT CMOS IC L VOUT 6.8µH VDD 2.6V~5V VDD SW SHDN ON/OFF D1 COUT 33µF R1 C2 0.47µF 274kΩ IN UTC UC3552 SS CSS 27nF C1 3.3µF 1.2MHz R2 44.2kΩ GND FREQ EO 640KHz CEO2 33pF CEO 1.3nF REO 47KΩ UNISONIC TECHNOLOGIES CO., LTD www.unisonic.com.tw 5 of 7 QW-R502-134.A UC3552 IN A SEPIC CONFIGURATION CMOS IC UNISONIC TECHNOLOGIES CO., LTD www.unisonic.com.tw 6 of 7 QW-R502-134.A UC3552 MULTIPLE-OUTPUT TFT LCD POWER SUPPLY CMOS IC EO 150kΩ 18pF SHDN SS 27nF UTC UC3552 V1 C5 C4 3.3µF 3.3µF C3 3.3µF 274kΩ IN FREQ 44.2kΩ GND VDD C2 0.47µF SW VDD C1 3.0V ~ 3.6V 3.3µF D1 L1 6.8µH V3 3.3µF D4 0.1µF 0.1µF D3 1µF 1µF D2 V2 +26V 5mA 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