UNISONIC TECHNOLOGIES CO., LTD UC3666 Preliminary CMOS IC DUAL CHANNEL 1A HIGH EFFICIENCY STEP-DOWN DC/DC CONVERTER 1 DESCRIPTION DFN-10(3x3) The UTC UC3666 is a dual channel high efficiency step-down DC/DC converter with constant frequency and current mode. A main switch and a synchronous rectifier for high efficiency are contained in each converter, and thus an external Schottky diode is saved. The output voltage can be adjusted to as low as 0.6V. With input voltage range from 2.5V ~ 5.5V , each converter can deliver 1A current to the load. Due to the internally fixed 1.6MHz switching frequency, small surface mount inductors and capacitors can be used. The UTC UC3666 is generally used in digital still cameras, portable instruments, slim-type DVD, microprocessors and DSP core supplies, wireless and DSL card, PDAs, smart phones, cellular telephones and so on. FEATURES * high efficiency * Current mode operation * Input voltage varying from 2.5V to 5.5V * Output current on each channel: 1A * Fixed frequency operation * 0.6V reference allows low output voltages * Over-temperature protection circuit * RoHS Compliant (100% green available) ORDERING INFORMATION Ordering Number UC3666G-K10-3030-R www.unisonic.com.tw Copyright © 2015 Unisonic Technologies Co., Ltd Package DFN-10(3×3) Packing Tape Reel 1 of 5 QW-R502-489.b UC3666 Preliminary MARKING PIN CONFIGURATION CMOS IC Top View EN1 1 10 SW1 FB1 2 9 GND1 VIN2 3 8 VIN1 GND2 4 7 FB2 SW2 5 6 EN2 Exposed Pad On Backside PIN DESCRIPTION PIN NO. PIN NAME 1 EN1 2 3 4 5 FB1 VIN2 GND2 SW2 6 EN2 7 8 9 10 FB2 VIN1 GND1 SW1 DESCRIPTION Channel 1 Regulator Enable Control Input Pin. Drive EN1 above 1.5V to turn on channel1. Drive EN1 below 0.3V to turn it off (shutdown current < 0.1uA). Channel 1 Voltage Feedback Pin Channel 2 Supply Pin Channel 2 Ground Pin Channel 2 Power Switch Output Channel 2 Regulator Enable Control Input Pin. Drive EN2 above 1.5V to turn on channel2. Drive EN2 below 0.3V to turn it off (shutdown current < 0.1uA). Channel 2 Voltage Feedback Pin Channel 1 Supply Pin Channel 1 Ground Pin Channel 1 Power Switch Output UNISONIC TECHNOLOGIES CO., LTD www.unisonic.com.tw 2 of 5 QW-R502-489.b UC3666 Preliminary CMOS IC BLOCK DIAGRAM VIN1 VIN2 EN1 EN2 EN Logic UVLO Reference + + Current Sense Amplifier Slop Comp Soft Start - M1 UG FB1 FB2 0.6V + - + Error Amplifier PWM Comparator PWM Logic SW1 SW2 RS & Drive M2 Oscillator LG Clock DCC + GND1 GND2 Zero-Current Comparator UNISONIC TECHNOLOGIES CO., LTD www.unisonic.com.tw 3 of 5 QW-R502-489.b UC3666 Preliminary CMOS IC ABSOLUTE MAXIMUM RATING PARAMETER SYMBOL RATINGS UNIT Input Supply Voltage VIN GND-0.3 ~ +6.5 V SW Voltage -0.3 ~ VIN +0.3 V ENB, VFB Voltage -0.3 ~ VIN V SW Peak Current 1.5 A Junction Temperature TJ 125 °C Operating Temperature TOPR -20 ~ +85 °C Storage Temperature Range TSTG -65 ~ +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. The IC has a protection circuit against static electricity. Do not apply high static electricity or high voltage that exceeds the performance of the protection circuit to the IC. THERMAL DATA PARAMETER SYMBOL Junction ambient θJA Note: The PCB area is 4 times larger than that of IC’s RATINGS 72 UNIT °C/W ELECTRICAL CHARACTERISTICS (Recommended Operating Conditions, unless otherwise specified; VIN=3.6V, TA=0 ~ 70°C (typical=25°C)) PARAMETER SYMBOL TEST CONDITIONS MIN TYP MAX UNIT Supply Voltage VIN 2.5 5.5 V Feedback Current IVFB -30 0.5 30 nA TA=25°C 0.588 0.6 0.612 V Regulated Feedback Voltage VFB -40°C≤TA≤85°C 0.582 0.6 0.618 V Reference Voltage Line Regulation ∆VFB VIN=2.5V ~ 5.5V 0.04 0.4 %V Output Voltage Line Regulation ∆VOUT VIN=2.5V ~ 5.5V 0.04 0.4 %V Output Voltage Load Regulation VLOADRGE 0.5 % Shutdown Current IS VEN=0V, VIN=5.5V 0.01 1 µA SW Leakage Current ILEAK VEN=0V, VIN=5.5V, VSW=0V or 5.5V -1 1 µA PMOSFET On Resistance RDSONP ISW=100mA 0.35 Ω NMOSFET On Resistance RDSONN ISW=100mA 0.24 Ω Duty Cycle=100% 0.9 1.2 1.4 A PMOSFET Current Limit IPCL Current Pulse Width<1ms Oscillator Frequency fOSC 1.2 1.6 2.0 MHZ Thermal Shutdown Threshold TS 145 °C EN High Level Input Voltage VEN -40°C≤TA≤+85°C 0.9 V EN Low Level Input Voltage VEN -40°C≤TA≤+85°C 0.3 V EN Input Current IEN VEN=0V ~ VIN -1 1 µA UNISONIC TECHNOLOGIES CO., LTD www.unisonic.com.tw 4 of 5 QW-R502-489.b UC3666 Preliminary CMOS IC TYPICAL APPLICATION CIRCUIT Adjustable Output Voltage A resistive divider adjusts the output voltage of the UTC UC3656, which divides a 0.6V reference voltage at FB pin. The output voltage can be obtained by the equation as follows: 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 5 of 5 QW-R502-489.b