UNISONIC TECHNOLOGIES CO., LTD USR1021 Preliminary LINEAR INTEGRATED CIRCUIT 3A SYNCHRONOUS BUCK REGULATOR DESCRIPTION The UTC USR1021 is a high efficiency, 3A synchronous buck regulator. The UTC USR1021 works from a 6V to 18V input voltage range, and provides up to 3A of continuous output current with an output voltage adjustable down to 0.8V. The UTC USR1021 comes in an SOP-8 packages and is rated over a -40°C~+85°C ambient temperature range. SOP-8 FEATURES * 6V~18V operating input voltage range * High efficiency * Internal soft start * 1.5% initial output accuracy * Output voltage adjustable to 0.8V * 3A continuous output current * Cycle-by-cycle current limit * 500kHz PWM operation * Thermal shutdown * Short-circuit protection ORDERING INFORMATION Ordering Number Lead Free Halogen Free USR1021L-S08-R USR1021G-S08-R USR1021L-S08-T USR1021G-S08-T Note: xx: Output Voltage, refer to Marking Information. www.unisonic.com.tw Copyright © 2013 Unisonic Technologies Co., Ltd Package Packing SOP-8 SOP-8 Tape Reel Tube 1 of 4 QW-R103-073.a USR1021 Preliminary PIN CONFIGURATION PIN DESCRIPTION PIN NO. 1 2 3 4 5 6 7, 8 PIN NAME PGND VIN AGND FB COMP EN LX LINEAR INTEGRATED CIRCUIT DESCRIPTION Power ground Supply voltage input Reference connectio for controller section Feedback voltage Compensation pin Enable pin Switch pin BLOCK DIAGRAM UNISONIC TECHNOLOGIES CO., LTD www.unisonic.com.tw 2 of 4 QW-R103-073.a USR1021 Preliminary LINEAR INTEGRATED CIRCUIT ABSOLUTE MAXIMUM RATING PARAMETER SYMBOL RATINGS UNIT Supply Voltage VIN 18 V LX to AGND -0.7~VIN+0.3 V EN to AGND -0.3~VIN+0.3 V FB to AGND -0.3~6.0 V COMP to AGND -0.3~6.0 V PGND to AGND -0.3~+0.3 V Junction Temperature TJ +150 °C Storage Temperature 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. THERMAL DATA PARAMETER Junction to Ambient (Note 2) RATINGS 87 UNIT °С/W RATINGS 6~18 0.8~VIN -40~+85 UNIT V V °C RECOMMENDED OPERATING CONDIIONS PARAMETER Supply Voltage Output Voltage Range Ambient Temperature SYMBOL θJA SYMBOL VIN TA ELECTRICAL CHARACTERISTICS (TA=25°C, VIN=VEN=12V, VOUT=3.3V, unless otherwise specified) (Note 3) PARAMETER Supply Voltage Supply Current (Quiescent) Shutdown Supply Current Feedback Voltage Load Regulation Line Regulation Feedback Voltage Input Current EN Input Threshold SS Time MODULATOR Frequency Maximum Duty Cycle Controllable Minimum On Time Current Sense Transconductance Error Amplifier Transconductance PROTECTION Current Limit SYMBOL VIN IIN IOFF VFB TEST CONDITIONS IOUT=0, VFB=1.2V, VEN>2V VEN=0V TA=25 °C MIN 6 0.788 TYP 3.5 1 0.8 0.5 1 IFB VEN fO DMAX TMIN Off Threshold On Threshold CSS=16nF 2 2 400 85 500 MAX UNIT 18 V 5 mA 10 µA 0.812 V % % 200 nA 0.6 V V ms 600 150 7 180 kHz % ns A/V µA/V ILIMT 3.5 4.5 A 150 °C TJ Rising Over-Temperature Shutdown Limit TJ Falling 100 °C Notes: 1. Devices are inherently ESD sensitive, handling precautions are required. Human body model rating: 1.5 kΩ in series with 100pF. 2. The value of θJA is measured with the device mounted on a 1-in2 FR-4 board with 2oz. Copper, in a still air environment with TA=25°C. The value in any given application depends on the user’s specific board design. 3. Specification in BOLD indicate an ambient temperature range of -40°C~+85°C. These specifications are guaranteed by design. UNISONIC TECHNOLOGIES CO., LTD www.unisonic.com.tw 3 of 4 QW-R103-073.a USR1021 Preliminary LINEAR INTEGRATED CIRCUIT TYPICAL APPLICATION CIRCUIT VIN C1 22µF Ceramic VIN L1 4.7µH EN COMP UTC USR1021 RC CC VOUT LX R1 FB AGND PGND C2, C3 22µF Ceramic R2 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 4 of 4 QW-R103-073.a