UNISONIC TECHNOLOGIES CO., LTD LD1596 Preliminary CMOS IC 2A 150kHz 40V BUCK DC/DC CONVERTER WITH LED DRIVER AND BATTERY CHARGE DESCRIPTION The UTC LD1596 is a 150KHz fixed frequency PWM buck (step-down) DC/DC converter, capable of driving a 2A load with high efficiency. The PWM control circuit is able to adjust the duty ratio linearly from 0~100%. An enable function, an over current protection function is built inside. An internal compensation block is built in to minimize external component count. SOP-8 FEATURES * Wide 4.5V~40V Input Voltage Range * Output Adjustable from 1.235V~37V * Minimum Drop Out 1.5V * Fixed 150kHz Switching Frequency * 2A Constant Output Current Capability * Internal Optimize Power Transistor * Excellent line and load regulation * TTL shutdown capability * ON/OFF pin with hysteresis function ORDERING INFORMATION Ordering Number LD1596G-S08-R Package SOP-8 Packing Tape Reel MARKING www.unisonic.com.tw Copyright © 2015 Unisonic Technologies Co., Ltd 1 of 5 QW-R502-A36.b LD1596 CMOS IC PIN CONFIGURATION SW 1 SW 2 GND 3 FB 4 UTC LD1596 8 VIN 7 VIN 6 EN 5 CS PIN DESCRIPTION PIN NO. 1, 2 3 4 5 6 7, 8 Preliminary PIN NAME SW GND FB CS EN VIN DESCRIPTION Power Switch Pin (SW). Ground Pin. Output control Pin Output Current Sense Pin Enable Pin. Supply Voltage Input Pin. BLOCK DIAGRAM EN 180mV VIN + 60mΩ 1.23V Reference Start Up Current Limit VREF - OCP CS FB + + EA - - COMP + Latch Driver Thermal Shutdown Switch SW Oscillator 150KHz + OVP GND VREF - UNISONIC TECHNOLOGIES CO., LTD www.unisonic.com.tw 2 of 5 QW-R502-A36.b LD1596 Preliminary CMOS IC ABSOLUTE MAXIMUM RATING PARAMETER SYMBOL RATINGS UNIT Input Voltage VIN -0.3~45 V FB Pin Voltage VFB -0.3~VIN V EN Pin Voltage VEN -0.3~VIN V SW Pin Voltage VSW -0.3~VIN V Power Dissipation PD Internally limited mW Thermal Resistance (Junction to Ambient, No RJA 50 °C/W Heatsink, Free Air) Operating Junction Temperature TJ -40~125 °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 SYMBOL θJA RATINGS 150 ELECTRICAL CHARACTERISTICS (TA=25°C, unless otherwise specified) PARAMETER SYMBOL TEST CONDITIONS MIN System Parameters Test Circuit Figure 1 Feedback Voltage VFB VIN=8V~32V, VOUT=5V, ILOAD=0.2A~2A 1.21 Efficiency η VIN=12V, VOUT=5V, IOUT=2A UNIT °C/W TYP MAX UNIT 1.235 81 1.26 V % ELECTRICAL CHARACTERISTICS (DC PARAMETERS) VIN=12V, GND=0V, VIN & GND parallel connect a 220uf/50V capacitor; IOUT=500mA, TA=25°C, the others floating unless otherwise specified PARAMETER SYMBOL TEST CONDITIONS MIN TYP MAX UNIT Input Operation Voltage VIN 4.5 40 V Shutdown Supply Current ISTBY VEN=5V 80 200 uA Quiescent Supply Current IQ VEN=0V, VFB=VIN 2 5 mA Oscillator Frequency Fosc 127 150 172 Khz Switch current Limit IL VFB=0 3 A High (Regulator OFF) 1.4 V EN Pin Threshold VEN Low (Regulator ON) 0.8 V Output Saturation Voltage VCE VFB=0V, ISW=2A 1.1 1.4 V Constant Current Sense Voltage VCS 0.132 0.155 0.178 V UNISONIC TECHNOLOGIES CO., LTD www.unisonic.com.tw 3 of 5 QW-R502-A36.b LD1596 Preliminary CMOS IC TYPICAL APPLICATION CIRCUIT CFF 33nF R1 +12~24V CIN 220uF/35V FB EN 4 6 VIN UTC 1, 2 SW 7, 8 LD1596 3 5 C1 GND CS 105 Figure 1. UTC +6~36V CIN 100uF/50V R2 VOUT Battery D1 1N5821 COUT 220uF/35V Rcs L 33uH Icharge=0.155V/Rcs LED 1~5W SK34 COUT 100uF/25V Rcs Typical Application Circuit (LED Constant Current Driver) UNISONIC TECHNOLOGIES CO., LTD www.unisonic.com.tw L 47uH Typical Application Circuit (Li Battery Charger) FB EN 4 6 VIN UTC 1, 2 SW 7, 8 LD1596 3 5 C1 GND CS 105 Figure 2. UTC VOUT=1.235×(1+R2/R1) Icharge=0.155V/Rcs 4 of 5 QW-R502-A36.b LD1596 Preliminary CMOS IC 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-A36.b