NOT RECOMMENDED FOR NEW DESIGN USE AP3428 AUR9703 1.5MHz, 800mA, STEP DOWN DC-DC CONVERTER Description Pin Assignments The AUR9703 is a high efficiency step-down DC-DC voltage converter. The chip operation is optimized using constant frequency, (Top View) peak-current mode architecture with built-in synchronous power MOSFET switchers and internal compensators to reduce external part counts. It is automatically switching between the normal PWM EN 1 5 FB mode and LDO mode to offer improved system power efficiency covering a wide range of loading conditions. GND 2 The oscillator and timing capacitors are all built-in providing an internal switching frequency of 1.5MHz that allows the use of small surface mount inductors and capacitors for portable product LX VIN implementations. Additional features included Soft Start (SS), Under 3 4 Voltage Lock Out (UVLO), and Thermal Shutdown Detection (TSD) to provide reliable product applications. TSOT-23-5 The device is available in adjustable output voltage versions ranging from 1V to 3.3V, and is able to deliver up to 800mA. Applications The AUR9703 is available in TSOT-23-5 package. Mobile Phone, Digital Camera and MP3 Player Headset, Radio and Other Hand-held Instrument Features Post DC-DC Voltage Regulation PDA and Notebook Computer High Efficiency Buck Power Converter Low Quiescent Current Output Current: 800mA Adjustable Output Voltage from 1V to 3.3V Wide Operating Voltage Range: 2.5V to 5.5V Built-In Power Switches for Synchronous Rectification with High Efficiency Feedback Voltage: 600mV 1.5MHz Constant Frequency Operation Automatic PWM/LDO Mode Switching Control Thermal Shutdown Protection Low Drop-out Operation at 100% Duty Cycle No Schottky Diode Required 1 of 16 AUR9703 June 2019 Diodes Incorporated www.diodes.com Document number: DS41588 Rev. 2 - 3 NOT RECOMMENDED FOR NEW DESIGN AUR9703 USE AP3428 Typical Applications Circuit (Note 1) R2 I R2 1 5 EN FB R1 C1 2 GND L 2.2H V =2.5V to 5.5V IN V OUT 3 4 LX VIN C C IN OUT 4.7mF 10 mF R 1 Note 1: V V (1 ) OUT1 REF R 2 -6 -6 When R2 = 300k to 60k, the I = 2A to 10A, and R1C1 should be in the range between 310 and 610 for component selection. R2 V (V) R1 (k ) R2 (k ) C1 (pF) L1 (H) OUT 1.0 68 100 82 2.2 1.2 100 100 56 2.2 1.8 200 100 30 2.2 2.5 320 100 18 2.2 3.3 453 100 13 2.2 Table 1. Component Guide Pin Descriptions Pin Number Pin Name Function 1 EN Enable signal input, active high This pin is the GND reference for the NMOS power stage. It must be 2 GND connected to the system ground 3 LX Connect to inductor 4 VIN Power supply input 5 FB Feedback voltage from the output 2 of 16 AUR9703 June 2019 Diodes Incorporated www.diodes.com Document number: DS41588 Rev. 2 - 3