SQ28706SYD

Application Note: SQ28706 High Efficiency, 1.0MHz, 6A Synchronous Step Down Regulator ` General Description Features The SQ28706 is a high efficiency 1.0MHz synchronous step down DC/DC regulator which is capable of delivering up to 6A output current. It can operate over a wide input voltage range from 2.5V to 6V and integrate main switch and synchronous switch with very low RDS (ON) to minimize the conduction loss. 2.5~6.0V Input Voltage Range 23μA Low Quiescent Current Low RDS(ON) for Internal Switches (Top/Bottom) 22mΩ /12mΩ Instant PWM Control Achieve Ultra Fast Dynamic Response 1.0MHz Switching Frequency Minimizes the External Components Internal Soft-start Limits the Inrush Current 100% Drop Out Operation Output Auto Discharge Function Hic-cup Mode for Short Circuit Protection RoHS Compliant and Halogen Free Compact Package: DFN2×2-7      Ordering Information    SQ28706 □(□□□ )   Package Code  Optional Spec Code Ordering Number SQ28706SYD Package type DFN2×2-7 Note -- Applications Set Top Box USB Dongle Media Player Smart Phone     Typical Applications L1:0.33µH VIN: 2.5-6.0V CIN 22μF Efficiency vs. Output Current VOUT:1.8V LX VIN (IOUT=0-6A, L=0.33μH/0420CDMCCDS-R33MC) 100 RPG 100k OUT RH 100k PG COUT 22μF×2 95 90 EN RL 49.9k GND Inductor and COUT Selection Table COUT [µF] VOUT L [V] [µH] 22 22×2 22×3 1.2 0.33 √ ☆ 1.8 0.33 √ ☆ 3.3 0.47 √ ☆ Note: ‘☆’ means recommended for most applications. Figure1. Schematic Diagram AN_SQ28706 Rev.0.9 © 2020 Silergy Corp. Efficiency (%) FB ON/ OFF 85 80 75 VIN=3.3V,VOUT=1.8V VIN=4.2V,VOUT=1.8V VIN=5.0V,VOUT=1.8V 70 65 60 0.001 0.01 0.1 1 10 Output Current (A) Figure2. Efficiency vs. Output Current Silergy Corp. Confidential- Prepared for Customer Use Only 1 All Rights Reserved. SQ28706 Pinout (Top View) EN 1 PG 2 FB 3 OUT 4 7 VIN 6 LX 5 GND (DFN2×2-7) Top Mark: 2Nxyz (device code: 2N, x=year code, y=week code, z= lot number code) Pin Name EN PG Pin Number 1 FB 3 OUT GND LX 4 5 6 IN 7 2 Pin Description Enable control. Pull high to turn on. Power good indicator. Output feedback pin. Connect this pin to the center point of the output resistor divider (as shown in Figure 1) to program the output voltage: VOUT=0.6×(1+RH/RL). Output voltage feedback pin, connect to the output capacitor side. Ground pin. Inductor pin. Connect this pin to the switching node of the inductor. Input pin. Decouple this pin to the GND pin with at least a 22µF ceramic capacitor. Absolute Maximum Ratings (Note 1) Supply Input Voltage ------------------------------------------------------------------------------------------------- -0.3V to 7.0V EN, PG, FB, OUT---------------------------------------------------------------------------------------------- -0.3V to VIN + 0.3V LX Voltage------------------------------------------------------------------------------------------------- -0.3V（*1） to 6.5V（*2） Power Dissipation, PD @ TA = 25°C, DFN2×2-7 ----------------------------------------------------------------------------------------------------------- 2.86W Package Thermal Resistance (Note 2) θ JA ----------------------------------------------------------------------------------------------------------------- 35°C/W θ JC ----------------------------------------------------------------------------------------------------------------- 10°C/W Junction Temperature Range ---------------------------------------------------------------------------------------- -40°C~150°C Lead Temperature (Soldering, 10 sec.) ------------------------------------------------------------------------------------- 260°C Storage Temperature Range --------------------------------------------------------------------------------------- -65°C to 150°C (*1) LX Voltage Tested Down to -3V