iWatt Inc. - iW1700

Description
The iW1700 is a high performance AC/DC controller designed to drive an external power bipolar junction transistor (BJT) for peak current mode PWM flyback power supplies. The iW1700 is a zero no-load power product, having less than 5mW of power consumption at no load, easily meeting the Energy-Star^® specification for AC/DC single output power supplies (rev 2.0). The virtually zero no-load power consumption makes it ideal for wall adapters in portable electronics and power supplies for consumer electronics. The iW1700 also meets the proposed mandatory efficiency standards for external power supplies and battery chargers. As a PrimAccurate™ controller, which use primary-side control algorithms, the iW1700 does not need any direct secondary-side feedback components, eliminating the need for opto-isolators, reducing component count and solution cost. Additional features include iWatt's proprietary EZ-EMI™ technology, quasi-resonant control for optimal efficiency at heavy loads, cable and connector voltage drop compensation options, full protection from fault conditions and tiny packaging. The iW1700 comes in four options, the iW1700-00 with zero voltage drop compensation, the iW1700-01 with a 300mV voltage drop compensation offset, the iW1700-03 with a 450mV voltage drop compensation offset and the iW1700-05, with 150mV of offset compensation.
Typical Applications Diagram
Low Power Off-Line Power Supply
Related Technical Documents
What is digital power and what are its benefits? By Zahid Rahim EE Times Power Management DesignLine September 16, 2010 Real Time Waveform Analysis Helps Optimize Charger Performance By Jerry Zehng, Yong Li, and Zahid Rahim Power Electronics Technology March 1, 2011 Why consider a power BJT rather than a MOSFET? By Yong Li, PhD EE Times Power Management DesignLine October 25, 2010 ¹US Department of Energy, Regulatory Information Number RIN-1904-AB57

Features
Zero No-Load Power Consumption - Easily Meets Energy-Star^® AC/DC Power Supply Efficiency Specs (Rev 2.0) Less than 5mW at No-Load Meets Proposed Mandatory Federal Efficiency Standards for External Power Supplies¹ Low 1.7uA Start-Up Current Active Start-Up Circuit to Reduce Turn-on Time 72kHz PWM Switching Frequency Voltage Offset Compensation for Voltage Loss in Cables and Connectors (4 Options) PrimAccurate™ - Primary-Side Control, No Opto-Coupler Needed Intrinsically Low Noise Solution - No Audible Noise Over Entire Operating Range Quasi-resonant Control for Optimal Efficiency EZ-EMI™ Design to Easily Meet Global EMI Specifications Fast Dynamic Load Regulation Fully Protected from Fault Conditions Over-Temperature Protection Output Over-Voltage and Over-Current Input Undervoltage Protection Sense-Resistor Short Circuit Protection
Functional Block Diagram

Applications
Chargers and Adapters for Portable Electronics Consumer Electronics Power Supplies Linear AC/DC Power Supply Replacement

Resources
	Datasheet
	App Notes
	Product Brief
	White Papers
	Samples
	Ref Designs
	Design Tool

Patents
6,385,059; 6,862,198; 6,900,995; 6,956,750; 6,990,000; 7,443,700; 7,505,287; 7,589,983; 6,972,969; 7,724,547; 7,876,582; 7,974,109; 8,018,743; 8,049,481; 7,974,107; 8,259,472; 8,289,732;

Technology