IW1760-00

iW1760 Product Brief Off-Line Digital Green-Mode Quasi-Resonant PWM Controller 1.0 Features 2.0 Description No-load power consumption < 50mW at 230V along The iW1760 is a high performance AC/DC power supply AC with fast dynamic load response and short turn-on delay controller which uses digital control technology to build peak in typical 20W and above adapter applications current mode PWM flyback power supplies. The device operates in quasi-resonant mode to provide high efficiency Primary-side feedback eliminates opto-isolators and along with a number of key built-in protection features simplifies design while minimizing the external component count, simplifying Adaptively controlled soft-start enables fast and smooth EMI design and lowering the total bill of material cost. The start-up for a wide range of capacitive loads (from iW1760 removes the need for secondary feedback circuit 330F to 6,000F) with output voltage up to 12V while achieving excellent line and load regulation. It also eliminates the need for loop compensation components Tight constant-voltage regulation across line and load while maintaining stability over all operating conditions. range Pulse-by-pulse waveform analysis allows for a loop response Proprietary optimized 79kHz maximum PWM switching that is much faster than traditional solutions, resulting in frequency with quasi-resonant operation achieves best improved dynamic load response. The built-in power limit size, efficiency and common mode noise function enables optimized transformer design in universal off-line applications and allows for a wide input voltage User-configurable 5-level cable drop compensation range. provides design flexibility iWatts innovative proprietary technology ensures that EZ-EMI design enhances manufacturability power supplies built with the iW1760 can achieve both Adaptive multi-mode PWM/PFM control improves highest average active efficiency and less than 50mW no- efficiency load power consumption in 20W output power range, and have fast yet smooth start-up with a wide range of capacitive No external loop compensation components required loads with output voltage up to 12V, and are ideal for network Built-in single-point fault protections against output and monitor adapter applications. short-circuit, output over-voltage, output over-current, and current-sense-resistor-short fault 3.0 Applications Dedicated pins for external over-temperature protection Power adapters for network devices and monitors and over-voltage protection, with latch function available AC/DC power supplies in home appliances Tight constant current control enables output current limit and over-load protection Universal input AC/DC adapters (15W - 40W) No audible noise over entire operating range L N V OUT + + RTN U1 iW1760 1 V V 8 SENSE CC + 2 SD GND 7 CFG OUTPUT 3 6 4 5 ASU I SENSE R NTC CDC Figure 3.1: iW1760 Typical Application Circuit (Using Depletion Mode N-FET as Active Start-up Device) (Achieving < 50mW No-load Power Consumption in 20W Adapter Designs) Rev . 0.3 iW1760 Pgea 1 May 3, 2012iW1760 Product Brief Off-Line Digital Green-Mode Quasi-Resonant PWM Controller L N V OUT + + RTN U1 iW1760 1 8 V V SENSE CC + 2 7 SD GND 3 CFG OUTPUT 6 4 5 ASU I SENSE R NTC CDC Figure 3.2: iW1760 Typical Application Circuit (Alternative Circuit without Using Active Start-up Device) Note: Pin 4 (ASU) can be left unconnected if an active start-up device is not needed in the application circuit. 4.0 Pinout Description iW1760 1 8 V V SENSE CC 2 7 SD GND CFG OUTPUT 3 6 4 5 ASU I SENSE Figure 4.1: 8 Lead SO-8 Package Pin # Name Type Pin Description 1 V Analog Input Auxiliary voltage sense (used for primary regulation). SENSE External shutdown control. Used for external over-temperature protection (OTP) 2 SD Analog Input by connecting an NTC resistor from this pin to Ground. Used for external cable drop compensation (CDC) configuration and 3 CFG Analog Input supplemental over-voltage protection (OVP). 4 ASU Output Control signal for active start-up device (BJT or depletion mode N-FET). 5 I Analog Input Primary current sense. Used for cycle-by-cycle peak current control and limit. SENSE 6 OUTPUT Output Gate drive for external MOSFET switch. 7 GND Ground Ground. 8 V Power Input Power supply for control logic. CC Rev . 0.3 iW1760 Pgea 2 May 3, 2012