iW1691 Digital PWM Current-Mode Controller for Quasi-Resonant Operation 1.0 Features 2.0 Description Primary-side feedback eliminates opto-isolators and The iW1691 is a high performance AC/DC power supply simplifies design controller which uses digital control technology to build peak current mode PWM flyback power supplies. The Quasi-resonant operation for highest overall efficiency device operates in quasi-resonant mode at heavy load to EZ-EMI design to easily meet global EMI standards provide high efficiency along with a number of key built-in protection features while minimizing the external component Up to 130 kHz switching frequency enables small count, simplifying EMI design and lowering the total bill of adapter size material cost. The iW1691 removes the need for secondary Built-in cable drop compensation feedback circuitry while achieving excellent line and load regulation. It also eliminates the need for loop compensation Very tight output voltage regulation components while maintaining stability over all operating No external compensation components required conditions. Pulse-by-pulse waveform analysis allows for a loop response that is much faster than traditional solutions, Complies with CEC/EPA no-load power consumption resulting in improved dynamic load response. The built-in and average efficiency regulations current limit function enables optimized transformer design Built-in output constant-current control with primary-side in universal off-line applications over a wide input voltage feedback range. Low start-up current (10 A typical) The ultra-low operating current at light load ensures that the iW1691 is ideal for applications targeting the newest Built-in soft start regulatory standards for average efficiency and standby Built-in short circuit protection and output overvoltage power. protection Optional AC line under/overvoltage protection 3.0 Applications PFM operation at light load AC/DC adapter/chargers for cell phones, PDAs, digital Current sense resistor short protection still cameras AC/DC adapters for consumer electronics Overtemperature Protection L N V OUT + + RTN + 1 8 NC V CC 2 V OUTPUT 7 SENSE V I 3 6 IN SENSE 4 SD GND 5 Optional U1 NTC iW1691 Thermistor Figure 3.1 : Typical Application Circuit Rev . 2.0 iW1691 Pgea 1 FReb Rau y 3, 2012 iW1691 Digital PWM Current-Mode Controller for Quasi-Resonant Operation 4.0 Pinout Description iW1691 1 NC V 8 CC 2 V OUTPUT 7 SENSE 3 V I 6 IN SENSE 4 5 SD GND Pin Name Type Pin Description 1 - No connection. NC 2 Analog Input Auxiliary voltage sense (used for primary side regulation). V SENSE 3 V Analog Input Rectified AC line average voltage sense. IN External shutdown control. Connect to ground through a resistor if not used. 4 SD Analog Input (see section 10.16) 5 GND Ground Ground. 6 I Analog Input Primary current sense (used for cycle-by-cycle peak current control and limit). SENSE 7 OUTPUT Output Gate drive for external MOSFET switch. 8 V Power Input Power supply for control logic and voltage sense for power-on reset circuitry. CC 5.0 Absolute Maximum Ratings Absolute maximum ratings are the parameter values or ranges which can cause permanent damage if exceeded. For maximum safe operating conditions, refer to Electrical Characteristics in Section 6.0. Parameter Symbol Value Units -0.3 to 18 V DC supply voltage range (pin 8, I = 20mA max) V CC CC 20 mA DC supply current at V pin I CC CC Output (pin 7) -0.3 to 18 V V input (pin 2, I 10 mA) -0.7 to 4.0 V SENSE Vsense V input (pin 3) -0.3 to 18 V IN I input (pin 6) -0.3 to 4.0 V SENSE SD input (pin 4) -0.3 to 18 V 526 mW Power dissipation at T 25C P A D Maximum junction temperature 125 C T J MAX Storage temperature 65 to 150 C T STG Lead temperature during IR reflow for 15 seconds 260 C T LEAD Thermal Resistance Junction-to-Ambient 160 C/W JA ESD rating per JEDEC JESD22-A114 2,000 V Latch-Up test per JEDEC 78 100 mA Rev . 2.0 iW1691 Pgea 2 FebR aRu y 3, 2012