DATASHEET ISL6446A FN8384 Rev 3.00 Dual (180Out-of-Phase) PWM and Linear Controller Aug 27, 2015 The ISL6446A is a high-performance, triple output controller Features that provides a single high-frequency power solution primarily 4.5V to 5.5V or 5.5V to 24V input voltage range for Broadband, DSL and Networking applications. This device integrates complete control, monitoring and protection Three programmable power output voltages functions for two synchronous buck PWM controllers and one - Two PWM controllers with out-of-phase operation linear controller. Input voltage ripple and total RMS input - Voltage-mode PWM control current is substantially reduced by synchronized 180 - One linear controller out-of-phase operation of the two PWMs. Programmable switching frequency from 100kHz to 2.5MHz The two PWM buck converters provide simple voltage mode control. The output voltage of the converters can be precisely Fast transient response regulated to as low as 0.6V, with a maximum tolerance of - High-bandwidth error amplifier 1.5% over-temperature and line variations. Programmable Extensive circuit protection functions switching frequency down to 100kHz provides optimized low cost solution for ATX power supplies. It is also able to operate - Undervoltage, and over-temperature up to 2.5MHz to deliver compact solutions. The linear - Overvoltage with latch-off mode controller provides a low-current output. - Programmable overcurrent limit with latch-off mode Each PWM controller has soft-start and independent enable - Lossless current sensing (no sense resistor needed) functions combined on a single pin. A capacitor from SS/EN to Externally adjustable soft-start time ground sets the soft-start time pulling SS/EN pin below 1V disables the controller. Both outputs can soft-start into a - Independent enable control prebiased load. - Voltage tracking capability The ISL6446A incorporates robust protection features. An - Able to soft-start into a prebiased load adjustable overcurrent protection circuit monitors the output PGOOD output with delay current by sensing the voltage drop across the upper MOSFET r . Latch-off mode overcurrent operation protects the DS(ON) Applications DC/DC converters from damage under overload and ATX power supplies short-circuit conditions. A PGOOD signal is issued when soft-start is complete and PWM outputs are within 10% of DSP, ASIC, and FPGA point-of-load regulation their regulated values and the linear regulator output is higher Industrial and security networking applications than 75% of its nominal value. Thermal shutdown circuitry turns the device off if the IC temperature exceeds +150C. FN8384 Rev 3.00 Page 1 of 22 Aug 27, 2015ISL6446A VCC VIN C VCC R OCSET1 100 VIN1 = VIN Feedback VCC VIN C OCSET1 and COMP1 OCSET1 VOUT1 98 C Compensation C BOOT1 IN1 FB1 Network BOOT1 R Q 96 1 UGATE1 1 Feedback VOUT1 and L PHASE1 COMP2 1 VOUT2 94 Compensation C FB2 OUT1 LGATE1 Q Network 2 V = 5V OUT R 2 92 R ISL6446A OCSET2 V = 3.3V OUT 90 VIN2 = VIN C OCSET2 OCSET2 C C BOOT2 88 IN2 BOOT2 UGATE2 Q 3 86 VOUT2 L PHASE2 2 84 C OUT2 LGATE2 Q 4 PGOOD 82 RT LCDR SS/EN1 SS/EN2 LCFB 80 SGND PGND 0 5 10 15 20 25 LOAD CURRENT (A) FIGURE 1. TYPICAL APPLICATION FIGURE 2. EFFICIENCY vs LOAD CURRENT (OBTAINED FROM ISL6446AEVAL1Z) FN8384 Rev 3.00 Page 2 of 22 Aug 27, 2015 EFFICIENCY (%)