The ISL6225 dual PWM controller delivers high efficiency and tight regulation from two voltage regulating synchronous buck DC/DC converters. The ISL6225 PWM power supply controller was designed especially for DDR DRAM, SDRAM, and graphic chipset applications in high performance desknote PCs, notebook PCs, sub-notebook PCs, and PDAs.
●Automatic mode selection of constant-frequency synchronous rectification at heavy load, and hysteretic diode-emulation at light load, assure high efficiency over a wide range of conditions. The hysteretic mode of operation can be disabled separately on each PWM converter if constant-frequency continuous-conduction operation is desired for all load levels. Efficiency is further enhanced by using the lower MOSFET rDS(ON) as the current sense element.
●Features
●• Provides regulated output voltage in the range of 0.9V-5.5V
● - High efficiency over wide load range
● - Synchronous buck converter with hysteretic operation at light load
● - Inhibit Hysteretic mode on one, or both channels
●• Complete DDR memory power solution
● - VTT tracks VDDQ/2
● - VDDQ/2 buffered reference output
●• No current-sense resistor required
● - Uses MOSFET rDS(ON)
● - Optional current-sense resistor for precision overcurrent
●• Under-voltage lock-out on VCC pin
●• Dual input voltage mode operation
● - Operates directly from battery 5V to 24V input
● - Operates from 3.3V or 5V system rail
● - VCC from 5V only
●• Excellent dynamic response
● - Combined voltage feed-forward and average current mode control
●• Power-good signal for each channel
●• 300kHz switching frequency
● - 180° channel to channel phase operation for reduced input ripple when not in DDR mode
● - 0° channel to channel phase operation in DDR mode for reduced channel interference
● - 90° channel to channel phase operation for reduced input ripple in DDR mode when VIN is at GND.
●• Pb-Free Available (RoHS Compliant)
●Applications
●• Mobile PCs
●• PDAs
●• Hand-held portable instruments
