DATASHEET ISL6539 FN9144 Rev 6.00 Wide Input Range Dual PWM Controller with DDR Option Apr 29, 2010 The ISL6539 dual PWM controller delivers high efficiency and Features tight regulation from two voltage regulating synchronous buck Provides Regulated Output Voltage in the Range of 0.9V DC/DC converters. It was designed especially for DDR DRAM, to 5.5V SDRAM, graphic chipset applications, and system regulators in high performance applications. Complete DDR Memory Power Solution with VTT Tracks VDDQ/2 and VDDQ/2 Buffered Reference Output Voltage-feed-forward ramp modulation, current mode Supports both DDR-I and DDR2 Memory control, and internal feedback compensation provide fast response to input voltage and output load transients. Input Lossless r Current-Sense Sensing DS(ON) current ripple is minimized by channel-to-channel PWM Excellent Dynamic Response with Voltage Feed-Forward phase shift of 0, 90 or 180 (determined by input voltage and Current Mode Control Accommodating Wide Range and status of the DDR pin). LC Filter Selections The ISL6539 can control two independent output voltages Dual Mode Operation - Operates Directly from a 5.0V to adjustable from 0.9V to 5.5V or, by activating the DDR pin, 15V Input or 3.3V/5V System Rail transform into a complete DDR memory power supply Undervoltage Lock-out on VCC Pin solution. In DDR mode, CH2 output voltage VTT tracks CH1 output voltage VDDQ. CH2 output can both source and sink Power-good, Overcurrent, Overvoltage, Undervoltage current, an essential power supply feature for DDR memory. protection for both Channels The reference voltage VREF required by DDR memory is Synchronized 300kHz PWM Operation in PWM Mode generated as well. Pb-Free (RoHS Compliant) In dual power supply applications the ISL6539 monitors the output voltage of both CH1 and CH2. An independent Applications PGOOD (power good) signal is asserted for each channel Single and Dual Channel DDR Memory Power Systems after the soft-start sequence has completed, and the output voltage is within PGOOD window. In DDR mode CH1 Graphics Cards - GPU and Memory Supplies generates the only PGOOD signal. Supplies for Servers, Motherboards, FPGAs Built-in overvoltage protection prevents the output from going ASIC Power Supplies above 115% of the set point by holding the lower MOSFET on Embedded Processor and I/O Supplies and the upper MOSFET off. When the output voltage decays below the overvoltage threshold, normal operation DSP Supplies automatically resumes. Once the soft-start sequence has completed, undervoltage protection latches the offending channel off if the output drops below 75% of its set point value for the dual switcher. Adjustable overcurrent protection (OCP) monitors the voltage drop across the r of the lower DS(ON) MOSFET. If more precise current-sensing is required, an external current sense resistor may be used. FN9144 Rev 6.00 Page 1 of 20 Apr 29, 2010ISL6539 Pinout Ordering Information ISL6539 TEMP. (28 LD QSOP) PART PART RANGE PKG. TOP VIEW NUMBER MARKING (C) PACKAGE DWG. GND 1 28 VCC ISL6539IAZ* ISL 6539IAZ -40 to +85 28 Ld QSOP M28.15 (Note) (Pb-free) LGATE1 2 27 LGATE2 PGND1 3 26 PGND2 ISL6539CAZ* ISL 6539CAZ -40 to +85 28 Ld QSOP M28.15 PHASE1 4 25 PHASE2 (Note) (Pb-free) UGATE1 5 24 UGATE2 *Add -T suffix for tape and reel. Please refer to TB347 for details BOOT1 6 23 BOOT2 on reel specifications. ISEN1 7 22 ISEN2 NOTE: These Intersil Pb-free plastic packaged products employ special Pb-free material sets, molding compounds/die attach 8 21 EN1 EN2 materials, and 100% matte tin plate plus anneal (e3 termination 9 20 GND GND finish, which is RoHS compliant and compatible with both SnPb and VSEN1 10 19 VSEN2 Pb-free soldering operations). Intersil Pb-free products are MSL classified at Pb-free peak reflow temperatures that meet or exceed OCSET1 11 18 OCSET2 the Pb-free requirements of IPC/JEDEC J STD-020. SOFT1 12 17 SOFT2 DDR 13 16 PG2/REF VIN 14 15 PG1 FN9144 Rev 6.00 Page 2 of 20 Apr 29, 2010