DATASHEET ISL9444 FN7665 Rev 3.00 Triple, 180 Out-of-Phase, Synchronous Step-Down PWM Controller May 29, 2012 The ISL9444 is a triple-output synchronous buck controller that Features integrates three PWM controllers which are fully featured and Three Integrated Synchronous Buck PWM Controllers designed to provide multi-rail power for use in products such as cable and satellite set-top boxes, VoIP gateways, cable modems, - Internal Bootstrap Diodes and other home connectivity products as well as a variety of - Independent Programmable Output Voltage industrial and general purpose applications. Each output is - Independent Power-Good Indicators, Soft-Starting and adjustable down to 0.7V. The PWMs are synchronized at 180 Tracking out-of-phase, thus reducing the input RMS current and ripple Power Failure Monitor voltage. Light Load Efficiency Enhancement The ISL9444 offers independent power-good indicators, - Low Ripple Diode Emulation Mode with Pulse Skipping programmable soft-start and tracking functions for ease of supply rail sequencing and integrated UV/OV/OC/OT Supports Pre-Biased Output protections in a space conscious 5mmx5mm QFN package. Programmable Frequency: 200kHz to 1200kHz Switching frequency can be set between 200kHz and 1200kHz Adaptive Shoot-through Protection using a resistor. The ISL9444 can be synchronized to another ISL9444 to reduce any beat frequency. Out-of-Phase Switching (0/180/0) No External Current Sense Resistor The ISL9444 utilizes internal loop compensation to keep minimum peripheral components for a compact design and a - Uses Lower MOSFETs r DS(ON) low total solution cost. These devices are implemented with Complete Protection current mode control with feed-forward to cover various - Overcurrent, Overvoltage, Over-Temperature applications even with fixed internal compensations. Wide Input Voltage Range: 4.5V to 28V Related Literature Pb-Free (RoHS Compliant) Technical Brief TB389 PCB Land Pattern Design and Surface Mount Guidelines for QFN (MLFP) Packages Applications VoX Gateway Devices NAS/SAN Devices ATX Power Supplies +12V + Q1 Q2 CIN1 CIN2 VOUT2 2.2H L2 +3.3V, 6A 0.1F 0.1F + CO2 R9 VOUT1 100F RESN2 L1 RESN1 +1.0V, 6A CB1 CB2 11.5k 1.3k 1.3k 1.0H + CO1 ISEN1 ISEN2 100F R8 VIN +12V FB2 3.09k VCC 5V +12V C1 R2 4.7F 62k EXTBIAS UGATE3 Q3 PFI ISL9444 BOOT3 R4 R1 CB3 VOUT3 L3 3.3H PFO 15.8k 0.1F +5.0V, 6A 10k PHASE3 EN2,3 + CO3 FB1 RESN3 LGATE3 100F 1.3k RT R3 ISEN3 R4 31.6k EN/SS1 RT CSS 49.9k 10.7k 10nF R5 R6 R7 R3 100k 200k 200k 1.74k FIGURE 1. TYPICAL APPLICATION FN7665 Rev 3.00 Page 1 of 25 May 29, 2012 SGND LGATE1 PHASE1 OCSET1 BOOT1 UGATE1 OCSET2 PGND UGATE2 OCSET2 BOOT2 MODE/SYNC CLKOUT PGOOD1,2,3 TK/SS2,3 PHASE2 FB3 LGATE2ISL9444 Ordering Information PART NUMBER PART TEMP. RANGE PACKAGE PKG. (Notes 1, 2, 3) MARKING (C) (Pb-Free) DWG. ISL9444IRZ ISL9444 IRZ -40 to +85 40 Ld 5x5 QFN L40.5X5B ISL9444CRZ ISL9444 CRZ -0 to +85 40 Ld 5x5 QFN L40.5X5B ISL9444EVAL1Z Evaluation Board NOTES: 1. Add -T* for tape and reel. Please refer to TB347 for details on reel specifications. 2. These Intersil Pb-free plastic packaged products employ special Pb-free material sets, molding compounds/die attach materials, and 100% matte tin plate plus anneal (e3 termination finish, which is RoHS compliant and compatible with both SnPb and Pb-free soldering operations). Intersil Pb-free products are MSL classified at Pb-free peak reflow temperatures that meet or exceed the Pb-free requirements of IPC/JEDEC J STD-020. 3. For Moisture Sensitivity Level (MSL), please see device information page for ISL9444. For more information on MSL please see techbrief TB363. Pin Configuration ISL9444 (40 LD 5x5 QFN) TOP VIEW 40 39 38 37 36 35 34 33 32 31 PFO 1 30 CLKOUT 2 29 PFI PGND 3 28 EXTBIAS LGATE3 VCC 5V 4 27 UGATE3 5 VIN 26 BOOT3 6 25 PHASE3 EN/SS1 7 24 ISEN3 FB1 8 23 MODE/SYNC OCSET1 9 22 EN3 RT 10 21 TK/SS3 PGOOD1 11 12 13 14 15 16 17 18 19 20 Pin Descriptions PIN NAME FUNCTION 1PFO Output of the auxiliary power monitor. PFO goes high if the voltage on PFI is greater than 1.2V (typical). Otherwise the PFO outputs low. 2 PFI Input to the auxiliary power monitor. The internal threshold voltage is 1.2V (typical). 3 EXTBIAS Input from an optional external 5V bias supply. There is an internal switch from this pin to VCC 5V. This switch closes and supplies the IC power, bypassing the internal linear regulator, when voltage at EXTBIAS is higher than 4.7V (typ). Do not allow voltage at the EXTBIAS pin to exceed VIN at any time. Decouple this pin to ground with a small ceramic capacitor (0.1F to 1F) when it is in use, otherwise tie this pin to ground. Do not float this pin. 4 VCC 5V Output of the internal 5V linear regulator. This output supplies bias for the IC, the low side gate drivers, and the external boot circuitry for the high-side gate drivers. The VCC 5V pin must be always decoupled to power ground with a minimum of 4.7F ceramic capacitor, placed very close to the pin. Do not allow the voltage at VCC 5V to exceed VIN at any time. FN7665 Rev 3.00 Page 2 of 25 May 29, 2012 PGOOD2 ISEN1 PGOOD3 PHASE1 PG3 DLY BOOT1 EN2 UGATE1 SGND LGATE1 OCSET2 LGATE2 FB2 UGATE2 TK/SS2 BOOT2 OCSTET3 PHASE2 FB3 ISEN2