ISL6228HRTZ-T

DATASHEET ISL6228 Data Sheet FN9095 Rev 2.00 May 7, 2008 May 7, 2008 High-Performance Dual-Output Buck Controller for Notebook Applications The ISL6228 IC is a dual channel synchronous-buck PWM controller featuring Intersil's Robust Ripple Regulator (R3) technology that delivers truly superior dynamic response to input voltage and output load transients. Integrated MOSFET drivers and bootstrap diodes result in fewer components and smaller implementation area. Intersil’s R3 technology combines the best features of fixedfrequency and hysteretic PWMs while eliminating many of their shortcomings. R3 technology employs an innovative modulator that synthesizes an AC ripple voltage signal VR, analogous to the output inductor ripple current. The AC signal VR enters a window comparator where the lower threshold is the error amplifier output VCOMP, and the upper threshold is a programmable voltage reference VW, resulting in generation of the PWM signal. The voltage reference VW sets the steady-state PWM frequency. Both edges of the PWM can be modulated in response to input voltage transients and output load transients, much faster than conventional fixedfrequency PWM controllers. Unlike a conventional hysteretic converter, each channel of the ISL6228 has an error amplifier that provides ±1% voltage regulation at the FB pin. Features • High performance R3 technology • Fast transient response • ±1% regulation accuracy: -40°C to +100°C • Individual power stage input rail for each channel • Wide input voltage range: +3.3V to +25V • Output voltage range: +0.6V to +5V • Diode emulation mode for increased light load efficiency • Programmable PWM frequency: 200kHz to 600kHz • Pre-biased output start-up capability • Integrated MOSFET drivers and bootstrap diode • Internal digital soft-start • Power good monitor • Fault protection - Undervoltage protection - Soft crowbar overvoltage protection - Inductor DCR overcurrent protection - Over-temperature protection - Fault identification by PGOOD pull-down resistance The ISL6228 has a 1.5ms digital soft-start and can be started into a pre-biased output voltage. A resistor divider is used to program the output voltage setpoint. The ISL6228 operates in continuous-conduction-mode (CCM) in heavy load, and in diode-emulation-mode (DEM) in light load to improve light-load efficiency. In CCM, the controller always operates as a synchronous rectifier. In DEM, the low-side MOSFET is permitted to stay off, blocking negative current flow into the low-side MOSFET from the output inductor. Applications Pinout • VRM OCSET2 26 UGATE2 VO2 27 EN2 FB2 28 PHASE2 PGOOD2 ISL6228 (28 LD 4x4 TQFN) 25 24 23 22 • Pb-free (RoHS compliant) • General purpose switching buck regulators • PCI express graphical processing unit • Auxiliary power rail • Network adaptor Ordering Information FSET2 1 21 BOOT2 PART NUMBER PART (Note) MARKING VIN2 2 20 PVCC2 ISL6228HRTZ 19 LGATE2 ISL6228HRTZ-T* 6228HRTZ -10 to +100 28 Ld 4x4 TQFN L28.4x4A Tape and Reel VCC2 3 VCC1 4 18 PGND2 GND 17 PGND1 VIN1 5 16 LGATE1 FSET1 6 PGOOD1 7 9 10 11 12 13 14 FB1 VO1 OCSET1 EN1 PHASE1 UGATE1 BOOT1 15 PVCC1 8 FN9095 Rev 2.00 May 7, 2008 ISL6228IRTZ TEMP (°C) PACKAGE (Pb-Free) PKG. DWG. # 6228HRTZ -10 to +100 28 Ld 4x4 TQFN L28.4x4A 6228IRTZ -40 to +100 28 Ld 4x4 TQFN L28.4x4A ISL6228IRTZ-T* 6228IRTZ -40 to +100 28 Ld 4x4 TQFN L28.4x4A Tape and Reel *Please refer to TB347 for details on reel specifications. NOTE: These Intersil Pb-free plastic packaged products employ special Pbfree 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. Page 1 of 17 VIN2 FB2 VCC1 VCC2 FB1 ISL6228 VIN1 VO1 VO2 PWM FREQUENCY CONTROL PWM FREQUENCY CONTROL   VW 10µA gm    PWM    EA   UVP  UVP  10µA 10µA  DRIVER +150° OT 60 90 30 30 PHASE1 SHOOT THROUGH PROTECTION  OCP   OCP UGATE1 DRIVER DIGITAL SOFTSTART  SHOOT THROUGH PROTECTION POR  OVP  OVP PWM CONTROL PHASE2 BOOT1   DIGITAL SOFTSTART  EN1  DRIVER VCOMP   VREF VREF EA POR CR R Q S 100pF 100pF BOOT2 VR  PWM CONTROL CR    VCOMP  gm  gm VR EN2 LGATE2  VW  gm PWM  UGATE2 FSET1  R Q S 10µA     FSET2  FN9095 Rev 2.00 May 7, 2008 Block Diagram LGATE1 DRIVER 90 60 +150° OT Page 2 of 17 PACKAGE BOTTOM PVCC2 PGND2 PGOOD2 OCSET2 GND OCSET1 FIGURE 1. SCHEMATIC BLOCK DIAGRAM PGOOD1 PGND1 PVCC1 ISL6228 Typical Application 5V RPGOOD2 RPVCC2 RVCC2 RVCC1 VCC2 VCC1 PVCC2 CPVCC2 RPGOOD1 RPVCC1 PVCC1 CVCC2 CVCC1 CPVCC1 PGOOD2 PGOOD1 PGOOD2 PGOOD1 VIN1 VIN2 VIN2 VIN1 3.3V TO 25V 3.3V TO 25V CIN2 UGATE1 UGATE2 BOOT2 BOOT1 CBOOT2 LO2 VO2 CIN1 QHIGH_SIDE1 QHIGH_SIDE2 CBOOT1 PHASE2 LO1 VO1 PHASE1 0.6V TO 5V 0.6V TO 5V CSEN2 CO2 ISL6228 QLOW_SIDE2 QLOW_SIDE1 ROCSET2 CFB2 PGND2 LGATE1 PGND1 OCSET2 OCSET1 VO2 RTOP2 VO1 RFB1 CFB1 FB1 FB2 FSET1 FSET2 RBOTTOM2 RTOP1 RO1 RO2 RFSET2 CO1 ROCSET1 LGATE2 RFB2 CSEN1 RBOTTOM1 CFSET1 CFSET2 RFSET1 EN1 EN2 GND FN9095 Rev 2.00 May 7, 2008 Page 3 of 17 ISL6228 Absolute Voltage Ratings Thermal Information VIN1,2 to GND . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3V to +28V VCC, PGOOD1,2 to GND . . . . . . . . . . . . . . . . . . . . . -0.3V to +7.0V PVCC to GND . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3V to +7.0V EN1,2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3V to GND, VCC +3.3V VO1,2, FB1,2, FSET1,2 . . . . . . . . . . . . . . -0.3V to GND, VCC +0.3V PHASE1,2 to GND . . . . . . . . . . . . . . . . . . . . . . . (DC) -0.3V to +28V (