DATASHEET ISL6228 FN9095 Data Sheet May 7, 2008 Rev 2.00 High-Performance Dual-Output Buck Controller for Notebook Applications May 7, 2008 The ISL6228 IC is a dual channel synchronous-buck PWM Features 3 controller featuring Intersil s Robust Ripple Regulator (R ) 3 High performance R technology technology that delivers truly superior dynamic response to input voltage and output load transients. Integrated Fast transient response MOSFET drivers and bootstrap diodes result in fewer 1% regulation accuracy: -40C to +100C components and smaller implementation area. Individual power stage input rail for each channel 3 Intersils R technology combines the best features of fixed- Wide input voltage range: +3.3V to +25V frequency and hysteretic PWMs while eliminating many of 3 Output voltage range: +0.6V to +5V their shortcomings. R technology employs an innovative modulator that synthesizes an AC ripple voltage signal V , R Diode emulation mode for increased light load efficiency analogous to the output inductor ripple current. The AC signal Programmable PWM frequency: 200kHz to 600kHz V enters a window comparator where the lower threshold is R Pre-biased output start-up capability the error amplifier output V , and the upper threshold is a COMP programmable voltage reference V resulting in generation W, Integrated MOSFET drivers and bootstrap diode of the PWM signal. The voltage reference V sets the W Internal digital soft-start steady-state PWM frequency. Both edges of the PWM can be Power good monitor modulated in response to input voltage transients and output load transients, much faster than conventional fixed- Fault protection frequency PWM controllers. Unlike a conventional hysteretic - Undervoltage protection converter, each channel of the ISL6228 has an error amplifier - Soft crowbar overvoltage protection that provides 1% voltage regulation at the FB pin. - Inductor DCR overcurrent protection The ISL6228 has a 1.5ms digital soft-start and can be - Over-temperature protection started into a pre-biased output voltage. A resistor divider is - Fault identification by PGOOD pull-down resistance used to program the output voltage setpoint. The ISL6228 Pb-free (RoHS compliant) operates in continuous-conduction-mode (CCM) in heavy load, and in diode-emulation-mode (DEM) in light load to Applications improve light-load efficiency. In CCM, the controller always General purpose switching buck regulators operates as a synchronous rectifier. In DEM, the low-side MOSFET is permitted to stay off, blocking negative current PCI express graphical processing unit flow into the low-side MOSFET from the output inductor. Auxiliary power rail Pinout VRM ISL6228 (28 LD 4x4 TQFN) Network adaptor Ordering Information 28 27 26 25 24 23 22 PART NUMBER PART TEMP PACKAGE PKG. (Note) MARKING (C) (Pb-Free) DWG. FSET2 1 21 BOOT2 ISL6228HRTZ 6228HRTZ -10 to +100 28 Ld 4x4 TQFN L28.4x4A VIN2 2 20 PVCC2 ISL6228HRTZ-T* 6228HRTZ -10 to +100 28 Ld 4x4 TQFN L28.4x4A VCC2 19 LGATE2 3 Tape and Reel VCC1 4 GND 18 PGND2 ISL6228IRTZ 6228IRTZ -40 to +100 28 Ld 4x4 TQFN L28.4x4A PGND1 VIN1 5 17 ISL6228IRTZ-T* 6228IRTZ -40 to +100 28 Ld 4x4 TQFN L28.4x4A FSET1 16 LGATE1 6 Tape and Reel PGOOD1 7 15 PVCC1 *Please refer to TB347 for details on reel specifications. 81910112 13 14 NOTE: 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. FN9095 Rev 2.00 Page 1 of 17 May 7, 2008 FB1 PGOOD2 VO1 FB2 OCSET1 VO2 EN1 OCSET2 PHASE1 EN2 UGATE1 PHASE2 BOOT1 UGATE2ISL6228 PWM CONTROL FN9095 Rev 2.00 Page 2 of 17 May 7, 2008 Block Diagram VCC1 VIN1 VIN2 FB2 VCC2 FB1 VO2 VO1 PWM FREQUENCY PWM FREQUENCY FSET2 FSET1 CONTROL CONTROL 10A 10A V g g V m W m W R R PWM PWM Q Q S S V V R R g g m m V V COMP C C COMP R R EN2 EN1 100pF 100pF V V REF REF BOOT2 EA EA BOOT1 POR POR UGATE2 DRIVER DRIVER UGATE1 DIGITAL DIGITAL OVP OVP SOFT- SOFT- START START PHASE2 PHASE1 SHOOT THROUGH SHOOT THROUGH UVP UVP PROTECTION PROTECTION 10A 10A OCP OCP LGATE2 DRIVER DRIVER LGATE1 60 90 30 30 90 60 +150 +150 OT OT PACKAGE BOTTOM PVCC2 PGND2 PGOOD2 OCSET2 GND OCSET1 PGOOD1 PGND1 PVCC1 FIGURE 1. SCHEMATIC BLOCK DIAGRAM PWM CONTROL