ISL6265 Datasheet, PDF (10/24 Pages) Intersil Corporation – Multi-Output Controller with Integrated MOSFET Drivers for AMD SVI Capable

ISL6265
PHASE_NB
Switch node of the Northbridge controller. This pin should
connect to the source of the Northbridge channel upper
MOSFET(s).
BOOT_NB
This pin is the upper gate drive supply voltage for the
Northbridge controller. Connect an appropriately sized
ceramic bootstrap capacitor between the BOOT_NB and
PHASE_NB pins. An internal bootstrap diode connected to
the PVCC pin provides the necessary bootstrap charge.
PGND_NB
The return path of the Northbridge controller lower gate
driver. Connect this pin to the source of the lower
MOSFET(s).
OCSET
CORE_0 and CORE_1 common overcurrent protection
selection input. The voltage on this pin sets the (ISPx - ISNx)
voltage limit for OC trip.
VW0, VW1
A resistor from this pin to corresponding COMPx pin
programs the switching frequency (for example, 6.81k ~
300kHz).
COMP0, COMP1
The output of the CORE_0 and CORE_1 controller error
amplifiers respectively. FBx, VDIFFx, and COMPx pins are
tied together through external R-C networks to compensate
the regulator.
FB0, FB1
These pins are the output voltage feedback to the inverting
input of the CORE_0 and CORE_1 error amplifiers.
VDIFF0, VDIFF1
Output of the CORE_0 and CORE_1 differential amplifiers.
VSEN0, RTN0
Inputs to the CORE_0 VR controller precision differential
remote sense amplifier. Connect to the sense pins of the
VDD0_FB[H,L] portion of the processor.
VSEN1, RTN1
Inputs to the CORE_1 VR controller precision differential
remote sense amplifier. Connect to the sense pins of the
VDD1_FB[H,L] portion of the processor. The RTN1 pin is
also used for detection of the VDD_PLANE_STRAP signal
prior to enable.
ISP0, ISN0, ISP1, ISN1
These pins are used for differentially sensing the
corresponding channel output current. The sensed current is
used for channel balancing, protection, and core load line
regulation.
Connect ISN0 and ISN1 to the node between the RC sense
elements surrounding the inductor of their respective
channel. Tie the ISP0 and ISP1 pins to the VCORE side of
their corresponding channel’s sense capacitor. These pins
can also be used for discrete resistor sensing.
BOOT0, BOOT1
These pins provide the bias voltage for the corresponding
upper MOSFET drives. Connect these pins to appropriately
chosen external bootstrap capacitors. Internal bootstrap
diodes connected to the PVCC pin provide the necessary
bootstrap charge.
UGATE0, UGATE1
Connect these pins to the corresponding upper MOSFET
gate(s). These pins control the upper MOSFET gate(s) and
are monitored for shoot-through prevention.
LGATE0, LGATE1
Connect these pins to the corresponding lower MOSFET
gate(s).
PHASE0, PHASE1
Switch node of the CORE_0 and CORE_1 controllers.
Connect these pins to the sources of the corresponding
upper MOSFET(s). These pins are the return path for the
upper MOSFET drives.
PGND0, PGND1
The return path of the lower gate driver for CORE_0 and
CORE_1 respectively. Connect these pins to the
corresponding sources of the lower MOSFETs.
Theory of Operation
The ISL6265 is a flexible multi-output controller supporting
Northbridge and single or dual power planes required by
Class M AMD Mobile CPUs. In dual plane applications, both
core voltage regulators operate single-phase. In uniplane
core applications, the core voltage regulators are configured
to operate as a two-phase regulator. All three regulator
outputs include integrated gate drivers for reduced system
cost and small board area. The regulators provide optimum
steady-state and transient performance for microprocessor
applications. System efficiency is enhanced by idling a
phase in uniplane configurations at low-current and
implementing automatic DCM-mode operation when PSI_L
is asserted to logic low.
The heart of the ISL6265 is the R³ Technology™, Intersil's
Robust Ripple Regulator modulator. The R³ modulator
combines the best features of fixed frequency PWM and
hysteretic PWM while eliminating many of their
shortcomings. The ISL6265 modulator internally synthesizes
an analog of the inductor ripple current and uses hysteretic
comparators on those signals to establish PWM pulse
widths. Operating on these large-amplitude, noise-free
synthesized signals allows the ISL6265 to achieve lower
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FN6599.1
May 13, 2009