NCP5393
http://onsemi.com
13
TYPICAL CHARACTERISTICS
Figure 7. 12VMON Undervoltage Lockout
Threshold Voltage vs. Temperature
Figure 8. PWRGOOD Voltage vs. Temperature
T
J
, JUNCTION TEMPERATURE (°C) T
J
, JUNCTION TEMPERATURE (°C)
7550250
7.0
7.5
8.0
8.5
9.0
9.5
10
7550250
310
320
330
340
350
360
370
V
CC
UVLO THRESHOLD VOLTAGE (V)
PWRGOOD THRESHOLD VOLTAGE (mV)
V
CC
Increasing Voltage
V
CC
Decreasing Voltage
PWRGOOD Upper Voltage
PWRGOOD Lower Voltage
Functional Description
General
NCP5393 is an universal CPU Power Supply Controller
compatible with both Parallel (PVI) and Serial (SVI)
protocols for AMD Processors. The device provides
complete control logic and protections for a
high-performance step-down DC-DC voltage regulator,
optimized for advanced microprocessor power supply
supporting both PVI and SVI communication. It embeds two
independent controllers for CPU CORE and the integrated
NB, each one with its set of protections. The Controller
performs a single-phase control for the NB Section and a
programmable 2- to-4 phase control for the CORE Section
featuring Dual-Edge multiphase architecture.
NCP5393 also supports V_FIX mode for board debug: in
this particular configuration the SVI bus is used as a static
bus configuring 4 operative voltages for both the sections
and ignoring any serial-VID command. It can be used for
the board debug before plugging-in the CPU.
The NCP5393 incorporates differential voltage sensing,
differential phase current sensing, optional load-line
voltage positioning, and programmable VDD and VDDNB
offsets to provide accurately regulated power parallel- and
serial-VID AMD processors. Dual-edge multiphase
modulation provides the fastest initial response to dynamic
load events.
NCP5393 is able to detect which kind of CPU is connected
in order to configure itself to work as a Single-Plane PVI
controller or Dual-Plane SVI controller. The NCP5393
manages On the Fly VID transitions and maintains the slew
rates as defined when the transitions take place. NCP5393
is available in TQFN48 Package.
Remote Output Sensing Amplifier (RSA)
A true differential amplifier allows the NCP5393 to measure
Vcore voltage feedback with respect to the Vcore ground
reference point by connecting the Vcore reference point to VSP,
and the Vcore ground reference point to VSN. This
configuration keeps ground potential differences between the
local controller ground and the Vcore ground reference point
from affecting regulation of Vcore between Vcore and Vcore
ground reference points. The RSA also subtracts the DAC
(minus VID offset) voltage, thereby producing an unamplified
output error voltage at the DIFFOUT pin. This output also has
a 1.3 V bias voltage as the floating ground to allow both
positive and negative error voltages.
Precision Programmable DAC
A precision programmable DAC is provided and system
trimmed. This DAC has 0.5% accuracy over the entire
operating temperature range of the part. The DAC can be
programmed to support both PVI and SVI VID code
specifications.
High Performance Voltage Error Amplifier
The error amplifier is designed to provide high slew rate
and bandwidth. Although not required when operating as the
controller of a voltage regulator, a capacitor from COMP to
VFB is required for stable unity gain test configurations.
Gate Driver Outputs and 2/3/4 Phase Operation
The part can be configured to run in 2-, 3-, or 4-phase
mode. In 2-phase mode, phases 1 and 3 should be used to
drive the external gate drivers, G2 and G4 must be grounded.
In 3-phase mode, gate output G4 must be grounded. In
4-phase mode all 4 gate outputs are used as shown in the
4-phase Applications Schematic. The Current Sense inputs
of unused channels should be connected to GND. Please
refer to table “PIN CONNECTIONS vs. PHASE COUNTS”
for details.
