ISL6592 Datasheet, PDF (15/21 Pages) Intersil Corporation – 6-Phase Digital Multiphase Controller

ISL6592
VID4
0
0
0
0
0
0
0
0
0
0
0
1
1
1
1
1
VID3
1
1
1
0
0
0
0
0
0
0
0
1
1
1
1
1
VID2
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
0
VID1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
TABLE 2. OUTPUT VOLTAGE vs AMD® VID CODES
VID0 VID5 VOUT
VID4 VID3 VID2
0
X
1.3000
1
1
0
1
X
1.3250
1
1
0
0
X
1.3500
1
1
0
1
X
1.3750
1
0
1
0
X
1.4000
1
0
1
1
X
1.4250
1
0
1
0
X
1.4500
1
0
1
1
X
1.4750
1
0
0
0
X
1.5000
1
0
0
1
X
1.5250
1
0
0
0
X
1.5500
1
0
0
1
X
OFF
0
1
1
0
X
0.8000
0
1
1
1
X
0.8250
0
1
1
0
X
0.8500
0
1
1
1
X
0.8750
0
1
0
VID1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
VID0
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
VID5
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
VOUT
0.9000
0.9250
0.9500
0.9750
1.0000
1.0250
1.0500
1.0750
1.1000
1.1250
1.1500
1.1750
1.2000
1.2250
1.2500
1.2750
Active Voltage Positioning (AVP)
The AVP loadline can be selected from 4 pre-programmed
values using the VRD/M 10.x compliant load line select (LL1
and LL0) inputs. This allows selection of both the loadline
slope and the VID setpoint offset. The loadline slope is
selectable from 0 to 4mΩ, and the setpoint offset is
selectable from 0 to 50mV in 1.56mV steps.
The total current is computed by adding the current
measured from each phase, then filtering with a single pole
programmable filter to set the AVP bandwidth.
Current Balancing/Thermal Balancing
The ISL6592 also uses the channel current measurements
to perform current balancing. To minimize thermal gradient
effects, each channel adaptively adjusts its current to match
the average channel current.
The current balance function can also be used to induce a
thermal gradient if, for example, some channels have
greater cooling capability due to better proximity to airflow.
The ISL6592 allows the user to independently force an offset
current to each channel, creating a current gradient. This
causes the current balance to force the channels with
greater cooling capability to supply a higher percentage of
the total current, creating a net thermal equilibrium amongst
all channels.
Active Transient Response (ATR)
Active Transient Response (ATR) is supported through load-
line tracking comparators with programmable thresholds.
Both internal- and external-loop ATR are supported. Internal-
loop ATR engages multiple phases to maximize output
current slew rate and minimize spike and droop due to large
transient events. Three independent window comparators
allows for variation in the number of phases that sink or
source. If the transient is slight, only one phase will respond.
If the transient is severe, up to three phases respond. This
avoids a dramatic sinking or sourcing event, which can
cause oscillation. The ISL6592 controller itself uses
hysteretic control algorithms after the transient event to
ensure that the power stages return to normal operation
smoothly with minimal ringing. External-loop ATR provides
additional outputs to engage an additional low latency power
stage capable of quick charge delivery to the load. This
consists of a small FET with a very fast gate driver. Internal-
and external-loop ATR can be used independently or in
conjunction to optimize transient performance.
Output Configurations
The ISL6592 provides 12 configurable outputs that are used
to drive up to 6 phase power stages. The outputs can be
configured as a single tri-valent pulse width modulated
(PWM) signal, or as dual complementary high side control
(PWM) and low side control (NDRIVE). In addition, the
outputs may also be configured to provide the ex-loop ATR
outputs, ATRH to drive a high side undershoot control FET,
and ATRL to drive a low side overshoot control FET.
For single output configurations, tri-valent FET drivers must
be used. The driver input circuit has two thresholds (upper
and lower) along with a bias network such that its input is
centered between the two thresholds when the ISL6592
output driver is three-stated. This allows three values to be
defined for the signal, depending whether the output is high,
15
FN9163.1
August 5, 2005