ISL6260CRZ Intersil, ISL6260CRZ Datasheet - Page 18

• Manufacturer Part Number: ISL6260CRZ
• Description: IC CORE REG MULTIPHASE 40-QFN
• Manufacturer: Intersil

Specifications of ISL6260CRZ

• Applications: Converter, Intel IMVP-6
• Number Of Outputs: 1
• Voltage - Output: 0.3 ~ 1.5 V
• Operating Temperature: -10°C ~ 100°C
• Mounting Type: Surface Mount
• Package / Case: 40-VFQFN, 40-VFQFPN
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Voltage - Input: -

Refer to Figure 26. The second level of overvoltage
protection behaves differently. If the output exceeds 1.7V, an
OV fault is immediately declared, PGOOD is latched low and
the low-side FETs are turned on. The low-side FETs will
remain on until the output voltage is pulled down below
0.85V at which time all FETs are turned off. If the output
again rises above 1.7V, the process is repeated. This affords
the maximum amount of protection against a shorted high-
side FET while preventing output ringing below ground. The
1.7V OV is not reset with VR_ON, but requires that VDD be
lowered to reset. The 1.7V OC detector is active at all times
that the controller is enabled including after one of the other
faults occurs so that the processor is protected against high-
side FET leakage while the FETs are commanded off.
The ISL6260 and ISL6260B have a thermal throttling
feature. If the voltage on the NTC pin goes below the 1.18V
OT threshold, the VR_TT# pin is pulled low indicating the
need for thermal throttling to the system oversight processor.
No other action is taken within the ISL6260 and ISL6260B in
response to NTC pin voltage.
Fault protection is summarized in Table 3.
Component Selection and Application
Soft-Start and Mode Change Slew Rates
The ISL6260 and ISL6260B use 2 slew rates for various
modes of operation. The first is a slow slew rate, used to
reduce inrush current on start-up. It is also used to reduce
audible noise when entering or exiting Deeper Sleep Mode.
A faster slew rate is used to exit out of Deeper Sleep and to
increase system performance by achieving active mode
regulation more quickly. Note that the SOFT cap current is
bidirectional and is flowing into the SOFT capacitor when the
output voltage is commanded to rise, and out of the SOFT
capacitor when the output voltage is commanded to fall.
The two slew rates are determined by commanding 1 of 2
currents onto the SOFT pin. As can be seen in Figure 40, the
SOFT pin has a capacitance to ground. Also, the SOFT pin
is the input to the error amplifier and is, therefore, the
Overcurrent
Way-Overcurrent
Overvoltage 1.7V
Overvoltage +200mV
Undervoltage -300mV
Phase Current Unbalance
Over Temperature
TABLE 3. SUMMARY OF THE FAULT PROTECTION AND RESET OPERATIONS OF ISL6260, ISL6260B
120µs
<2µs
Immediately
1ms
1ms
1ms
Immediately
FAULT DURATION
18
PROTECTION
PRIOR TO
PWMs tri-state, Pgood latched low
PWMs tri-state, Pgood latched low
Low side MOSFET on until Vcore <0.85V, then PWM
tri-state, Pgood latched low.
PWMs tri-state, Pgood latched low
PWMs tri-state, Pgood latched low
PWMs tri-state, Pgood latched low
VR_TT# goes low
ISL6260, ISL6260B
PROTECTION
ACTIONS
commanded system voltage. Depending on the state of the
system, i.e. Start-Up or Active mode, and the state of the
DPRSLPVR pin, one of the two currents shown in Figure 40
will be used to charge or discharge this capacitor, thereby
controlling the slew rate of the commanded voltage. These
currents can be found under the Soft Current section of the
Electrical Specification Table.
The first current, labeled I
Table as 41μA. This current is used during Soft-Start. The
second current, I
currents, labeled I
This total current is typically 200μA with a minimum of
175μA.
The IMVP-6™ specification reveals the critical timing
associated with regulating the output voltage. The symbol,
Slewrate, as given in the IMVP-6™ specification, will
determine the choice of the SOFT capacitor, C
following equation:
C
FIGURE 40. SOFT PIN CURRENT SOURCES FOR FAST AND
SOFT
=
----------------------------------- -
SLEWRATE
SLOW SLEW RATES
C
SOFT
I
GV
2
GV
sums with I
in the Electrical Specification Table.
SOFT
V
I
REF
+
SS
SS
, is given in the Specification
SS
VR_ON toggle or VDD toggle
VR_ON toggle or VDD toggle
VR_ON toggle or VDD toggle
VR_ON toggle or VDD toggle
VR_ON toggle or VDD toggle
N/A
VDD toggle
to get the larger of the two
I
2
ISL6260(B)
AMPLIFIER
+
ERROR
FAULT RESET
SOFT
January 3, 2006
, by the
FN9162.1