ISL6568CR-T Intersil, ISL6568CR-T Datasheet - Page 12

• Manufacturer Part Number: ISL6568CR-T
• Description: IC CTRLR PWM BUCK 2PHASE 32-QFN
• Manufacturer: Intersil

Specifications of ISL6568CR-T

• Applications: Controller, Intel VRM9, VRM10, and AMD Hammer Applications
• Voltage - Input: 3 ~ 12 V
• Number Of Outputs: 1
• Voltage - Output: 0.84 ~ 1.6 V
• Operating Temperature: 0°C ~ 70°C
• Mounting Type: Surface Mount
• Package / Case: 32-VQFN Exposed Pad, 32-HVQFN, 32-SQFN, 32-DHVQFN
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

depending on the status of the BOOT2 and PHASE2 pins,
as described in the PWM Operation section.
The ISL6568 senses the channel load current by sampling
the voltage across the lower MOSFET r
Figure 5. A ground-referenced operational amplifier, internal
to the ISL6568, is connected to the PHASE node through a
resistor, R
the voltage drop across the r
while it is conducting. The resulting current into the ISEN pin
is proportional to the channel current, I
sampled and held as described in the Current Sampling
section. From Figure 5, the following equation for I
derived where I
Output Voltage Setting
The ISL6568 uses a digital to analog converter (DAC) to
generate a reference voltage based on the logic signals at the
VID pins. The DAC decodes the 5 or 6-bit logic signals into
one of the discrete voltages shown in Tables 2, 3, and 4.
Each VID pin is pulled up to an internal 1.2V voltage by a
weak current source (40µA current), which decreases to 0 as
the voltage at the VID pin varies from 0 to the internal 1.2V
pull-up voltage. External pull-up resistors or active-high
output stages can augment the pull-up current sources, up to
a voltage of 5V.
.
The ISL6568 accommodates three different DAC ranges:
Intel VRM9.0, AMD Hammer, or Intel VRM10.0. The state of
the VID12.5 pin decides which DAC version is active. Refer
to Table 1 for a description of how to select the desired DAC
version.
I
n
SAMPLE
ISL6565A INTERNAL CIRCUIT
HOLD
FIGURE 5. ISL6568 INTERNAL AND EXTERNAL CURRENT-
=
I
&
I
DAC VERSION
AMD HAMMER
n
L
r
----------------------
VRM10.0
DS ON
R
VRM9.0
I
SEN
ISEN
ISEN
(
TABLE 1. ISL6568 DAC SELECT TABLE
SENSING CIRCUITRY FOR CURRENT BALANCE
=
)
. The voltage across R
L
I
L
is the channel current.
r
------------------------- -
+
DS ON
R
-
ISEN
(
Less then 3V
50kΩ resistor to +5V
5kΩ resistor to +5V
)
DS(ON)
12
ISEN(n)
EXTERNAL CIRCUIT
VID12.5 PIN CONDITION
CHANNEL N
LOWER MOSFET
R
of the lower MOSFET
ISEN
ISEN
L
. The ISEN current is
DS(ON)
V
is equivalent to
IN
+
CHANNEL N
UPPER MOSFET
-
I L r DS ON
, as shown in
n
I
L
is
(
(EQ. 3)
)
ISL6568
TABLE 2. AMD HAMMER VOLTAGE IDENTIFICATION CODES
VID4
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
VID3
1
1
1
1
1
1
1
1
0
0
0
0
0
0
0
0
1
1
1
1
1
1
1
1
0
0
0
0
0
0
0
0
VID2
1
1
1
1
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
0
0
0
0
1
1
1
1
0
0
0
0
VID1
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
1
1
0
0
VID0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
1
0
March 9, 2006
VDAC
0.800
0.825
0.850
0.875
0.900
0.925
0.950
0.975
1.000
1.025
1.050
1.075
1.100
1.125
1.150
1.175
1.200
1.225
1.250
1.275
1.300
1.325
1.350
1.375
1.400
1.425
1.450
1.475
1.500
1.525
1.550
FN9187.4
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