ISL6227CA Intersil, ISL6227CA Datasheet - Page 11

• Manufacturer Part Number: ISL6227CA
• Description: IC CONTROLLER DDR, DDR2 28QSOP
• Manufacturer: Intersil

Specifications of ISL6227CA

• Applications: Controller, DDR, DDR2
• Voltage - Input: 5 ~ 28 V
• Number Of Outputs: 2
• Voltage - Output: 0.9 ~ 5.5 V
• Operating Temperature: -10°C ~ 100°C
• Mounting Type: Surface Mount
• Package / Case: 28-QSOP
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

PG2/REF
This pin has a double function, depending on the mode of
operation.
When the chip is used as a dual channel PWM controller
(DDR = 0), the pin provides an open drain PGOOD2 function
for the second channel the same way as PG1. The pin is
pulled low when the second channel output is out of
-11% to +15% of the set value.
In DDR mode (DDR = 1), this pin is the output of the buffer
amplifier that takes VDDQ/2 voltage applied to OCSET2 pin
from the resister divider. It can source a typical 10mA
current.
OCSET2
In a dual channel application with DDR = 0, a resistor from
this pin to ground sets the overcurrent threshold for the
second channel controller. Its voltage is the buffered internal
0.9V reference.
In the DDR application with DDR = 1, this pin connects to the
center point of a resistor divider tracking the VDDQ/2. This
voltage is then buffered by an amplifier voltage follower and
sent to the PG2/REF pin. It sets the reference voltage of
Channel 2 for its regulation.
VCC
This pin powers the controller.
11
ISL6227
Typical Application
Figures 31 and 32 show the application circuits of a dual
channel DC/DC converter for a notebook PC.
The power supply in Figure 31 provides +2.5V and +1.8V
voltages for memory and the graphics interface chipset from
a +5.0VDC to a 28VDC battery voltage.
Figure 32 illustrates the application circuit for a DDR memory
power solution. The power supply shown in Figure 32
generates +2.5V VDDQ voltage from a battery. The +1.25V
VTT termination voltage tracks VDDQ/2 and is derived from
+2.5V VDDQ. To complete the DDR memory power
requirements, the +1.25V reference voltage is provided
through the PG2 pin.
May 4, 2009
FN9094.7