ISL6227CAZ New New
Dual Mobile-Friendly PWM Controller with
DDR Option
jual ic ISL6227CAZ laptop
jual ic ISL6227CAZ notebook
The ISL6227 dual PWM controller delivers high efficiency
precision voltage regulation from two synchronous buck DC/DC
converters. It was designed especially to provide power
regulation for DDR memory, chipsets, graphics and other
system electronics in Notebook PCs. The ISL6227’s wide
input voltage range capability allows for voltage conversion
directly from AC/DC adaptor or Li-Ion battery pack.
Automatic mode transition of constant-frequency synchronous
rectification at heavy load, and hysteretic (HYS)
diode-emulation at light load, assure high efficiency over a wide
range of conditions. The HYS mode of operation can be
disabled separately on each PWM converter if
constant-frequency continuous-conduction operation is desired
for all load levels. Efficiency is further enhanced by using the
lower MOSFET rDS(ON) as the current sense element.
Voltage-feed-forward ramp modulation, current mode
control, and internal feedback compensation provide fast
response to input voltage and load transients. Input current
ripple is minimized by channel-to-channel PWM phase shift
of 0°, 90° or 180° (determined by input voltage and status of
the DDR pin).
The ISL6227 can control two independent output voltages
adjustable from 0.9V to 5.5V, or by activating the DDR pin,
transform into a complete DDR memory power supply
solution. In DDR mode, CH2 output voltage VTT tracks CH1
output voltage VDDQ. CH2 output can both source and sink
current, an essential power supply feature for DDR memory.
The reference voltage VREF required by DDR memory is
generated as well.
In dual power supply applications the ISL6227 monitors the
output voltage of both CH1 and CH2. An independent PGOOD
(power good) signal is asserted for each channel after the
soft-start sequence has completed, and the output voltage is
within PGOOD window. In DDR mode CH1 generates the only
PGOOD signal.
Built-in overvoltage protection prevents the output from going
above 115% of the set point by holding the lower MOSFET on
and the upper MOSFET off. When the output voltage re-enters
regulation, PGOOD will go HIGH and normal operation
automatically resumes. Once the soft-start sequence has
completed, undervoltage protection latches the offending
channel off if the output drops below 75% of its set point value.
Adjustable overcurrent protection (OCP) monitors the voltage
drop across the rDS(ON) of the lower MOSFET. If more precise
current-sensing is required, an external current sense resistor
may be used.
Dual Mobile-Friendly PWM Controller with
DDR Option
The ISL6227 dual PWM controller delivers high efficiency
precision voltage regulation from two synchronous buck DC/DC
converters. It was designed especially to provide power
regulation for DDR memory, chipsets, graphics and other
system electronics in Notebook PCs. The ISL6227’s wide
input voltage range capability allows for voltage conversion
directly from AC/DC adaptor or Li-Ion battery pack.
Automatic mode transition of constant-frequency synchronous
rectification at heavy load, and hysteretic (HYS)
diode-emulation at light load, assure high efficiency over a wide
range of conditions. The HYS mode of operation can be
disabled separately on each PWM converter if
constant-frequency continuous-conduction operation is desired
for all load levels. Efficiency is further enhanced by using the
lower MOSFET rDS(ON) as the current sense element.
Voltage-feed-forward ramp modulation, current mode
control, and internal feedback compensation provide fast
response to input voltage and load transients. Input current
ripple is minimized by channel-to-channel PWM phase shift
of 0°, 90° or 180° (determined by input voltage and status of
the DDR pin).
The ISL6227 can control two independent output voltages
adjustable from 0.9V to 5.5V, or by activating the DDR pin,
transform into a complete DDR memory power supply
solution. In DDR mode, CH2 output voltage VTT tracks CH1
output voltage VDDQ. CH2 output can both source and sink
current, an essential power supply feature for DDR memory.
The reference voltage VREF required by DDR memory is
generated as well.
In dual power supply applications the ISL6227 monitors the
output voltage of both CH1 and CH2. An independent PGOOD
(power good) signal is asserted for each channel after the
soft-start sequence has completed, and the output voltage is
within PGOOD window. In DDR mode CH1 generates the only
PGOOD signal.
Built-in overvoltage protection prevents the output from going
above 115% of the set point by holding the lower MOSFET on
and the upper MOSFET off. When the output voltage re-enters
regulation, PGOOD will go HIGH and normal operation
automatically resumes. Once the soft-start sequence has
completed, undervoltage protection latches the offending
channel off if the output drops below 75% of its set point value.
Adjustable overcurrent protection (OCP) monitors the voltage
drop across the rDS(ON) of the lower MOSFET. If more precise
current-sensing is required, an external current sense resistor
may be used.
CONDITION: NEW
WARRANTY: NO