NCP5208DR2 ON Semiconductor, NCP5208DR2 Datasheet - Page 8

• Manufacturer Part Number: NCP5208DR2
• Description: IC REG TERM DDR-I/II 1.7V 8SOIC
• Manufacturer: ON Semiconductor

Specifications of NCP5208DR2

• Applications: Controller, DDR, DDR2
• Voltage - Input: 1.7 ~ 5.5 V
• Number Of Outputs: 2
• Voltage - Output: 0.9 V, 1.25V
• Operating Temperature: 0°C ~ 70°C
• Mounting Type: Surface Mount
• Package / Case: 8-SOIC (3.9mm Width)
• Polarity: Positive
• Output Type: Fixed
• Output Voltage: 0.9 V
• Output Current: 1.5 A
• Load Regulation: 20 mV
• Input Voltage Max: 5.5 V
• Maximum Operating Temperature: + 70 C
• Minimum Operating Temperature: 0 C
• Mounting Style: SMD/SMT
• Voltage Regulation Accuracy: 3 %
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Other names: NCP5208DR2OS

Typical Application Circuit
regulator. For most applications, an input and output
capacitor and a pullup resistor for the power OK output, are
the only external components needed. For typical
application circuit, refer to Figure 1.
AVIN and VDDQ Supply
voltage must be kept clean and free from transients. A small
capacitor, 1.0 mF is recommended at this input to provide
the required supply filtering and ripple rejection. VDDQ is
primarily used to generate the internal voltage reference, so
any noise or transient at this pin will be directly reflected
at the VTT output. In order to avoid undesired interference
injected into this pin, appropriate de−coupling and careful
design of PCB layout is required.
Input Capacitor Selection
stability, however it is still recommended for better overall
performance during large load transients that can cause
sudden drop of the power rail voltage. The input capacitor
must be located as close as possible to the PVIN pin to
avoid a transient voltage dip affecting the quality of AVIN
and VDDQ. For typical DDR−I applications, a low ESR
electrolytic capacitor of 100 mF or larger is recommended.
By adding a small ceramic capacitor of 0.1 mF in parallel,
the best high frequency transient filtering will result. If the
device is located near the main supply bulk capacitors, the
input capacitance can be reduced accordingly.
Output Capacitor Selection
output capacitor with capacitance greater than 220 mF and
with ESR ranging from 2 mW to 400 mW. The choice for this
output capacitor is determined solely by the application and
the requirements for load transient characteristic of VTT
output. As a general recommendation, the capacitance should
be larger than 220 mF with low ESR for SSTL and DDR
memory applications.
The NCP5208 is a highly integrated termination
AVIN provides power for the device to operate. This
The NCP5208 does not require an input capacitor for
The NCP5208 is internally compensated and stable for any
APPLICATIONS INFORMATION
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NCP5208
8
Thermal Dissipation
from/to VTT will result in internal power dissipation and
generating heat. In order to prevent un−wanted shutdown
of the device during operation, care should be taken to
de−rate the power capability according to the maximum
expected ambient temperature and power dissipation. The
maximum allowable internal temperature rise, T
can be calculated from the equation in below:
temperature and T
ambient temperature.
condition is given by:
dissipation and R
resistance for specific package.
variables. Increasing the thickness and area of the copper
and adding vias and airflow can improve the thermal
performance.
The NCP5208 is a linear regulator, any current flow
Where T
The maximum allowable power dissipation for a specific
Where P
The thermal handling capability depends on several
J−MAX
D−MAX
T R−MAX + T J−MAX * T A−MAX
P D−MAX +
is the maximum allowable junction
A−MAX
qJA_T
is the maximum allowable power
is Junction−to−Air thermal
is the maximum expected
T R−MAX
R qJA_T
R−MAX