LM3488MM National Semiconductor, LM3488MM Datasheet - Page 11

• Manufacturer Part Number: LM3488MM
• Description: IC, N-CH CONTROLLER, MSOP-8
• Manufacturer: National Semiconductor

Specifications of LM3488MM

• Primary Input Voltage: 40V
• No. Of Outputs: 1
• Output Current: 1A
• No. Of Pins: 8
• Operating Temperature Range: -40°C To +125°C
• Termination Type: SMD
• Input Voltage Primary Min: 2.95V
• Output Voltage Min: 1.26V
• Rohs Compliant: No
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

The compensation ramp has been added internally in
LM3488. The slope of this compensation ramp has been se-
lected to satisfy most of the applications. The slope of the
internal compensation ramp depends on the frequency. This
slope can be calculated using the formula:
In the above equation, V
compensation ramp. Limits for V
electrical characteristics.
In order to provide the user additional flexibility, a patented
scheme has been implemented inside the IC to increase the
slope of the compensation ramp externally, if the need arises.
Adding a single external resistor, R
increases the slope of the compensation ramp, M
M
C
= V
SL
SL
.F
S
is the amplitude of the internal
FIGURE 3. Compensation Ramp Avoids Sub-Harmonic Oscillation
Volts/second
SL
FIGURE 4. Increasing the Slope of the Compensation Ramp
have been specified in the
SL
(as shown in
C
Figure
by :
4)
11
In this equation, ΔV
ΔV
quencies.
SL
versus R
SL
has been plotted in
SL
is equal to 40.10
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Figure 5
-6
R
SL
. Hence,
for different fre-
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