LM3488MM/NOPB National Semiconductor, LM3488MM/NOPB Datasheet - Page 11

• Manufacturer Part Number: LM3488MM/NOPB
• Description: IC CTRLR SWITCH REG N-CH 8-MSOP
• Manufacturer: National Semiconductor
• Type: Step-Up (Boost), Flyback, Sepicr

Specifications of LM3488MM/NOPB

• Internal Switch(s): No
• Synchronous Rectifier: No
• Number Of Outputs: 1
• Voltage - Output: Adj to 1.26V
• Current - Output: 1A
• Frequency - Switching: 100kHz ~ 1MHz
• Voltage - Input: 2.97 ~ 40 V
• Operating Temperature: -40°C ~ 125°C
• Mounting Type: Surface Mount
• Package / Case: 8-MSOP, Micro8™, 8-uMAX, 8-uSOP,
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Power - Output: -
• Other names: LM3488MM; LM3488MM; LM3488MMTR

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
10138813
Figure 5
-6
R
SL
. Hence,
for different fre-
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