LM2587EVAL National Semiconductor, LM2587EVAL Datasheet - Page 18
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LM2587EVAL
Manufacturer Part Number
LM2587EVAL
Description
EVALUATION BOARD FOR LM2587
Manufacturer
National Semiconductor
Series
SIMPLE SWITCHER®r
Datasheet
1.LM2587S-ADJNOPB.pdf
(28 pages)
Specifications of LM2587EVAL
Main Purpose
DC/DC, Step Up
Outputs And Type
1, Non-Isolated
Voltage - Output
12V
Current - Output
1A
Voltage - Input
4 ~ 40V
Regulator Topology
Boost
Frequency - Switching
100kHz
Board Type
Fully Populated
Utilized Ic / Part
LM2587
For Use With
551011367-061 - BOARD WEBENCH LM2577,LM2585/87
Lead Free Status / RoHS Status
Contains lead / RoHS non-compliant
Power - Output
-
Other names
*LM2587EVAL
www.national.com
Step-Up (Boost) Regulator
Operation
Figure 33
ulator. This is a switching regulator that produces an output
voltage greater than the input supply voltage.
A brief explanation of how the LM2587 Boost Regulator works
is as follows (refer to
By adding a small number of external components (as shown in
the applied input voltage. The switching waveforms observed during the operation of this circuit are shown in
shown in
Figure
shows the LM2587 used as a step-up (boost) reg-
35.
Figure
33). When the NPN switch turns
FIGURE 33. 12V Boost Regulator
FIGURE 32. Schott 67140930
Figure
33), the LM2587 can be used to produce a regulated output voltage that is greater than
Top View
T4
18
on, the inductor current ramps up at the rate of V
energy in the inductor. When the switch turns off, the lower
end of the inductor flies above V
through diode (D) into the output capacitor (C
(V
switch on time is transferred to the output during the switch
off time. The output voltage is controlled by adjusting the peak
switch current, as described in the flyback regulator section.
OUT
− V
IN
)/L. Thus, energy stored in the inductor during the
1231647
Figure
34. Typical performance of this regulator is
IN
, discharging its current
1231619
OUT
) at a rate of
IN
/L, storing