LM2587S-ADJ/NOPB National Semiconductor, LM2587S-ADJ/NOPB Datasheet - Page 18

• Manufacturer Part Number: LM2587S-ADJ/NOPB
• Description: IC REG SIMPLE SWITCHER TO-263-5
• Manufacturer: National Semiconductor
• Series: SIMPLE SWITCHER®r
• Type: Step-Up (Boost), Flyback, Forward Converterr

Specifications of LM2587S-ADJ/NOPB

• Internal Switch(s): Yes
• Synchronous Rectifier: No
• Number Of Outputs: 1
• Voltage - Output: Adjustable
• Current - Output: 5A
• Frequency - Switching: 100kHz
• Voltage - Input: 4 ~ 40 V
• Operating Temperature: -40°C ~ 125°C
• Mounting Type: Surface Mount
• Package / Case: D²Pak, TO-263 (5 leads + tab)
• Package: 6TO-263
• Minimum Input Voltage: 4 V
• Maximum Input Voltage: 40 V
• Switching Frequency: 115 KHz
• Operating Supply Voltage: 4 to 40 V
• Output Type: Adjustable
• Output Voltage: 1.23(Min) V
• Efficiency: 90(Typ) %
• Primary Input Voltage: 40V
• No. Of Outputs: 1
• Output Current: 5A
• No. Of Pins: 5
• Operating Temperature Range: -40°C To +125°C
• Msl: MSL 3 - 168 Hours
• Filter Terminals: SMD
• Rohs Compliant: Yes
• For Use With: 551011367-061 - BOARD WEBENCH LM2577,LM2585/87LM2587EVAL - EVALUATION BOARD FOR LM2587
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Power - Output: -
• Other names: *LM2587S-ADJ; *LM2587S-ADJ/NOPB; LM2587S-ADJ

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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