LM2825 Datasheet, PDF (1/12 Pages) National Semiconductor (TI) – Integrated Power Supply 1A DC-DC Converter

May 1997
LM2825
Integrated Power Supply 1A DC-DC Converter
General Description
The LM2825 is a complete 1A DC-DC Buck converter pack-
aged in a 24-lead molded Dual-In-Line integrated circuit
package.
Contained within the package are all the active and passive
components for a high efficiency step-down (buck) switching
regulator. Available in fixed output voltages of 3.3V, 5V and
12V, as well as two adjustable versions, these devices can
provide up to 1A of load current with fully guaranteed electri-
cal specifications.
Self-contained, this converter is also fully protected from out-
put fault conditions, such as excessive load current, short
circuits, or excessive temperatures.
Highlights
n No external components required (fixed output voltage
versions)
n Integrated circuit reliability
n MTBF over 20 million hours
n Radiated EMI meets Class B stipulated by CISPR 22
n High power density, 35 W/in³
n 24-pin DIP package profile (1.25 x 0.54 x 0.26 inches)
Features
n Minimum design time required
n 3.3V, 5V and 12V fixed output versions
n Two adjustable versions allow 1.23V to 15V outputs
n Wide input voltage range, up to 40V
n Low-power standby mode, I_Q typically 65 µA
n High efficiency, typically 80%
n ±4% output voltage tolerance
n Excellent line and load regulation
n TTL shutdown capability/programmable Soft-start
n Thermal shutdown and current limit protection
n −40˚C to +85˚C ambient temperature range
Applications
n Simple high-efficiency step-down (buck) regulator
n On-card switching regulators
n Efficient pre-regulator for linear regulators
n Distributed power systems
n DC/DC module replacement
Connection Diagram
Standard Application
(Fixed output voltage versions)
DS012661-27
DS012661-1
Radiated EMI
Radiated emission of electromagnetic fields is measured at
10m distance. The emission levels are within the Class B
limits stipulated by CISPR 22.
30. . . .230 MHz
230. . . .1000 MHz
1. . . .10 GHz
30 dB µV/m
37 dB µV/m
46 dB µV/m
“NC (Do not use)” pins: See Figure 11.
Top View
DS012661-2
Ordering Information
Order Number LM2825N-3.3, LM2825N-5.0, LM2825N-12,
LM2825N-ADJ or LM2825HN-ADJ
See NS Package Number NA24F
© 1997 National Semiconductor Corporation DS012661
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