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LM2574N-ADJ

P1-P3P4-P6P7-P9P10-P12P13-P15P16-P18P19-P21P22-P24P25-P26
© Semiconductor Components Industries, LLC, 2006
August, 2006 − Rev. 8
1 Publication Order Number:
LM2574/D
LM2574, NCV2574
0.5 A, Adjustable Output
Voltage, Step−Down
Switching Regulator
The LM2574 series of regulators are monolithic integrated circuits
ideally suited for easy and convenient design of a step−down
switching regulator (buck converter). All circuits of this series are
capable of driving a 0.5 A load with excellent line and load regulation.
These devices are available in fixed output voltages of 3.3 V, 5.0 V,
12 V, 15 V, and an adjustable output version.
These regulators were designed to minimize the number of external
components to simplify the power supply design. Standard series of
inductors optimized for use with the LM2574 are offered by several
different inductor manufacturers.
Since the LM2574 converter is a switch−mode power supply, its
efficiency is significantly higher in comparison with popular
three−terminal linear regulators, especially with higher input voltages.
In most cases, the power dissipated by the LM2574 regulator is so low,
that the copper traces on the printed circuit board are normally the only
heatsink needed and no additional heatsinking is required.
The LM2574 features include a guaranteed ±4% tolerance on output
voltage within specified input voltages and output load conditions, and
±10% on the oscillator frequency (±2% over 0°C to +125°C). External
shutdown is included, featuring 60 mA (typical) standby current. The
output switch includes cycle−by−cycle current limiting, as well as
thermal shutdown for full protection under fault conditions.
Features
• 3.3 V, 5.0 V, 12 V, 15 V, and Adjustable Output Versions
• Adjustable Version Output Voltage Range, 1.23 to 37 V ±4% max
over Line and Load Conditions
• Guaranteed 0.5 A Output Current
• Wide Input Voltage Range: 4.75 to 40 V
• Requires Only 4 External Components
• 52 kHz Fixed Frequency Internal Oscillator
• TTL Shutdown Capability, Low Power Standby Mode
• High Efficiency
• Uses Readily Available Standard Inductors
• Thermal Shutdown and Current Limit Protection
• NCV Prefix for Automotive and Other Applications Requiring Site
and Control Changes
• Pb−Free Packages are Available*
Applications
• Simple and High−Efficiency Step−Down (Buck) Regulators
• Efficient Pre−regulator for Linear Regulators
• On−Card Switching Regulators
• Positive to Negative Converters (Buck−Boost)
• Negative Step−Up Converters
• Power Supply for Battery Chargers
*For additional information on our Pb−Free strategy and soldering details, please download the ON Semiconductor Soldering and Mounting
Techniques Reference Manual, SOLDERRM/D.
1
16
SO−16 WB
DW SUFFIX
CASE 751G
PIN CONNECTIONS
*
(Top View)
12
Pwr Gnd
ON
/OFF
*
*
*
*
11
10
9
5
6
7
8
*
16
*
*
FB
Sig Gnd
Output
*
V
in
15
14
13
1
2
3
4
*
* No internal connection, but should be soldered to
* PC board for best heat transfer.
*
(Top View)
8
FB
Sig Gnd
ON
/OFF
Pwr Gnd
Output
*
V
in
7
6
5
1
2
3
4
See detailed ordering and shipping information in the package
dimensions section on page 24 of this data sheet.
ORDERING INFORMATION
See general marking information in the device marking
section on page 24 of this data sheet.
DEVICE MARKING INFORMATION
PDIP−8
N SUFFIX
CASE 626
1
8
http://onsemi.com
LM2574, NCV2574
http://onsemi.com
2
Figure 1. Block Diagram and Typical Application
7.0 − 40 V
Unregulated
DC Input
L1
330 mH
Pwr
Gnd
+V
in
5
C
in
22 mF
4ON
/OFF3
Output
7
Feedback
1
D1
1N5819
C
out
220 mF
Typical Application (Fixed Output Voltage Versions)
Representative Block Diagram and Typical Application
Unregulated
DC Input
+V
in
5
C
out
Feedback
1
C
in
L1
D1
R2
R1
1.0 k
Output
7
Pwr Gnd
4
ON
/OFF
3
Reset
Latch
Thermal
Shutdown
52 kHz
Oscillator
1.235 V
Band−Gap
Reference
Freq
Shift
18 kHz
Comparator
Fixed Gain
Error Amplifier
Current
Limit
Driver
1.0 Amp
Switch
ON
/OFF
3.1 V Internal
Regulator
V
out
Load
Output
Voltage Versions
3.3 V
5.0 V
12 V
15 V
R2
(W)
1.7 k
3.1 k
8.84 k
11.3 k
For adjustable version
R1 = open, R2 = 0 W
LM2574
5.0 V Regulated
Output 0.5 A Load
Sig
Gnd
2
Sig Gnd
2
(12)
(14)
(3)
(4) (6) (5)
(5)
(12)
(3)
(4)
(14)
(6)
NOTE: Pin numbers in ( ) are for the SO−16W package.
ABSOLUTE MAXIMUM RATINGS (Absolute Maximum Ratings indicate limits beyond which damage to the device may occur).
Rating
Symbol Value Unit
Maximum Supply Voltage V
in
45 V
ON/OFF Pin Input Voltage − −0.3 V ≤ V ≤ +V
in
V
Output Voltage to Ground (Steady State) − −1.0 V
DW Suffix, Plastic Package Case 751G
Max Power Dissipation P
D
Internally Limited W
Thermal Resistance, Junction−to−Air
R
q
JA
145 °C/W
N Suffix, Plastic Package Case 626
Max Power Dissipation P
D
Internally Limited W
Thermal Resistance, Junction−to−Ambient
R
q
JA
100 °C/W
Thermal Resistance, Junction−to−Case
R
q
JC
5.0 °C/W
Storage Temperature Range T
stg
−65°C to +150°C °C
Minimum ESD Rating − 2.0 kV
(Human Body Model: C = 100 pF, R = 1.5 kW)
Lead Temperature (Soldering, 10 seconds) − 260 °C
Maximum Junction Temperature T
J
150 °C
Maximum ratings are those values beyond which device damage can occur. Maximum ratings applied to the device are individual stress limit
values (not normal operating conditions) and are not valid simultaneously. If these limits are exceeded, device functional operation is not implied,
damage may occur and reliability may be affected.
NOTE: ESD data available upon request.
LM2574, NCV2574
http://onsemi.com
3
OPERATING RATINGS (Operating Ratings indicate conditions for which the device is intended to be functional, but do not guarantee
specific performance limits. For guaranteed specifications and test conditions, see the Electrical Characteristics).
Rating
Symbol Value Unit
Operating Junction Temperature Range T
J
−40 to +125 °C
Supply Voltage V
in
40 V
SYSTEM PARAMETERS ([Note 1] Test Circuit Figure 16)
ELECTRICAL CHARACTERISTICS (Unless otherwise specified, V
in
= 12 V for the 3.3 V, 5.0 V, and Adjustable
version, V
in
= 25 V for the 12 V version, V
in
= 30 V for the 15 V version. I
Load
= 100 mA. For typical values T
J
= 25°C, for min/max values
T
J
is the operating junction temperature range that applies [Note 2], unless otherwise noted).
Characteristic
Symbol Min Typ Max Unit
LM2574−3.3 ([Note 1] Test Circuit Figure 16)
Output Voltage (V
in
= 12 V, I
Load
= 100 mA, T
J
= 25°C) V
out
3.234 3.3 3.366 V
Output Voltage (4.75 V ≤ V
in
≤ 40 V, 0.1 A ≤ I
Load
≤ 0.5 A) V
out
V
T
J
= 25°C 3.168 3.3 3.432
T
J
= −40 to +125°C 3.135 − 3.465
Efficiency (V
in
= 12 V, I
Load
= 0.5 A) η − 72 − %
LM2574−5 ([Note 1] Test Circuit Figure 16)
Output Voltage (V
in
= 12 V, I
Load
= 100 mA, T
J
= 25°C) V
out
4.9 5.0 5.1 V
Output Voltage (7.0 V ≤ V
in
≤ 40 V, 0.1 A ≤ I
Load
≤ 0.5 A) V
out
V
T
J
= 25°C
4.8 5.0 5.2
T
J
= −40 to +125°C
4.75 5.25
Efficiency (V
in
= 12 V, I
Load
= 0.5 A) η − 77 − %
LM2574−12 ([Note 1] Test Circuit Figure 16)
Output Voltage (V
in
= 25 V, I
Load
= 100 mA, T
J
= 25°C) V
out
11.76 10 12.24 V
Output Voltage (15 V ≤ V
in
≤ 40 V, 0.1 A ≤ I
Load
≤ 0.5 A) V
out
V
T
J
= 25°C
11.52 12 12.48
T
J
= −40 to +125°C
11.4 − 12.6
Efficiency (V
in
= 15 V, I
Load
= 0.5 A) η − 88 − %
LM2574−15 ([Note 1] Test Circuit Figure 16)
Output Voltage (V
in
= 30 V, I
Load
= 100 mA, T
J
= 25°C) V
out
14.7 15 15.3 V
Output Voltage (18 V < V
in
< 40 V, 0.1 A < I
Load
< 0.5 A) V
out
V
T
J
= 25°C 14.4 15 15.6
T
J
= −40 to +125°C 14.25 15.75
Efficiency (V
in
= 18 V, I
Load
= 0.5 A) η − 88 − %
LM2574 ADJUSTABLE VERSION ([Note 1] Test Circuit Figure 16)
Feedback Voltage V
in
= 12 V, I
Load
= 100 mA, V
out
= 5.0 V, T
J
= 25°C V
FB
1.217 1.23 1.243 V
Feedback Voltage 7.0 V ≤ V
in
≤ 40 V, 0.1 A ≤ I
Load
≤ 0.5 A, V
out
= 5.0
V
V
FBT
V
T
J
= 25°C 1.193 1.23 1.267
T
J
= −40 to +125°C 1.18 1.28
Efficiency (V
in
= 12 V, I
Load
= 0.5 A, V
out
= 5.0 V) η − 77 − %
1. External components such as the catch diode, inductor, input and output capacitors can affect the switching regulator system performance.
When the LM2574 is used as shown in the Figure 16 test circuit, the system performance will be as shown in the system parameters section
of the Electrical Characteristics.
2. Tested junction temperature range for the LM2574, NCV2574: T
low
= −40°C T
high
= +125°C.
P1-P3P4-P6P7-P9P10-P12P13-P15P16-P18P19-P21P22-P24P25-P26

LM2574N-ADJ

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Buy LM2574N-ADJ
Manufacturer:
ON Semiconductor
Description:
IC REG MULT CONFG ADJ 500MA 8DIP
Lifecycle:
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