NSC LM2575HVT-ADJ, LM2575HVT-5.0, LM2575HVT-3.3, LM2575HVT-15, LM2575HVT-12 Datasheet
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May 1999
LM1575/LM2575/LM2575HV Series
SIMPLE SWITCHER® 1A Step-Down Voltage Regulator
General Description
The LM2575 series of regulators are monolithic integrated circuits that provide all the active functions for a step-down (buck) switching regulator, capable of driving a 1A load with excellent line and load regulation. These devices are available in fixed output voltages of 3.3V, 5V, 12V, 15V, and an adjustable output version.
Requiring a minimum number of external components, these regulators are simple to use and include internal frequency compensation and a fixed-frequency oscillator.
The LM2575 series offers a high-efficiency replacement for popular three-terminal linear regulators. It substantially reduces the size of the heat sink, and in many cases no heat sink is required.
A standard series of inductors optimized for use with the LM2575 are available from several different manufacturers. This feature greatly simplifies the design of switch-mode power supplies.
Other features include a guaranteed ±4% tolerance on output voltage within specified input voltages and output load conditions, and ±10% on the oscillator frequency. External shutdown is included, featuring 50 µA (typical) standby current. The output switch includes cycle-by-cycle current limiting, as well as thermal shutdown for full protection under fault conditions.
Features
n3.3V, 5V, 12V, 15V, and adjustable output versions
nAdjustable version output voltage range,
1.23V to 37V (57V for HV version) ±4% max over line and load conditions
nGuaranteed 1A output current
nWide input voltage range, 40V up to 60V for HV version
nRequires only 4 external components
n52 kHz fixed frequency internal oscillator
nTTL shutdown capability, low power standby mode
nHigh efficiency
nUses readily available standard inductors
nThermal shutdown and current limit protection
nP+ Product Enhancement tested
Applications
nSimple high-efficiency step-down (buck) regulator
nEfficient pre-regualtor for linear regulators
nOn-card switching regulators
nPositive to negative converter (Buck-Boost)
Typical Application (Fixed Output Voltage Versions)
DS011475-1
Note: Pin numbers are for the TO-220 package.
SIMPLE SWITCHER® is a registered trademark of National Semiconductor Corporation.
Regulator Voltage Down-Step 1A SWITCHER SIMPLE Series LM1575/LM2575/LM2575HV
© 1999 National Semiconductor Corporation |
DS011475 |
www.national.com |
Block Diagram and Typical Application
DS011475-2
3.3V, R2 = 1.7k
5V, R2 = 3.1k 12V, R2 = 8.84k 15V, R2 = 11.3k For ADJ. Version
R1 = Open, R2 = 0Ω
Note: Pin numbers are for the TO-220 package.
FIGURE 1.
Connection Diagrams (XX indicates output voltage option. See Ordering Information table for complete part number.)
Straight Leads 5±Lead TO-22 (T)
Bent, Staggered Leads
5-Lead TO-220 (T)
DS011475-22
Top View
LM2575T-XX or LM2575HVT-XX
See NS Package Number T05A
16±Lead DIP (N or J)
DS011475-25
*No Internal Connection
Top View
LM2575N-XX or LM2575HVN-XX
See NS Package Number N16A
LM1575J-XX-QML
See NS Package Number J16A
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DS011475-24 |
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Side View |
DS011475-23 |
LM2575T-XX Flow LB03 or |
Top View |
LM2575HVT-XX Flow LB03 |
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See NS Package Number T05D |
24-Lead Surface Mount (M)
DS011475-26
*No Internal Connection
Top View
LM2575M-XX or LM2575HVM-XX
See NS Package Number M24B
www.national.com |
2 |
Connection Diagrams (XX indicates output voltage option. See Ordering Information table for complete part number.) (Continued)
TO-263(S)
5-Lead Surface-Mount Package
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DS011475-29 |
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Top View |
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DS011475-30 |
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Side View |
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LM2575S-XX or LM2575HVS-XX |
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See NS Package Number TS5B |
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Ordering Information |
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Package |
NSC |
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Standard |
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High |
Temperature |
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Type |
Package |
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Voltage Rating |
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Voltage Rating |
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Range |
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Number |
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(40V) |
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(60V) |
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5-Lead TO-220 |
T05A |
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LM2575T-3.3 |
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LM2575HVT-3.3 |
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Straight Leads |
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LM2575T-5.0 |
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LM2575HVT-5.0 |
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LM2575T-12 |
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LM2575HVT-12 |
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LM2575T-15 |
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LM2575HVT-15 |
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LM2575T-ADJ |
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LM2575HVT-ADJ |
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5-Lead TO-220 |
T05D |
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LM2575T-3.3 Flow LB03 |
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LM2575HVT-3.3 Flow LB03 |
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Bent and |
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LM2575T-5.0 Flow LB03 |
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LM2575HVT-5.0 Flow LB03 |
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Staggered Leads |
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LM2575T-12 Flow LB03 |
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LM2575HVT-12 Flow LB03 |
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LM2575T-15 Flow LB03 |
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LM2575HVT-15 Flow LB03 |
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LM2575T-ADJ Flow LB03 |
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LM2575HVT-ADJ Flow LB03 |
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≤ TJ ≤ +125ÊC |
16-Pin Molded |
N16A |
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LM2575N-5.0 |
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LM2575HVN-5.0 |
−40ÊC |
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DIP |
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LM2575N-12 |
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LM2575HVN-12 |
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LM2575N-15 |
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LM2575HVN-15 |
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LM2575N-ADJ |
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LM2575HVN-ADJ |
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24-Pin |
M24B |
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LM2575M-5.0 |
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LM2575HVM-5.0 |
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Surface Mount |
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LM2575M-12 |
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LM2575HVM-12 |
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LM2575M-15 |
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LM2575HVM-15 |
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LM2575M-ADJ |
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LM2575HVM-ADJ |
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5-Lead TO-236 |
TS5B |
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LM2575S-3.3 |
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LM2575HVS-3.3 |
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Surface Mount |
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LM2575S-5.0 |
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LM2575HVS-5.0 |
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LM2575S-12 |
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LM2575HVS-12 |
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LM2575S-15 |
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LM2575HVS-15 |
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LM2575S-ADJ |
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LM2575HVS-ADJ |
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16-Pin Ceramic |
J16A |
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LM1575J-3.3-QML |
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DIP |
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LM1575J-5.0-QML |
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LM1575J-12-QML |
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−55ÊC |
≤ TJ ≤ +150ÊC |
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LM1575J-15-QML |
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LM1575J-ADJ-QML |
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3 |
www.national.com |
Absolute Maximum Ratings (Note 1)
If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/ Distributors for availability and specifications.
Maximum Supply Voltage |
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LM1575/LM2575 |
45V |
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LM2575HV |
63V |
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−0.3V ≤ V ≤ +VIN |
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ON |
/OFF Pin Input Voltage |
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Output Voltage to Ground |
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(Steady State) |
−1V |
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Power Dissipation |
Internally Limited |
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Storage Temperature Range |
−65ÊC to +150ÊC |
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Maximum Junction Temperature |
150ÊC |
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Minimum ESD Rating |
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(C = 100 pF, R = 1.5 kΩ) |
2 kV |
Lead Temperature |
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(Soldering, 10 sec.) |
260ÊC |
Operating Ratings
Temperature Range |
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LM1575 |
−55ÊC |
≤ TJ ≤ +150ÊC |
LM2575/LM2575HV |
−40ÊC |
≤ TJ ≤ +125ÊC |
Supply Voltage |
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LM1575/LM2575 |
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40V |
LM2575HV |
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60V |
LM1575-3.3, LM2575-3.3, LM2575HV-3.3 Electrical Characteristics
Specifications with standard type face are for TJ = 25ÊC, and those with boldface type apply over full Operating Temperature Range .
Symbol |
Parameter |
Conditions |
Typ |
LM1575-3.3 |
LM2575-3.3 |
Units |
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LM2575HV-3.3 |
(Limits) |
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Limit |
Limit |
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(Note 2) |
(Note 3) |
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SYSTEM PARAMETERS (Note 4) Test Circuit Figure 2 |
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VOUT |
Output Voltage |
VIN = 12V, ILOAD = 0.2A |
3.3 |
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V |
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Circuit of Figure 2 |
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3.267 |
3.234 |
V(Min) |
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3.333 |
3.366 |
V(Max) |
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VOUT |
Output Voltage |
4.75V ≤ VIN ≤ 40V, 0.2A ≤ ILOAD ≤ 1A |
3.3 |
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V |
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LM1575/LM2575 |
Circuit of Figure 2 |
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3.200/3.168 |
3.168/3.135 |
V(Min) |
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3.400/3.432 |
3.432/3.465 |
V(Max) |
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VOUT |
Output Voltage |
4.75V ≤ VIN ≤ 60V, 0.2A ≤ ILOAD ≤ 1A |
3.3 |
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V |
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LM2575HV |
Circuit of Figure 2 |
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3.200/3.168 |
3.168/3.135 |
V(Min) |
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3.416/3.450 |
3.450/3.482 |
V(Max) |
η |
Efficiency |
VIN = 12V, ILOAD = 1A |
75 |
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% |
LM1575-5.0, LM2575-5.0, LM2575HV-5.0 Electrical Characteristics
Specifications with standard type face are for TJ = 25ÊC, and those with boldface type apply over full Operating Temperature Range.
Symbol |
Parameter |
Conditions |
Typ |
LM1575-5.0 |
LM2575-5.0 |
Units |
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LM2575HV-5.0 |
(Limits) |
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Limit |
Limit |
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(Note 2) |
(Note 3) |
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SYSTEM PARAMETERS (Note 4) Test Circuit Figure 2 |
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VOUT |
Output Voltage |
VIN = 12V, ILOAD = 0.2A |
5.0 |
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V |
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Circuit of Figure 2 |
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4.950 |
4.900 |
V(Min) |
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5.050 |
5.100 |
V(Max) |
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VOUT |
Output Voltage |
0.2A ≤ ILOAD ≤ 1A, |
5.0 |
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V |
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LM1575/LM2575 |
8V ≤ VIN ≤ 40V |
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4.850/4.800 |
4.800/4.750 |
V(Min) |
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Circuit of Figure 2 |
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5.150/5.200 |
5.200/5.250 |
V(Max) |
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VOUT |
Output Voltage |
0.2A ≤ ILOAD ≤ 1A, |
5.0 |
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V |
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LM2575HV |
8V ≤ VIN ≤ 60V |
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4.850/4.800 |
4.800/4.750 |
V(Min) |
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Circuit of Figure 2 |
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5.175/5.225 |
5.225/5.275 |
V(Max) |
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η |
Efficiency |
VIN = 12V, ILOAD = 1A |
77 |
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% |
www.national.com |
4 |
LM1575-12, LM2575-12, LM2575HV-12 Electrical Characteristics
Specifications with standard type face are for TJ = 25ÊC, and those with boldface type apply over full Operating Temperature Range .
Symbol |
Parameter |
Conditions |
Typ |
LM1575-12 |
LM2575-12 |
Units |
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LM2575HV-12 |
(Limits) |
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Limit |
Limit |
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(Note 2) |
(Note 3) |
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SYSTEM PARAMETERS (Note 4) Test Circuit Figure 2 |
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VOUT |
Output Voltage |
VIN = 25V, ILOAD = 0.2A |
12 |
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V |
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Circuit of Figure 2 |
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11.88 |
11.76 |
V(Min) |
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12.12 |
12.24 |
V(Max) |
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VOUT |
Output Voltage |
0.2A ≤ ILOAD ≤ 1A, |
12 |
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V |
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LM1575/LM2575 |
15V ≤ VIN ≤ 40V |
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11.64/11.52 |
11.52/11.40 |
V(Min) |
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Circuit of Figure 2 |
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12.36/12.48 |
12.48/12.60 |
V(Max) |
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VOUT |
Output Voltage |
0.2A ≤ ILOAD ≤ 1A, |
12 |
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V |
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LM2575HV |
15V ≤ VIN ≤ 60V |
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11.64/11.52 |
11.52/11.40 |
V(Min) |
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Circuit of Figure 2 |
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12.42/12.54 |
12.54/12.66 |
V(Max) |
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η |
Efficiency |
VIN = 15V, ILOAD = 1A |
88 |
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LM1575-15, LM2575-15, LM2575HV-15 Electrical Characteristics
Specifications with standard type face are for TJ = 25ÊC, and those with boldface type apply over full Operating Temperature Range .
Symbol |
Parameter |
Conditions |
Typ |
LM1575-15 |
LM2575-15 |
Units |
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LM2575HV-15 |
(Limits) |
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Limit |
Limit |
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(Note 2) |
(Note 3) |
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SYSTEM PARAMETERS (Note 4) Test Circuit Figure 2 |
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VOUT |
Output Voltage |
VIN = 30V, ILOAD = 0.2A |
15 |
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V |
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Circuit of Figure 2 |
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14.85 |
14.70 |
V(Min) |
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15.15 |
15.30 |
V(Max) |
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VOUT |
Output Voltage |
0.2A ≤ ILOAD ≤ 1A, |
15 |
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V |
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LM1575/LM2575 |
18V ≤ VIN ≤ 40V |
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14.55/14.40 |
14.40/14.25 |
V(Min) |
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Circuit of Figure 2 |
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15.45/15.60 |
15.60/15.75 |
V(Max) |
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VOUT |
Output Voltage |
0.2A ≤ ILOAD ≤ 1A, |
15 |
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V |
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LM2575HV |
18V ≤ VIN ≤ 60V |
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14.55/14.40 |
14.40/14.25 |
V(Min) |
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Circuit of Figure 2 |
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15.525/15.675 |
15.68/15.83 |
V(Max) |
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η |
Efficiency |
VIN = 18V, ILOAD = 1A |
88 |
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% |
LM1575-ADJ, LM2575-ADJ, LM2575HV-ADJ Electrical Characteristics
Specifications with standard type face are for TJ= 25ÊC, and those with boldface type apply over full Operating Temperature Range.
Symbol |
Parameter |
Conditions |
Typ |
LM1575-ADJ |
LM2575-ADJ |
Units |
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LM2575HV-ADJ |
(Limits) |
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Limit |
Limit |
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(Note 2) |
(Note 3) |
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SYSTEM PARAMETERS (Note 4) Test Circuit Figure 2 |
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VOUT |
Feedback Voltage |
VIN = 12V, ILOAD = 0.2A |
1.230 |
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V |
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VOUT = 5V |
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1.217 |
1.217 |
V(Min) |
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Circuit of Figure 2 |
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1.243 |
1.243 |
V(Max) |
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5 |
www.national.com |
LM1575-ADJ, LM2575-ADJ, LM2575HV-ADJ
Electrical Characteristics (Continued)
Specifications with standard type face are for TJ= 25ÊC, and those with boldface type apply over full Operating Temperature Range.
Symbol |
Parameter |
Conditions |
Typ |
LM1575-ADJ |
LM2575-ADJ |
Units |
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LM2575HV-ADJ |
(Limits) |
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Limit |
Limit |
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(Note 2) |
(Note 3) |
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SYSTEM PARAMETERS (Note 4) Test Circuit Figure 2 |
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VOUT |
Feedback Voltage |
0.2A ≤ ILOAD ≤ 1A, |
1.230 |
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V |
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LM1575/LM2575 |
8V ≤ VIN ≤ 40V |
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1.205/1.193 |
1.193/1.180 |
V(Min) |
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VOUT = 5V, Circuit of Figure 2 |
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1.255/1.267 |
1.267/1.280 |
V(Max) |
VOUT |
Feedback Voltage |
0.2A ≤ ILOAD ≤ 1A, |
1.230 |
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V |
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LM2575HV |
8V ≤ VIN ≤ 60V |
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1.205/1.193 |
1.193/1.180 |
V(Min) |
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VOUT = 5V, Circuit of Figure 2 |
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1.261/1.273 |
1.273/1.286 |
V(Max) |
η |
Efficiency |
VIN = 12V, ILOAD = 1A, VOUT = 5V |
77 |
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% |
All Output Voltage Versions Electrical Characteristics
Specifications with standard type face are for TJ = 25ÊC, and those with boldface type apply over full Operating Temperature Range. Unless otherwise specified, VIN = 12V for the 3.3V, 5V, and Adjustable version, VIN = 25V for the 12V version, and VIN = 30V for the 15V version. ILOAD = 200 mA.
Symbol |
Parameter |
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Conditions |
Typ |
LM1575-XX |
LM2575-XX |
Units |
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LM2575HV-XX |
(Limits) |
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Limit |
Limit |
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(Note 2) |
(Note 3) |
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DEVICE PARAMETERS |
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Ib |
Feedback Bias |
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VOUT = 5V (Adjustable Version Only) |
50 |
100/500 |
100/500 |
nA |
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Current |
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fO |
Oscillator Frequency |
(Note 13) |
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52 |
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kHz |
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47/43 |
47/42 |
kHz(Min) |
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58/62 |
58/63 |
kHz(Max) |
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VSAT |
Saturation Voltage |
IOUT = 1A (Note 5) |
0.9 |
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V |
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1.2/1.4 |
1.2/1.4 |
V(Max) |
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DC |
Max Duty Cycle (ON) |
(Note 6) |
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98 |
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% |
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93 |
93 |
%(Min) |
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ICL |
Current Limit |
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Peak Current (Notes 5, 13) |
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A(Max) |
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Output Leakage |
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mA(Max) |
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Current |
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Output = −1V |
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mA |
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Output = −1V |
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30 |
30 |
mA(Max) |
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IQ |
Quiescent Current |
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mA(Max) |
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ISTBY |
Standby Quiescent |
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µA(Max) |
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θJA |
Thermal Resistance |
T Package, Junction to Ambient (Note 9) |
65 |
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T Package, Junction to Ambient (Note 10) |
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θJC |
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T Package, Junction to Case |
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N Package, Junction to Ambient (Note 11) |
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M Package, Junction to Ambient (Note 11) |
100 |
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S Package, Junction to Ambient (Note 12) |
37 |
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www.national.com |
6 |
All Output Voltage Versions
Electrical Characteristics (Continued)
Specifications with standard type face are for TJ = 25ÊC, and those with boldface type apply over full Operating Temperature Range. Unless otherwise specified, VIN = 12V for the 3.3V, 5V, and Adjustable version, VIN = 25V for the 12V version, and VIN = 30V for the 15V version. ILOAD = 200 mA.
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Typ |
LM1575-XX |
LM2575-XX |
Units |
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LM2575HV-XX |
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Limit |
Limit |
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(Note 2) |
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/OFF CONTROL Test Circuit Figure 2 |
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/OFF Pin Logic |
VOUT = 0V |
1.4 |
2.2/2.4 |
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V(Min) |
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VIL |
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Input Level |
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VOUT = Nominal Output Voltage |
1.2 |
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IIH |
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/OFF Pin Input |
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Current |
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µA(Max) |
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IIL |
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/OFF Pin = 0V (ON) |
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µA(Max) |
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Note 1: Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. 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.
Note 2: All limits guaranteed at room temperature (standard type face) and at temperature extremes (bold type face). All limts are used to calculate Average Outgoing Quality Level, and all are 100% production tested.
Note 3: All limits guaranteed at room temperature (standard type face) and at temperature extremes (bold type face). All room temperature limits are 100% production tested. All limits at temperature extremes are guaranteed via correlation using standard Statistical Quality Control (SQC) methods.
Note 4: External components such as the catch diode, inductor, input and output capacitors can affect switching regulator system performance. When the LM1575/ LM2575 is used as shown in the Figure 2 test circuit, system performance will be as shown in system parameters section of Electrical Characteristics.
Note 5: Output (pin 2) sourcing current. No diode, inductor or capacitor connected to output pin.
Note 6: Feedback (pin 4) removed from output and connected to 0V.
Note 7: Feedback (pin 4) removed from output and connected to +12V for the Adjustable, 3.3V, and 5V versions, and +25V for the 12V and 15V versions, to force the output transistor OFF.
Note 8: VIN = 40V (60V for the high voltage version).
Note 9: Junction to ambient thermal resistance (no external heat sink) for the 5 lead TO-220 package mounted vertically, with 1¤2 inch leads in a socket, or on a PC board with minimum copper area.
Note 10: Junction to ambient thermal resistance (no external heat sink) for the 5 lead TO-220 package mounted vertically, with 1¤2 inch leads soldered to a PC board containing approximately 4 square inches of copper area surrounding the leads.
Note 11: Junction to ambient thermal resistance with approxmiately 1 square inch of pc board copper surrounding the leads. Additional copper area will lower thermal resistance further. See thermal model in Switchers made Simple software.
Note 12: If the TO-263 package is used, the thermal resistance can be reduced by increasing the PC board copper area thermally connected to the package: Using 0.5 square inches of copper area, θJA is 50ÊC/W; with 1 square inch of copper area, θJA is 37ÊC/W; and with 1.6 or more square inches of copper area, θJA is 32ÊC/W.
Note 13: The oscillator frequency reduces to approximately 18 kHz in the event of an output short or an overload which causes the regulated output voltage to drop approximately 40% from the nominal output voltage. This self protection feature lowers the average power dissipation of the IC by lowering the minimum duty cycle from 5% down to approximately 2%.
Note 14: Refer to RETS LM1575J for current revision of military RETS/SMD.
Typical Performance Characteristics (Circuit of Figure 2)
Normalized Output Voltage |
Line Regulation |
Dropout Voltage |
DS011475-32 |
DS011475-33 |
DS011475-34 |
7 |
www.national.com |
Typical Performance Characteristics (Circuit of Figure 2) (Continued)
Current Limit |
Quiescent Current |
Standby |
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Quiescent Current |
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DS011475-35 |
DS011475-36 |
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DS011475-37 |
Oscillator Frequency |
Switch Saturation |
Efficiency |
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Voltage |
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DS011475-38 |
DS011475-40 |
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DS011475-39 |
Minimum Operating Voltage |
Quiescent Current |
Feedback Voltage |
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vs Duty Cycle |
vs Duty Cycle |
DS011475-41
DS011475-42 |
DS011475-43 |
www.national.com |
8 |
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