LM2596 SIMPLE SWITCHER® Power Converter 150 kHz 3A Step-Down
Voltage Regulator
FEATURES
- 3.3V, 5V, 12V, and Adjustable Output Versions
- Adjustable Version Output Voltage Range, 1.2V to 37V ±4% Max Over
Line and Load Conditions
- Available in TO-220 and TO-263 Packages
- Ensured 3A Output Load Current
- Input Voltage Range Up to 40V
- Requires Only 4 External Components
- Excellent Line and Load Regulation Specifications
- 150 kHz Fixed Frequency Internal Oscillator
- TTL Shutdown Capability
- Low Power Standby Mode, IQ Typically 80 μA
- High Efficiency
- Uses Readily Available Standard Inductors
- Thermal Shutdown and Current Limit Protection
APPLICATIONS
- Simple High-Efficiency Step-Down (Buck) Regulator
- On-Card Switching Regulators
- Positive to Negative Converter
DESCRIPTION
The LM2596 series of regulators are monolithic integrated circuits
that provide all the active functions for a step-down (buck)
switching regulator, capable of driving a 3A load with excellent
line and load regulation. These devices are available in fixed
output voltages of 3.3V, 5V, 12V, 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 LM2596 series operates at a switching frequency of 150 kHz thus
allowing smaller sized filter components than what would be needed
with lower frequency switching regulators. Available in a
standard 5-lead TO-220 package with several different lead bend
options, and a 5-lead TO-263 surface mount package.
A standard series of inductors are available from several different
manufacturers optimized for use with the LM2596 series. This
feature greatly simplifies the design of switch-mode power
supplies.
Other features include a ensured ±4% tolerance on output voltage
under specified input voltage and output load conditions, and ±15%
on the oscillator frequency. External shutdown is included,
featuring typically 80 μA standby current. Self protection features
include a two stage frequency reducing current limit for the output
switch and an over temperature shutdown for complete protection
under fault conditions. (1)
(1) † Patent Number 5,382,918.
Absolute Maximum Ratings (1)(2)
| Maximum Supply Voltage | 45V |
| ON /OFF Pin Input Voltage | −0.3 ≤ V ≤ +25V |
| Feedback Pin Voltage | −0.3 ≤ V ≤+25V |
| Output Voltage to Ground (Steady State) | −1V |
| Power Dissipation | Internally limited |
| Storage Temperature Range | −65°C to +150°C |
| ESD Susceptibility |
| Human Body Model (3) | 2 kV |
| Lead Temperature |
| DDPAK/TO-263 Package |
| Vapor Phase (60 sec.) | +215°C |
| Infrared (10 sec.) | +245°C |
| TO-220 Package (Soldering, 10 sec.) | +260°C |
| Maximum Junction Temperature | +150°C |
(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 ensure
specific performance limits.
(2) If Military/Aerospace specified devices are required, please
contact the Texas Instruments Sales Office/ Distributors for
availability and specifications.
(3) The human body model is a 100 pF capacitor discharged through a
1.5k resistor into each pin.
Operating Conditions
| Temperature Range | −40°C ≤ TJ ≤ +125°C |
| Supply Voltage | 4.5V to 40V |
Typical Application
(Fixed Output Voltage Versions)
Connection Diagrams
Figure 1. 5-Lead Bent and Staggered Leads, Through Hole TO-220 (T)
Package
Figure 2. 5-Lead DDPAK/TO-263 (S) Package
These devices have limited built-in ESD protection. The leads
should be shorted together or the device placed in conductive foam
during storage or handling to prevent electrostatic damage to the
MOS gates.
