LM2596 IC LM2596T Adjustable LM2596 Voltage Regulator Buck IC Input 40V Output Fixed 37V Step Down Voltage Regulator IC 5 Pin Leads TO-220-5 Switching Voltage Regulator

Description: LM2596 Adjustable Voltage Regulator

LM2596 IC LM2596T Adjustable LM2596 Voltage Regulator Buck IC Input 40V Output Fixed 37V Step Down Voltage Regulator IC 5 Pin Leads TO-220-5 Switching Voltage Regulator

The LM2596 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 3.0 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 LM2596 are offered by several different inductor manufacturers. Since the LM2596 converter is a switch−mode power supply, its efficiency is significantly higher in comparison with popular three−terminal linear regulators, espely with higher input voltages.

In many cases, the power dissipated is so low that no heatsink is required or its size could be reduced dramatically. A standard series of inductors optimized for use with the LM2596 are available from several different manufacturers. This feature greatly simplifies the design of switch−mode power supplies.

The LM2596 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 80 A (typical) standby current. The output switch includes cycle−by−cycle current limiting, as well as thermal shutdown for full protection under fault conditions.

Features:

• Adjustable Version Output Voltage Range,1.23V to 37V (57V for HV Version) ±4% Max Over Line and Load Conditions
• Specified 3A Output Current
• Wide Input Voltage Range, 40V Up to 60V for HV Version
• 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

Specification:

• Adjustable Output Voltage: Range,1.23V to 37V
• ±4% Max Over Line and Load Conditions
• Specified 3A Output Current
• Wide Input Voltage Range upto 40V
• Requires Only 4 External Components
• 52 kHz Fixed Frequency Internal Oscillator
• TTL Shutdown Capability
• Low Power Standby mode
• High Efficiency
• Thermal Shutdown and Current Limit Protection.

Equivalent for LM2596

LM2576, BD9876, ACT4523

Alternative Switching Regulators

XL6009, TPS5430, MC34063

LM2596 Introduction 

The LM2596 is known for its high current rating of 3A. It is available in many versions with fixed output voltage like 3.3V, 5V and 12V. But, the most famous one is the LM2596-ADJ which has variable output voltage. The IC is basically a buck converter that operates on 150KHz switching frequency, it takes in an input voltage and uses the internal switching circuit to regulated a desired output voltage. It has high efficiency and in-built Thermal shutdown and current limit functionalities. So if you are looking for a small high package, easy to use high current buck converter IC then LM2596 might me the right choice for you.

How to use the LM2596 Regulator

The LM2596 is very easy to use because it requires very minimum number of components. The unregulated voltage is given to pin 1 (Vin) across a filter capacitor to reduce input noise. The ON/OFF or enable pin (pin 5) should be connected to ground to enable the IC. If made high the IC will enter shutdown mode and prevent leakage current. This feature will be useful to save input power when operating via battery. The feedback pin is the important pin which sets the output voltage. It sense the output voltage and based on the value of this output voltage the switching frequency of the internal switch is adjusted to provide the desired output voltage. Finally the output voltage is obtained through pin 2 through an LC filter. The complete circuit diagram is given below, you can often find these circuit in the LM2596 DC Converter module.

Calculating output voltage for LM2596

As told earlier the output voltage of the LM2596-ADJ can be controlled by using the feedback pin. The aboce circuit diagram shows the feedback pin getting the feedback voltage from a voltage divider circuit formed with Resistors R1 and R2. The value of this R1 and R2 decides the output voltage of the IC. The formula to calculate R1 and R2 is given below.

V_out = V_ref (1.0 + R2/R1)

Here the value of Vref can be considered as 1.23V hence the formula becomes Vout = 1.23*(1+(R2/R1)), where the value of R1 should be between 1k to 5k. It is also possible to use a variable resistor in place of R1 to control the output voltage. This makes the IC easier to use in Variable power supply circuits.

Application:

• Simple High-Efficiency Step-Down (Buck) Regulator
• Efficient Pre-Regulator for Linear Regulators
• On-Card Switching Regulators
• Positive to Negative Converter (Buck-Boost)

Package Include:

• 1 x LM2596T LM2596 LM 2596 Adjustable Voltage Regulator Buck IC Max Input 40V Max Output Fixed 37V Step Down Voltage Regulator IC 5 Pin TO-220-5 Switching Voltage Regulator