I did run the same module in a power LED project before a few weeks and found it’s good for that application. Honestly, it depends on the design of the module and its supporting components. Besides, the Schottky diode recommended should have a 3A rating, but looking at the SS34 diode’s dimension it seems like a bogus part rated for 1A only – probably a relabelled SS14 Schottky diode. And, certainly, a heatsink is a must for continuous operation at over 1.5A is mandatory.Ī quick physical inspection shows the regulator chip at the core is one LM2596S -ADJ with the familiar NSC logo but feels like a counterfeit product – wasn’t NSC took over by TI before a long time?Īnother noticeable thing while referring back to the official reference diagram is the value of the inductor – it’s 47uH not 33uH. Given the component values used in my module (10KΩ/2 trimpot and 330Ω resistor) the output voltage can be regulated between 1.23V to 20V only. But the recommended capacitor is present on my module.įor LM2596, the output voltage is determined by the equation Vo = 1.23(R2/R1 +1). The Schottky diode is SS34, and the inductor is a 47uH SMD.Īccording to the datasheet, a feedforward capacitor (C FF) is needed in parallel of R2 (here the trimpot) when the output voltage is greater than 10V to ensure stability. In my module (HW-411) the input capacitor is 50V rated, and the output capacitor is a 35V type. Below is the reverse-engineered basic schematic of the particular LM2596S module I bought from a Chinese online store. but it’s mostly based on the typical application circuit (shown above). In my module, however, it appears that there’re a couple of disparities to the reference design – slightly different inductor value, capacitor voltage rating, etc. Thermal Shutdown and Current Limit Protection.150 kHz Fixed Frequency Internal Oscillator.Adjustable Output Voltage Range 1.23 V − 37 V.Electronics insightĪccording to ON Semiconductor’s ( ) LM2596 datasheet, the LM2596 regulator is a monolithic integrated circuit, operates at a switching frequency of 150 kHz, capable of driving a 3.0 A load with excellent line and load regulation. The lowest output voltage is approximately 1.25V while the upper limit of the scale will rest on the actual input voltage and is typically about 1.5V less than the input voltage. Turning the trimpot clockwise (CW) increases the output voltage while turning it counter-clockwise (CCW) decreases the output voltage. There is also a large white arrow (conversion direction and polarity) on the back of the module to help you get it right. With the silkscreen right-side-up, the input solder pads will be on the left side.

The module itself, true to its word is compact – with input power applied to one end and output power available on another end. Output current up to 3A (additional heatsink is required).Short circuit protection (current limiting).Multi-turn trimpot for adjustment of the output voltage.Here’re some quick pointers that will (hopefully) help you get it right! Impressive claimsĪccording to one eBay seller’s description, the LM2596S Adjustable DC-DC Step-Down Module can step-down the input voltage to a range of 1.25 – 35V at up to 3A (1.5A continuous). When using this minuscule dc-dc buck (stepdown) converter modules, it’s important to consider what components are at play and reduce the number of possible causes of catastrophic failures out of the blue. I too have more than a dozen of these blue modules. You can buy this module from electronics web stores very cheaply. The most popular module still widely available is one with the LM2596S adjustable regulator, it’s a pretty old design, though. There are different types of cheap Chinese dc-dc buck converter modules.

Lm2596 dc dc