I already had some 5V 7805 TO-220 regulators (10 for a quid off eBay), see spec sheet, but I subsequently realised that I needed some 3V3 regulators for my XBee (and Raspberry Pi)  circuits.

However, which ones should I choose?

Options available

A quick google search revealed a number of options. The most similar seemed the LD1117V33 (COM 00526), which was in a TO-220 package. However, there was also the 5 pin LM2596. What was the difference and why the increased number of pins?

The principle difference is that the LM25xx series is a more efficient, switching regulator, whereas the LD1117 is the usual linear (non-switching) type. The additional two pins of the 25xx are used for ON/OFF control and feedback.

There are, as well, the following regulators:


The cheapest 1117V33 at £2.17 for 10, was the 10pcs LM1117T-3.3 LM1117T LD1117 3.3V TO-220 Voltage Regulator HW

The cheapest LM2596 at £1.81 for 10, was the 10PCS IC LM2596T-3.3 LM2596 NSC TO-220 Voltage Regulator 3A 3.3V NEW


An interesting article on building your own 5V regulator, from instructables, The Introduction of LM2596 Step Down Power Module DC …


Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s