LDO opinion - Page 1
Forum section: electronics / projects

author: mojoe
author_rank: Frequent Contributor
timestamp: September 10, 2025, 07:53:50 pm
content: Has anyone used these:https://www.ldovr.com/TPS7A4700-Ultra-Low-Noise-LDO-Voltage-Regulator-p/tps7a4700-78xxg.htmAny opinion on actual performance? Are there any less expensive alternatives in the same form factor?Alternately, are there any small, complete DC-DC 12 V supplies with low noise and LDO for a small price? 1-2 A would be ideal. I want to power something from a 12 V LiFePo4 battery, and need a fairly tight 12 V output.

author: Uunoctium
author_rank: Frequent Contributor
timestamp: September 10, 2025, 08:55:12 pm
content: 12V in, 12V out means zero drop - that seems difficult to find.And no, had no experience with TPS7Axxx.Alternatives are LT3042 and LT3045 (42=200mA, 45 =500mA max). I tried - strong oriented at datasheets recommendtion - the power-boost circuit with additional PNP in two different layouts, but failed. Application needs 3..5V out, preregulated, into a 100mA load at end of 10 meter cable. I was unable to get the circuit stable, unwanted hefty oscillations at aproxx 55kHz occured sporadic.LT1963AEQ (adjustable) is an 1.5A LDO available in TO220, TO263, 3-pin SOT and TSOP and a dozen of other variants with fixed outputs from 1.5 to xx Volts. Input limit is at 20V.Mouser canceled my order and stopped the delivery with the reason, that AD would prohibit it. Digikey not.Ordered 38 pcs in TO220 & 263, a couple of them full assembled from Alliexpress - half of with heatsink.First batch arrived today and in the next days i will test them in my application on a protoboard setup.

author: langwadt
author_rank: Super Contributor
timestamp: September 10, 2025, 08:58:10 pm
content: Quote from: Uunoctium on September 10, 2025, 08:55:12 pmhttps://footprinthero.com/wp-content/uploads/2022/05/LiFePO4-Battery-Voltage-Charts-Image-8.jpg

author: mojoe
author_rank: Frequent Contributor
timestamp: September 10, 2025, 10:21:09 pm
content: LT1863AEQ - I can't find anything at Mouser with that part number, or even searching the web. Got a link?

author: Uunoctium
author_rank: Frequent Contributor
timestamp: September 11, 2025, 03:51:12 am
content: Sorry, that's the second mistake I've made while typing. It should of course be LT1963.I've corrected it above.https://www2.mouser.com/c/?q=LT%201963%20AEQ&_gl=1%2Apvpf5a%2A_ga%2AdW5kZWZpbmVk%2A_ga_15W4STQT4T%2AdW5kZWZpbmVk%2A_ga_1KQLCYKRX3%2AdW5kZWZpbmVk

author: Uunoctium
author_rank: Frequent Contributor
timestamp: September 11, 2025, 01:08:21 pm
content: Brief interim report: works as expected. Like a drop-in for 78xx.The assembled boards are adjusted for 5V out; R2=1500Ohm, R1=470. Easy to convert for own requirements. Formula in datasheet

author: mojoe
author_rank: Frequent Contributor
timestamp: September 12, 2025, 07:44:45 am
content: What boards are you referring to? Did you make some?

author: Uunoctium
author_rank: Frequent Contributor
timestamp: September 12, 2025, 08:11:13 am
content: For testing purposes i used readymade boards from Aliexpress.Desingn an own PCB follows nexthttps://de.aliexpress.com/item/1005005887238866.html?