Help identify SOT23-5 marked LAD - Page 1
Forum section: electronics / repair

author: geeja
author_rank: Newbie
timestamp: June 01, 2015, 08:52:42 pm
content: I'm trying to find the part number for this 5 pin SOT23. It is marked as LAD. I think it's an Analog Devices or TI voltage regulator.

author: mengfei
author_rank: Regular Contributor
timestamp: June 02, 2015, 03:50:33 am
content: check out the link, hope it's therehttp://www.digikey.hk/Web%20Export/Supplier%20Content/MCC_353/PDF/MCC_SMD_Marking_Codes.pdf?redirected=1

author: geeja
author_rank: Newbie
timestamp: June 02, 2015, 02:01:31 pm
content: Quote from: mengfei on June 02, 2015, 03:50:33 amunfortunately that's just for MCC parts.

author: bktemp
author_rank: Super Contributor
timestamp: June 02, 2015, 02:05:02 pm
content: TI has a LADQ marked device:http://www.ti.com/product/lmv331-q1

author: wraper
author_rank: Unknown
timestamp: June 02, 2015, 02:53:11 pm
content: Don't know what it is but seem to available for purchasehttp://www.aliexpress.com/store/product/MARKING-CODE-SMD-5pin-LAD-SOT23-5-PACKING/1747258_32295379429.html

author: geeja
author_rank: Newbie
timestamp: June 02, 2015, 03:33:50 pm
content: Here's some more info I've measured on a working unit.pin#1: 5v2: GND3: 3.3v4,5 : 1.8vpins 4 and 5 are shorted together which is odd. Seems like a 1.8v voltage regulator with enable but 4 and 5 shouldn't be shorted together.The marking seems to follow TI or Analog Devices convention, but the TI mark search for LAD turns up no match.

author: bktemp
author_rank: Super Contributor
timestamp: June 02, 2015, 03:53:04 pm
content: The TI marking search gives a a few matches, but only one with SOT23-5, but it is marked LADQ. Therefore it is probably not a TI part.I tried a few other marking code searches, but all show the same part.Could it be a voltage supervisor? Then the shorted pins could make sense (disabled external reset input).Voltage supervisor ics have a different marking for each voltage variant and are therefore rarely listet on marking code sites because a single ic would fill a whole page with all its variants.

author: wraper
author_rank: Unknown
timestamp: June 02, 2015, 03:57:40 pm
content: Quote from: geeja on June 02, 2015, 03:33:50 pmAre you sure that pins 4 and 5 are shorted, not just same voltage? Some regulators have pin 4 as power good output with open drain which is then connected with resistor to Vout. Many regulators have pin 4 as NC, somebody could decide to connect it to Vout for some reason too.

author: geeja
author_rank: Newbie
timestamp: June 02, 2015, 05:17:16 pm
content: Yes, 4 and 5 definitely shorted together. Measured the board with and without chip installed.

author: bingo600
author_rank: Super Contributor
timestamp: June 02, 2015, 05:44:29 pm
content: These are the ones i have in the smd book/Bingo

author: geeja
author_rank: Newbie
timestamp: June 08, 2015, 08:39:13 pm
content: Unfortunately, none of the above looks right, still think it's an Analog Devices part, does anyone have an Analog Devices lookup?

author: arny
author_rank: Newbie
timestamp: June 09, 2015, 08:25:16 pm
content: check this outhttp://datasheetz.com/data/Integrated%20Circuits%20%28ICs%29/Voltage%20Regulators%20-%20Linear/NCP561SN15T1OSCT-datasheetz.html

author: c4757p
author_rank: Super Contributor
timestamp: June 09, 2015, 08:33:45 pm
content: Quote from: geeja on June 08, 2015, 08:39:13 pmwhy?

author: geeja
author_rank: Newbie
timestamp: June 09, 2015, 10:33:18 pm
content: Thanks to everyone that replied. I found it,http://www.analog.com/en/products/power-management/linear-regulators/adp2108.htmlI saw that there was an inductor and cap hanging on what should be an output pin 1 and started looking at Analog Devices switching regulators and found it.