Help identifying this part - 1178H - Page 1
Forum section: electronics / repair

author: daisizhou
author_rank: Super Contributor
timestamp: September 06, 2024, 05:03:09 pm
content: Hallo everyoneI don't know what model this patch represents, I saw the mark is "1178H"。If you know please tell me, thanks

author: fzabkar
author_rank: Super Contributor
timestamp: September 06, 2024, 07:54:15 pm
content: Can you provide some context? What are the surrounding components? Is the "8" likely to be a year code? Can you identify the Vcc and Ground pins?

author: daisizhou
author_rank: Super Contributor
timestamp: September 06, 2024, 09:34:32 pm
content: Quote from: fzabkar on September 06, 2024, 07:54:15 pmThe middle is connected to VCC and GND, and the other pins are connected to the inductor. Please see the figure below.Looks like a DC/DC control chip.

author: fzabkar
author_rank: Super Contributor
timestamp: September 06, 2024, 09:51:31 pm
content: The IC appears to be driving 4 inductors, but there are no feedback pins. :-?

author: daisizhou
author_rank: Super Contributor
timestamp: September 06, 2024, 10:34:13 pm
content: Quote from: fzabkar on September 06, 2024, 09:51:31 pmIt looks like the 4 inductors connected to it are connected to the output jackEach of these chips is always connected to 6 inductors, see the figure below.

author: fzabkar
author_rank: Super Contributor
timestamp: September 06, 2024, 11:14:54 pm
content: Could it be an ESD protection diode array?

author: daisizhou
author_rank: Super Contributor
timestamp: September 06, 2024, 11:18:08 pm
content: It looks like a 74HC4052D driving 1178H.ESD Protection Diode Array How do I confirm it?Should I disassemble a normal 1178H for measurement?

author: daisizhou
author_rank: Super Contributor
timestamp: September 06, 2024, 11:24:34 pm
content: Quote from: fzabkar on September 06, 2024, 11:14:54 pmThis is the actual connection after I measured it

author: daisizhou
author_rank: Super Contributor
timestamp: September 06, 2024, 11:46:55 pm
content: Each 1178H is always connected like this.VCC and GND are connected to a "3CWU" component, which looks like a voltage-stabilizing transistor.

author: fzabkar
author_rank: Super Contributor
timestamp: September 07, 2024, 12:01:06 am
content: 3.0SMJC series are TVS diodes.https://www.mouser.com/datasheet/2/1057/3_0SMCJ_SERIES-1865170.pdf

author: daisizhou
author_rank: Super Contributor
timestamp: September 07, 2024, 12:16:21 am
content: Quote from: fzabkar on September 07, 2024, 12:01:06 amPlease see the picture

author: fzabkar
author_rank: Super Contributor
timestamp: September 07, 2024, 12:22:49 am
content: It appears to be a fixed 3-terminal 3.3V linear regulator. The pinout from left to right appears to be Ground, Vin, Vout.

author: daisizhou
author_rank: Super Contributor
timestamp: September 07, 2024, 12:33:15 am
content: Very true.I found that the output port and GND resistance is only 15 ohms.I uninstalled the 1178H and the 15 ohm disappeared.Finally 1178H is damaged,But I still don't know what the exact model of 1178H is

author: fzabkar
author_rank: Super Contributor
timestamp: September 07, 2024, 12:49:53 am
content: What is the device and what is the output port connected to?

author: daisizhou
author_rank: Super Contributor
timestamp: September 07, 2024, 01:50:06 am
content: Quote from: fzabkar on September 07, 2024, 12:49:53 amThe sensor is connected.I don't know the details, because I didn't see the sensor appear, only the sensor interface

author: daisizhou
author_rank: Super Contributor
timestamp: September 07, 2024, 02:49:03 am
content: Quote from: fzabkar on September 06, 2024, 11:14:54 pmI separated a normal 1178H from the PCB.Use the diode range of a digital multimeter to measure each pin separately. The values ​​are shown in the figure below.

author: fzabkar
author_rank: Super Contributor
timestamp: September 07, 2024, 03:10:41 am
content: Similar to this?https://www.ti.com/lit/ds/symlink/tpd4s009.pdfBTW, could the device be an ECG? That could explain the "SKIN" on the PCB.

author: daisizhou
author_rank: Super Contributor
timestamp: September 07, 2024, 03:17:43 am
content: Quote from: fzabkar on September 07, 2024, 03:10:41 amhttps://www.flukebiomedical.com/products/biomedical-test-equipment/incubator-radiant-warmer-analyzersThis is the host introduction.The 5 interfaces below the display are connected to the 1178H

author: daisizhou
author_rank: Super Contributor
timestamp: September 07, 2024, 03:20:29 am
content: Quote from: fzabkar on September 07, 2024, 03:10:41 amBut there is another 3.3v DC voltage coming in,It turns out that the 1178H is short-circuited because the vcc3.3v port and GND are broken down.I don't see any power supply in your schematic.

author: fzabkar
author_rank: Super Contributor
timestamp: September 07, 2024, 03:22:06 am
content: You have some interesting jobs.

author: daisizhou
author_rank: Super Contributor
timestamp: September 07, 2024, 04:31:27 am
content: Quote from: fzabkar on September 07, 2024, 03:22:06 amThanks.I am more interested in simulators and analyzers in the biomedical field

author: daisizhou
author_rank: Super Contributor
timestamp: September 07, 2024, 04:34:30 am
content: Can't find the same 1178H, can only choose the alternative shown in the figure below