What is a latch-up and how to prevent it? | Forum for Electronics
WEBJan 16, 2005 · Strictly speaking, latch-up is a process of firing up a parasitic thyristor formed by juctions n+/substaret/nwell/p+. In a commonly used layout slang, latch-up is a substrate or nwell tie used to prevent the firing up of the parasitic thyristor. This tie prevents the junctions to become forward biased. Jan 24, 2005. #3.
How to implement "latch-up" guard rings and prevent parasitic …
WEBJan 17, 2013 · I am trying to create latch-up guard rings for IO "low-side" BJT_36V and HVNMOS_36V according to TSMC BCD 0.18 design rule. And there is a requirement of design rule to keep huge space between two Nwells connected to two different pads to prevent parasitic NPN.
help needed on MCU "latch up" - Forum for Electronics
WEBFeb 15, 2002 · Added after 7 minutes: ravimarcus said: MCU latch up can occur due to EMI, RFI and noise. If the MCU has a WDT, it is better to enable it so that when a latch up occurs, the WDT will reset the uC and the uC can start executing the code again. Cheers. Ravi. thank you! the WDT is already enabled in the code,.
how guard ring prevent latch up | Forum for Electronics
WEBJan 17, 2013 · 1,308. Location. United States. Activity points. 2,713. You will always have the parasitic bjt's, guard rings try to minimize the chances of turning on these bjts which result in latch up. consider you get a esd current spike, and you sink that current into your nwell, via a protection diode.
Latchup prevention using Deep Nwell - Forum for Electronics
WEBMay 5, 2017 · Never seen Deep Nwell process option mentioned for latchup prevention. It's good for isolation from substrate, by this achieves substrate noise reduction of -50dB .. -35dB for LF up to ≈ 100MHz, lower flicker noise for BJTs, and better RF transistors (lower parasitic substrate capacitances). Moreover, additional useful - otherwise called ...
Explanation of Latch-up in MOSFET gate driver
WEBOct 25, 2008 · Latchup is triggered by forward biasing IC junctions that are part of parasitic (unwanted but unavoidable) thyristor structures. The text/example is talking about latch-up and the risk of overvoltage. It says that the capacitor can be overcharged, causing failure of the parasitic diode.
how tap cell is used to prevent latchup effect
WEBMar 31, 2012 · The latch up problem can be avoided by increasing the parasitic switch breakdown voltage above CMOS Inverter (VDD/VSS) supply voltage.This is realized by shunting low resistance across Emitter-Base junction of parasitic BJT as shown in Fig.The resistor connected across PNP is kown as well tap …
which device induces latch-up? - Forum for Electronics
WEBDec 1, 2006 · Re: Help: latch up Thank everybody for your attention! <D0 4> are in a separate n-well (separate from <D5 9> and pmos P18 n-well). The distance between these two n-wells is about 17um without GuardRing. The width of mos is 0.6um. When "on", the circuit draws a rather high current about 170mA.
STI role in LATCH UP | Forum for Electronics
WEBFeb 23, 2017 · 73,233. It does not. It makes some of the paths longer and you'd hope it. raises the trigger voltage and holding current but "hope. is not a strategy". You still need close-in well ties ("taps") to do the shunt job, complementing the series (STI). STI is just the modern successor to LOCOS. Neither.
epitaxial layer and latch up | Forum for Electronics
WEBJul 2, 2009 · See e.g. Allen/Holberg book, p.22 (below). The heavily doped wafer substrate (below the lightly doped epi layer) reduces the p-bulk resistance, and thus reduces the B-E resistance of the parasitic npn transistor of an NMOS/PMOS transistor pair, which means a higher current must flow through it in order to forward bias the B-E-region of this transistor (which then could trigger latch-up in ...