[time-nuts] One sure way to kill your FE-5680A or FE-5650A

Clint Jay cjaysharp at gmail.com
Wed Jun 8 12:22:38 EDT 2016

Sounds similar to the issues you encounter with Atmel and some other
EEPROM/Flash based MCUs when they're not held in reset until VCC becomes


Some more info:


On 8 June 2016 at 16:20, jimlux <jimlux at earthlink.net> wrote:

> On 6/8/16 6:19 AM, paul swed wrote:
>> The units were never intended for a slow ramp
>> I assume it runs into a meta stable condition
>> Neither on or off and then corruption
>> Glad you're can repair them
>> On Tuesday, June 7, 2016, Bob Camp <kb8tq at n1k.org> wrote:
> Interesting, we just had a similar issue on a circuit here at work..
> someone slowly brought the supply voltage up on a bunch of DC/DC
> converters, and some didn't start. This was in initial checkout of a new
> board.
> Switch it on with a bang, and it works just fine.
> So for some of these things there's apparently a minimum dv/dt.
> I've seen this before with DC/DC converters.. if the voltage drops too
> low, they draw too much current - because they're basically constant power
> devices- and the overcurrent trip shuts them down.  There's a delicate
> interplay between the overcurrent and undervoltage trips,both of which have
> some sort of time constant, and I suspect that for a lot of circuits, the
> "slow ramp up of input voltage" isn't something they are designed for.
> Once it's up and running, when the supply sags, the UV trip works just
> fine, tripping before the OC trip goes.
> Linear regulators.. they may be not the most efficient thing in the world,
> but they have a lot less "weird" behavior.  (although I've had linear
> regulators go into thermally driven oscillation)
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