Re: LF: Si5351A syntehsiser able to fire a FET driver chip directly??

[Markus Vester <markusvester@aol.com>]

> Any ideas please?

As Andy said, bias half way: place another pair of 15k from the inputs (Pins 12,10) to 5V (pin9).

73, Markus

-----Ursprüngliche Mitteilung-----
Von: Chris Wilson <dead.fets@gmail.com>
An: rsgb_lf_group <rsgb_lf_group@blacksheep.org>
Verschickt: Mo, 1. Jan 2018 22:26
Betreff: Re: LF: Si5351A syntehsiser able to fire a FET driver chip directly??

Hello Andy,

MCP1404 IC fitted, as soon as power to the PA FETS is applied (even
6V) one of the gate square waves either disappears or becomes
extremely random. Swapping inputs to the driver IC makes no
difference, it's one pair of PA FET's dependent. FET's work fine when
returned to "as designed" status! Driving the driver IC through the
1nF caps and 15k resistors to ground. Outputs from CLK0 and CLK1 are
180 out of phase and seem correct. Any ideas please? Thank you!

http://www.gatesgarth.com/amp-modded.jpg

Monday, January 1, 2018, 11:27:20 AM, you wrote:



> Seems an odd choice of driver chip.  A high/low side driver used in
> a non-bootstrapped mode to drive two low-side FETs 


> How about one of the normal FET driver chips - picking out one I've
> used in the past, the MCP14E 3/4/5 family.   Logic level input,
> spec. Logic '0' max 1.3V, Logic '1' min 2.4V.   So bias half way and
> your 2.2V swing takes it into the valid range.




> They three types are inverting, non inverting, and one of each in a package


> Andy  G4JNT





--
Best regards,
Chris mailto:dead.fets@gmail.com