alternative of LTC6992?

Piyush Kamdi

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Jul 19, 2022, 7:37:53 AM7/19/22

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can anyone tell me the alternative of the IC LTC6992

jla...@highlandsniptechnology.com

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Jul 19, 2022, 8:23:42 AM7/19/22

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On Tue, 19 Jul 2022 04:37:49 -0700 (PDT), Piyush Kamdi
<piyush...@gmail.com> wrote:

>can anyone tell me the alternative of the IC LTC6992

You could make something out of cheap parts... depends on your exact
needs.

Phil Hobbs

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Jul 19, 2022, 9:05:18 AM7/19/22

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jla...@highlandsniptechnology.com wrote:
> On Tue, 19 Jul 2022 04:37:49 -0700 (PDT), Piyush Kamdi
> <piyush...@gmail.com> wrote:
>
>> can anyone tell me the alternative of the IC LTC6992

Yikes! $5 in onesies, $3 in reels for a glorified RC monostable?

> You could make something out of cheap parts... depends on your exact
> needs.

Such as an NE556D dual timer, with one side being an astable and the
other side a monostable with a variable threshold. Ten cents in any
quantity, direct from TI.

<https://www.ti.com/product/NE556/part-details/NE556DR>

A bit more design is required, of course--you have to take account of
the tolerances of the chip and timing components, especially if you want
to get duty cycles near 0.

OTOH if the OP uses a resistor to a higher supply rail (and a diode to
V+ for protection), the ramp will linearize pretty well. Extra points
for using a BJT current source. ;)

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal Consultant
ElectroOptical Innovations LLC / Hobbs ElectroOptics
Optics, Electro-optics, Photonics, Analog Electronics
Briarcliff Manor NY 10510

http://electrooptical.net
http://hobbs-eo.com

Anthony William Sloman

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Jul 19, 2022, 9:12:19 AM7/19/22

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On Tuesday, July 19, 2022 at 9:37:53 PM UTC+10, piyush...@gmail.com wrote:
> can anyone tell me the alternative of the IC LTC6992

Single chip microcontrollers can do the same job. You need an internal clock that runs faster than 1MHz to get the same frequency range, but some run up to 100MHz and faster (though they tend to be bit greedy with supply current).

--
Bill Sloman, Sydney

Mike Monett

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Jul 19, 2022, 10:17:16 AM7/19/22

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Piyush Kamdi <piyush...@gmail.com> wrote:

> can anyone tell me the alternative of the IC LTC6992

Depends on what you want to do. Check Octopart:

https://octopart.com/search?q=Voltage-Controlled+Pulse+Width+Modulator

--
MRM

jla...@highlandsniptechnology.com

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Jul 19, 2022, 10:54:44 AM7/19/22

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On Tue, 19 Jul 2022 09:05:07 -0400, Phil Hobbs
<pcdhSpamM...@electrooptical.net> wrote:

>jla...@highlandsniptechnology.com wrote:
>> On Tue, 19 Jul 2022 04:37:49 -0700 (PDT), Piyush Kamdi
>> <piyush...@gmail.com> wrote:
>>
>>> can anyone tell me the alternative of the IC LTC6992
>
>Yikes! $5 in onesies, $3 in reels for a glorified RC monostable?
>
>> You could make something out of cheap parts... depends on your exact
>> needs.
>
>Such as an NE556D dual timer, with one side being an astable and the
>other side a monostable with a variable threshold. Ten cents in any
>quantity, direct from TI.
>
><https://www.ti.com/product/NE556/part-details/NE556DR>
>
>A bit more design is required, of course--you have to take account of
>the tolerances of the chip and timing components, especially if you want
>to get duty cycles near 0.
>
>OTOH if the OP uses a resistor to a higher supply rail (and a diode to
>V+ for protection), the ramp will linearize pretty well. Extra points
>for using a BJT current source. ;)
>
>Cheers
>
>Phil Hobbs

About the simplest voltage to duty cycle converter is a schmitt gate
oscillator and one added resistor. Real cheapskates can delete the
cap.

Fancier, use a dial opamp or comparator as a triangle oscillator +
comparator.

If Piyush can give us some details of the requirements, we could
design something with him. Group design is fun.

Phil Hobbs

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Jul 19, 2022, 2:26:15 PM7/19/22

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Yeah, if the rep rate doesn't need to be constant you can do without a
lot of stuff. Simplifies the tolerances too.

John Larkin

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Jul 19, 2022, 4:33:58 PM7/19/22

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On Tue, 19 Jul 2022 14:26:01 -0400, Phil Hobbs

Schmitt gate inverter, one resistor, one thermistor. It's a PWM
temperature controller!

Phil Hobbs

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Jul 19, 2022, 5:20:54 PM7/19/22

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> Schmitt gate inverter, one resistor, one thermistor. It's a PWM
> temperature controller!
>

For sufficiently permissive definitions of 'controller'. ;0

(It would be fairly challenging without at least one other resistor for
heating, unless you're just trying to control the temperature of the
thermistor.)

John Larkin

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Jul 19, 2022, 6:51:39 PM7/19/22

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On Tue, 19 Jul 2022 17:20:43 -0400, Phil Hobbs

It would drive a mosfet or an SSR or something.