output driver

[Simon]

quite, i'd want a lower power version with more drivers in one package

[BrianHG]

4x 50ma drivers for $1.02us.  << They don't guarantee short circuit conditions.
http://www.digikey.com/product-detail/en/on-semiconductor/NCS20074DR2G/NCS20074DR2GOSCT-ND/5801744

4x 1amp drivers for $2.43us.  <<< This is your closest one.  And it does have thermal shutdown if too much current is being drawn.
http://www.digikey.com/product-detail/en/texas-instruments/SN754410NE/296-9911-5-ND/380180

[Zero999]

quite, i'd want a lower power version with more drivers in one package

You still haven't said how fast it needs to be?

Does it matter if it's inverted?

Why not use discrete components?

Try this. Current limiting is implemented with potential dividers (R3 & R4 and R1 & R6) on the bases and emitter resistors (R2 and R5).


Note that, in the attached schematic, CL represents a capacitive load, not part of the circuit.

[Simon]

Well the other option was to go descreet and use emitter resistors. I was hoping for one mutichannel chip. I only need a few KHz.

[Zero999]

How near to either supply rail does the output have to go?

The previous example I posted will only go to within 0.7V of either rail. Lots of the ICs mentioned have Darlington output stages and will only reach 1.2V at low currents.

Here's an example for a driver which will go to within 100mV of either rail.

Note that in both of the above schematics, the IC at the input needs to be able to sink all the current, as the lower transistor is in common base configuration.

[T3sl4co1l]

This works, but as mentioned, it does require some current capacity to operate the input.  I "created" that years ago, here for example,


In this case, using both polarities of transistor "gain stage", to get complementary outputs.  Rather than driving the high side, a CCS load is used; using common bias means the CCS is really only active during transition, and doesn't consume much current once one or the other output is saturated (near +V).

Tim

[Simon]

strict rail to rail is not neccessary, but 18V is not enough on a 24+V system.

[Zero999]

What about the ADG3123? It's pricey but may be economical, in small volumes, especially if you're building them by hand, as less time will be spent placing parts.

http://uk.rs-online.com/web/p/voltage-translators/7097657/?searchTerm=ADG3123&relevancy-data=636F3D3126696E3D4931384E4B6E6F776E41734D504E266C753D656E266D6D3D6D61746368616C6C7061727469616C26706D3D5E5B5C707B4C7D5C707B4E647D2D2C2F255C2E5D2B2426706F3D313326736E3D592673743D4B4559574F52445F53494E474C455F414C5048415F4E554D455249432677633D424F5448267573743D41444733313233267374613D4144473331323326