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A IC form of NPN transistor ?


Is there  such thing as a DIP package of transistors ? (not sure if that is the right way to put it) 
 
I need to control 12 digital connections and putting 12 transistors on a PCB will take up a decent amount of space 
so I was wondering if there is a chip like version.
 
If possible a high voltage ~40V and high amperage trnasistor would be perfect it it exists. 

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Two last quick question, with the ULN2003A, isn't the output the opposite of the input ? and can I use the darlinton arrays with no other components (resistors, diodes, caps) ? excluding the microcontoller and the device being controlled of course.

The ULN2003A works just the same as 7 NPN darlington transistors, so if the input voltage is high, though corresponding output will be pulled low. Conversely, if the input is low, the output is not pulled high but simply left floating (no connection).

In the case of both the ULN2003A and the ULN2803a (the 8 channel version), you can drive them straight from almost any microcontroller. The resistors and diodes needed for them to function properly are built right into the package. The '3' in the part names indicates that those models are built to work with 5V TTL/CMOS level parts.

Thanks!! I wonder how I got that idea that they were opposite :p

When you say pulled to "low", do you mean to ground or to the common emitter?  

The common emitter is designed to be connected to ground, make sure you get the datasheet and examine where all the protection diodes are connected if you plan on connecting the emitter to something else.

Well from this http://focus.ti.com/lit/ds/symlink/uln2003a.pdf 

it seems that the emitter is not meant to be tied to ground but V, odd ? If this is the case it is perfect for my application,

but it contradicts what you and previous users have said. Why is it all so complicated...  

I think you're getting confused between the common emitter, and the common diode pins. The common emitter goes to ground, while the common diode normally goes to V+ for overvoltage protection on the outputs.

oooo thank you so much for that ! What was messing me up was the schematic from diptrace, the chis had a com pin and a ground pin so I assumed the com pin was the common emitter. 

Well since the emitter is tied to ground this driver is useless in my case.

Thanks for your help in me understanding it!   

 
It is for my version on of a universal Nihm battery charger  using a MAX712 chip, http://letsmakerobots.com/node/9272 .
For that charger you need to set the number of cells to charge by connecting 4 connections to REF, Batt-, V+ or left open.
So if the emitters are all connected to one pin it wont be useful for me.
 
Unless .... I have 4 ICs each one for its own specific connection( one for Batt-, one for V+...)  with the common emitter pin connected to the specific connection. Wonder if that  would be a possible solution .. ?   
 
I would need to see your schematic. Another possibility is a bilateral switch IC such as the CD4066B as long as the current being switched is less than 10mA.

Here is a schematic of what it should look like;

MAX713_EV_Pin_out.png `

On the left the number 1 Pin can be connected to 1 of the 3 others directly in fornt or be left open. Instead of soldering a jumper to make the connections I would like to use transistors so that I can use the digital outputs of a picaxe to choose what pin 1 is connected to.