Perhaps these can help: http://www.voti.nl/shop/catalog.html?IC-UDN2981-DIP

Marcel

Brent Brown wrote:
> On 3 Nov 2004 at 17:15, Dominic Stratten wrote:
>
>> I need to drive a blue 7 segment LED display with a PIC. The problem is 
>> that
>> it uses a 7.4 volt nominal supply.
>
> Me too, in the near future...
>
>> PIC PIN --> RESISTOR --> NPN TRANSISTOR BASE
>> NPN TRANSISTOR COLLECTOR --> RESISTOR --> PNP TRANSISTOR BASE
>> NPN TRANSISTOR EMITTER --> GND
>> PNP TRANSISTOR EMITTER --> +7.4 volts
>> PNP TRANSISTOR COLLECTOR --> SEGMENT OF DISPLAY
>> (OPTIONAL - PNP TRANSISTOR BASE --> RESISTOR --> +7.4 volts)
>
> Yeah that sounds right. Like others have said, the "optional" resistor is
> important for turning the tansistor off.
>
> The parts count is pretty high, but not easy to get around. If you use N 
> and P
> channel MOSFET's (logic level) instead of BJT's then you can do away with
> the series base resistors. The next option would be a chip that has a 
> bunch
> of high side drivers, can't recall what's available right now. 

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