Low Power Logic Circuit

[Paul]

Hi Folks

I am trying design a NOT gate and two OR functions (Z= /A + B + C) but
the only problem is the current consumption and the VCC. The current
allowed for the logic is 5uA and the VCC is approx. 5V. I have tried
looking for low powered ICs from Philips and Fairchild but the only
problem is the maximum VCC is 3.3V and also it does not meet the
current consumption. Is there a way of designing the logic using
discretes without increasing the impedance of the circuit.
I have used a transistor and two diodes but the resistor at the
collector suggested by a colleague will have to be large to reduce the
current consumption.

Any help will be great.

Thanks

Paul

 

[Jim Thompson]

On 7 Oct 2003 01:46:19 -0700, paul.lee@sli-institute.ac.uk (Paul)
wrote:

Hi Folks

I am trying design a NOT gate and two OR functions (Z= /A + B + C) but
the only problem is the current consumption and the VCC. The current
allowed for the logic is 5uA and the VCC is approx. 5V. I have tried
looking for low powered ICs from Philips and Fairchild but the only
problem is the maximum VCC is 3.3V and also it does not meet the
current consumption. Is there a way of designing the logic using
discretes without increasing the impedance of the circuit.
I have used a transistor and two diodes but the resistor at the
collector suggested by a colleague will have to be large to reduce the
current consumption.

Any help will be great.

Thanks

Paul

Are you living in a cave? ANY CMOS device will meet the power
consumption easily. Their static consumption is zilch... just
leakage.

...Jim Thompson
--
| James E.Thompson, P.E. | mens |
| Analog Innovations, Inc. | et |
| Analog/Mixed-Signal ASIC's and Discrete Systems | manus |
| Phoenix, Arizona Voice480)460-2350 | |
| E-mail Address at Website Fax480)460-2142 | Brass Rat |
| http://www.analog-innovations.com | 1962 |

I love to cook with wine. Sometimes I even put it in the food.

 

[John Fields]

On 7 Oct 2003 01:46:19 -0700, paul.lee@sli-institute.ac.uk (Paul) wrote:

Hi Folks

I am trying design a NOT gate and two OR functions (Z= /A + B + C) but
the only problem is the current consumption and the VCC. The current
allowed for the logic is 5uA and the VCC is approx. 5V. I have tried
looking for low powered ICs from Philips and Fairchild but the only
problem is the maximum VCC is 3.3V and also it does not meet the
current consumption. Is there a way of designing the logic using
discretes without increasing the impedance of the circuit.
I have used a transistor and two diodes but the resistor at the
collector suggested by a colleague will have to be large to reduce the
current consumption.

---
Are you living in a cave?^)

Here's a single chip solution: U1 is an HC27 triple 3-input NOR and

A,B, and C are the inputs and Y is the output of each gate.


U1A
_ +---A U1B U1C
A>-------+---B Y--------A +---A _
+---C +----B Y----+---B Y--->/A+B+C
| +--C +---C
B>------------------+ |
|
C>--------------------+

_
U1A-Y = A
__
U1B-Y = ABC
_
U1C-Y = A+B+C

--
John Fields