Hi folks 
I'm currently trying to design a CommonEmitter amplifier based on the "Comprehensive AC Coupled Design" on this page: http://www.radioelectronics.com/info/circuits/transistor/commonemitteramplifierdesign.php
I'm a little bit uncertain about a few things and had the following questions:
1. I'm calculating this circuit based on a speculation about what sort of current I might need at the output stage. I'm mainly using this circuit for voltage gain, though. How does one design this circuit using the intended voltage gain as the starting point?
2. On Step 4, the instructions are to "determine the base current by dividing the collector current by hFE." I'm a little unsure about where the decimal point goes here. Let's say I've got a 1mA current divded by an hFE of 160. Is the solution here going to be 0.00625mA?
3. Step 5 explains the voltage needed at the base. It's going to be 1.6v, in my particular application. If I know this, can I just use the voltage divider provided by R1 and R2? Or do I need to factor the current into this decision somehow? I'm a little unclear on what is being recommended here. Do I add R1+R2 together and use the V+ supply to get the range?
Thanks all...
I'm currently trying to design a CommonEmitter amplifier based on the "Comprehensive AC Coupled Design" on this page: http://www.radioelectronics.com/info/circuits/transistor/commonemitteramplifierdesign.php
I'm a little bit uncertain about a few things and had the following questions:
1. I'm calculating this circuit based on a speculation about what sort of current I might need at the output stage. I'm mainly using this circuit for voltage gain, though. How does one design this circuit using the intended voltage gain as the starting point?
2. On Step 4, the instructions are to "determine the base current by dividing the collector current by hFE." I'm a little unsure about where the decimal point goes here. Let's say I've got a 1mA current divded by an hFE of 160. Is the solution here going to be 0.00625mA?
3. Step 5 explains the voltage needed at the base. It's going to be 1.6v, in my particular application. If I know this, can I just use the voltage divider provided by R1 and R2? Or do I need to factor the current into this decision somehow? I'm a little unclear on what is being recommended here. Do I add R1+R2 together and use the V+ supply to get the range?
Thanks all...
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