Chapter 4 - Revision history

Fonggr: /* Large-Signal DC Analysis */

2010-03-12T17:57:02Z

Large-Signal DC Analysis

← Older revision		Revision as of 10:57, 12 March 2010
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	\| [[Image:IMG_0287.jpg\|x350px\|none]]		\| [[Image:IMG_0287.jpg\|x350px\|none]]
	\|}		\|}

			*Active region: The current source is on the collector side and points towards the emitter
			*Saturation region: The voltage sources have the same orientation

	===Bias-Circuit Design===		===Bias-Circuit Design===

2010-03-12T17:55:19Z

Large-Signal DC models

← Older revision		Revision as of 10:55, 12 March 2010
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	*'''Saturation''': High current from the emitter to collector. Logical "on".		*'''Saturation''': High current from the emitter to collector. Logical "on".
	*'''Cutoff''': Very little current flow. Logical "off".		*'''Cutoff''': Very little current flow. Logical "off".

			*Instead of memorizing the region constraints for NPN & PNP BJTs, it is easier to remember the BJT regions as they work for both NPN & PNP.

	===Large-Signal DC Analysis===		===Large-Signal DC Analysis===

2010-03-08T23:17:20Z

BJT models?

← Older revision		Revision as of 16:17, 8 March 2010
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	\| Common-emitter\|\|<math>R_B \parallel (r_\pi + (\beta + 1)R_{E1})</math> \|\| <math>R_C\,</math> \|\| <math>-\frac{\beta R^'_L}{r_\pi+(\beta+1)R_{E1}}</math>\|\| \|\|		\| Common-emitter\|\|<math>R_B \parallel (r_\pi + (\beta + 1)R_{E1})</math> \|\| <math>R_C\,</math> \|\| <math>-\frac{\beta R^'_L}{r_\pi+(\beta+1)R_{E1}}</math>\|\| \|\|
	\|-		\|-
	\| Common-collector\|\| <math>R_B \parallel (r_\pi + (\beta+1) R^'_L)</math> \|\| \|\| <math>\frac{(\beta+1)R^'_L}{r_\pi + (\beta+1) R^'_L}</math> \|\| \|\|		\| Common-collector\|\| <math>R_B \parallel (r_\pi + (\beta+1) R^'_L)</math> \|\|<math>\frac{R_E(R^'_s+R_\pi)}{R_s+R_\pi+R_E(\beta+1)}</math> \|\| <math>\frac{(\beta+1)R^'_L}{r_\pi + (\beta+1) R^'_L}</math> \|\| \|\|
	\|-		\|-
	\| Common-base\|\| \|\|~~<math>\frac{R_E(R^'_s+R_\pi)}{R_s+R_\pi+R_E(\beta+1)}</math>~~ \|\| \|\| \|\|		\| Common-base\|\| \|\| \|\| \|\| \|\|
	\|}		\|}

2010-03-08T23:17:02Z

BJT models?

← Older revision		Revision as of 16:17, 8 March 2010
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	\| Common-collector\|\| <math>R_B \parallel (r_\pi + (\beta+1) R^'_L)</math> \|\| \|\| <math>\frac{(\beta+1)R^'_L}{r_\pi + (\beta+1) R^'_L}</math> \|\| \|\|		\| Common-collector\|\| <math>R_B \parallel (r_\pi + (\beta+1) R^'_L)</math> \|\| \|\| <math>\frac{(\beta+1)R^'_L}{r_\pi + (\beta+1) R^'_L}</math> \|\| \|\|
	\|-		\|-
	\| Common-base\|\| \|\| \|\| \|\| \|\|		\| Common-base\|\| \|\|<math>\frac{R_E(R^'_s+R_\pi)}{R_s+R_\pi+R_E(\beta+1)}</math> \|\| \|\| \|\|
	\|}		\|}

2010-03-08T23:16:44Z

Common-Collector Amplifier (Emitter Follower)

← Older revision		Revision as of 16:16, 8 March 2010
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	::*<math>v_x/R_E-i_x-(\beta+1)i_b=0\,</math>		::*<math>v_x/R_E-i_x-(\beta+1)i_b=0\,</math>
	::*<math>R^'_s i_b + r_\pi i_b + v_x =0</math>		::*<math>R^'_s i_b + r_\pi i_b + v_x =0</math>
			:*<math>Z_o=\frac{v_x}{i_x}=\frac{R_E(R^'_s+R_\pi)}{R_s+R_\pi+R_E(\beta+1)}</math>

	===BJT models?===		===BJT models?===

2010-03-08T23:11:42Z

Common-Collector Amplifier (Emitter Follower)

← Older revision		Revision as of 16:11, 8 March 2010
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	:*<math>Z_{in}=R_B \parallel \frac{v_in}{i_b} = R_B \parallel (r_\pi + (1+\beta) R^'_L)</math>		:*<math>Z_{in}=R_B \parallel \frac{v_in}{i_b} = R_B \parallel (r_\pi + (1+\beta) R^'_L)</math>
	*Output Impedance		*Output Impedance
	:*		:*<math>Z_o=v_x/i_x\,</math>
			::*<math>v_x/R_E-i_x-(\beta+1)i_b=0\,</math>
			::*<math>R^'_s i_b + r_\pi i_b + v_x =0</math>

	===BJT models?===		===BJT models?===

2010-03-08T20:54:26Z

BJT models?

← Older revision		Revision as of 13:54, 8 March 2010
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	\| Common-emitter\|\|<math>R_B \parallel (r_\pi + (\beta + 1)R_{E1})</math> \|\| <math>R_C\,</math> \|\| <math>-\frac{\beta R^'_L}{r_\pi+(\beta+1)R_{E1}}</math>\|\| \|\|		\| Common-emitter\|\|<math>R_B \parallel (r_\pi + (\beta + 1)R_{E1})</math> \|\| <math>R_C\,</math> \|\| <math>-\frac{\beta R^'_L}{r_\pi+(\beta+1)R_{E1}}</math>\|\| \|\|
	\|-		\|-
	\| Common-collector\|\| <math>R_B \parallel (r_\pi + (\beta+1) R^'_L)</math> \|\| \|\| <math>\frac{(1+\beta)R^'_L}{r_\pi + (1+\beta) R^'_L}</math> \|\| \|\|		\| Common-collector\|\| <math>R_B \parallel (r_\pi + (\beta+1) R^'_L)</math> \|\| \|\| <math>\frac{(\beta+1)R^'_L}{r_\pi + (\beta+1) R^'_L}</math> \|\| \|\|
	\|-		\|-
	\| Common-base\|\| \|\| \|\| \|\| \|\|		\| Common-base\|\| \|\| \|\| \|\| \|\|

2010-03-08T20:54:10Z

Common-Collector Amplifier (Emitter Follower)

← Older revision		Revision as of 13:54, 8 March 2010
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	[[Image:IMG 0291.JPG\|400px\|thumb\|Common-collector amplifier small-signal equivalent]]		[[Image:IMG 0291.JPG\|400px\|thumb\|Common-collector amplifier small-signal equivalent]]
	*Voltage Gain		*Voltage Gain
	:*<math>v_o=R^'_L (1+\beta)i_b</math>		:*<math>v_o=R^'_L (\beta+1)i_b</math>
	:*<math>v_{in}=i_b r_\pi + (1+\beta) i_b R^'_L</math>		:*<math>v_{in}=i_b r_\pi + (\beta+1) i_b R^'_L</math>
	:*<math>A_v=\frac{(1+\beta)R^'_L}{r_\pi + (1+\beta) R^'_L}</math>, thus the gain is less than one, but is positive		:*<math>A_v=\frac{(\beta+1)R^'_L}{r_\pi + (\beta+1) R^'_L}</math>, thus the gain is less than one, but is positive
	*Input Impedance		*Input Impedance
	:*<math>Z_{in}=R_B \parallel \frac{v_in}{i_b} = R_B \parallel (r_\pi + (1+\beta) R^'_L)</math>		:*<math>Z_{in}=R_B \parallel \frac{v_in}{i_b} = R_B \parallel (r_\pi + (1+\beta) R^'_L)</math>

2010-03-08T20:53:45Z

BJT models?

← Older revision		Revision as of 13:53, 8 March 2010
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	\| Common-emitter\|\|<math>R_B \parallel (r_\pi + (\beta + 1)R_{E1})</math> \|\| <math>R_C\,</math> \|\| <math>-\frac{\beta R^'_L}{r_\pi+(\beta+1)R_{E1}}</math>\|\| \|\|		\| Common-emitter\|\|<math>R_B \parallel (r_\pi + (\beta + 1)R_{E1})</math> \|\| <math>R_C\,</math> \|\| <math>-\frac{\beta R^'_L}{r_\pi+(\beta+1)R_{E1}}</math>\|\| \|\|
	\|-		\|-
	\| Common-collector\|\| <math>R_B \parallel (r_\pi + (1+\beta) R^'_L)</math> \|\| \|\| <math>\frac{(1+\beta)R^'_L}{r_\pi + (1+\beta) R^'_L}</math> \|\| \|\|		\| Common-collector\|\| <math>R_B \parallel (r_\pi + (\beta+1) R^'_L)</math> \|\| \|\| <math>\frac{(1+\beta)R^'_L}{r_\pi + (1+\beta) R^'_L}</math> \|\| \|\|
	\|-		\|-
	\| Common-base\|\| \|\| \|\| \|\| \|\|		\| Common-base\|\| \|\| \|\| \|\| \|\|

2010-03-08T20:53:02Z

BJT models?

← Older revision		Revision as of 13:53, 8 March 2010
Line 141:		Line 141:
	\| Common-emitter\|\|<math>R_B \parallel (r_\pi + (\beta + 1)R_{E1})</math> \|\| <math>R_C\,</math> \|\| <math>-\frac{\beta R^'_L}{r_\pi+(\beta+1)R_{E1}}</math>\|\| \|\|		\| Common-emitter\|\|<math>R_B \parallel (r_\pi + (\beta + 1)R_{E1})</math> \|\| <math>R_C\,</math> \|\| <math>-\frac{\beta R^'_L}{r_\pi+(\beta+1)R_{E1}}</math>\|\| \|\|
	\|-		\|-
	\| Common-collector\|\| <math>R_B \parallel r_\pi + (1+\beta) R^'_L</math> \|\| \|\| <math>\frac{(1+\beta)R^'_L}{r_\pi + (1+\beta) R^'_L}</math> \|\| \|\|		\| Common-collector\|\| <math>R_B \parallel (r_\pi + (1+\beta) R^'_L)</math> \|\| \|\| <math>\frac{(1+\beta)R^'_L}{r_\pi + (1+\beta) R^'_L}</math> \|\| \|\|
	\|-		\|-
	\| Common-base\|\| \|\| \|\| \|\| \|\|		\| Common-base\|\| \|\| \|\| \|\| \|\|