Firm! Diode clamp circuit is in this
[introduction] clamp circuit (Clamping Circuit) is secure the some part of pulse signal in appoint voltage value to go up, maintain the circuit with original undee changeless figure. Clamp the undee coping that the action of circuit is will periodic change or bottom maintain the dc n that decides in some to go up.
Clamp circuit brief introduction
Clamp circuit (Clamping Circuit) is secure the some part of pulse signal in appoint voltage value to go up, maintain the circuit with original undee changeless figure. Clamp the undee coping that the action of circuit is will periodic change or bottom maintain the dc n that decides in some to go up.
1, function: Will move on input signal or next moving, do not change the weaveform that inputs signal.
2, main element: C of diode D, capacitor and resistor R (dc pool VR) .
3, category: Negative clamp implement with clamp implement.
4, note: D all is ideal diode suppose, the time constant of RC is enough also big, do not cause output undee and lack fidelity. Any communication signal can produce clamp action.
Negative clamp implement
(1) brief monotype
Working principle:
Vi half Zhou Shi, diode guides, c charges to be worth to V, vo=0V
When Vi loses half weeks, diode is shut, vo= – 2V
(2) adds bias voltage model
Working principle:
Vi half Zhou Shi, diode guides, c is charged to be worth to V (Zun Zheng, right negative) , vo=+V1 (graph A) or – V1 (graph B) .
When Vi loses half weeks, diode closes, RC time constant is enough big, vo=VC+Vi (lose half weeks) =2V.
A few kinds of diode lose grip implement circuit compares:
clamp implement
(1) brief monotype
Working principle
When Vi loses half weeks, diode guides, c charges to be worth to V (left negative, right) , vo=0V.
Vi half Zhou Shi, diode closes, vo=VC+Vi (half weeks) =2V.
(2) adds bias voltage model
Judgement outputs undee simple and easy method:
1, the reference point that decides to output weaveform to go up at reference axis by referenced voltage V1.
2, the mobile way that decides former weaveform by the direction of diode D, the direction that is like diode to leaked diode pursues, undee must move up; The direction that is like diode to leaked diode pursues, undee must move downward.
3, after deciding reference point and way, it is with reference point again fiducial, get on original undee picture at outputting reference axis, be begged for us namely.
