1. Double-ended input single-ended output circuit
The circuit is shown on the right, as a double-ended input, single-ended output differential amplifier circuit. Due to the asymmetry of the circuit parameters, the static operating point and dynamic parameters are affected.
DC analysis:
Draw the DC path as shown in the lower right figure. In the figure, and are the equivalent power supply and resistance obtained by the Thevenin's theorem, and their expressions are:
Communication analysis:
When the differential mode signal acts, the load resistance only obtains the amount of change in the collector potential of the T1 tube, so compared with the double-ended output circuit, the value of the differential mode amplification factor decreases.
As shown in the lower right figure is the equivalent circuit of the differential mode signal. When the differential mode signal acts, since the currents in the T1 and T2 tubes are equal in the opposite direction, the emitter is equivalent to ground.
The output voltage

half. If the polarity of the input differential mode signal does not change, and the output signal is taken from the collector of the T2 tube, the output is in phase with the input. When a common-mode signal is input, the polarities are the same because the input signals on both sides are equal in size. The equivalent circuit of the circuit on the side of the T1 tube related to the output voltage to the common mode signal is as follows
It can be seen that the difference between the single-ended input circuit and the double-ended input circuit is that the differential mode signal input is accompanied by the common mode signal input.
The output voltage
The analysis of the static operating point and dynamic parameters is completely the same as the double-ended input and double-ended output.
3. Single-ended input, single-ended output circuit
As shown on the right, there is a single-ended input and single-ended output circuit. The analysis of the static operating point, differential-mode gain, common-mode gain, input and output resistance is the same as the single-ended output circuit. The analysis of the input signal is the same as the single-ended input circuit.

APM 80V dc switching power supply is applicable to automobile electronics product testing sector. It also covers the 48v power supply. APM power supply is built-in 12V DIN4089 automobile starting voltage waveform, be able to simulate automobile engine electronic performance test;Meanwhile ,the built-in 12V ISO-16750-2 engine start test waveform enable simulation of voltage drop test waveform and restoration function test waveform.
Some features of the DC Power Supply as below:
- Ultrafast respond time and high efficiency.
- Accurate voltage and current measurement capability
- Constant Power and wide range of voltage and current output
- Equips with LIST waveform editing function
- Compliant with SCPI communication protocol
- Support RS232/RS485/LAN/USB (standard) ,GPIB (optional)
- Master/Slave parallel and series operation mode for up to 10 units
- Full protection: OVP/OCP/OPP/OTP/SCP
- Voltage drop compensation by remote sense line.
- Have obtained CE,UL,CSA,FCC.ROHS
80V DC Power Supply,Variable DC Power Supply,Laboratory Power Supply,Modular Power Supply
APM Technologies Ltd , https://www.apmpowersupply.com