- Power supply requirements: 230VAC 50 Hz
- Fixed gain: 10x
- Max. input amplitude: up to ±4V
- Bandwidth: DC to 100kHz for square waves signals
- High output load drive: 50mA continuous
- Board size: 160 x 100mm, using prototyping boards
- Casing: 160 x 103 x 53 mm
- Linear analogue amplifier
For the amplification an OPA453 high voltage operational amplifier is used, because a standard operational amplifier cannot be used in the voltage range of ±40V. This rail-to-rail OpAmp can operate with a power supply in the range of ±10V to ±40V. Thus the output amplitude can reach almost ±40V (which is acceptable). That is: 10x (fixed gain) ±4V (input amplitude). Furthermore the OPA453 has a 7.5MHz bandwidth and a high output load drive of 50mA continuous current. To sum up, the OPA453 is the ideal component to fulfil all the constraints for our linear amplifier.
- Supply
A solution using the 230VAC mains supply was selected for this project. It is fed into a 230VAC to 18V/18V transformer (1:(1+1)) with two voltage doublers in order to obtain two 48V voltages. Then two LT3010 adjustable linear regulators are added in order to obtain a smooth ±40V supply voltage for our OPA453 OpAmp.
(click for larger image)
(click for larger image)
During the tests, no problems have occurred. The amplifier ran several days with a high voltage output signal (±40V square wave with 20kHz) without any variation of the signal.
Build-in circuit board of the Amplifier
The ready to use 10x Linear Laboratory Amplifier
The use of the mains-operated voltage is very dangerous!
This circuit should only be assembled, tested and used by skilled electronics technicians.
NO WARRANTY WHATSOEVER IS GIVEN FOR THIS CIRCUIT!
PROTOTYPE THIS CIRCUIT IS AT YOUR OWN RISK!