LME49830 non audio application

82026

Member
2012-07-18 5:02 pm
I'm a bit new to analog world and need a +/- 100V amplifier for electrostatic deflection application (not audio). Signal bandwidth is from DC to ~100kHz.
Considering LME49830 amplifier.
Does anyone knows - can it be used without any output stage to drive small purely capacitive loads (100pF .. 200pF). From datasheet its gain looks very linear up to 200kHz which is just fine, but what is its DC performance?
Any ideas or suggestions?
 

mjselan

Member
2004-09-15 9:17 pm
I have designed a high voltage fully differential amplifier that may be some use to you.
Specs are:
Supply Voltage +-100 to 300V
Output Curent = 12mA
Bandwith DC to about 100Khz
V Out max 1000 Vp-p
Max Vin = 5Vrms
Distortion at 100Vrms 1kHz 0.002% into 150pF 130k load


I have two spare PCB's Ver 1.00 so silkscreen has a few mistakes. If you are interested I may solder it for you. If you need more info please let me know.

Regards

Martin
 
I'm a bit new to analog world and need a +/- 100V amplifier for electrostatic deflection application (not audio). Signal bandwidth is from DC to ~100kHz. ....
Any ideas or suggestions?

Work out the slew rate and HF output current that the amplifier will need. The LME amps will not be able to slew a 100KHz sine wave to +/-100V, even with no load.
 
How much linearity do you need? Do you really need to go down to DC?

Do you need an amp capable of sweeping the entire range? It's straightforward if you can tolerate fractional ranges. The higher frequencies are starting to be in the lower SMPSU ranges, you could wind a transformer and generate your input at comparatively low voltage.

Look at some of the amplifiers intended to drive Stax headphones...

HeadAmp - Audio Electronics (Gilmore Electrostatic Headphone Amp [KGSS])

Dirt Cheap Stax Amp DIY - new schematic updated!

Some of them have bandwidth out to 100kHz and some drive 600v differential. DC is a problem though, most roll of at 20Hz or so.