High Voltage Power Amplifier

  • Product No:20/20C
  • Manufacturer:Trek, Inc.

The Model 20/20C is a DC-stable, high-voltage power amplifier used in industrial and research applications. It features an all-solid-state design for high slew rate, wide bandwidth and low-noise operation.  The four-quadrant, active output stage sinks or sources current into reactive or resistive loads throughout the output voltage range.  This type of output is essential to achieve an accurate output response and high slew rate demanded by a variety of loads such as highly capacitive or reactive loads. It is configured as a non-inverting amplifier.

Features and Benefits

Four-quadrant output for driving capacitive loads 

Closed loop system for high accuracy 

Short-circuit protected for equipment protection 

CE compliant for assured reliability 

All solid-state design for maintenance free operation 

DC-stable for programmable supply applications 

Low output noise for ultra-accurate outputs

Model 20/20C Specifications 


Output Voltage Range: 0 to ±20 kV DC or peak AC

Output Current Range: 0 to ±20 mA DC or peak AC 

Input Voltage Range: 0 to ±10 V DC or peak AC 

Input Impedance: 25 kW, nominal 

DC Voltage Gain: 2000 V/V 

DC Voltage Gain Accuracy: Better than 0.1% of full scale

DC Offset Voltage: Less than ±2 V 

Output Noise: Less than 1.5 V rms* 

Slew Rate(10% to 90%, typical): Greater than 450 V/µs

Large Signal Bandwidth (-3 dB): DC to greater than 7.5 kHz 

Large Signal Bandwidth (1% distortion): DC to greater than 3.75 kHz

Small Signal Bandwidth (-3dB):DC to greater than 20 kHz

Stability: Drift with Time Less than 50 ppm/hr, noncumulative

           Drift with Temp Less than 100 ppm/°C

Voltage Monitor 

Ratio: 1/2000th of the high-voltage output 

DC Accuracy: Better than 0.1% of full scale 

DC Offset Voltage: Less than ±2 mV 

Output Noise: Less than 10 mV rms* 

Output Impedance: 47 W 

Current Monitor 

Ratio: 0.5 V/ mA 

DC Accuracy: Better than 1% of full scale 

Offset Voltage: Less than ±10 mV 

Output Noise: Less than 30 mV rms* 

Bandwidth (-3dB): DC to greater than 10 kHz 

Output Impedance: 47 W 


High-Voltage On/Off: Local Individual push-button switch   

           Remote (TTL    compatible input) TTL high (or open) turns off high-voltage output. TTL low turns on high-voltage output.

Dynamic Adjustment: Graduated 1-turn panel potentiometer is used to optimize the AC response for various load parameters

Current Limit/Trip: Switch selectable for either limit or trip. Graduated 1-turn panel potentiometer is used to adjust limit or trip level from 0 to ±20 mA 

Out of Regulation: Status Illuminates and a TTL low is provided when unit fails to produce required HV output such as during current limit or short circuit load conditions

Trip Statu: Illuminates and a TTL low is provided when the high-voltage output is disabled due to the output current exceeding the current trip level, the detection of a high-voltage supply fault or the removal of the top cover

Fault Status: A BNC provides a TTL low when the Model 20/20C is out of regulation for greater than 500 ms


Dimensions: 279 mm H x 482 mm W 654 mm D (11” H x 19” W x 25.75” D) 

Weight: 24.9 kg (55 lb) 

HV Connector: Caton High Voltage Connector 

BNC Connectors: Amplifier Input, Voltage Monitor, Current Monitor, Remote High Voltage ON/OFF, Out of Regulation Status, Fault/Trip Status Operating 


Temperature: 0°C to 40°C (32°F to 104°F)

Relative Humidity: To 85%, noncondensing

Altitude: To 2000 meters (6561.68 ft.) 


Line: Voltage Factory Set for one of two ranges: 104 to 127 V AC or 180 to 250 V AC,either at 48 to 63 Hz

AC Line Receptacle: Standard IEC 320 three-prong AC line connector 

Power Consumption: 1000 VA, maximum

Supplied Accessories 

Operators’ Manual PN: 23177 

HV Output: Cable PN: 43466

Line Cord, Spare Fuses PN: N5011; selected per geographic destination

Optional Accessories

19” Rack Mount Kit Model:  608RA (with EIA hole spacing) Model:  608RAJ (with JIS hole spacing)