A400DI
Dual Channel High Voltage Linear Amplifiers
- Category: Dual Channel High Voltage Linear Amplifiers
- Manufacturer: Pendulum Instruments
- Gain: ×20 (fixed)
- Output voltage range: ±200 V (bipolar); up to 800 Vpp in counter-phase mode
- Maximum output current: 150 mA (current limiting included)
- Bandwidth: DC to 1 MHz (100 Vpp); DC to 500 kHz (at maximum voltage)
- Data sheet: Download PDF
- External link: Official product page
Overview
The A400DI dual-channel high voltage linear amplifier consists of two independent A400 amplifiers sharing a power supply and ground reference, with a low voltage phase inverter built into the enclosure so that channel 2 can take the inverted channel 1 signal and work in counter-phase drive mode. A fixed gain of ×20 means the operator only has to set the source voltage to control the high voltage output precisely, with no gain setting to get wrong. When the two outputs drive a floating load in counter-phase, the effective output amplitude reaches 800 Vpp, greatly extending what can be driven — piezo actuators, MEMS devices, OLED panels and liquid crystal materials. A built-in current limiting circuit prevents damage from an accidental short circuit, and an output impedance below 0.1 Ω gives steady drive into both capacitive and resistive loads. The A400DI is widely used in research institutes, R&D laboratories and component manufacturing, and is the first choice wherever a low voltage signal source has to be stepped up into a high voltage test environment.
Key features
- Dual-channel counter-phase drive — Two independent amplifiers share a power supply and ground reference; the built-in low voltage phase inverter inverts the channel 1 input signal and feeds it to channel 2 over a BNC link, giving counter-phase dual-output drive.
- High voltage, large amplitude output — At a fixed gain of ×20, each channel delivers ±200 V / 150 mA; with a load bridged across the two outputs, the effective amplitude doubles to as much as 800 Vpp, driving high voltage devices and materials test equipment easily.
- Very wide, ultra-linear gain — Bandwidth extends from DC to 1 MHz (100 Vpp) and to 500 kHz at maximum voltage; the 400 V/µs slew rate and ultra-linear gain across the whole bandwidth keep the signal faithful.
- Current limiting protection circuit — The built-in current limiting circuit protects both the amplifier and the device under test automatically in the event of an accidental short circuit, making laboratory work safer and reducing the risk of damage through mishandling.
- Steady drive from a low output impedance — An output impedance below 0.1 Ω gives steady voltage drive into both resistive and small capacitive loads, suiting precision devices such as piezo actuators, MEMS, OLED and liquid crystal materials.
- Flexible operating modes — It can be used as two fully independent high voltage channels, or switched to counter-phase mode to double the effective output amplitude; both modes use the same instrument, adapting to varied measurement requirements.
Typical applications
- Piezo actuator drive and nanopositioning control — On an optical bench or in a precision positioning system, an R&D engineer uses the A400DI to amplify the ±10 V low voltage output of a function generator to ±200 V, driving a piezo stack actuator accurately for nanometre displacement control. The counter-phase dual output can be bridged directly across the actuator, doubling the effective voltage swing to ±400 V with no external step-up circuit.
- Electrical characterisation and functional verification of MEMS devices — MEMS sensors, microactuators and micromirror arrays need precise high voltage excitation during development to measure their electrostatic or piezoelectric response. A laboratory engineer uses the two independent A400DI channels to excite the differential electrodes of one MEMS device separately, then compares the phase and amplitude relationship between channels using oscilloscope maths to obtain the device's transfer function and non-linear behaviour quickly.
- Evaluating drive waveforms for liquid crystal panels and OLEDs — During materials development or reliability testing, liquid crystal modules and OLED display devices need high voltage AC waveforms of variable frequency to assess their electro-optical characteristics and threshold voltage. The A400DI's inverter produces a differential drive signal directly, so a floating device under test sees the full bipolar voltage while the 1 MHz bandwidth requirement is still met — suitable for fast sweep measurement of material characteristic curves over a wide temperature range.
Key specifications
Key specifications for A400DI, as published by Pendulum Instruments. For the full datasheet or a customized configuration, please get in touch.
| Gain | ×20 (fixed) |
|---|---|
| Output voltage range | ±200 V (bipolar); up to 800 Vpp in counter-phase mode |
| Maximum output current | 150 mA (current limiting included) |
| Bandwidth | DC to 1 MHz (100 Vpp); DC to 500 kHz (at maximum voltage) |
| Slew rate | 400 V/µs |
| Input voltage (nominal) | max. ±10 V |
| Input impedance | 1 MΩ (30 pF) |
| Output impedance | < 0.1 Ω |
| Channels | 2 (independent channels sharing power supply and ground) |
| Power supply | 100 V, 110 V or 220 V, 50/60 Hz (a version with a 110/220 V selector switch is also available) |
| Dimensions (W x H x D) | 257 mm × 102 mm × 262 mm |
| Weight | 4 kg |
Frequently asked questions
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