PX200 - 140W Voltage Amplifier
|Output Voltage Ranges||100Vp-p||150Vp-p||200Vp-p|
|RMS Current||3.1 A||2.0 A||1.5 A|
|Pulse Current||8.0 A||8.0 A||8.0 A|
|Power Bandwidth||110 kHz||93 kHz||55 kHz|
|Slew Rate||35 V/us|
|Signal Bandwidth||390 kHz|
|Max Power||140 W Dissipation|
|Offset||0V to Full Range with front panel adjustment|
|Load||Stable with any load|
|Noise||150 uV RMS (10 uF Load, 0.03 Hz to 1 MHz)|
|Overload||Continuous short-circuit, thermal|
|Voltage Monitor||1/20 V/V (BNC)|
|Current Monitor||1 V/A (BNC)|
|Analog Input||Signal input (BNC, Zin = 48.7k)|
|Output Connectors||LEMO 0B, LEMO 00, Screw Terminals|
|Power Supply||90 Vac to 250 Vac|
|Environment||0 - 40 C (32-104 F), Non-condensing humidity|
|Dimensions||212 x 304.8 x 88 mm (8.35 x 12 x 3.46 in)|
|Weight||2 kg (4.4 lb)|
The PX200 is a low-noise voltage amplifier designed to drive capacitive and other loads from DC to hundreds of kHz. The output voltage range can be unipolar, bipolar, or asymmetric with a peak-to-peak value of between 50V and 200V. Two amplifiers can be connected in bridge-mode to provide ±200V or +400V. The amplifier will deliver up to 4 Amps peak with a sinusoidal output, or up to 8 Amps peak for pulse applications.
The amplifier is compact, light-weight, and can be powered from any mains supply. The output connectors include LEMO 00, LEMO 0B, and 4mm Banana Jacks so many commercially available piezoelectric stack actuators can be directly connected. The PX200 is suited to a wide range of applications including: electro-optics, ultrasonics, vibration control, nanopositioning systems, and piezoelectric motors.
Output Voltage Range
The desired output voltage range is specified when ordering. The default output range is 0V to +200V (PX200-V0,200). The available voltage ranges and associated current limits are listed below.
|Voltage Range||RMS Current||Peak Current||Order Code|
|0V to +200||1.5A||2.0A||PX200-V0,200|
|0V to +150||2.0A||4.0||PX200-V0,150|
|0V to +100||3.1A||4.0A||PX200-V0,100|
|0V to +50||3.1A||8.0A||PX200-V0,50|
|-50V to +50||3.1A||4.0A||PX200-V50,50|
|-50V to +100||2.0A||4.0A||PX200-V50,100|
|-50V to +150||1.5A||2.0A||PX200-V50,150|
|-100V to +50||2.0A||4.0A||PX200-V100,50|
|100V to +100||1.5A||2.0A||PX200-V100,100|
|-100V to 0||3.1A||4.0A||PX200-V100,0|
|-150V to 0||2.0A||4.0A||PX200-V150,0|
|-200V to 0||1.5A||2.0A||PX200-V200,0|
The PX200 has a peak and average current limits as described in Table 1. The RMS current limit defines the maximum frequency that is achievable with a capacitive load. This topic is discussed in “Power Bandwidth”.
During short-circuit the output current is limited to the rated maximum. The peak current can be drawn for up to five milliseconds before the output is disabled for three seconds. The average current limit has a time-constant of ten milliseconds and is reset 50 milliseconds after a previous current pulse. This behaviour is described in “Overload and Shutdown”.
Pulse Current Option
For applications that require a high peak current, the peak current limit can be increased to 8 Amps by appending the order code with “-PULSE”, e.g. “PX200-V0,200-PULSE”. In this configuration, the average current limit remains the same; however, the peak current limit is increased to 8 Amps and the maximum pulse duration is reduced to the time listed in Table 2. The voltage span is the peak-to-peak output voltage range, e.g. the voltage span for the -50V to +150V range is 200V .
|Voltage Span||Pulse Current||Pulse Time|
For a current pulse that is less than the peak current limit, the maximum pulse duration is described in the Figure below
With a capacitive load, the RMS current for a sine-wave is
where Vpp is the peak-to-peak output voltage, C is the load capacitance and f is the frequency. Therefore, the maximum frequency for a given RMS current limit Irms, capacitance, and voltage is
The above equation is also true for any periodic waveform, including triangle waves and square waves. This property arises since the amplifier detects average current, which not affected by the waveform shape.
The ‘power bandwidth’ is the maximum frequency at full output voltage. When the amplifier output is open-circuit, the power bandwidth is limited by the slew-rate; however, with a capacitive load, the maximum frequency is limited by the RMS current and load capacitance. The power bandwidth for a range of capacitive loads is listed below.
|Load Capacitance||50V Range||100V Range||150V Range||200V Range|
|10 nF||222 kHz*||111 kHz*||74 kHz*||55 kHz*|
|30 nF||222 kHz*||111 kHz*||74 kHz*||55 kHz*|
|100 nF||222 kHz*||111 kHz*||62 kHz||35 kHz|
|300 nF||93 kHz||46 kHz||20 kHz||11 kHz|
|1 uF||28 kHz||14 kHz||6.2 kHz||3.5 kHz|
|3 uF||9.3 kHz||4.6 kHz||2.0 kHz||1.1 kHz|
|10 uF||2.8 kHz||1.4 kHz||60 Hz||350 Hz|
|30 uF||930 Hz||460 Hz||200 Hz||117 Hz|
In the above table, the frequencies limited by slew-rate are marked with an asterisk. The slew-rate is approximately 35 V/uS which implies a maximum frequency of
Small Signal Bandwidth
The small-signal frequency response and -3 dB bandwidth is described in the Figures below
|10 nf||393 kHz|
|30 nf||431 kHz|
|100 nf||367 kHz|
|300 nf||208 kHz|
|1 uf||88 kHz|
|3 uf||30 kHz|
|10 uf||9.3 kHz|
|30 uf||3.7 kHz|
|110 uf||1.3 kHz|
The output voltage noise contains a low frequency component (0.03 Hz to 20 Hz) that is independent of the load capacitance; and a high frequency (20 Hz to 1 MHz) component that is approximately inversely proportional to the load capacitance.
The noise is measured with an SR560 low-noise amplifier (Gain = 1000), oscilloscope, and Agilent 34461A Voltmeter. The low-frequency noise is plotted in the figure below. The RMS value is 120 uV with a peak-to-peak voltage of 600 uV.
The high frequency noise (20 Hz to 1 MHz) is listed in the table below versus load capacitance. The total RMS noise from 0.03 Hz to 1 MHz is found by summing the RMS values, that is For a load capacitance of less than 1 uF, the noise is primarily broadband thermal noise; however, for a capacitance of greater than 1 uF, the noise is primarily due to low-frequency noise.
|Load Cap.||Bandwidth||HF Noise RMS||Total Noise RMS|
|10 nf||393 kHz||530 uV||543 uV|
|30 nF||431 kHz||586 uV||598 uV|
|100 nF||367 kHz||689 uV||699 uV|
|300 nF||208 kHz||452 uV||468 uV|
|1 uF||88 kHz||261 uV||287 uV|
|3 uF||30 kHz||106 uV||160 uV|
|10 uF||9.3 kHz||56 uV||132 uV|
|30 uF||3.7 kHz||52 uV||131 uV|
|100 uF||1.3 kHz||47 uV||129 uV|
|Offset||Adds a DC offset to the input signal|
|Input||Input||Input signal ( +/-15V max)|
|Voltage Monitor||Output||The measured output voltage, scaled by 1/20|
|Current Monitor||Output||The measured output current, 1 A/V|
|Input+||Input||Internally connected to the centre pin of the Input BNC connector|
|Input-||Input||Internally connected to the shield of the Input BNC connector|
|Volt Mon||Output||Internally connected to the Voltage Monitor BNC Output|
|Current Mon||Output||Internally connected to the Voltage Monitor BNC Output|
|Shutdown||Input||A voltage from +2V to +24V (relative to Input-) disables the amplifier|
|Overload Out||Output||+5V output when the amplifier is disabled or in overload state|
|Voltage Limits||Limits the maximum negative and positive output voltage|
|Overload||RED when the amplifier is disabled or in an overload state|
|Power||GREEN when the power is on|
|HV-||Output||Connected to the negative high-voltage power supply rail|
|HV+||Output||Connected to the positive high-voltage power supply rail|
|Output-||Output||High-voltage output signal return (used to measure current)|
|Output+||Output||High-voltage output signal|
|LEMO 00 Output||Output||High-voltage output connector, suits LEMO FFA.00.250 cable plug|
|LEMO 0B Output||Output||High-voltage output connector, suits LEMO FGG.0B.302 cable plug|
|DC Output Volt.||Display showing average output voltage|
The amplifier can be configured with an inverting, or non-inverting input, and a gain of either 20 or 10.
|Amplifier Configuration||Order Code||Notes|
|Gain = 20||(default)|
The DC offset control is configurable with a positive range, or a bipolar range. The front panel potentiometer can be disabled by enabling a PCB mounted trim-pot.
|Offset Configuration||Order Code||Notes|
|0V to +200V Range (default)||(default)|
|+/- 200V Offset Range||-OR2|
|Front panel source||(default)|
|PCB trim-pot source||-OS2||Disables front panel adjustment|
In bridged mode, two amplifiers are connected in series to double the output voltage range and power. For example, the Figure below shows the configuration to obtain ±200V across the load. A ±5V signal applied to both inputs produces ±200V across the load. In bridged mode, only the Output+ terminal from each amplifier is used, the negative output terminal is not connected. Since there is no current returning through the negative terminal, the current monitor is disabled; however, the overload and protection features are unaffected. Common bridged-mode configurations are listed in the Table below.
|Load Voltage||RMS Current||Positive Amp||Negative Amp|
|0V to 200V||3.1 A||PX200-V0,100||PX200-V100,0-INV|
|0V to 300V||2.0 A||PX200-V0,150||PX200-V150,0-INV|
|0V to 400V||1.5 A||PX200-V0,200||PX200-V200,0-INV|
The amplifier is protected against short-circuit, over-current, and excessive temperature. During these conditions, the front panel overload indicator will illuminate and the Overload Out signal is +5V. During an overload or shutdown state, the output is partially disabled and may float at approximately 50% of the voltage range. When the amplifier is switched on, the overload protection circuit is engaged by default and clears after three seconds. The amplifier can be shut down by an external source by applying a voltage of between +2V and +24V to the Shutdown input (relative to Input-). The impedance of the shutdown input is approximately 5 kΩ.
The PX200 has a side air intake and rear exhaust, which can not be obstructed. If sufficient airflow is not available, the amplifier will enter a thermal overload state as discussed in “Overload and Shutdown”.
The PX200 can be installed in a 19-inch x 2U rack space using the PX200-Rack1 kit. Two amplifiers can also be installed in a side-by-side configuration using the PX200-Rack2 kit.
PiezoDrive amplifiers are guaranteed for a period of 3 months. The warranty does not cover damage due to misuse or incorrect user configuration of the amplifier.
|V1||2014-2017||Download User Manual|