LE-41 Charge amplifier, 4 channels, bandwidth 0.3 Hz - 22 kHz

Charge amplifier, 4 channels, bandwidth 0.3 Hz - 22 kHz
  • Запоминание настроек в энергонезависимой памяти
  • 4 independent channels
  • Settings are stored in non-volatile memory
  • RS-485 control interface
  • Software-control function of breakage or short circuit monitoring in input lines
  • Software-installed bandwidth

The external module LE-41 is a 4-channel charge amplifier. It is used as a matching device for piezoelectric sensors (accelerometers) for vibrometry tasks.

LE-41 can be interfaced with LTR22, LTR24E14-140M ADC modules (powered by them), or with LTR11. It is possible to manufacture custom cables.

LE-41 amplifier can be used either with preset settings (in accordance with the order) or in controlled mode with an RS-485 interface, for example, from the LTR43 control module, or from the LTR-EU crate via RS-485/422-UART cable, or from any RS-485 adapter connected to the computer.

LE-41 supports the next modes: channel-by-channel software sensitivity switching and an upper bound of the bandwidth of the controlled low-pass filter, control of the input circuit breakage.

Number of channels 4
Transmission ratio 0.9 mV/pC, 10 mV/pC
Accuracy of transmission ratio ± 9% without calibration
± 1% with calibration
The lower limit of bandwidth frequencies 0,3 Hz (at –3 dB level)
The upper limit of bandwidth frequencies 2200 Hz, 22000 Hz (at –3 dB level)
The decay of the frequency response above 20000 Hz Not less than 12 dB/octave
The decay of the frequency response below 0.3 Hz 12 dB/octave
Inter-channel signal interference Not worse than -90 dB
Charge input
Maximum charge amplitude in the passband, nC 9.0 (for a transmission ratio of 0.9 mV/pC)
0.8 (for a transmission ratio of 10 mV/pC)
Typical value of the noise level,
reduced to the input (with a capacity of
source of charge 1000 pF)

6 fC (in the transmission bandwidth 0,3 ... 2200 Hz)
15 fC (in the transmission bandwidth of 0.3 ... 22000 Hz)

Connectors TNC (4 pcs)
Voltage outputs with common ground
Output peak-peak voltage, not less than ±8 V (1 mA)
Output impedance 62 Ohm ± 1%
Output bias voltage Not more than ±10 mV
Connector DRB-25F
Control interface RS-485, eg from LTR43 module or other system
The main functions of microcontroller
  • Storage of calibration factors and serial number for software access to them from RS-485.
  • Storage of specified settings (in particular, when using LE-41 without software control).
  • Program on/off test mode (for checking the integrity of the input circuit of each channel).
  • Software control of the input range and the upper frequency of the bandwidth.
Power supply
From LTR22LTR24-1 module or an external bipolar voltage source +12…+15 V (not more than 30 mA)
-12…-15 V (not more than 16 mA)
Dimensions 95х150х26 mm
Design features
  • Plastic case
  • Screening inside the case
  • Potential technical possibility of application in embedded systems (including without case)
  • Separate ground terminal
Operating condition
Operating temperature range -40...+55 ºС  (without condensation of moisture, without contact with chemically aggressive substances)

For more detailed technical information, see Manual.

For your reference: The charge amplifiers can be used to obtain the signal from charge sources (sensors having a piezo-crystal without a built-in amplifier) ​​and to convert it into an output signal (voltage) suitable for feeding to a general-purpose ADC. This is a traditional (historical) way for accelerometers for vibrometry tasks. But there is a modern alternative way to build such systems — to use accelerometers with built-in amplifier and current supply (ICP-sensors) in conjunction with ADCs (such as LTR24-2, LTR25) that can directly connect ICP sensors.

  • LE-41
    LE-41 module


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Fax: +7 (495) 785-95-14

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Technical support: en@lcard.ru

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Russian Federation

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