ELECTRONIC DESIGN & ENGINEERING. ICP_FM3 Versatile DC AC IEPE Signal Conditioning. 1 ICP_FM3 Introduction

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1 1 ICP_FM3 Introduction ICP_FM3 is a versatile signal conditioning module for DC / AC or IEPE (ICP TM ) applications. The amplifying circuit is additionally equipped with a switchable constant current source, which is supplied with 24V in order to fulfil the requirements of the 2-wire IEPE technology. Because the quality of the signal is dependent in no small measure on the power supply, the ICP_FM3 does without an "on-board" switching regulator (in contrast to the ICP_FM1) in order to guarantee the best possible signal quality. The 3 supply voltages +15V, -15V and +24V must be supplied externally. Amplifiers To permit adaptation to different measuring applications, the modules can be equipped with different types of amplifiers: Type 1: Single FET amplifier with gain factor +1 Type 2: Instrumentation amplifier type PGA207 with switchable gain factor Type 3: Combination of the single FET amplifier and a downstream amplifier type PGA103 with switchable gain factor Type 4: Combination of the PGA207 and the downstream amplifier PGA103. Gain factors of can be programmed. Amplification in excess of 100 cannot be used for high-impedance AC or IEPE applications. These are reserved for measurement configurations of low-source impedance such as strain gauges or other DC measurements because with high-source impedance factors and high amplifications, the DC offset can no longer be controlled. Even input offset voltages in the uv range result in output errors in the 2-digit mv range. Active filters The versatility of the ICP_FM3 module is increased even more by combining amplifier, IEPE current source plus active filters for anti-aliasing applications on the module. The "Sallen-Key" low-pass filter connection can be laid out for the filter characteristics "Butterworth" (standard) or "Bessel" (in special cases) in the 4th or 8th order. The filters can be equipped for fixed cut-off frequencies of between 500Hz and 20kHz. Definition of the cut-off frequency, order and characteristic is dependent on the measuring task and is the responsibility of the user. ICP TM trademark of PCB Group EIGNER MESSTECHNIK GmbH Augsburg Germany info@eigner-messtechnik.de 1 / 11

2 2 ICP_FM3 block schematic IEPE power source Amplifier Active filters 3 Equipment variants Amplifier type 1: single FET amplifier G = 1 - AC - DC - IEPE Amplifier type 2: instrumentation amplifier PGA207 single-ended input G = AC - DC - IEPE EIGNER MESSTECHNIK GmbH Augsburg Germany info@eigner-messtechnik.de 2 / 11

3 Amplifier type 2: instrumentation amplifier PGA207 real instrumentation input G = AC - DC Amplifier type 3: single FET amplifier plus Programmable Gain Amplifier PGA103 single-ended input G = AC - DC - IEPE Amplifier type 4: PGA207 and PGA103 single-ended input G = low-imped. DC EIGNER MESSTECHNIK GmbH Augsburg Germany info@eigner-messtechnik.de 3 / 11

4 Amplifier type 4: PGA207 and PGA103 real instrumentation input G low-imped. DC The most simple IEPE configuration: single-ended input G = 1 IEPE current: 4mA The most common IEPE configuration: single-ended input G = 1-10 IEPE current: 4mA EIGNER MESSTECHNIK GmbH Augsburg Germany info@eigner-messtechnik.de 4 / 11

5 4 Module versions different applications different connectors Version A: Front-panel installation module Input: BNC Output and power supply: 5-pin terminal block Version B: Mainboard plug-on module Input: male connector X1 4-pin Output and power supply: male connector X2 5-pin Standard profile: AMP Modu II male connector plus AMP HV-100 female connector M2x6 screw, clearance to PCB 10.5mm = 10mm bolt + 1 washer Option: low-profile male and female connectors available for a lower installation height. EIGNER MESSTECHNIK GmbH Augsburg Germany info@eigner-messtechnik.de 5 / 11

6 Installation example: 4-channel ICP_FM3 Version A Power supply board for 4 modules EIGNER MESSTECHNIK GmbH Augsburg Germany info@eigner-messtechnik.de 6 / 11

7 Installation of 4 modules incl. power supply board EIGNER MESSTECHNIK GmbH Augsburg Germany info@eigner-messtechnik.de 7 / 11

8 5 ICP_FM3 module technical specifications Overall dimensions - w/o BNCs: x 18 [mm] with BNCs: 77.7 x 18 [mm] Male connector to male connector and male connector to mounting hole: Suitable for mainboards with 1/10" grid 6 Switches and jumpers Position: Offset trimpot P1, X1-pin1, X2-pin1, Cl1-pin1, DIP switch, jumper J5 Position: I _IEPE set-up: jumper J5 Option: I _IEPE [ma] EIGNER MESSTECHNIK GmbH Augsburg Germany info@eigner-messtechnik.de 8 / 11

9 7 PIN assignment module Male connector or terminal block X1 X2 CL 1 GND 1 +24V 1 Output 2 + Input 2 +15V 2 GND 3 - Input 3-15V 3-15V 4 GND 4 GND 4 +15V 5 Output 5 +24V 8 Amplification settings Amplifier type 2: programmable instrumentation amplifier PGA207 DIP switch on module PGA GAIN OFF OFF 1 recommended for DC / AC / IEPE ON OFF 2 recommended for DC / AC / IEPE OFF ON 5 recommended for DC / AC / IEPE ON ON 10 recommended for DC / AC / IEPE Amplifier type 3: Programmable Gain Amplifier PGA103 DIP switch on module PGA GAIN ON ON 1 recommended for DC / AC / IEPE OFF ON 10 recommended for DC / AC / IEPE ON OFF 100 recommended for DC / AC / IEPE OFF OFF not valid invalid setting Amplifier type 4: combination PGA207 and PGA103 DIP switch on module PGA207 PGA GAIN OFF OFF ON ON 1 recommended for DC / AC / IEPE ON OFF ON ON 2 recommended for DC / AC / IEPE OFF ON ON ON 5 recommended for DC / AC / IEPE ON ON ON ON 10 recommended for DC / AC / IEPE OFF OFF OFF ON 10 not recommended ON OFF OFF ON 20 recommended for DC / AC / IEPE OFF ON OFF ON 50 recommended for DC / AC / IEPE ON ON OFF ON 100 recommended for DC / AC / IEPE OFF OFF ON OFF 100 not recommended ON OFF ON OFF 200 recom. only for low-imped. DC OFF ON ON OFF 500 recom. only for low-imped. DC ON ON ON OFF 1000 recom. only for low-imped. DC X X OFF OFF not valid invalid setting EIGNER MESSTECHNIK GmbH Augsburg Germany info@eigner-messtechnik.de 9 / 11

10 9 Active filters: cut-off frequencies group delay times Blue: amplitude over frequency Black: group delay time over frequency Red: cut-off frequency (-3dB) Butterworth 4th order Example 1 khz Butterworth 8th order Example 1 khz EIGNER MESSTECHNIK GmbH Augsburg Germany info@eigner-messtechnik.de 10 / 11

11 10 Electrical specifications Power supply: Signal range: Frequency range: Amplifier precision: DC offset: Amplifier, filter: +/-12VDC to +/-15VDC IEPE current source: +22VDC to +26VDC Current +15V max. -15V max: 18mA (dependent on the amp types) Current +24V max. programmed IEPE current plus approx. Supply +/-12V: V Signal = 0 to +/-8V Supply +/-15V: V Signal = 0 to +/-10V (min DC: 0 to 20kHz (min.) AC / IEPE: 0.5 (-3dB) to 20kHz (min.) PGA207: max. +/- 0.1% PGA103: max. +/- 0.2% Gain = 1: < +/- 5mV Gain > 1: adjustable EIGNER MESSTECHNIK GmbH Augsburg Germany info@eigner-messtechnik.de 11 / 11