GP (General Purpose) Amp

Overview:

The ML142 GP Amp is a general-purpose non-isolated amplifier with high input impedance suitable for use with strain-gauge or powered transducers requiring power in the range ±10 V. Full scale ranges (2 mV to 10 V) are supported as well as both hardware and software filters.

The following are some of the transducers suitable for use with the GP amp:

• MLT0015 High Grade Isotonic Transducer
• MLT201 Cardio Microphone
• MLT1020 Plethysmographs
• MLT409 Skin Temperature Probe
• MLT415 Nasal Temperature Probe
• MLT003 Hand Dynamometer (discontinued)

Hardware:
ADInstruments signal conditioners only function with PowerLab data acquisition units and therefore are not suitable for use with other data acquisition systems.

Features:

Applications:

Temperature measurement, powered transducers and measuring systems of various kinds. The GP Amp can be used with intracellular head stages.

Specifications:

Input

• Number of inputs: 1 (standard 8-pin DIN)
• Input configuration: Differential
• Amplification ranges: ±2 mV to ±10 V full scale in 12 steps (combined PowerLab and GP Amp)

• Amplification accuracy: ±0.5% (combined PowerLab and GP Amp)
• Maximum input voltage: ±15 V
• Input impedance: 100 MΩ
• Frequency response ( 3 dB): 5 kHz maximum at all gains with filters off
• CMRR (differential): 100 dB @ 50 Hz (typical)
• Input noise: <2 μV_rms referred to input at highest gain

Excitation and Zeroing

• Excitation voltage range: 0 to 20 V DC (±10 V referred to ground), adjusted by external resistor
• Transducer drive current: ±100 mA maximum
• Zeroing circuitry: Software-controlled, either manual or automatic
• Internal offset resolution: 12-bit (internal DAC) ±2048 steps about 0 V
• Designed to offset a maximum of ±5 V, giving a resolution of ~2.5 mV

Filters

• Low-pass filtering: 1, 10, or 100 Hz (software-selectable) using fourth-order Bessel filter, or Off (the non-filtered GP Amp bandwidth is 5 kHz)
• High-pass filtering: DC or 0.3 Hz (software-selectable)

Control Port

• I²C port: Provides control and power. Interface communications rate of ~50 Kbits/s.

Physical Configuration

• Dimensions (h × w × d): 50 mm × 76 mm × 260 mm (1.96” × 3.0” × 10.2”)
• Weight: 775 g (1 lb 11 oz)
• Power requirements: 3.2 W (with no transducer)
• Operating temperature range: 0 to 35 °C, 0 to 90% humidity (non-condensing)

ADInstruments reserves the right to alter these specifications at any time.