Gamry Instruments Interface 1000, Operator'S Manual

Page: 48 / 88

Chapter 6: Instrument Circuitry--Interface 1000 Schematic/Block Diagrams
6 - 4
Figure 6-3
One A/D Signal Chain in the Interface 1000
Notes for Figure 6-3:

This diagram shows one of two identical ADC channels. One channel is dedicated to measurement of
the potentiostat’s current signal and the other is used to measure the voltage signal.

Both A/D converters are triggered simultaneously to start a conversion. This trigger and the pulse
updating the Scan DAC voltage are under the control of a hardware state-machine. This insures that all
waveform and data-acquisition timing is tightly controlled and reproducible point-to-point.
By default, the data acquisition is synchronized with the system’s 600 kHz power-supply switching-
frequency reducing noise from the power supply. Data-acquisition times that are a multiple of 1.666
µs will maintain this synchronization.

All analog signals are received differentially as shown here.

The 5 Hz, 1 kHz, 10 kHz, 200 kHz and 1.4 MHz filters are two-pole Butterworth filters.

The voltage-measurement channel includes a programmable 1×−0.25× gain circuit. In the 0.25 gain
position, voltages as high as 12 V can be measured.