Circuit design considerations for current preamplifiers for scanning tunneling microscopy

Abstract

Current-to-voltage preamplifiers for scanning tunneling microscopy were tested side-by-side using a consistent testing protocol, to optimize performance and understand potential design trade-offs. Current-to-voltage gain and voltage noise density were measured as functions of frequency for two different circuit architectures: the feedback transimpedance amplifier and the current-shunt electrometer. The effect of specific component choices—of the integrated circuits, resistors, and capacitors—was also investigated.

Open STM: A low-cost scanning tunneling microscope with a fast approach method

“… Pre-amplifier: Given that tunneling currents typically range from picoamps to nanoamps [13] , a pre-amplifier is essential for detecting such minuscule currents using conventional circuits. Common designs include Transimpedance Amplifiers (TIA) and instrumentation amplifiers [14] . Control Circuit: The control circuit controls the various components of the STM system and facilitates communication with a computer.…”

Transimpedance Amplifier Design for Millisecond Current Pulses

“…The basic TIA in figure 2(a) has an op-amp embedded in the negative feedback loop with the resistor RF in the feedback path. Here, the feedback resistor RF converts the input current into a voltage [9]. The value of the feedback resistor is the transimpedance gain of the amplifier.…”

A low-cost, ultra-fast and ultra-low noise preamplifier for silicon avalanche photodiodes

“…Silicon avalanche photodiodes (Si APDs) are widely used in many laser applications such as light detection and ranging (LiDAR), laser rangefinding, fluorescence measurement and photon counting [1][2][3][4][5][6]. Si APD is a high-speed photodetector that internally multiplies the photocurrent generated from the incident light on its active area when it is reverse biased [7].…”