A1436 / A1436A

Overview

The A1436 is a series of transimpedance amplifiers designed with a differential input configuration. Its primary function is to generate an output voltage proportional to the difference between the input currents. This design choice is crucial, as it minimizes induced noise in applications where significant sources of interference are present.

Both versions are well suited for reading currents from various semiconductor detectors, such as diamond detectors, silicon detectors, and photodiodes. They can operate in both photovoltaic and photoconductive modes. A bias voltage can be internally generated and supplied to the differential inputs, programmable up to a maximum of 10 V. This bias voltage is applied differentially, with a positive bias to the cathode and a negative bias to the anode, ensuring reverse junction polarization of the detector. Both models also feature electrostatic discharge (ESD) input protection.

All operational parameters of the A1436 preamplifiers are individually programmable via an RS485 connection. Configuration is performed using a Command Line Interface (CLI) through a USB-RS485 adapter connected to a PC and a terminal emulator (such as PuTTY). The module settings are stored in non-volatile memory and are automatically restored upon power-on. The devices operate from a ±12 V power supply.

For system integration, up to 254 modules can be connected in a chain, each requiring a unique ID from 1 to 254. Communication occurs in half-duplex mode. To conserve power and further reduce noise, the modules enter sleep mode after 20 seconds of inactivity, greatly reducing microcontroller-induced noise on the preamplifier outputs. They can be reactivated by sending any two characters followed by the Enter key.

Both versions include a programmable 1 kHz low-pass filter. The 8-channel (A1436) version provides seven selectable transimpedance values per channel (10⁹ to 10³), while the 1-channel (A1436A) version provides six values (10⁸ to 10³).