Servoflo Corporation Voltage-to-Current Converter AM452 With Differential Input

Input: Differential input voltages Output: 0/4...20mA adjustable BLOCK DIAGRAM FEATURES Wide supply voltage range: 6...35V Wide operating temperature range: -40°C...+85°C Internal voltage reference for transducer excitation Operational amplifier input Adjustable gain and offset Analog Current Output: Three-wire or two-wire output Protection against reverse polarity and short-circuiting Instrumentation amplifier input with a wide voltage range of ±400 mV Suitable for HART applications Output signal limiting Integrated current source Adjustable integrated reference voltage source of 5V to 10V APPLICATIONS Sensor Current Transmitter (for example pressure) Programmable Current Source GENERAL DESCRIPTION AM452 is an integrated transducer with an adjustable current output which has been specifically designed for the conditioning of differential input signals. It permits the independent adjustment of the offset and full-scale current using just a few components. The IC consists of various functional modules. In addition to the instrumentation amplifier in the signal path, there is an operational amplifier which is used to set the gain. The offset can be adjusted using the zero adjust stage and/or the SET stage module. An additional operational amplifer can supply external components. The adjustable current output stage permits 2 and 3-wire operaton by way of a simple amendment to the circuitry. The IC is distinguished by its many protective functions which include protection against reverse polarity and short-circuiting as well as an internal current limit.