DESCRIPTIONThe 1B22 is an isolated voltage-to-current converter thatincorporates transformer isolation to achieve high performanceand automated surface mount manufacturing for low costand increased reliability. Designed for industrial applications,it is especially suited for harsh environments with extremelyhigh common-mode interference. With programmable inputsand outputs, the 1B22 provides an unbeatable combination ofversatility and performance in a compact plastic package.Functionally, the V/I converter consists of four basic sections:input conditioning, modulator/demodulator, isolated loopsupply and current source (Figure 1). The 1B22 is pin program-or 4 to 20 mA outputs using an internal resistor network. It canalso be set by an external resistor to accept 0 V to +1 V to 0 Vto +10 V inputs. Transformer coupling provides 1500 V rmsgalvanic isolation between the inputs and the current loop.Nonlinearity is an excellent 0.05% max.Loop power is generated internally through a dc/dc conv FEATURESInternal Isolated Loop Supply Drives 1000 LoadPin Programmable Inputs: 0 V to +5 V or 0 V to +10 VPin Programmable Outputs: 4 to 20 mA or 0 to 20 mAHigh CMV Isolation: 1500 V RMSNormal-Mode Output Protection: 240 V RMSHigh AccuracyLow Offset Tempco: 300 nA/CLow Gain Tempco: 50 ppm/CLow Nonlinearity: 0.02%High CMR: 90 dB minSmall Package: 1.0" 2.10" 0.35"Meets IEEE STD 472: CMV Transient Protection (SWC)APPLICATIONSMultichannel Process ControlD/A ConverterCurrent Loop InterfaceAnalog Transmitters and ControllersRemote Data Acquisition SystemsGENERAL DESCRIPTIONThe 1B22 is an isolated voltage-to-current converter thatincorporates transformer isolation to achieve high performanceand automated surface mount manufacturing for low costand increased reliability. Designed for industrial applications,it is especially suited for harsh environments with extremelyhigh common-mode interference. With programmable inputsand outputs, the 1B22 provides an unbeatable combination ofversatility an SPECIFICATIONS(typical @ +25C a