Data converter and line driver for a digital data communication system
AssigneeSundstrand Corporation
InventorJohn E. Shepler
Life of this patent
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Abstract
A data converter comprises a pair of NAND gates and a pair of bipolar differential operational amplifiers. Monopolar binary digital data in uninverted and inverted forms and a clock signal are connected with the NAND gate inputs. The NAND gate outputs are complementary monopolar data signals at the clock frequency and are cross-coupled to the direct and inverting inputs of the operational amplifiers. The outputs of the operational amplifiers are complementary bipolar data signals. Low pass filters establish the rise and fall times of the bipolar data signals and the high frequency response limit. Voltage buffers isolate the converter from the data transmission line and include current limiting resistors which prevent damage in the event of a short circuit of the line.
Claims9
In a digital data communication system having sources of univerted and inverted monopolar digital data signals and a source of clock signals at a frequency twice the frequency of the data, a data converter comprising:
- first and second two input NAND gates each having one input connected with said clock signal source, the first NAND gate having its other input connected with said uninverted data source and the second NAND gate having its other input connected with the inverted data source, the outputs of the NAND gates being complementary monopolar data signals at the clock frequency;
- and
- first and second bipolar operational amplifiers having inverting and noninverting inputs crosscoupled to the outputs of said NAND gates, the outputs of the operational amplifiers being complementary bipolar data signals with intervals between data pulses.
Dependencies are inferred from the claim text.