| 摘要 |
PCT No. PCT/JP86/00240 Sec. 371 Date Jan. 9, 1987 Sec. 102(e) Date Jan. 9, 1987 PCT Filed May 9, 1986 PCT Pub. No. WO86/06896 PCT Pub. Date Nov. 20, 1986.There are provided a current-voltage converting means (22) for converting a constant current from a constant current supplying circuit into a voltage, an integration circuit (26), a switched capacitor (23) arranged between the current-voltage converting means (22) and the integration circuit (26) for controlling the charge amount supplied to the integration circuit, and first and second control signal generating circuits (28, 31) respectively having counters (29, 32) and comparators (30, 33) and supplied with first and second digital input signals for controlling switching frequency of the switched capacitor (23) to thereby generate, at an output of the integration circuit (26), an analog signal proportional to a product of the first and second digital input signals, to thereby simplify the circuit configuration and reduce the production cost.
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