| 摘要 |
PURPOSE:To generate automatically an optional level of resistance value with high accuracy and without effected by the ambient temperature, etc., by compensating the resistance value of a reference resistor with arithmetic compensation and in response to the ambient temperature and deciding the current ratio of a constant current based on the compensated resistance value. CONSTITUTION:A compensation data on the temperature coefficient, etc. is previously stored in an arithmetic circuit OPS. Then the arithmetic compensation is given to the resistance value of a reference resistor Rs based on the ambient temperature detected by a temperature detector TMP. Based on this compensated value, the circuit OPS calculates a constant alpha corresponding to the ratio between the resistance value of the resistor Rs and optional value R0 set at a resistance setter SET. This constant alpha is applied to a constant current source CCS to decide a current ratio alpha of the constant current. As a result, the resistance value can be generated without effected by the ambient temperature, etc. |
