Patent ID: 9030041
Filing Date: 2015-05-12
Classification: B60R,G06F

Abstract:
1. An on-vehicle electronic control apparatus comprising a microprocessor for drivingly controlling an electrical load group in response to operating states of on-vehicle sensor groups and contents of a control program stored in a non-volatile program memory, and a constant-voltage power circuit powered from an on-vehicle battery and generating a plurality of types of output voltages, wherein the microprocessor comprises: an arithmetic circuit section cooperating with the non-volatile program memory; a volatile RAM memory with at least a partial region as a backup memory; an input/output interface circuit; and a standby open-circuit switch that cuts off a feeder circuit against circuits other than the backup memory at standby, wherein the constant-voltage power circuit comprises a first, a second and a fourth constant-voltage power circuit powered from the on-vehicle battery and supplying a stabilized output voltage to the microprocessor, the first constant-voltage power circuit is powered from the on-vehicle battery through an output contact of a power relay energized when a power switch is closed, and de-energized at an interval of a predetermined delay time when the power switch is opened, to generate a first output voltage Vif, the first output voltage Vif is applied to the input/output interface circuit, the second constant-voltage power circuit is powered from the on-vehicle battery through the output contact of at least the power relay to generate a second output voltage Vcp, the second output voltage Vcp is applied to the arithmetic circuit section provided in the microprocessor, the non-volatile program memory, the RAM memory, and the backup memory, and the fourth constant-voltage power circuit is directly powered from the on-vehicle battery to generate a fourth output voltage Vup and is connected with an output terminal of the second constant-voltage power circuit through a serial resistor, and wherein a resistance value R of the serial resistor is defined as follows: when the standby open-circuit switch is opened and the fourth output voltage Vup supplies power to the backup memory, an upper limit is regulated on that a predetermined hold current is supplied, and when the standby open-circuit switch is closed and power supply is performed in parallel to the second constant-voltage power circuit, a lower limit is regulated no that an upper limit of the current shunted to the fourth constant-voltage power circuit is less that or equal to the allowable current of the fourth constant-voltage power circuit.