Hitachi RAM-40QH5 Service Manual page 48

7. Peripheral circuits of microcomputer
Fig. 7-1 shows the microcomputer and its peripheral circuits.
G
Table 7-1, the basic operations of each circuit block and Fig. 7-2, the system configuration.
Table 7-1
Circuit block
Peak current
cutoff circuit
Overload external
judgment circuit
Voltage amplifier
circuit
Reset circuit
Fig. 7-1 Peripheral circuit of microcomputer (AX-6M01)
This circuit detects DC current flowing to power module: When over-current
(instantaneous value) flows, it stops upper and lower arm drive circuits and also
produces lp signal to stop microcomputer.
This circuit detects DC current flowing to power module and produces signal to
notify microcomputer of overload status.
This circuit voltage-amplifies DC current level detected by detection resistor and
sends it to microcomputer. In addition, setting of internal/external overload
judgment is performed.
This circuit produces reset voltage.
Basic operation
– 54 –