S-7750C Datasheet, PDF (24/44 Pages) Seiko Instruments Inc – PROGRAMMABLE PORT CONTROLLER (PORT EXPANDER WITH BUILT-IN E2PROM CIRCUIT)

PROGRAMMABLE PORT CONTROLLER (PORT EXPANDER WITH BUILT-IN E²PROM CIRCUIT)
S-7750C
Rev.1.1_00
„ Action of Circuit for Prevention Malfunction by Low Voltage
The S-7750C has a detection circuit which works with the low power supply voltage, cancels Write in order to reset the
internal circuit when power-on and the power supply voltage is dropping. When the power supply voltage is restored and
exceeds the level of release voltage, the S-7750C automatically reloads command. The detection voltage is 1.75 V typ.,
the release voltage is 2.05 V typ., its hysteresis width is approx. 0.3 V. Refer to Figure 30.
The S-7750C cancels Write by detecting a low power supply voltage when it receives a stop condition. Both in the data
transmission and the Write operation, data in the address written during the low power supply voltage is not assured.
Power supply voltage
Detection voltage (−V_DET)
1.75 V Typ.
Starts reloading command automatically
Hysteresis width
approx. 0.3 V
Release voltage (+V_DET)
2.05 V Typ.
Cancel the Write instruction /
Internal circuit in reset
Figure 30 Action during Low Power Voltage
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Seiko Instruments Inc.