S-93L46A Datasheet, PDF (19/48 Pages) Seiko Instruments Inc – LOW VOLTAGE OPERATION CMOS SERIAL E2PROM

Rev.3.1_00
LOW VOLTAGE OPERATION CMOS SERIAL E²PROM
S-93L46A/56A/66A
„ Write Disable Function when Power Supply Voltage is Low
The S-93L46A/56A/66A provides a built-in detector to detect a low power supply voltage and disable
writing. When the power supply voltage is low or at power application, the write instructions (WRITE,
ERASE, WRAL, and ERAL) are cancelled, and the write disable state (EWDS) is automatically set. The
detection voltage and the release voltage are 1.4 V typ.(refer to Figure 21).
Therefore, when a write operation is performed after the power supply voltage has dropped and then risen
again up to the level at which writing is possible, a write enable instruction (EWEN) must be sent before a
write instruction (WRITE, ERASE, WRAL, or ERAL) is executed.
When the power supply voltage drops during a write operation, the data being written to an address at that
time is not guaranteed.
Power supply
Detection voltage (−V_DET)
1.4 V Typ.
Release voltage (+V_DET)
1.4 V Typ.
Write instruction cancelled
Write disable state (EWDS) automatically set
Figure 21 Operation when Power Supply Voltage is Low
Seiko Instruments Inc.
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