S93S46A Datasheet, PDF (17/25 Pages) Seiko Instruments Inc – 3-WIRE SERIAL E2PROM FOR AUTOMOTIVE

Rev.2.1_00
150°C OPERATION 3-WIRE SERIAL E²PROM FOR AUTOMOTIVE
S-93S46A/56A/66A
 Write Protect Function during the Low Power Supply Voltage
This IC provides a built-in detection circuit to detect a low power supply voltage. When the power supply voltage is low or
at power-on, the write instructions (WRITE, ERASE, WRAL, and ERAL) are cancelled, and the write disable (EWDS)
status is automatically set. The detection voltage is 1.75 V typ., the release voltage is 2.05 V typ., and there is a
hysteresis of about 0.3 V (refer to Figure 14). 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 voltage
Hysteresis
about 0.3 V
Detection voltage (−V_DET)
1.75 V typ.
Release voltage (+V_DET)
2.05 V typ.
Write instructions are cancelled
Write disable status (EWDS) is automatically set
Figure 14 Operation during the Low Power Supply Voltage
Seiko Instruments Inc.
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