TL7702 Datasheet, PDF (13/17 Pages) Texas Instruments – Supply voltage Supervisor

Application examples
therefore the shift of the low level at the CS input) is very small (typ. 40mV). When the chip select line is
switched high again by the processor, the transistor Q₁ is turned off (the influence of the inverse current
gain is negligible); the diode D₁ conducts and charges the circuit capacitance. In the case of a power-
failure the TL7705B is triggered and its RESET output becomes low. The base of transistor Q₁ can no
longer draw current. Thus the CS input of the memory is separated from the chip select line.
Figure 10. Circuit Diagram for Data Protection in a battery buffered
memory
Vref
2,513 V
2,512 V
2,511 V
2,51 V
2,509 V
2,508 V
2,507 V
2,506 V
2,505 V
0V
5V
10 V
15 V
20 V ^Vcc
Supply voltage Supervisor TL77xx Series
9