B3-22

EM78P156E

VDD

33K

10K

IN4684

Q1

VDD

/RESET

EM78P156E

100K

Fig. 15 Circuit 1 for the residue voltage protection

VDD

R1

R2

Q1

VDD

/RESET

EM78P156E

R3

Fig. 16 Circuit 2 for the residue voltage protection

VI.11 Residue Voltage Protection

In some applications, replacing battery as an instance, device power (Vdd) is taken off and recovered within a few

seconds. A residue voltage, which trips below Vdd min but not to zero, may exist. This condition may cause a poor

power-on reset. Fig.15 and Fig.16 show how to build the residue voltage protection circuit