em78p156n ELAN Microelectronics Corp, em78p156n Datasheet - Page 32

• Manufacturer Part Number: em78p156n
• Description: 8-bit Micro-controller
• Manufacturer: ELAN Microelectronics Corp

When battery is replaced, device power (Vdd) is taken off but residue-voltage remains. The residue-voltage
may trips below Vdd minimum, but not to zero. This condition may cause a poor power on reset. Fig.18 and Fig.
19 show how to build a residue-voltage protection circuit.
This specification is subject to change without prior notice.
4.11 Residue-Voltage Protection
EM78P156N
EM78P156N
/RESET
Fig. 15 Circuit 1 for the Residue Voltage Protection
Fig. 14 External Power-Up Reset Circuit
/RESET
Vdd
Vdd
40K
Q1
32
Rin
R
C
10K
1N4684
33K
D
Vdd
EM78P156N
OTP ROM
07.29.2004 (V1.2)