Rainbow Electronics DS1846 - Manual (Page 11)

DS1846
11 of 16
o
NON-MASKABLE INTERRUPT EXAMPLE Figure 6
V
SENSE
=
R2
R2 R1
+
X 1.25 V
MAX
=
TP
SENSE
V
V
X V
CC
Example: V
SENSE
= 4.70V at the trip point
V
CC
= 3.3V
10 k Ω = R2
Therefore:
25 . 1
70 . 4
X 3.3 = 12.4V maximum
4.70 =
10k
10k R1
+
X 1.25 R1 = 27.6 k Ω
DS1846
SDA
SCL
A0
WP
NMI
L0
W1
L1
L2
GND
V
CC
IN
PBRST
RST
RST
H0
W0
H1
W2
H2
5V
RST
INTO
8051
µp
V
SENSE