TC7129
FIGURE 4-11:
TC7129 FUNCTIONAL BLOCK DIAGRAM
Low Battery
Continuity
Backplane
Drives
Segment Drives
Annunciator
Drive
TC7129
OSC1
V
Latch, Decode Display Multiplexer
DISP
OSC2
OSC3
Up/Down Results Counter
Sequence Counter/Decoder
Control Logic
RANGE
DP
DP
1
L/H
2
CONT
UR/DP
3
OR/DP
4
V+
V-
Analog Section
REF HI
DGND
REF LO
INT OUT
INT IN
BUFF
COMMON
IN IN
HI LO
FIGURE 4-12:
INTEGRATOR BLOCK DIAGRAM
C
C
REF
R
INT
INT
REF HI
REF LO
DE
DE
Integrator
X10
Comparator 1
–
10
pF
INT
1
–
+
IN HI
+
To Digital
Section
Buffer
DE-
DE+
DE-
+
–
100pF
Comparator 2
DE+
ZI, X10
Common
INT
REST
INT INT
1
2
,
IN LO
–
500kΩ
TC7129
+
–
+
V
Continuity
Comparator
200mV
Continuity
To Display Driver
DS21459B-page 14
2002 Microchip Technology Inc.
MICROCHIP [ MICROCHIP ]
