CD22859 Datasheet, PDF (5/5 Pages) Intersil Corporation – Monolithic Silicon COS/MOS Dual-Tone Multifrequency Tone Generator

Functional Diagram
C1 3
C2 4
C3 5
C4 9
CD 15
V_DD
R1 14
R2 13
R3 12
R4 11
OSC 1 7
OSC 2 8
CD22859
V_DD
COUNT CONT.
COL. DIVIDER
C1-46 C3-38
C2-42 C4-34
COL
SENSE
COL INH
÷ 32
D
A
ROW
SENSE
ROW DIVIDER
R1-80 R3-66
R2-73 R4-59
COUNT
CONT.
÷ 32
D
A
ROW INH
ENABLE
OP AMP
OSC
÷2
MUTE
CONTROL
V_DD
1
16
V_OUT
R_X
10
T_X
2
V_SS
6
d
a
D₁
L1
G
1K
D₂
1.65K
2.55K
I
51K
g
T_X
R_X
f
F RR
B GN
GN
I_T
V_DD
+
R_X
T_X
/CD
1
OSC1
A
K
a
b
L2
c
C₂ ^R1
C₁
V₁
L₄
R₂
V₂
C₃
L₁
L₂
D₃
NETWORK
8
OSC2
V_OUT
R_L
R₄
R₃
V_SS
C
D₄
FIGURE 2. INTERFACE WITH STANDARD K500 TELEPHONE NETWORK
KEYPAD
123
456
789
*^0#
4-130