MT88L70 Zarlink Semiconductor, MT88L70 Datasheet - Page 5

• Manufacturer Part Number: MT88L70
• Description: 3 Volt Integrated DTMF Receiver
• Manufacturer: Zarlink Semiconductor

the input pins are connected as shown in Figure 6
with the op-amp connected for unity gain and V
biasing the input at 1/2V
differential
adjustment of gain with the feedback resistor R
Crystal Oscillator
The internal clock circuit is completed with the
addition of an external 3.579545 MHz crystal and is
connected as shown in Figure 6 (Single-ended Input
Configuration).
configuration,
DTMF
Input
C
1
DD
X-tal
. Figure 5 shows the
which
R
R
2
1
Figure 6 - Single-Ended Input Configuration
permits
IN+
IN-
GS
V
INH
PDWN
OSC1
OSC2
V
Ref
SS
MT88L70
V
5
DD
.
the
Ref
St/GT
TOE
V
ESt
StD
Q4
Q3
Q2
Q1
DD
Applications
A single-ended input configuration is shown in Figure
6. For applications with differential signal inputs the
circuit shown in Figure 5 may be used.
R
C
3
NOTES:
R
R
C
X-tal = 3.579545 MHz ±0.1%
V
2
DD
1
3
1
, R
,C
= 300 kΩ ±1%
= 3.0V + 20% / -10%
2
2
= 100 nF ±5%
= 100 kΩ ±1%
MT88L70
4-27