MT88L70AN1 Zarlink, MT88L70AN1 Datasheet - Page 6

• Manufacturer Part Number: MT88L70AN1
• Description: DTMF RX 3.58MHz CMOS 3V 20-Pin SSOP Tube
• Manufacturer: Zarlink

Specifications of MT88L70AN1

• Package: 20SSOP
• Operating Frequency: 3.58 MHz
• Typical Supply Current: 2 mA
• Typical Operating Supply Voltage: 3 V
• Minimum Operating Supply Voltage: 2.7 V
• Maximum Operating Supply Voltage: 3.6 V

Differential Input Configuration
The input arrangement of the MT88L70 provides a differential-input operational amplifier as well as a bias source
(V
amp output (GS) for adjustment of gain. In a single-ended configuration, the input pins are connected as shown in
Figure 6 with the op-amp connected for unity gain and V
differential configuration, which permits the 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).
Ref
) which is used to bias the inputs at mid-rail. Provision is made for connection of a feedback resistor to the op-
DIFFERNTIAL INPUT AMPLIFIER
C
R
R
R
VOLTAGE GAIN (A
INPUT IMPEDANCE
1
1
2
3
C
= C
= R
= 60 kΩ, R
=
C
(Z
1
2
Figure 5 - Differential Input Configuration
R
2
4
INDIFF
R
2
= 10 nF
= R
2
+ R
R
R
R
5
5
) = 2
4
5
1
= 100 kΩ
3
, = 37.5 kΩ
Zarlink Semiconductor Inc.
V
R
diff) =
R
3
1
MT88L70
2
+
R
R5
R1
IN+
IN-
2
ωC
All resistors are ± 1% tolerance.
All capacitors are ± 5% tolerance.
6
1
R
5
2
Ref
V
GS
Ref
biasing the input at 1/2V
+
-
MT88L70
DD
. Figure 5 shows the
5
.
Data Sheet