MT88L89
C1
C2
V
DD
MT88L89
C3
R1
R4
VDD
St/GT
ESt
D3
IN+
IN-
GS
C5
DTMF/CP
INPUT
R5
R7
R3
R2
R6
VRef
VSS
D2
X-tal
D1
OSC1
D0
OSC2
NC
NC
NC
To µP
or µC
C4
NC
IRQ/CP
DTMF
OUTPUT
TONE
R/W/WR
CS
DS/RD
RS0
C6
R
LT
Notes:
Example of External Component Values:
R1, R4 = 100 kΩ 1%
*
Microprocessor based systems can inject undesirable noise into the supply rails.
The performance of the MT88L89 can be optimized by keeping
noise on the supply rails to a minimum. The decoupling capacitor (C3) should be
connected close to the device and ground loops should be avoided.
R2 = 60.4 kΩ 1%
R6 = 374 kΩ 1%
R7 = 3.3 kΩ 10%
R
= 10 kΩ (min.) 50 kΩ (max.)
LT
C1 = 10 nF 5%
C2 = 10 nF 5%
C3 = 100 nF 10%
C4 = 0.1 µF (to remove the DC component)
C5= 100 nF 5%
C6 = 10 nF 10% (to remove any high frequency components)
X-tal = 3.579545 MHz
For Unity Gain:
R3 = 37.4 kΩ 1%
R5 = 100 kΩ 1%
For +2dB Gain:
R3 = 40.2 kΩ 1%
R5 = 127 kΩ 1%
Figure 14 - Application Circuit (Differential Input Configuration)
4-135
ZARLINK [ ZARLINK SEMICONDUCTOR INC ]
