MT88L85
Advance Information
V
DD
MT88L85
C1
DTMF/CP
INPUT
R2
R1
IN+
IN-
GS
VRef
VSS
X-tal
OSC1
OSC2
NC
NC
DTMF
OUTPUT
R
L
TONE
R/W/WR
CS
VDD
St/GT
ESt
D3
D2
D1
D0
NC
PWDN
IRQ/CP
DS/RD
RS0
To
µP
or
µC
R3
C2
R4
C3
Notes:
R1, R2 = 100 kΩ 1%
R3 = 374
Ω
1%
R4 = 3.3 kΩ 10%
R
L
= 10 k
Ω
(min.)
C1 = 100 nF 5%
C2 = 100 nF 5%
C3 = 100 nF 10%*
X-tal = 3.579545 MHz
* Microprocessor based systems can inject undesirable noise into the supply rails.
The performance of the MT88L85 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.
Figure 13 - Application Circuit (Single-Ended Input)
4-82