Preliminary Information
MH88520-1
TIP
RING
1
Optional
Protection
Circuit
3
MH88520-1
TIP
16
RING
JUNC
15
MUTE
AUDIO
INPUT/OUTPUT
MUTE CONTROL
INPUT
SWITCH HOOK
OUTPUT
OFF-HOOK LED
DS1
RING CONTROL
INPUT
K1
Earth Ground
K1
4
10
RF1
SHK
9
19
17
R1
6
RINGING
GENERATOR
90VRMS
LED
∼
-24V
RF2
RRC
RRD
14
VBAT
VRLY 20
VEE AGND VDD RGND
8
13
12
18
Notes:
R1= 200Ω, 1/4W, 5%
K1= Relay E/M 5V, 1Form C
C1, C2 = 0.1uF, 50V, Ceramic
-5V
C1
C2
+5V
Figure 5 - Typical Application Circuit
R and R
THRESH
(kΩ)
GND
R and R
THRESH
(kΩ)
VBAT
RG
RV
SLIC
11
THRESH
ADJ
SLIC
11
THRESH
ADJ
RG = 6000 x I
VDD - (501 x I)
R
(kΩ)
60
50
40
30
20
10
2
3
RV= (100 x VDD) - (6000 x I)
(501 x I) - VDD
R
(kΩ)
RG(kΩ)
(a)
I = Threshold current
in Amps
V
DD
= +5V
400
RV(kΩ)
(b)
200
4
5
6
7
8
10
15
20
25
Figure 6 - Off-Hook Threshold Adjust
2-69
MITEL [ MITEL NETWORKS CORPORATION ]
