APPLICATION CIRCUIT
-5 V
+5 V
RTRIP1
RTRIP2
VCC
VNEG
RRT1
715 kΩ
CRT
RRT2
1.0 µF
42 kΩ
RD
RSGH
66 kΩ short
CAX = 2.2 nF
RSGL
open
RD
RSGH
RSGL
VTX
U1
Le79R101
RFA = 50 Ω
A(TIP)
HPA
VTX
TIP
D3
U2
U3
RT1 125 kΩ
CHP
18 nF
BAT1
RRX
125 kΩ
CT
RT2
HPB
B(RING)
250 kΩ
D4
RSN
VRX
RING
RFB = 50 Ω
CBX = 2.2 nF
RDC2
50 kΩ
RDC1
50 kΩ
RDCR2
15 kΩ
RDC
CDC
820 nF
RDCR1
RDCR
RYOUT1
RYOUT1
RYOUT2
RYE
15 kΩ
CDCR
10 nF
RYOUT2
RYE
C1
C2
C3
D1
D2
E1
C1
C2
C3
D1
D2
E1
D1
BAT1
VBAT1
VBAT2
BGND
0.1 µF
0.1 µF
D2
BAT2
DET
DET
VRING
See note below.
RREF
AGND/
DGND
BATTERY
GROUND
Assumptions:
4. 5.2 KΩ
ANALOG
GROUND
1. Vring is 0.65 Vrms for 65 Vrms
ringing
2. 25 mA I LOOP
High Battery Loop Threshold
5. 1200 Ω Ringing Loop Threshold
7. G42L = 1
8. -95 V BAT1, -24 V BAT2
6. 600 Ω Two-wire Impedance, 600 Ω ZL
3. 75 mA Ringing Current Limit
DIGITAL
GROUND
Note:
The input should be sinusoidal with less than ± 1 V peak amplitude.
U2, U3 - TECCOR BATTRAX P1001SC protector or TISP61089AD from Power Innovation. For battery voltages below 80 V, see Le79R79 for
alternate protection.
D3, D4: 1A, 100 V
Le79R101 Data Sheet
19
ZARLINK [ ZARLINK SEMICONDUCTOR INC ]
