Avago Technologies ACPL-224-500E - Manual (Page 39)

AV02-4387EN 36 Avago Technologies
Description
The HCPL-4701 Low Power Opto-
coupler is suitable for standard tel-
ephone line interface functions such
as: ring detection, line polarity, and
power on/off detection. Integrated
Services Digital Network (ISDN)
applica tions severely restrict the
input power that an optocoupler in-
terface circuit can use, which makes
the HCPL-4701 an ideal choice. Simi-
larly, HCPL-270L, 3.3V optocoupler
could be used which is compatible
with JEDEC low voltage specifica-
tions.
Performance of Optocoupler
• Input current for turn­on: 40 µA
• Typical total power dissipation
with I
F
= 40 µA: < 3 mW
• Typical propagation delay: 65 µs
Benefits
• Low power dissipation
• Compatible with 3 V Logic
References
• HCPL­4701 Lower Power Optocou-
pler Technical Data
• HCPL­270L 3.3V Optocoupler
Technical Data
Telecommunications Applications
ISDN Interface
2-WIRE
ISDN
LINE
PROTECTION
CIRCUIT
P0WER
SUPPLY
SECONDARY
POWER
EMERGENCY
POWER
PRIMARY–SECONDARY
POWER ISOLATION
BARRIER
PRIMARY
AC VOLTAGE
TELEPHONE LINE
ISOLATION BARRIER
HCPL-4731
HCPL-4701
SWITCHED–
MODE
POWER
SUPPLY
RECEIVE
TRANSMIT
LINE POLARITY
LINE RESPONSE
SECONDARY/
EMERGENCY
POWER
V
CC
V CC – RETURN
TELEPHONE
LINE
INTERFACE
CIRCUIT
1
2
3
4
8
7
6
5
2
8
3
6
5