HCPL-800J-000E Avago Technologies US Inc., HCPL-800J-000E Datasheet - Page 15

• Manufacturer Part Number: HCPL-800J-000E
• Description: OPTOCOUPLER DAA PLC ISO 16SOIC
• Manufacturer: Avago Technologies US Inc.

Specifications of HCPL-800J-000E

• Package / Case: SO-16
• Mounting Type: Surface Mount
• Current - Supply: 28mA
• Voltage - Supply: 4.75 V ~ 5.25 V
• Operating Temperature: -40°C ~ 85°C
• Applications: Powerline Data Access
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Figure 25. Schematic of HCPL - 800J application for FSK modulation scheme
Typical application for FSK modulation scheme
The HCPL-800J is designed to work with various trans-
ceivers and can be used with a variety of modulation
methods including ASK, FSK and BPSK. Figure 25 shows
a typical application in a powerline modem using
Frequency Shift Keying (FSK) modulation scheme.
Transmitter
The analogue Tx input pin is connected to the
modulator via an external coupling capacitor C1 and a
series resistor R3 (see Figure 25). Optimal performance
is obtained with an input signal of 250 µA
a modulator with an output signal of 0.5 V
coupling capacitor of 100 nF, the optimal series resistor
R3 would be 2 kΩ.
TX AGC
To ensure a stable and constant output voltage at Tx-PD-
out, the HCPL-800J includes an Automatic Gain Control
(AGC) circuit in the isolated transmit signal path.
This AGC circuit compensates for variations in the input
signal level presented at Tx-in and variations in the
optical channel over temperature and time. The Tx-PD-
out output signal is effectively stabilized for input Tx-in
signals of between 150 µA
The AGC circuit starts to function 10 µs after the Tx-en
signal is set to logic high. After a period of 180 µs the Tx-
PD-out signal typically reaches 66% of its steady state
Rx-out
Status
Tx-en
Tx-in
C1
5 kÙ
10 kÙ
R1
R2
100 nF
100 nF
V
100 nF
CC1
R3
2 kÙ
GND1
PP
and 250 µA
GND1
1
2
3
4
5
6
7
8
HCPL-800J
Tx-en
Tx-in
Rx-PD-out
Rx-Amp-in
Status
Rx-out
V
GND1
CC1
PP
(see Figure 8).
PP
PP
. E.g., for
using a
Tx-PD-out
Tx-LD-in
GND2
Tx-out
Rx-in
V
C
R
CC2
ext
ref
16
15
14
13
12
11
10
9
level (see Figure 26). To ensure correct operation of the
internal circuitry, an external 1 µF capacitor needs to be
connected from pin 11 to GND2.
The optical signal coupling technology used in the
HCPL-800J transmit path achieves very good harmonic
distortion typically HD2 < -50 dB and HD3 < -62 dB,
which is usually significantly better than the distortion
performance of the modulated input signal. However to
meet the requirements of some international EMC regu-
lations it is often necessary to filter the modulated input
signal. The optimal position for such a filter is between
pins 13 and 12 as shown in Figure 25. A possible band-
pass filter topology is shown in Figure 27, some typical
values of the components in this filter are listed in Table
1.
Figure 26. Tx-PD-out AGC response time
GND2
Tx-PD-out 1 V/Div
Tx-en 5 V/Div
1 µF
R
24 kÙ
GND2
ref
GND2
Filter
Filter
R4
2 Ù
t
s, Tx
1 µF
100 nF
GND2
L2
D1
t
GND2
AGC
GND2
100 µF
V
CC2
L1
330 µH
C2
X2
5 0 µs/Div
L
N