HCPL-788J Avago Technologies US Inc., HCPL-788J Datasheet - Page 14

• Manufacturer Part Number: HCPL-788J
• Description: OPTOCOUPLR AMP CURR SENSE 16SOIC
• Manufacturer: Avago Technologies US Inc.
• Series: -r
• Type: Current Sensorr

Specifications of HCPL-788J

• Package Type: SOIC
• Operating Supply Voltage (typ): 5V
• Voltage - Isolation: 3750Vrms
• Input Type: DC
• Voltage - Supply: 4.5 V ~ 5.5 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 16-SOIC (0.295", 7.50mm Width)
• No. Of Amplifiers: 1
• Input Offset Voltage: 3mV
• Bandwidth: 30kHz
• Isolation Voltage: 3.75kV
• Supply Voltage Range: ± 4.5V To ± 5.5V
• Supply Current: 20mA
• Amplifier Case Style: SOIC
• No. Of Pins: 16
• Rohs Compliant: No
• Lead Free Status / RoHS Status: Not Compliant

Figure 25. Recommended applications circuit.
Figure 26. Recommended supply and sense resistor connections.
Analog Interfacing
Power Supplies and Bypassing
The recommended supply con nec tions are shown in
Figure 26. A floating power supply (which in many ap-
plications could be the same supply that is used to drive
the high-side power transistor) is regulated to 5 V us-
ing a simple zener diode (D1); the value of resistor R4
should be chosen to supply sufficient current from the
existing floating supply. The voltage from the current
sensing resistor (Rsense) is applied to the input of the
HCPL-788J through an RC anti-aliasing filter (R2 and C2).
14
CURRENT
INPUT
MOTOR
R
SHUNT
0.02 Ω
ISOLATED +5 V
+
+
R
R1
SENSE
R1
39 Ω
+
R2
0.1 μF
0.1 μF
.01 μF
HV-
HV+
C3
C1
C2
GATE DRIVE
CIRCUIT
39 Ω
R2
1
2
3
4
5
6
7
8
V
V
C
C
V
V
V
GND
IN+
IN-
DD1
LED1+
DD1
H
L
5.1 V
1
D1
HCPL-788J
R4
C1
0.1 μF
ABSVAL
FAULT
C2
0.01 μF
GND
GND
V
V
V
V
+
–
OUT
DD2
REF
DD2
FLOATING
Although the application cir cuit is relatively simple, a few
re c ommendations should be followed to ensure optimal
performance.
The power supply for the HCPL-788J is most often ob-
tained from the same supply used to power the power
transistor gate drive circuit. If a dedicated supply is re-
quired, in many cases it is possible to add an additional
winding on an existing trans former. Otherwise, some
sort of simple isolated supply can be used, such as a line
powered transformer or a high-frequency DC-DC con-
verter.
SUPPLY
POWER
2
2
16
15
14
13
12
11
10
9
5
1
2
8
7
3
4
6
+5 V
V
V
V
GND
V
C
C
V
DD1
IN+
IN-
DD1
H
L
LED+
C6
0.1 μF
1
C8
C5 = C7 = C8 = 470 pF
R3 4.7 kΩ
HCPL-788J
C4
C4 = 0.1 μF
C7
ABSVAL
PHASE OUTPUTS
FAULT
GND
GND
V
V
V
V
TO OTHER
OUT
DD2
REF
DD2
C5
2
2
16
15
14
13
12
11
10
9
A/D
V
GND
REF
μC