ACPL-782T-500E Avago Technologies US Inc., ACPL-782T-500E Datasheet - Page 17

• Manufacturer Part Number: ACPL-782T-500E
• Description: OPTO AMP ISOLATION AUTO 8-DIP GW
• Manufacturer: Avago Technologies US Inc.
• Series: R²Coupler™r

Specifications of ACPL-782T-500E

• Amplifier Type: Isolation
• Number Of Circuits: 1
• Output Type: Differential
• -3db Bandwidth: 100kHz
• Voltage - Input Offset: 300µV
• Current - Supply: 10.86mA
• Current - Output / Channel: 18.6mA
• Voltage - Supply, Single/dual (±): 4.5 V ~ 5.5 V
• Operating Temperature: -40°C ~ 125°C
• Mounting Type: Surface Mount
• Package / Case: 8-SMD Gull Wing
• No. Of Amplifiers: 1
• Isolation Voltage: 891V
• Gain Non-linearity Max: 2%
• Slew Rate: 1500V/µs
• Supply Voltage Range: 4.5V To 5.5V
• Input Offset Voltage: 300µV
• Bandwidth: 100kHz
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Gain Bandwidth Product: -
• Current - Input Bias: -
• Lead Free Status / Rohs Status: Compliant

Voltage sensing for DC rail measurement
ACPL-782T is a suitable device to measure the DC rail
voltage over different potentials. In a DC rail voltage
sensing application, the Line1 and Line2 in Figure 21 are
the DC lines to be measured.
Dividing ratio error due to the tolerances of the resistors
From a differential calculation, the error in the voltage
divider of Ra and Rb is expressed as
Where A is the ratio of the resistor divider consisting of Ra
and Rb.
Since the errors of the resistors, 'Rb/Rb and 'Ra/Ra are
independent to each other, we need to take absolute
values in equation (1) to know the maximum possible
gain error of the divider and it gives
Figure 22 is the plot of the equation (2) when the resistors
have 1% tolerance expressing the relationship between
the ratio of Ra to (Ra+Rb) and the possible maximum error
of the dividing ratio.
IGBT attaching type
Note on the thermistor and the RL:
V
Rth: Resistance of thermistor
RL: Linearizing resistor value = R1//(R2+R3)
Figure 23. Recommended circuit for temperature sensing application.
17
dd
EC2F103A2-40113
RL = R1//(R2+R3)
'A/A = Ra/(Ra + Rb) * ('Rb/Rb – 'Ra/Ra)
'A/A = Ra/(Ra + Rb) * ( |'Rb/Rb| + |'Ra/Ra|)
x [RL/(Rth + RL)] x [ R3/(R2 + R3)] <= 200 mV, assuming R2+R3 >> R1
Thermistor
Semitec
R1
R3
R2
TH
0.1 PF
+ SUPPLY
IN
78L05
39:
OUT
+5 V
(1)
(2)
0.1 PF
1 PF
1
3
4
2
ACPL-782T
Figure 22: Divider Error % Vs Resistors Divider
1.5
0.5
2
1
0
0.5
8
7
6
5
+5 V
Dividing error when 1% resistors are used(%)
0.6
0.1 PF
150 pF
2.0 k:
2.0
k:
0.7
Ra/(Ra+Rb)
10.0 k:
0.8
+15 V
6
5
10.0 k:
150 pF
+
-
-15 V
8
4
0.9
TL032A
0.1 PF
0.1 PF
7
1.0
V
OUT