AMP04FSZ-RL Analog Devices Inc, AMP04FSZ-RL Datasheet - Page 11

• Manufacturer Part Number: AMP04FSZ-RL
• Description: UNITY GAIN DIFF AM IC
• Manufacturer: Analog Devices Inc

Specifications of AMP04FSZ-RL

• Amplifier Type: Instrumentation
• Number Of Circuits: 1
• -3db Bandwidth: 700kHz
• Current - Input Bias: 22nA
• Voltage - Input Offset: 30µV
• Current - Supply: 750µA
• Current - Output / Channel: 30mA
• Voltage - Supply, Single/dual (±): 5 V ~ 30 V, ±2.5 V ~ 15 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 8-SOIC (3.9mm Width)
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Output Type: -
• Slew Rate: -
• Gain Bandwidth Product: -
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

4-20 mA Loop Receiver
At the receiving end of a 4-20 mA loop, the AMP04 makes a
convenient differential receiver to convert the current back to
a usable voltage (Figure 13). The 4-20 mA signal current passes
through a 100 Ω sense resistor. The voltage drop is differentially
amplified by the AMP04. The 4 mA offset is removed by the
offset correction circuit.
Low Power, Pulsed Load-Cell Amplifier
Figure 14 shows a 350 Ω load cell that is pulsed with a low duty
cycle to conserve power. The OP295’s rail-to-rail output capa-
bility allows a maximum voltage of 10 volts to be applied to the
bridge. The bridge voltage is selectively pulsed on when a mea-
surement is made. A negative-going pulse lasting 200 ms should
be applied to the MEASURE input. The long pulsewidth is
necessary to allow ample settling time for the long time constant
of the low-pass filter around the AMP04. A much faster settling
time can be achieved by omitting the filter capacitor.
TRANSMITTER
4–20mA
350
330
4–20mA
OP295
2
3
1/2
SUPPLY
POWER
AMP04
4–20mA
12V
7
4
1
12V
100
1%
WIRE
RESISTANCE
5
8
6
2N3904
1k
1k
1k
0.22 F
10k
1N4002
–15V
OUT
1N4148
3
2
50k
AMP04
GND
+15V
–15V
IN
27k
REF01
4
7
1
V
100k
OUT
6
8
5
6
OP177
0.15 F
MEASURE
AD589
–0.400V
0–1.6V FS
3
2
V
10k
OUT
Single Supply Programmable Gain Instrumentation Amplifier
Combining with the single supply ADG221 quad analog switch,
the AMP04 makes a useful programmable gain amplifier that
can handle input and output signals at zero volts. Figure 15
shows the implementation. A logic low input to any of the gain
control ports will cause the gain to change by shorting a gain-
set resistor across AMP04’s Pins 1 and 8. Trimming is required
at higher gains to improve accuracy because the switch ON-
resistance becomes a more significant part of the gain-set
resistance. The gain of 500 setting has two switches connected
in parallel to reduce the switch resistance.
The switch ON resistance is lower if the supply voltage is 12 volts
or higher. Additionally, the overall amplifier’s temperature coeffi-
cient also improves with higher supply voltage.
CONTROL
GAIN
10 F
GAIN OF 500
GAIN OF 100
INPUT
GAIN OF 10
5V TO 30V
WR
0.1 F
13
10
15
16
9
7
8
2
1
1
2
3
4
ADG221
R
V–
G
AMP04
12
5
4
11
6
14
3
10.9k
REF
715
R
V+
100k
G
200
200
8
7
6
5
0.22 F
0.1 F
AMP04
5V TO
30V
V
OUT