datasheetbank_Logo
Integrated circuits, Transistor, Semiconductors Search and Datasheet PDF Download Site

AD210 View Datasheet(PDF) - Analog Devices

Part Name
Description
View to exact match
AD210 Datasheet PDF : 8 Pages
1 2 3 4 5 6 7 8
AD210
Isolated Power: The AD210 provides isolated power at the
input and output ports. This power is useful for various signal
conditioning tasks. Both ports are rated at a nominal ± 15 V at
5 mA.
The load characteristics of the isolated power supplies are
shown in Figure 15. For example, when measuring the load
rejection of the input isolated supplies VISS, the load is placed
between +VISS and –VISS. The curves labeled VISS and VOSS are
the individual load rejection characteristics of the input and the
output supplies, respectively.
There is also some effect on either isolated supply when loading
the other supply. The curve labeled CROSSLOAD indicates the
sensitivity of either the input or output supplies as a function of
the load on the opposite supply.
30
The isolated power supplies exhibit some ripple which varies as
a function of load. Figure 16a shows this relationship. The
AD210 has internal bypass capacitance to reduce the ripple to a
point where performance is not affected, even under full load.
Since the internal circuitry is more sensitive to noise on the
negative supplies, these supplies have been filtered more heavily.
Should a specific application require more bypassing on the iso-
lated power supplies, there is no problem with adding external
capacitors. Figure 16b depicts supply ripple as a function of
external bypass capacitance under full load.
1V
100mV
30
CROSSLOAD
10mV
( ) +VISS
+VOSS
25
20
0
VOSS
VOSS SIMULTANEOUS
VISS
VISS SIMULTANEOUS
5
10
CURRENT – mA
Figure 15. Isolated Power Supplies vs. Load
Lastly, the curves labeled VOSS simultaneous and VISS simulta-
neous indicate the load characteristics of the isolated power sup-
plies when an equal load is placed on both supplies.
The AD210 provides short circuit protection for its isolated
power supplies. When either the input supplies or the output
supplies are shorted to input common or output common,
respectively, no damage will be incurred, even under continuous
application of the short. However, the AD210 may be damaged
if the input and output supplies are shorted simultaneously.
30
+VISS
100
75
+VOSS
50
–VISS
–VOSS
25
0
0
1
2
3
4
5
6
7
LOAD – mA
Figure 16a. Isolated Supply Ripple vs. Load
(External 4.7 µF Bypass)
Under any circumstances, care should be taken to ensure that
the power supplies do not accidentally become shorted.
1mV
0.1µF
1µF
10µF
( ) –VISS
–VOSS
100µF
CAPACITANCE
Figure 16b. Isolated Power Supply Ripple vs. Bypass
Capacitance (Volts p-p, 1 MHz Bandwidth, 5 mA Load)
APPLICATIONS EXAMPLES
Noise Reduction in Data Acquisition Systems: Transformer
coupled isolation amplifiers must have a carrier to pass both ac
and dc signals through their signal transformers. Therefore,
some carrier ripple is inevitably passed through to the isolator
output. As the bandwidth of the isolator is increased more of the
carrier signal will be present at the output. In most cases, the
ripple at the AD210’s output will be insignificant when com-
pared to the measured signal. However, in some applications,
particularly when a fast analog-to-digital converter is used fol-
lowing the isolator, it may be desirable to add filtering; other-
wise ripple may cause inaccurate measurements. Figure 17
shows a circuit that will limit the isolator’s bandwidth, thereby
reducing the carrier ripple.
16
17
VSIG 19
18
R
R
1
AD210
0.001µF
2
+VOSS
AD542
–VOSS
VOUT
0.002µF
14
+VISS
15
–VISS
30 29
+VOSS
–VOSS
3
( ) 4
R (k) =
112.5
fC (kHz)
+15V
Figure 17. 2-Pole, Output Filter
Self-Powered Current Source
The output circuit shown in Figure 18 can be used to create a
self-powered output current source using the AD210. The 2 k
resistor converts the voltage output of the AD210 to an equiva-
–6–
REV. A
 

Share Link: 

datasheetbank.com [ Privacy Policy ] [ Request Datasheet ] [ Contact Us ]