Datasheet

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APPLICATIONS INFORMATION
BASIC CONNECTION
POWER SUPPLY
Normal Case 1: V
SENSE
≥ 20mV, V
CM
≥ V
S
ACCURACY VARIATIONS AS A RESULT OF
G +
V
OUT1
* V
OUT2
100mV * 20mV
(1)
V
OS
RTI (Referred−To−Input) +
ǒ
V
OUT1
G
Ǔ
* 100mV
(2)
INA206
x20
Load
5V Supply
V
S
OUT
CMP1 IN–/0.6REF
CMP1 IN+
CMP2 IN–
CMP2 IN+/0.6 REF
GND
V
IN+
V
IN–
1.2V REF OUT
CMP1 OUT
CMP2 OUT
CMP2 DELAY
CMP1
RESET
1.2V REF
Transparent/Reset
Latch
LoadSupply
–18Vto+80V
R
3m
SHUNT
W
R
4.7k
PULL-UP
W
R
4.7k
PULL-UP
W
Optional Delay
Capacitor
0.2 Fm
Current Shunt
Monitor Output
C
0.01 F
BYPASS
m
INA206
INA207
INA208
SBOS360E – JUNE 2006 – REVISED OCTOBER 2007
This section addresses the accuracy of these specific
operating regions:
Figure 30 shows the basic connection of the INA206,
Normal Case 1:
INA207, and INA208. The input pins, V
IN+
and V
IN –
,
V
SENSE
≥ 20mV, V
CM
≥ V
S
should be connected as closely as possible to the
shunt resistor to minimize any resistance in series
Normal Case 2:
with the shunt resistance.
V
SENSE
≥ 20mV, V
CM
< V
S
Power-supply bypass capacitors are required for
Low V
SENSE
Case 1:
stability. Applications with noisy or high impedance
V
SENSE
< 20mV, − 16V ≤ V
CM
< 0
power supplies may require additional decoupling
Low V
SENSE
Case 2:
capacitors to reject power-supply noise. Connect
V
SENSE
< 20mV, 0V ≤ V
CM
≤ V
S
bypass capacitors close to the device pins.
Low V
SENSE
Case 3:
V
SENSE
< 20mV, V
S
< V
CM
≤ 80V
The input circuitry of the INA206, INA207, and
INA208 can accurately measure beyond the
power-supply voltage, V+. For example, the V+ power
This region of operation provides the highest
supply can be 5V, whereas the load power-supply
accuracy. Here, the input offset voltage is
voltage is up to +80V. The output voltage range of
characterized and measured using a two-step
the OUT terminal, however, is limited by the voltages
method. First, the gain is determined by Equation 1 .
on the power-supply pin.
V
SENSE
AND COMMON-MODE VOLTAGE
where:
The accuracy of the INA206, INA207, and INA208
V
OUT1
= Output Voltage with V
SENSE
= 100mV
current-shunt monitors is a function of two main
V
OUT2
= Output Voltage with V
SENSE
= 20mV
variables: V
SENSE
(V
IN+
– V
IN –
) and common-mode
Then the offset voltage is measured at
voltage, V
CM
, relative to the supply voltage, V
S
. V
CM
is
V
SENSE
= 100mV and referred to the input (RTI) of the
expressed as (V
IN+
+ V
IN –
)/2; however, in practice,
current-shunt monitor, as shown in Equation 2 .
V
CM
is seen as the voltage at V
IN+
because the
voltage drop across V
SENSE
is usually small.
Figure 30. INA20x Basic Connection
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