INA200A BURR-BROWN [Burr-Brown Corporation], INA200A Datasheet - Page 10

• Manufacturer Part Number: INA200A
• Description: High-Side Measurement Current-Shunt Monitor with Comparator and Reference
• Manufacturer: BURR-BROWN [Burr-Brown Corporation]

INA200
INA201
INA202
SBOS374 − NOVEMBER 2006
APPLICATIONS INFORMATION
BASIC CONNECTIONS
Figure 2 shows the basic connections of the INA200,
INA201, and INA202. The input pins, V
be connected as closely as possible to the shunt resistor
to minimize any resistance in series with the shunt
resistance.
Power-supply bypass capacitors are required for stability.
Applications with noisy or high-impedance power supplies
may require additional decoupling capacitors to reject
power-supply noise. Connect bypass capacitors close to
the device pins.
POWER SUPPLY
The input circuitry of the INA200, INA201, and INA202 can
accurately measure beyond the power-supply voltage, V+.
For example, the V+ power supply can be 5V, whereas the
load power-supply voltage is up to +80V. The output
voltage range of the OUT terminal, however, is limited by
the voltages on the power-supply pin.
ACCURACY VARIATIONS AS A RESULT OF
V
The accuracy of the INA200, INA201, and INA202 current
shunt monitors is a function of two main variables: V
(V
10
SENSE
IN+
− V
IN−
AND COMMON-MODE VOLTAGE
) and common-mode voltage, V
−18V to +80V
Load Supply
C
0.01µF
BYPASS
R
R
1
2
4
1
2
3
OUT
CMP
GND
V+
IN+
IN
Figure 2. INA200 Basic Connections
Reference
and V
0.6V
CM
, relative to
IN−
(G = 20)
INA200
Comparator
, should
SENSE
G
Transparent/Reset
CMP
RESET
V
V
the supply voltage, V
however, in practice, V
because the voltage drop across V
This section addresses the accuracy of these specific
operating regions:
Normal Case 1: V
This region of operation provides the highest accuracy.
Here, the input offset voltage is characterized and
measured using a two-step method. First, the gain is
determined by Equation 1.
where:
V
V
Then the offset voltage is measured at V
and referred to the input (RTI) of the current shunt monitor,
as shown in Equation 2.
OUT
IN+
IN−
V
OUT1
OUT2
OS
Normal Case 1: V
Normal Case 2: V
Low V
Low V
Low V
8
7
6
5
RTI ( Referred−To−Input ) +
= Output Voltage with V
= Output Voltage with V
R
SENSE
SENSE
SENSE
3mΩ
SHUNT
Latch
G +
Case 1: V
Case 2: V
Case 3: V
100mV * 20mV
SENSE
S
V
. V
SENSE
SENSE
OUT1
R
4.7k Ω
CM
PULL−UP
CM
SENSE
SENSE
* V
is seen as the voltage at V
SENSE
≥ 20mV, V
is expressed as (V
≥ 20mV, V
≥ 20mV, V
SENSE
SENSE
OUT2
V
< 20mV, −16V ≤ V
< 20mV, V
< 20mV, 0V ≤ V
OUT1
G
SENSE
= 100mV
= 20mV
5V Supply
Load
CM
CM
CM
* 100mV
is usually small.
≥ V
SENSE
≥ V
< V
S
www.ti.com
< V
IN+
S
S
S
= 100mV
+ V
CM
CM
CM
≤ 80V
IN−
≤ V
(1)
(2)
)/2;
< 0
IN+
S