AD8213YRMZ Analog Devices Inc, AD8213YRMZ Datasheet - Page 10

• Manufacturer Part Number: AD8213YRMZ
• Description: IC CURRENT MONITOR 0.25% 10MSOP
• Manufacturer: Analog Devices Inc

Specifications of AD8213YRMZ

• Function: Current Monitor
• Sensing Method: High-Side
• Accuracy: ±0.25%
• Voltage - Input: -2 ~ 65 V
• Operating Temperature: -40°C ~ 125°C
• Mounting Type: Surface Mount
• Package / Case: 10-MSOP, Micro10™, 10-uMAX, 10-uSOP
• No. Of Amplifiers: 2
• Input Offset Voltage: 1mV
• Gain Db Max: 20dB
• Bandwidth: 500kHz
• Cmrr: 120dB
• Slew Rate: 4.5V/µs
• Supply Voltage Range: 4.5V To 5.5V
• Supply Current: 2.5mA
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Current - Output: -

AD8213
THEORY OF OPERATION
In typical applications, the AD8213 amplifies a small differential
input voltage generated by the load current flowing through a
shunt resistor. The AD8213 rejects high common-mode
voltages (up to 65 V) and provides a ground referenced, buffered
output that interfaces with an analog-to-digital converter (ADC).
Figure 25 shows a simplified schematic of the AD8213.
The following explanation refers exclusively to Channel 1 of the
AD8213, however, the same explanation applies to Channel 2.
A load current flowing through the external shunt resistor
produces a voltage at the input terminals of the AD8213. The
input terminals are connected to Amplifier A1 by Resistor R1
and Resistor R1
input impedance is held to (V
negligible current flows through Resistor R1
forces the noninverting input to the same potential. Therefore,
the current that flows through Resistor R1
I
IN1
= (I
SHUNT1
OUT2 = (I
(2)
. The inverting terminal, which has very high
× R
SHUNT1
SHUNT2
)/R1
× R
CM
SHUNT2
(1)
) – (I
) × 20
SHUNT
(1)
× R
G = +20
, is equal to
PROPRIETARY
(2)
R2
CIRCUITRY
. Amplifier A1
SHUNT
OFFSET
(1)
), since
CF2
R
I
SHUNT2
SHUNT2
Figure 25. Simplified Schematic
20kΩ
A2
R
R2
OUT2
Rev. A | Page 10 of 16
(2)
(1)
Q2
I
IN2
GND
I
IN1
Q1
R1
R
OUT1
This current (I
output buffer amplifier has a gain of 20 V/V, and offers excellent
accuracy as the internal gain setting resistors are precision
trimmed to within 0.01% matching. The resulting output
voltage is equal to
Prior to the buffer amplifier, a precision-trimmed 20 kΩ resistor
is available to perform low-pass filtering of the input signal
prior to the amplification stage. This means that the noise of the
input signal is not amplified, but rejected, resulting in a more
precise output signal that will directly interface with a converter.
A capacitor from the CF1 pin to GND, will result in a low-pass
filter with a corner frequency of
20kΩ
(1)
R
I
SHUNT1
A1
SHUNT1
PROPRIETARY
V
f
CF1
CIRCUITRY
OUT1
−
OFFSET
3
dB
AD8213
= (I
=
R1
G = +20
2
(2)
π
SHUNT1
IN1
(
20000
) is converted back to a voltage via R
V+
OUT1 = (I
× R
1
)
C
SHUNT1
FILTER
SHUNT1
) × 20
× R
SHUNT1
) × 20
OUT1
. The