lt6109-1 Linear Technology Corporation, lt6109-1 Datasheet - Page 22
![no-image](/images/manufacturer_photos/0/3/389/linear_technology_corporation_sml.jpg)
lt6109-1
Manufacturer Part Number
lt6109-1
Description
High Side Current Sense Amplifer With Reference And Comparators
Manufacturer
Linear Technology Corporation
Datasheet
1.LT6109-1.pdf
(28 pages)
LT6109-1/LT6109-2
APPLICATIONS INFORMATION
Note that since the amplifier gain error is specified with an
R
R
reduce the gain error since R
as shown in Figure 6.
Supply Rejection: The amplifier supply rejection is a
measure of how the input offset voltage changes with a
change in supply and input common mode voltage. With
114dB, a 10V supply that varies by ±10% will cause the
following error:
Common Mode Rejection: The amplifier common mode
rejection is a measure of how the input offset voltage
changes as the SENSEHI and SENSELO pins move com-
mon mode. If the inputs are tied to V
not need to be considered because of the way PSRR is
specified (see Note 7). With 103dB, the resulting change
in offset voltage due to a ±10% variation in a 12V battery
connected to SENSEHI, SENSELO voltage creates the
following error:
22
IN
P
, with value 200mΩ. Using a larger value of R
2µV
7µV
= 100Ω it can be represented as a series resistance,
V
V
100mV
100mV
• 1.2V
• 1.2V
= 0.0024%
= 0.0084%
12V
5V
10k
R
50m
1%
I
2A FS
SENSE
100
LOAD
P
R
1%
will be less as a percentage
IN
10
1
4
2
+
SENSEHI
SENSELO
OUTC1
EN/RST
COMP 2 NOT SHOWN
LT6109-1
then this error does
Figure 17. LT6109-1 Error Budget Configuration
170nA
R
I
P
B
V
–
IN
can
I
170nA
I
±50nA
B
OS
+
±450µV
V
OS
V
V
V
+
9
+
–
Accuracy of External Gain Set Resistors: The gain is set
by external resistors R
external resistors contributes directly to the system error.
Using 0.1% resistors results in the following error:
Drift of Gain Set Resistors: The drift of the external gain
set resistors also contributes directly to the system er-
ror. Using resistors with a maximum drift specification of
50ppm/°C results in the following error:
Threshold Accuracy: The total error of the comparators
and reference result in the following error:
Accuracy of External Resistors: The comparator trip point
is set by external resistors R1 and R
these external resistors contribute directly to the system
error. Using 0.1% resistors results in the following error:
2 • 0.1% = 0.2%
2 • 0.1% = 0.2%
2 • 50
–
–
+
400mV
+
8mV
V
V
+
–
ppm
+
400mV
°C
±8mV
= 2%
5
V
–
• 100°C = 1%
OUTA
INC1
IN
and R
610912 F16
8
6
R
OUT
R2
1.5k
1%
R1
500
1%
OUT
= R1 + R2
. The precision of these
IN
. The precision of
610912f