TS1102-100 TOUCHSTONE [Touchstone Semiconductor Inc], TS1102-100 Datasheet - Page 8

• Manufacturer Part Number: TS1102-100
• Description: A 1?A, 200?VOS SOT23 Precision Current-Sense Amplifier
• Manufacturer: TOUCHSTONE [Touchstone Semiconductor Inc]

TS1102
or
Since the FET’s drain terminal is connected to R
the output voltage of the TS1102 at the OUT
terminal is, therefore;
The current-sense amplifier’s gain accuracy is
therefore the ratio match of R
of the four gain options available, Table 1 lists the
values for R
stage is protected against input overdrive by use of
an output current-limiting circuit of
a
APPLICATIONS INFORMATION
Choosing the Sense Resistor
Selecting the optimal value for the external RSENSE
is based on the following criteria and for each
commentary follows:
1) RSENSE Voltage Loss
For lowest IR voltage loss in RSENSE, the smallest
usable value for RSENSE should be selected.
2) V
and Desired V
As there is no separate power supply pin for the
TS1102, the circuit draws its power from the applied
voltage at both its RS+ and RS- terminals.
Therefore, the signal voltage at the OUT terminal is
bounded by the minimum supply voltage applied to
the TS1102.
Page 8
7V
1) RSENSE Voltage Loss
2) V
3) Total I
4) Circuit Efficiency and Power Dissipation
5) RSENSE Kelvin Connections
6) Sense Resistor Composition
OUT
internal clamp protection
Swing vs. Applied Input Voltage at V
and Desired V
OUT
V
Swing vs. Applied Input Voltage at V
OUT
LOAD
T
SENSE
and R
S
Accuracy
L A
L A
SENSE
x R
GAIN
R
x R
SE SE
. The TS1102’s output
A
SE SE
OUT
circuit.
x
to R
3mA
R
R
GAIN
A
(typical) and
T
. For each
RS+
OUT
RS+
,
Table 1: Internal Gain Setting Resistors (Typical
Values)
To achieve its
performance over temperature, VSENSE voltage,
and power supply voltage, the design of the
TS1102’s
commonly-used technique to reduce significantly the
input offset voltage of amplifiers. This method,
however, does employ the use of sampling
techniques and therefore residue of the TS1102’s
10kHz internal clock is contained in the TS1102’s
output voltage spectrum.
Therefore,
and
where the full-scale V
V
terminal voltage. For best performance with a 3.6V
power supply, RSENSE should be chosen to
generate a V
option), b) 60mV (for the 50V/V GAIN option), c)
30mV (for the 100V/V GAIN option), or d) 15mV (for
the 200V/V GAIN option) at the full-scale I
current in each application. For the case where the
minimum power supply voltage is higher than 3.6V,
each of the four full-scale V
increased.
3) Total I
In
V
to the circuit’s accuracy: a) the TS1102’s input offset
voltage (V
(GE(max) = 0.5%).
OUT(MAX)
OUT
GAIN (V/V)
< V
V
the
100
200
25
50
OUT(max)
/ A
OUT(MAX)
LOAD
OS
R
amplifier
SENSE
TS1102’s
SE SE
= 200μV, max) and b) its gain error
Accuracy
= V
R
, there are two specifications related
at the application’s minimum RS+
GAIN
RS+(min)
400
200
100
100
of: a) 120mV (for the 25V/V GAIN
very-low input offset voltage
(Ω)
A
SENSE
is
- V
V
linear
R
SENSE(max)
OUT
10k
10k
10k
20k
chopper-stabilized,
T
L A
SENSE
should be less than
(Ω)
max
s above can be
max
region
TS1102DS r1p0
Part Number
– V
TS1102-100
TS1102-200
TS1102-25
TS1102-50
OH(max)
LOAD(MAX)
where
RTFDS
a