TS1100/01/02/03 Data Sheet
TS1100/01/02/03 Uni- and Bidirectional Current-Sense Amplifiers
The TS1100/01/02/03 Unidirectional and Bidirectional Current Sense Amplifiers con-
sume a very low 0.68 µA supply current.
The TS1100 and TS1101 high-side current sense amplifiers (CSA) combine a 100 µV
(max) input offset voltage (V
OS
) and a 0.6% (max) gain error (GE), with both specifica-
tions optimized for any precision current measurement.
The TS1102 and TS1103 CSAs combine a 200 µV (max) V
OS
and a 0.6% (max) GE for
cost-sensitive applications.
For all high-side current sensing applications, the TS1100/01/02/03 CSAs are self-pow-
ered and feature a wide input common-mode voltage range from 2 to 27 V.
For the bidirectional CSAs, TS1101 and TS1103, a SIGN comparator digital output is
provided that indicates the direction of current flow. All CSAs are specified for operation
over the –40 °C to +105 °C temperature range.
Applications
• Power Management Systems
• Portable/Battery-Powered Systems
• Smart Chargers
• Battery Monitoring
• Overcurrent and Undercurrent Detection
• Remote Sensing
• Industrial Control
KEY FEATURES
• Low Supply Current
• Current Sense Amplifier: 0.68 µA
• I
VDD
: 0.02 µA
• High Side Bidirectional and Unidirectional
Current Sense Amplifier
• Wide CSA Input Common Mode Range: +2
V to +27 V
• Low CSA Input Offset Voltage: 100 µV
(max) (TS1100 and TS1101 Only)
• Low Gain Error: 0.6% (max)
• Four Gain Options Available:
• 25 V/V
• 50 V/V
• 100 V/V
• 200 V/V
• 5-Lead and 6-Lead SOT23 Packaging
silabs.com
| Smart. Connected. Energy-friendly.
Rev. 1.0
TS1100/01/02/03 Data Sheet
Ordering Information
1. Ordering Information
Ordering Number
1
TS1100-25EG5
TS1100-50EG5
TS1100-100EG5
TS1100-200EG5
TS1101-25EG6
TS1101-50EG6
TS1101-100EG6
TS1101-200EG6
TS1102-25EG5
TS1102-50EG5
TS1102-100EG5
TS1102-200EG5
TS1101-25EG6
TS1101-50EG6
TS1101-100EG6
TS1101-200EG6
Part Marking
TADJ
TADK
TADL
TADM
TADN
TADP
TADQ
TADR
TADS
TADT
TADU
TADV
TADW
TADX
TADY
TADZ
Bidirectional current sense amplifier (V
OS(MAX)
= 300 µV)
Unidirectional current sense amplifier (V
OS(MAX)
= 300 µV)
Bidirectional current sense amplifier (V
OS(MAX)
= 200 µV)
Unidirectional current sense amplifier (V
OS(MAX)
= 200 µV)
Description
Gain V/V
25
50
100
200
25
50
100
200
25
50
100
200
25
50
100
200
Note:
1. Adding the suffix, "T", to the part number (e.g., TS1101-25EG6T) denotes tape and reel.
silabs.com
| Smart. Connected. Energy-friendly.
Rev. 1.0 | 1
TS1100/01/02/03 Data Sheet
System Overview
2. System Overview
2.1 Typical Application Circuits
Figure 2.1. TS1100 and TS1102 Typical Application Circuit
Figure 2.2. TS1101 and TS1103 Typical Application Circuit
silabs.com
| Smart. Connected. Energy-friendly.
Rev. 1.0 | 2
TS1100/01/02/03 Data Sheet
System Overview
2.2 Theory of Operation
The internal configuration of the TS1100/02 (a unidirectional high-side, current-sense amplifier) is based on a common operational am-
plifier circuit used for measuring load currents (in one direction) in the presence of high common-mode voltages. In the general case, a
current-sense amplifier monitors the voltage caused by a load current through an external sense resistor and generates an output volt-
age as a function of that load current.
The internal configuration of the TS1101/03 (a bidirectional high-side, current-sense amplifier) is a variation of the TS1100/02 unidirec-
tional current-sense amplifier. In the design of the TS1101/03, the input amplifier was reconfigured for fully differential input/output oper-
ation and a second low-threshold p-channel FET (M2) was added where the drain terminal of M2 is also connected to R
OUT
. Therefore,
the behavior of the TS1101/03 for when V
RS–
> V
RS+
is identical for when V
RS+
> V
RS–
.
Referring to the typical application circuit, the inputs of the op-amp based circuit are connected across an external R
SENSE
resistor that
is used to measure load current. At the non-inverting input of the current-sense amplifier (the RS+ terminal), the applied voltage is
I
LOAD
× R
SENSE
. Since the RS– terminal is the non-inverting input of the internal op-amp, op-amp feedback action forces the inverting
input of the internal op-amp to the same potential. Therefore, the voltage drop across R
SENSE
(V
SENSE
) and the voltage drop across
R
GAINA
(at the RS+ terminal) are equal. Necessary for gain ratio matched, both R
GAINA
and R
GAINB
are the same value.
Since p-channel M1’s source is connected to the inverting input of the internal op amp and since the voltage drop across R
GAINA
is the
same as the external V
SENSE
, op amp feedback action drives the gate of M1 such that M1’s drain-source current is equal to:
V
SENSE
I
DS
(M 1)
=
R
GAINA
or
I
DS
(M 1)
=
I
LOAD
×
R
SENSE
R
GAINA
Since M1’s drain terminal is connected to R
OUT
, the output voltage of the current-sense amplifier at the OUT terminal is, therefore:
V
OUT
=
I
LOAD
×
R
SENSE
×
R
GAINA
For the TS1101 and TS1103, when the voltage at the RS– terminal is greater than the voltage at the RS+ terminal, the external
VSENSE voltage drop is impressed upon R
GAINB
. The voltage drop across R
GAINB
is then converted into a current by M2 that then
produces an output voltage across R
OUT
. In this design, when M1 is conducting current (V
RS+
> V
RS–
), the TS1101/03’s internal amplifi-
er holds M2 OFF. When M2 is conducting current (V
RS–
> V
RS+
), the internal amplifier holds M1 OFF. In either case, the disabled FET
does not contribute to the resultant output voltage.
The current-sense amplifier’s gain accuracy is therefore the ratio match of R
OUT
to R
GAIN[A/B]
. For each of the four gain options availa-
ble, Table 1 lists the values for R
OUT
and R
GAIN[A/B]
. The TS1101’s output stage is protected against input overdrive by use of an output
current-limiting circuit of 3 mA (typical) and a 7 V internal clamp protection circuit.
R
OUT
silabs.com
| Smart. Connected. Energy-friendly.
Rev. 1.0 | 3
TS1100/01/02/03 Data Sheet
System Overview
2.3 SIGN Comparator Output
As shown in the TS1101/03’s block diagram, the design of the TS1101/03 incorporated one additional feature: an analog comparator
whose inputs monitor the internal amplifier’s differential output voltage. While the voltage at the TS1101/03’s OUT terminal indicates the
magnitude of the load current, the TS1101/03’s SIGN output indicates the load current’s direction. The SIGN output is a logic high when
M1 is conducting current (V
RS+
> V
RS–
). Alternatively, the SIGN output is a logic low when M2 is conducting current (V
RS+
< V
RS–
). The
SIGN comparator’s transfer characteristic is illustrated in the figure below. Unlike other current-sense amplifiers that implement a OUT/
SIGN arrangement, the TS1101/03 exhibits no “dead zone” at I
LOAD
switchover. The other attribute of the SIGN comparator’s behavior
is its propagation delay as a function of applied V
SENSE
[(V
RS+
– V
RS–
) or (V
RS–
– V
RS+
)]. As shown below, the SIGN comparator’s
propagation delay behavior is symmetric regardless of current-flow direction and is inversely proportional to V
SENSE
.
Figure 2.3. SIGN Comparator Transfer Characteristic and Propagation Delay
Figure 2.4. SIGN Comparator Propagation Delay vs. V
SENSE
silabs.com
| Smart. Connected. Energy-friendly.
Rev. 1.0 | 4
京公网安备 11010802033920号
EEWORLD
