March 2011 Doc ID 13313 Rev 3 1/18
18
TSC101
High side current sense amplifier
Features
■Independent supply and input common-mode
voltages
■Wide common-mode operating range:
2.8 to 30 V
■Wide common-mode surviving range:
-0.3 to 60 V (load-dump)
■Wide supply voltage range: 4 to 24 V
■Low current consumption: ICC max = 300 µA
■Internally fixed gain: 20 V/V, 50 V/V or 100 V/V
■Buffered output
Applications
■Automotive current monitoring
■Notebook computers
■DC motor controls
■Photovoltaic systems
■Battery chargers
■Precision current sources
Description
The TSC101 measures a small differential voltage
on a high-side shunt resistor and translates it into
a ground-referenced output voltage. The gain is
internally fixed.
Wide input common-mode voltage range, low
quiescent current, and tiny SOT23 packaging
enable use in a wide variety of applications.
The input common-mode and power supply
voltages are independent. The common-mode
voltage can range from 2.8 to 30 V in operating
conditions and up to 60 V in absolute maximum
rating conditions.
The current consumption below 300 µA and the
wide supply voltage range enable the power
supply to be connected to either side of the
current measurement shunt with minimal error.
L
SOT23-5
(Plastic package)
2
1
3V
p
Ou
t
Gnd
4
5
Vm
Vcc
Pin connections
(top view)
www.st.com
Application schematics and pin description TSC101
2/18 Doc ID 13313 Rev 3
1 Application schematics and pin description
The TSC101 high-side current sense amplifier features a 2.8 to 30 V input common-mode
range that is independent of the supply voltage. The main advantage of this feature is that it
allows high-side current sensing at voltages much greater than the supply voltage (VCC).
Figure 1. Application schematics
Ta bl e 1 describes the function of each pin. The pin positions are shown in the illustration on
the cover page and in Figure 1 above.
Table 1. Pin descriptions
Symbol Type Function
Out Analog output Output voltage, proportional to the magnitude of the sense voltage
Vp-Vm.
Gnd Power supply Ground line
VCC Power supply Positive power supply line
VpAnalog input Connection for the external sense resistor. The measured current
enters the shunt on the Vp side.
VmAnalog input Connection for the external sense resistor. The measured current
exits the shunt on the Vm side.
6SENSE
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6##
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2G 2G
2G
2SENSE
TO6
!-
TSC101 Absolute maximum ratings and operating conditions
Doc ID 13313 Rev 3 3/18
2 Absolute maximum ratings and operating conditions
Table 2. Absolute maximum ratings
Symbol Parameter Value Unit
Vid Input pins differential voltage (Vp-Vm)±60V
ViInput pin voltages (Vp and Vm)(1)
1. Voltage values are measured with respect to the ground pin.
-0.3 to 60 V
VCC DC supply voltage(1) -0.3 to 25 V
Vout DC output pin voltage(1) -0.3 to VCC V
Tstg Storage temperature -55 to 150 °C
TjMaximum junction temperature 150 °C
Rthja SOT23-5 thermal resistance junction to ambient 250 °C/W
ESD
HBM: human body model(2)
2. Human body model: a 100 pF capacitor is charged to the specified voltage, then discharged through a
1.5kΩ resistor between two pins of the device. This is done for all couples of connected pin combinations
while the other pins are floating.
2.5 kV
MM: machine model(3)
3. Machine model: a 200 pF capacitor is charged to the specified voltage, then discharged directly between
two pins of the device with no external series resistor (internal resistor < 5 Ω). This is done for all couples of
connected pin combinations while the other pins are floating.
150 V
CDM: charged device model(4)
4. Charged device model: all pins plus package are charged together to the specified voltage and then
discharged directly to the ground.
1.5 kV
Table 3. Operating conditions
Symbol Parameter Value Unit
VCC DC supply voltage from Tmin to Tmax 4.0 to 24 V
Toper Operational temperature range (Tmin to Tmax) -40 to 125 °C
Vicm Common mode voltage range 2.8 to 30 V
Electrical characteristics TSC101
4/18 Doc ID 13313 Rev 3
3 Electrical characteristics
Table 4. Supply(1)
Symbol Parameter Test conditions Min. Typ. Max. Unit
ICC Total supply current Vsense =0V
Tmin < Tamb < Tmax
165 300 µA
1. Unless otherwise specified, the test conditions are Tamb = 25°C, VCC =12V, V
sense =V
p-Vm=50mV, V
m= 12 V, no load
on Out.
Table 5. Input(1)
Symbol Parameter Test conditions Min. Typ. Max. Unit
CMR
Common mode rejection
Variation of Vout versus Vicm
referred to input(2)
2.8 V < Vicm < 30 V
Tmin < Tamb < Tmax
90 105 dB
SVR Supply voltage rejection
Variation of Vout versus VCC(3)
4.0 V < VCC < 24 V
Vsense =30mV
Tmin < Tamb < Tmax
90 105 dB
Vos Input offset voltage(4) Tamb = 25°C
Tmin < Tamb < Tmax
±0.2
±0.9
±1.5
±2.3 mV
dVos/dT Input offset drift vs. T Tmin < Tamb < Tmax -3 µV/°C
Ilk Input leakage current VCC = 0 V
Tmin < Tamb < Tmax
1µA
Iib Input bias current Vsense = 0 V
Tmin < Tamb < Tmax
5.5 8 µA
1. Unless otherwise specified, the test conditions are Tamb = 25°C, VCC =12V, V
sense =V
p-Vm=50mV, V
m= 12 V, no load
on Out.
2. See Section 4.1: Common mode rejection ratio (CMR) on page 11 for the definition of CMR.
3. See Section 4.2: Supply voltage rejection ratio (SVR) on page 11 for the definition of SVR.
4. See Section 4.3: Gain (Av) and input offset voltage (Vos) on page 11 for the definition of Vos.
TSC101 Electrical characteristics
Doc ID 13313 Rev 3 5/18
Table 6. Output(1)
Symbol Parameter Test conditions Min. Typ. Max. Unit
Av Gain
TSC101A
TSC101B
TSC101C
20
50
100
V/V
ΔAv Gain accuracy Tamb = 25°C
Tmin < Tamb < Tmax
±2.5
±4.5 %
ΔVout/ΔT Output voltage drift vs. T(2) Tmin < Tamb < Tmax 0.4 mV/°C
ΔVout/ΔIout Output stage load regulation -10 mA < Iout <10 mA
Iout sink or source current 34mV/mA
ΔVout Total output voltage accuracy(3) Vsense = 50 mV Tamb = 25°C
Tmin < Tamb < Tmax
±2.5
±4.5 %
ΔVout Total output voltage accuracy Vsense = 100 mV Tamb = 25°C
Tmin < Tamb < Tmax
±3.5
±5 %
ΔVout Total output voltage accuracy Vsense = 20 mV Tamb = 25°C
Tmin < Tamb < Tmax
±8
±11 %
ΔVout Total output voltage accuracy Vsense = 10 mV Tamb = 25°C
Tmin < Tamb < Tmax
±15
±20 %
Isc-sink Short-circuit sink current Out connected to VCC,
Vsense = -1 V 30 60 mA
Isc-source Short-circuit source current Out connected to Gnd
Vsense = 1 V 15 26 mA
Voh
Output stage high-state saturation
voltage
Voh=VCC-Vout
Vsense = 1 V
Iout = 1 mA 0.8 1 V
Vol
Output stage low-state saturation
voltage
Vsense = -1 V
Iout = 1 mA 50 100 mV
1. Unless otherwise specified, the test conditions are Tamb = 25°C, VCC = 12 V, Vsense = Vp-Vm = 50 mV, Vm = 12 V, no load on
Out.
2. See Output voltage drift versus temperature on page 12 for the definition.
3. Output voltage accuracy is the difference with the expected theoretical output voltage Vout-th = Av*Vsense.
See Output voltage accuracy on page 13 for a more detailed definition.
Electrical characteristics TSC101
6/18 Doc ID 13313 Rev 3
Table 7. Frequency response(1)
Symbol Parameter Test conditions Min. Typ. Max. Unit
ts Output settling to 1% final value
Vsense = 10 mV to 100 mV
Cload = 47 pF(2)
TSC101A
TSC101B
TSC101C
3
6
10
µs
SR Slew rate Vsense = 10 mV to 100 mV 0.55 0.9 V/µs
BW 3dB bandwidth
Cload = 47 pF(2)
Vsense = 100 mV
TSC101A
TSC101B
TSC101C
500
670
450
kHz
1. Unless otherwise specified, the test conditions are Tamb = 25°C, VCC = 12 V, Vsense = Vp-Vm = 50 mV, Vm = 12 V, no load
on Out.
2. For stability purposes, we do not recommend using a greater value of load capacitor.
Table 8. Noise(1)
Symbol Parameter Test conditions Min. Typ. Max. Unit
Total output voltage noise 50 nV/√ Hz
1. Unless otherwise specified, the test conditions are Tamb = 25°C, VCC = 12 V, Vsense = Vp-Vm = 50 mV, Vm = 12 V, no load
on Out.
TSC101 Electrical characteristics
Doc ID 13313 Rev 3 7/18
3.1 Electrical characteristics curves
For the following curves, the tested device is a TSC101C, and the test conditions are
Tamb= 25°C, VCC = 12 V, Vsense = Vp-Vm = 50 mV, Vm = 12 V, no load on Out unless
otherwise specified.
Figure 2. Supply current vs. supply voltage
(Vsense = 0 V)
Figure 3. Supply current vs. Vsense
Figure 4. Vp pin input bias current vs. Vsense Figure 5. Vm pin input bias current vs. Vsense
Electrical characteristics TSC101
8/18 Doc ID 13313 Rev 3
Figure 6. Minimum common mode operating
voltage vs. temperature
Figure 7. Output stage low-state saturation
voltage versus output current
(Vsense =-1 V)
Figure 8. Output stage high-state saturation
voltage versus output current
(Vsense =+1V)
Figure 9. Output short-circuit source current
versus temperature (Out pin
connected to ground)
TSC101 Electrical characteristics
Doc ID 13313 Rev 3 9/18
Figure 10. Output short-circuit sink current
versus temperature (Out pin
connected to VCC)
Figure 11. Output stage load regulation
Figure 12. Input offset drift versus
temperature
Figure 13. Output voltage drift versus
temperature
Figure 14. Bode diagram (Vsense=100mV) Figure 15. Power-supply rejection ratio versus
frequency
Electrical characteristics TSC101
10/18 Doc ID 13313 Rev 3
Figure 16. Total output voltage accuracy
versus Vsense
Figure 17. Output voltage versus Vsense
Figure 18. Output voltage versus Vsense (detail
for low Vsense values)
Figure 19. Step response
TSC101 Parameter definitions
Doc ID 13313 Rev 3 11/18
4 Parameter definitions
4.1 Common mode rejection ratio (CMR)
The common-mode rejection ratio (CMR) measures the ability of the current-sensing
amplifier to reject any DC voltage applied on both inputs Vp and Vm. The CMR is referred
back to the input so that its effect can be compared with the applied differential signal. The
CMR is defined by the formula:
4.2 Supply voltage rejection ratio (SVR)
The supply-voltage rejection ratio (SVR) measures the ability of the current-sensing
amplifier to reject any variation of the supply voltage VCC. The SVR is referred back to the
input so that its effect can be compared with the applied differential signal. The SVR is
defined by the formula:
4.3 Gain (Av) and input offset voltage (Vos)
The input offset voltage is defined as the intersection between the linear regression of the
Vout versus Vsense curve with the X-axis (see Figure 20). If Vout1 is the output voltage with
Vsense=Vsense1=50mV and Vout2 is the output voltage with Vsense=Vsense2=5mV, then Vos
can be calculated with the following formula:
The amplification gain Av is defined as the ratio between output voltage and input differential
voltage:
CMR 20–
ΔVout
ΔVicm Av⋅
------------------------------log⋅=
SVR 20–
ΔVout
ΔVCC Av⋅
------------------------------log⋅=
Vos Vsense1
Vsense1 Vsense2
–
Vout1 Vout2
–
------------------------------------------------Vout1
⋅
⎝⎠
⎛⎞
–=
Av Vout
Vsense
------------------=
Parameter definitions TSC101
12/18 Doc ID 13313 Rev 3
Figure 20. Vout versus Vsense characteristics: detail for low Vsense values
4.4 Output voltage drift versus temperature
The output voltage drift versus temperature is defined as the maximum variation of Vout with
respect to its value at 25°C, over the temperature range. It is calculated as follows:
with Tmin < Tamb < Tmax.
Figure 21 provides a graphical definition of output voltage drift versus temperature. On this
chart, Vout is always comprised in the area defined by dotted lines representing the
maximum and minimum variation of Vout versus T.
Figure 21. Output voltage drift versus temperature
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6SENSE
M6
6OUT
6OUT
!-
6OUT
ΔVout
ΔT
-----------------max
Vout Tamb
()Vout 25°C()–
Tamb 25°C–
--------------------------------------------------------------------------=
TSC101 Parameter definitions
Doc ID 13313 Rev 3 13/18
4.5 Output voltage accuracy
The output voltage accuracy is the difference between the actual output voltage and the
theoretical output voltage. Ideally, the current sensing output voltage should be equal to the
input differential voltage multiplied by the theoretical gain, as in the following formula:
Vout-th=Av . Vsense
The actual value is very slightly different, mainly due to the effects of:
●the input offset voltage Vos,
●non-linearity
Figure 22. Vout vs. Vsense theoretical and actual characteristics
The output voltage accuracy, expressed in percentage, can be calculated with the following
formula:
with Av = 20 V/V for TSC101A, Av = 50 V/V for TSC101B and Av = 100 V/V for TSC101C.
6SENSE
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!-
ΔVout
abs Vout AvVsense
⋅()–()
AvVsense
⋅
--------------------------------------------------------------------------=
Application information TSC101
14/18 Doc ID 13313 Rev 3
5 Application information
The TSC101 can be used to measure current and to feed back the information to a
microcontroller, as shown in Figure 23.
Figure 23. Typical application schematic
The current from the supply flows to the load through the Rsense resistor causing a voltage
drop equal to Vsense across Rsense. The amplifier input currents are negligible, therefore its
inverting input voltage is equal to Vm. The amplifier's open-loop gain forces its non-inverting
input to the same voltage as the inverting input. As a consequence, the amplifier adjusts
current flowing through Rg1 so that the voltage drop across Rg1 exactly matches Vsense.
Therefore, the drop across Rg1 is: VRg1=Vsense=Rsense.Iload
If IRg1 is the current flowing through Rg1, then IRg1 is given by the formula: IRg1=Vsense/Rg1
The IRg1 current flows entirely into resistor Rg3 (the input bias current of the buffer is
negligible). Therefore, the voltage drop on the Rg3 resistor can be calculated as follows:
VRg3=Rg3.IRg1=(Rg3/Rg1).Vsense
Because the voltage across the Rg3 resistor is buffered to the Out pin, Vout can be
expressed as:
Vout=(Rg3/Rg1).Vsense or Vout=(Rg3/Rg1).Rsense.Iload
The resistor ratio Rg3/Rg1 is internally set to 20V/V for TSC101A, to 50V/V for TSC101B and
to 100V/V for TSC101C.
The Rsense resistor and the Rg3/Rg1 resistor ratio (equal to Av) are important parameters
because they define the full scale output range of your application. Therefore, they must be
selected carefully.
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TSC101 Package information
Doc ID 13313 Rev 3 15/18
6 Package information
In order to meet environmental requirements, ST offers these devices in different grades of
ECOPACK® packages, depending on their level of environmental compliance. ECOPACK®
specifications, grade definitions and product status are available at: www.st.com.
ECOPACK® is an ST trademark.
Figure 24. SOT23-5L package mechanical drawing
Table 9. SOT23-5L package mechanical data
Ref.
Dimensions
Millimeters Inches
Min. Typ. Max. Min. Typ. Max.
A 0.90 1.20 1.45 0.035 0.047 0.057
A1 0.15 0.006
A2 0.90 1.05 1.30 0.035 0.041 0.051
B 0.35 0.40 0.50 0.013 0.015 0.019
C 0.09 0.15 0.20 0.003 0.006 0.008
D 2.80 2.90 3.00 0.110 0.114 0.118
D1 1.90 0.075
e 0.95 0.037
E 2.60 2.80 3.00 0.102 0.110 0.118
F 1.50 1.60 1.75 0.059 0.063 0.069
L 0.10 0.35 0.60 0.004 0.013 0.023
K 0 degrees 10 degrees
Ordering information TSC101
16/18 Doc ID 13313 Rev 3
7 Ordering information
Table 10. Order codes
Part number Temperature
range Package Packaging Marking Gain
TSC101AILT
-40°C, +125°C SOT23-5 Tape & reel
O104 20
TSC101BILT O105 50
TSC101CILT O106 100
TSC101AIYLT(1)
-40°C, +125°C SOT23-5
(Automotive grade) Tape & reel
O101 20
TSC101BIYLT(1) O102 50
TSC101CIYLT(1) O103 100
1. Qualified and characterized according to AEC Q100 and Q003 or equivalent, advanced screening according to AEC Q001
& Q 002 or equivalent.
TSC101 Revision history
Doc ID 13313 Rev 3 17/18
8 Revision history
Table 11. Document revision history
Date Revision Changes
05-Mar-2007 1 First release, preliminary data.
22-Oct-2007 2
Document status promoted from preliminary data to datasheet.
Added test results in electrical characteristics tables.
Added electrical characteristics curves.
14-Mar-2011 3
Added ESD charged device model values in Table 2: Absolute
maximum ratings.
Added automotive grade qualification in Table 10: Order codes.
TSC101
18/18 Doc ID 13313 Rev 3
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