-32 to 60 V (reversed battery and load-dump
conditions)
■ Maximum input offset voltage:
– ±1.5 mV for T
– ±2.3 mV for -40
■ Maximum total output voltage error:
– ±1.5% for T
– ±2.5% for -40°C < T
■ Maximum variation over temperature:
–dV
–dV
■ Low current consumption: I
■ -40 to 125°C operating temperature range
■ Internally fixed gain: 20 V/V, 50 V/V
■ EMI filtering
/dT = 8 µV/°C
os
/dT = 100 ppm/°C
out
amb
amb
= 25°C
°C < T
= 25°C
amb
< 125°C
amb
< 125°C
max = 300 µA
CC
Applications
■ Automotive current monitoring
■ Notebook computers
■ Server power supplies
■ Telecom equipment
■ Industrial SMPS
■ Current sharing
■ LED current measurement
TSC1021
High-side current sense amplifier
TSSOP8
(Plastic package)
Description
The TSC1021 measures a small differential
voltage on a high-side shunt resistor and
translates it into a ground-referenced output
voltage.
The TSC1021 has been specifically designed to
deal with automotive conditions: load-dump
protection up to 60 V, reverse-battery protection
up to -32 V, ESD protection up to 4 kV and
internal filtering for EMI performance.
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 ratings while the
TSC1021 can be supplied by a 5 V independent
supply line.
The TSC1021 is housed in a tiny TSSOP8
package and integrates a buffer that provides low
impedance output to ease interfacing and avoid
accuracy losses. The overall device current
consumption is lower than 300 µA.
September 2010Doc ID 17857 Rev 11/12
www.st.com
12
Application diagramTSC1021
1 Application diagram
The TSC1021 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 (V
Figure 1.Application schematic: high-line current sensing
Vsense
Iload
Common-mode range
R
sense
CC
).
Supply voltage
Vcc
Rg3
Gnd
Vp
Rg1
Vm
Rg2
Out
V
out
= Av.V
sense
AM06135
2/12Doc ID 17857 Rev 1
TSC1021Pin configuration
2 Pin configuration
Figure 2.Pin connections (top view)
Vm
NC
Gnd
Out
1
2
3
4
Vp
8
NC
7
Vcc
6
NC
5
Ta bl e 1 describes the function of each pin. Their position is shown in the illustration on the
cover page and in Figure 1 above.
A1
Table 1.Pin description
Pin numberSymbolTypeFunction
1V
m
Analog input
3GndPower supplyGround line
4OutAnalog outputBuffered output of the current sensing amplifier
6V
8V
CC
p
Power supplyPositive power supply line
Analog input
Connection for the external sense resistor. The
measured current exits the shunt on the V
side.
m
Connection for the external sense resistor. The
measured current enters the shunt on the V
side.
p
Doc ID 17857 Rev 13/12
Absolute maximum ratings and operating conditionsTSC1021
3 Absolute maximum ratings and operating conditions
Table 2.Absolute maximum ratings
SymbolParameterValueUnit
V
id
V
V
1
T
stg
T
R
thja
ESD
1. Voltage values are measured with respect to the GND pin.
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.
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.
4. Charged device model: all pins and package are charged together to the specified voltage and then
discharged directly to ground.
Table 3.Operating conditions
Input pins differential voltage (Vp-Vm)±20V
Current sensing input pin voltages (Vp and Vm)
i
Voltage for Vcc, Out pins
(1)
(1)
-32 to 60V
-0.3 to 7V
Storage temperature-65 to 150°C
Maximum junction temperature150°C
j
TSSOP8 thermal resistance junction to ambient 120°C/W
HBM: human body model for V
HBM: human body model
MM: machine model
CDM: charged device model
(2)
(3)
(4)
and Vm pins
p
(2)
4kV
2kV
250V
1.5kV
SymbolParameterValueUnit
V
T
V
CC
oper
icm
DC supply voltage from T
Operational temperature range (T
min
to T
max
min
to T
Common mode voltage range (Vm and Vp pins
voltages)
4/12Doc ID 17857 Rev 1
3.5 to 5.5V
)-40 to 125°C
max
2.8 to 30V
TSC1021Electrical characteristics
4 Electrical characteristics
The electrical characteristics given in the following tables are measured under the following
test conditions unless otherwise specified: T
V
= 12 V, no load on Out, all gain configurations.
m
Table 4.Supply
SymbolParameterTest conditionsMin.Typ.Max.Unit
I
CC
I
CC1
Table 5.Electrical performances
SymbolParameterTest conditionsMin.Typ.Max.Unit
Total supply current
Total supply current
= 0 V
V
sense
-40°C < T
V
= 50 mV
sense
-40°C < T
amb
amb
= 25°C, V
amb
< 125°C
< 125°C
CC
= 5 V, V
= Vp-Vm = 50 mV,
sense
300µA
450µA
DC common-mode rejection
DC CMR
Variation of V
(1)
to input
versus Vm referred
out
AC common mode rejection
AC CMR
Variation of V
to input (peak-to-peak voltage
versus Vm referred
out
variation)
Supply voltage rejection
Variation of V
Input offset voltage
os
versus V
out
(1)
CC
(1)
/dTInput offset drift vs. T-40°C< T
/dTOutput voltage drift vs. T-40°C< T
Input leakage current
lk
Input bias current
ib
Gain
(variation of V
Total output voltage accuracy
out
Total output voltage accuracy
out
Total output voltage accuracy
out
out
versus V
sense
)
(2)
(2)
(2)
dV
dV
SVR
V
os
out
I
I
Av
ΔV
ΔV
ΔV
2.8 V< Vm < 30 V
-40°C < T
2.8 V< V
amb
< 30 V
m
< 125°C
DC to 1 kHz sine wave
3.5 V< VCC < 5.5 V
-40°C< T
< 125°C
amb
2.8 V< Vm < 30 V
T
= 25° C
amb
-40°C < T
V
= 0 V
CC
-40°C < T
V
sense
-40°C < T
< 125°C
amb
< 125°C8µV/°C
amb
< 125°C100ppm/°C
amb
< 125°C
amb
= 0 V
< 125°C
amb
TSC1021A
TSC1021B
V
= 50 mV
sense
T
= 25° C
amb
T
< T
amb
= 100 mV
= 25° C
< T
amb
= 20 mV
= 25° C
< T
amb
< T
< T
< T
max
max
max
min
V
sense
T
amb
T
min
V
sense
T
amb
T
min
90105dB
75dB
8095dB
±1.5
mV
±2.3
1µA
7µA
20
50
±1.5
V/V
%
±2.5
±1.5
%
±2.5
±7
%
±9
Doc ID 17857 Rev 15/12
Electrical characteristicsTSC1021
Table 5.Electrical performances
SymbolParameterTest conditionsMin.Typ.Max.Unit
V
= 10 mV
ΔV
ΔV
out
V
V
1. See Chapter 5: Parameter definitions.
2. Output voltage accuracy is the difference with the expected theoretical output voltage V
See Chapter 5: Parameter definitions for a more detailed definition.
Table 6.Dynamic performances
Total output voltage accuracy
out
/ΔI
Output stage load regulation
out
Out high level saturation voltage
oh
Voh=Vcc-V
Out low level saturation voltage
ol
out
(2)
SymbolParameterTest conditionsMin.Typ.Max.Unit
sense
= 25° C
T
amb
T
< T
amb
out
= 1 V, I
= 25° C
amb
= -1 V, I
= 25° C
amb
< T
max
<5 mA
= 1 mA
out
< 125°C
out
< 125°C
min
-5 mA < I
sink or source current
I
out
V
sense
T
amb
-40°C< T
V
sense
T
amb
-40°C< T
= 1 mA
out-th
±12
±15
±0.4±2mV/mA
90135
185
80125
165
= Av x V
sense
.
%
mV
mV
tsV
settling to 1% final value
out
SRSlew rateV
BW3 dB bandwidthC
e
Equivalent input noise voltagef = 1 kHz50nV/√ Hz
N
V
= 10 mV to 100 mV,
sense
C
= 47 pF
load
= 10 mV to 100 mV0.30.45V/µs
sense
= 47 pF800kHz
load
7µs
6/12Doc ID 17857 Rev 1
TSC1021Parameter definitions
5 Parameter definitions
5.1 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 V
back to the input so that its effect can be compared with the applied differential signal. The
CMR is defined by the formula:
ΔV
CMR20–
------------------------------log⋅=ΔV
out
icm
5.2 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 V
input so that its effect can be compared with the applied differential signal. The SVR is
defined by the formula:
Av⋅
and Vm. The CMR is referred
p
. The SVR is referred back to the
CC
ΔV
out
SVR20–
---------------------------log⋅=ΔVccAv⋅
5.3 Gain (Av) and input offset voltage (Vos)
The input offset voltage is defined as the intersection between the linear regression of the
V
vs. the V
out
V
V
= V
sense
can be calculated with the following formula.
os
sense1
curve with the X-axis. If V
sense
= 50 mV and V
V
os
V
sense1
out2
is the output voltage with
out1
is the output voltage with V
V
⎛⎞
------------------------------------------------
–=
⎝⎠
–
sense1Vsense2
V
–
out1Vout2
V
⋅
out1
5.4 Output voltage drift versus temperature
The output voltage drift versus temperature is defined as the maximum variation of V
respect to its value at 25°C, over the temperature range. It is calculated as follows:
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.
V
out-th
AvV
⋅=
sense
The actual value is very slightly different, mainly due to the effects of:
●the input offset voltage V
●the non-linearity,
●the voltage saturation of V
,
os
and VOH.
OL
The output voltage accuracy, expressed as a percentage, can be calculated with the
following formula.
with Av = 20 V/V for TSC1021A and Av = 50 V/V for TSC1021B.
8/12Doc ID 17857 Rev 1
TSC1021Package information
6 Package information
In order to meet environmental requirements, ST offers these devices in different grades of
ECOPACK
specifications, grade definitions and product status are available at: www.st.com.
ECOPACK
®
packages, depending on their level of environmental compliance. ECOPACK®
®
is an ST trademark.
Figure 3.TSSOP8 package mechanical drawing
Table 7.TSSOP8 package mechanical data
Dimensions
Ref.
Min.Typ.Max.Min.Typ.Max.
A1.200.047
A10.050.150.0020.006
A20.801.001.050.0310.0390.041
b0.190.300.0070.012
c0.090.200.0040.008
D2.903.003.100.1140.1180.122
E6.206.406.600.2440.2520.260
E14.304.404.500.1690.1730.177
e0.650.0256
k0°8°0°8°
L0.450.600.750.0180.0240.030
L110.039
aaa0.100.004
MillimetersInches
Doc ID 17857 Rev 19/12
Ordering informationTSC1021
7 Ordering information
Table 8.Order codes
Part numberTemperature rangePackagePackagingMarkingGain
TSC1021AIPT
O21AI20
-40°C, +125°C
TSC1021BIPTO21BI50
TSSOP8Tape & reel
TSC1021AIYPT
TSC1021BIYPTO21BY50
1. Qualification and characterization according to AEC Q100 and Q003 or equivalent, advanced screening
according to AEC Q001 & Q 002 or equivalent are ongoing.
-40°C, +125°C
Automotive grad
(1)
e
O21AY20
10/12Doc ID 17857 Rev 1
TSC1021Revision history
8 Revision history
Table 9.Document revision history
DateRevisionChanges
23-Sep-20101Initial release.
Doc ID 17857 Rev 111/12
TSC1021
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