TMCS1108
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TMCS1108 3% Functional Isolation Hall-Effect Current Sensor With ±100-V Working
Voltage
1 Features
3 Description
•
The TMCS1108 is a galvanically isolated Hall-effect
current sensor capable of DC or AC current
measurement with high accuracy, excellent linearity,
and temperature stability. A low-drift, temperaturecompensated signal chain provides 3 V to valid output
25
5.5
mA
6
mA
ms
Excludes effect of external magnetic fields. See the Accuracy Parameters section for details to calculate error due to external magnetic
fields.
Excluding magnetic coupling from layout deviation from recommended layout. See the Layout section for more information.
RTI = referred-to-input. Output voltage is divided by device sensitivity to refer signal to input current. See the Parameter Measurement
Information section.
Thermally limited by junction temperature. Applies when device mounted on TMCS1108EVM. For more details, see the Safe Operating
Area section.
Lifetime and environmental drift specifications based on three lot AEC-Q100 qualification stress test results. Typical values are
population mean+1σ from worst case stress test condition. Min/max are tested device population mean±6σ; devices tested in AECQ100 qualification stayed within min/max limits for all stress conditions. See Lifetime and Environmental Stability section for more
details.
Refer to the Transient Response section for details of frequency and transient response of the device.
Centered parameter based on TMCS1108EVM PCB layout. See Layout section. Device must be operated below maximum junction
temperature.
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7.7 Typical Characteristics
200
0.9
Sensitivty Error (%)
0.6
0.3
0
-0.3
-0.6
-0.9
A1B/U
A2B/U
A3B/U
A4B/U
160
Input Current Offset (mA)
A1B/U
A2B/U
A3B/U
A4B/U
120
80
40
0
-40
-80
-120
-1.2
-160
-1.5
-50
-200
-50
-25
0
25
50
75
Temperature (°C)
100
125
150
Figure 7-1. TMCS1108 Sensitivity Error vs. Temperature
-25
0
25
50
75
Temperature (°C)
100
125
150
Figure 7-2. TMCS1108 Input Offset Current vs. Temperature
4
30
3
0
2
-30
0
Phase (°)
Gain (dB)
1
-1
-2
-3
-60
-90
-120
-4
All gains 80kHz -3dB
-150
-5
-6
10
100
1k
10k
Frequency (Hz)
100k
1M
-180
10
1k
Frequency (Hz)
10k
100k
Figure 7-4. Phase vs. Frequency, All Gains
100
VS
(VS) – 0.5
(VS) – 1
(VS) – 1.5
(VS) – 2
(VS) – 2.5
(VS) – 3
Closed-loop Output Impedance (:)
Output Voltage Swing (V)
Figure 7-3. Sensitivity vs. Frequency, All Gains Normalized to 1
Hz
100
GND + 3
GND + 2.5
GND + 2
GND + 1.5
GND + 1
GND + 0.5
GND
0
20
40
60
80
100
120
140
160
10
1
0.1
10
Output Current (mA)
Figure 7-5. Output Swing vs. Output Current
100
1k
10k
Frequency (Hz)
100k
1M
Figure 7-6. Output Impedance vs. Frequency
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7.7 Typical Characteristics (continued)
A1B/U
A2B/U
A3B/U
A4B/U
4.8
4.6
4.4
4.2
-50
-25
0
25
50
75
Temperature (°C)
100
125
400
350
300
250
200
A1
A2
150
10
150
1k
Frequency (Hz)
10k
100k
90
75
3.5
75
60
3
60
3
45
2.5
45
2.5
30
2
30
2
15
1.5
15
1.5
IIN
V1 1
V2
0.5
0
-15
4
IIN
V1 3.5
V2
0
1
-15
0.5
Time (4Ps/div)
Time (4Ps/div)
Figure 7-9. Voltage Output Step, Rising
Figure 7-10. Voltage Output Step, Falling
70
Input Current (A)
Input Current (A)
4
Output Voltage (V)
90
60
6
IIN
VOUT 5
50
4
40
3
30
2
20
1
10
0
0
-1
-10
Output Voltage (V)
Input Current (A)
100
Figure 7-8. Input-Referred Noise vs. Frequency
Figure 7-7. Quiescent Current vs. Temperature
-2
Time (4Ps/div)
Figure 7-11. Current Overload Response
10
A3
A4
Output Voltage (V)
5
Quiescent Current (mA)
Referred-to-Input Current Noise (uA/—Hz)
5.2
Figure 7-12. Startup Transient Response
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7.7 Typical Characteristics (continued)
2.4
2.3
2.2
RIN (m:)
2.1
2
1.9
1.8
1.7
1.6
1.5
1.4
-50
-25
0
25
50
75
Temperature (°C)
100
125
150
Figure 7-13. Input Conductor Resistance vs. Temperature
35
0.8
30
0.7
Safety Limiting Current (A)
Safety Limiting Current (A)
7.7.1 Insulation Characteristics Curves
25
20
15
10
5
0.6
0.5
0.4
0.3
0.2
0.1
0
0
0
20
40
60
80
100
120
Ambient Temperature (°C)
140
160
Figure 7-14. Thermal Derating Curve for SafetyLimiting Current, Side 1
0
20
40
60
80
100
120
Ambient Temperature (°C)
140
160
Figure 7-15. Thermal Derating Curve for SafetyLimiting Current, Side 2
4
Saftey Limiting Power (W)
3.5
3
2.5
2
1.5
1
0.5
0
0
20
40
60
80
100
120
Ambient Temperature (°C)
140
160
Figure 7-16. Thermal Derating Curve for Safety-Limiting Power
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8 Parameter Measurement Information
8.1 Accuracy Parameters
The ideal first-order transfer function of the TMCS1108 is given by Equation 1, where the output voltage is a
linear function of input current. The accuracy of the device is quantified both by the error terms in the transfer
function parameters, as well as by nonidealities that introduce additional error terms not in the simplified linear
model. See Total Error Calculation Examples for example calculations of total error, including all device error
terms.
VOUT = S × IIN + VOUT,0A
(1)
where
•
•
•
•
VOUT is the analog output voltage.
S is the ideal sensitivity of the device.
IIN is the isolated input current.
VOUT,0A is the zero current output voltage for the device variant.
8.1.1 Sensitivity Error
Sensitivity is the proportional change in the sensor output voltage due to a change in the input conductor
current. This sensitivity is the slope of the first-order transfer function of the sensor, as shown in Figure 8-1. The
sensitivity of the TMCS1108 is tested and calibrated at the factory for high accuracy.
VOUT (V)
VOUT, 0 A + VFS+
VNL
S = Slope (V/A)
best fit linear
VOUT, 0 A
VOUT, 0 A
VOE
0.1xVS (AxU)
0.5xVS (AxB)
VOUT, 0 A ± VFS±
IFS±
IIN (A)
IFS+
Figure 8-1. Sensitivity, Offset, and Nonlinearity Error
Deviation from ideal sensitivity is quantified by sensitivity error, defined as the percent variation of the best-fit
measured sensitivity from the ideal sensitivity. When specified over a temperature range, this is the worst-case
sensitivity error at any temperature within the range.
eS = [(Sfit – Sideal) / Sideal] × 100%
(2)
where
•
•
•
eS is the sensitivity error.
Sfit is the best fit sensitivity.
SIdeal is the ideal sensitivity.
8.1.2 Offset Error and Offset Error Drift
Offset error is the deviation from the ideal output voltage with zero input current through the device. Offset error
can be referred to the output as a voltage error VOE or referred to the input as a current offset error IOS. Offset
error is a single error source, however, and must only be included once in error calculations.
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The output voltage offset error of the TMCS1108 is the deviation of the measured VOUT with zero input current
from the ideal value of the zero current output voltage. This ideal voltage is either 10% of VS for unidirectional
devices (AxU) or 50% of VS for bidirectional devices (AxB), as shown in Equation 3 and Equation 4, respectively.
VOE
VOUT,0A
VS * 0.1
(3)
VOE
VOUT,0A
VS * 0.5
(4)
where
• VOUT,0A is the device output voltage with zero input current.
The offset error includes errors in the internal reference, the magnetic offset of the Hall sensor and any offset
voltage errors of the signal chain.
The input referred (RTI) offset error is the output voltage offset error divided by the sensitivity of the device,
shown in Equation 5. Refer the offset error to the input of the device to allow for easier total error calculations
and direct comparison to input current levels. No matter how the calculations are done, the error sources
quantified by VOE and IOS are the same, and should only be included once for error calculations.
IOS
VOE / S
(5)
Offset error drift is the change in the input-referred offset error per degree Celsius change in ambient
temperature. This parameter is reported in µA/°C. To convert offset drift to an absolute offset for a given change
in temperature, multiply the drift by the change in temperature and convert to percentage, as in Equation 6.
IOS,25qC
eIOS ,'T %
§ PA ·
IOS,drift ¨
¸ u 'T
© qC ¹
IIN
(6)
where
•
•
IOS,drift is the specified input-referred device offset drift.
ΔT is the temperature range from 25°C.
8.1.3 Nonlinearity Error
Nonlinearity is the deviation of the output voltage from a linear relationship to the input current. Nonlinearity
voltage, as shown in Figure 8-1, is the maximum voltage deviation from the best-fit line based on measured
parameters, calculated by Equation 7.
VNL = VOUT,MEAS – (IMEAS × Sfit + VOUT,0A)
(7)
where
•
•
•
•
VOUT,MEAS is the voltage output at maximum deviation from best fit.
IMEAS is the input current at maximum deviation from best fit.
Sfit is the best-fit sensitivity of the device.
VOUT,0A is the device zero current output voltage.
Nonlinearity error (eNL) for the TMCS1108 is the nonlinearity voltage specified as a percentage of the full-scale
output range (VFS), as shown in Equation 8.
eNL
100% *
VNL
VFS
(8)
8.1.4 Power Supply Rejection Ratio
Power supply rejection ratio (PSRR) is the change in device offset due to variation of supply voltage from the
nominal 5 V. The error contribution at the input current of interest can be calculated by Equation 9.
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ePSRR (%)
PSRR * (VS
S
IIN
5)
(9)
where
•
•
VS is the operational supply voltage.
S is the device senstivity.
8.1.5 Common-Mode Rejection Ratio
Common-mode rejection ratio (CMRR) quantifies the effective input current error due to a varying voltage on the
isolated input of the device. Due to magnetic coupling and galvanic isolation of the current signal, the TMCS1108
has very high rejection of input common-mode voltage. Percent error contribution from input common-mode
variation can be calculated by Equation 10.
eCMRR (%)
CMRR * VCM
IIN
(10)
where
•
VCM is the maximum operational AC or DC voltage on the input of the device.
8.1.6 External Magnetic Field Errors
The TMCS1108 does not have stray field-rejection capabilities, so external magnetic fields from adjacent highcurrent traces or nearby magnets can impact the output measurement. The total sensitivity (S) of the device is
comprised of the initial transformation of input current to magnetic field quantified as the magnetic coupling factor
(G), as well as the sensitivity of the Hall element and the analog circuitry that is factory calibrated to provide
a final sensitivity. The output voltage is proportional to the input current by the device sensitivity, as defined in
Equation 11.
S
G * SHall * A V
(11)
where
•
•
•
•
S is the TMCS1108 sensitivity in mV/A.
G is the magnetic coupling factor in mT/A.
SHall is the sensitivity of the Hall plate in mV/mT.
AV is the calibrated analog circuitry gain in V/V.
An external field, BEXT, is measured by the Hall sensor and signal chain, in addition to the field generated by the
leadframe current, and is added as an extra input term in the total output voltage function:
VOUT
BEXT * SHall * A V
IIN * G * SHall * A V
VOUT,0A
(12)
Observable from Equation 12 is that the impact of an external field is an additional equivalent input current
signal, IBEXT, shown in Equation 13. This effective additional input current has no dependence on Hall or analog
circuitry sensitivity, so all gain variants have equivalent input-referred current error due to external magnetic
fields.
IBEXT
BEXT
G
(13)
This additional current error generates a percentage error defined by Equation 14.
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BEXT
G
IIN
eBEXT (%)
(14)
8.2 Transient Response Parameters
90
4
75
3.5
60
3
45
2.5
30
2
15
1.5
Output Voltage (V)
Input Current (A)
The transient response of the TMCS1108 is impacted by the 250 kHz sampling rate as defined in Transient
Response. Figure 8-2 shows the TMCS1108 response to an input current step sufficient to generate a 1-V output
change. The typical 4-µs sampling window can be observed as a periodic step. This sampling window dominates
the response of the device, and the response will have some probabilistic nature due to alignment of the input
step and the sampling window interval.
IIN
V1 1
V2
0.5
0
-15
Time (4Ps/div)
Figure 8-2. Transient Step Response
8.2.1 Slew Rate
Slew rate (SR) is defined as the VOUT rate of change for a single integration step’s output transition, as shown
in Figure 8-3. Because the device often requires two sampling windows to reach a full 90% settling of its final
value, this slew rate is not equal to the 10%-90% transition time for the full output swing.
Input Current
Input Current
Input Current
tr
90%
4 s Sample
Window
1V
SR
tr
90%
4 s Sample
Window
SR
tr
90%
4 s Sample
Window
1V
VOUT response
1V
VOUT response
SR
VOUT response
10%
tp
10%
tp
10%
tp
Figure 8-3. Small Current Input Step Transient Response
8.2.2 Propagation Delay and Response Time
Propagation delay is the time period between the input current waveform reaching 10% of its final value and
VOUT reaching 10% of its final value. This propagation delay is heavily dependent upon the alignment of the
input current step and the sampling period of the TMCS1108, as shown for several different sampling window
cases in Figure 8-3.
Response time is the time period between the input current reaching 90% of its final value and the output
reaching 90% of its final value, for an input current step sufficient to cause a 1-V transition on the output. Figure
8-3 shows the response time of the TMCS1108 under three different time cases. Unless a step input occurs
directly during the beginning of one sampling window the response time will include two sampling intervals.
8.2.3 Current Overload Parameters
Current overload response parameters are the transient behavior of the TMCS1108 to an input current step
consistent with a short circuit or fault event. Tested amplitude is twice the full scale range of the device, or 10V /
Sensitivity in V/A. Under these conditions, the TMCS1108 output will respond faster than in the case of a small
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input current step due to the higher input amplitude signal. Response time and propagation delay are measured
in a similar manner to the case of a small input current step, as shown in Figure 8-4.
Input Current
tr
90%
û IIN =
10 V / S
VOUT response
SR
10%
tp
Figure 8-4. Current Overload Transient Response
Current overload recovery time is the required time for the device output to exit a saturated condition and return
to normal operation. The transient response of the device during this recovery period from a current overload is
shown in Figure 7-11.
8.2.4 CMTI, Common-Mode Transient Immunity
CMTI is the capability of the device to tolerate a rising/falling voltage step on the input without disturbance on
the output signal. The device is specified for the maximum common-mode transition rate under which the output
signal will not experience a greater than 200-mV disturbance that lasts longer than 1 µs. Higher edge rates than
the specified CMTI can be supported with sufficient filtering or blanking time after common-mode transitions.
8.3 Safe Operating Area
The input current safe operating area (SOA) of the TMCS1108 is constrained by self-heating due to power
dissipation in the input conductor. Depending upon use case, the SOA is constrained by multiple conditions,
including exceeding maximum junction temperature, Joule heating in the leadframe, or leadframe fusing under
extremely high currents. These mechanisms depend on pulse duration, amplitude, and device thermal states.
Current SOA strongly depends on the thermal environment and design of the system-level board. Multiple
thermal variables control the transfer of heat from the device to the surrounding environment, including air flow,
ambient temperature, and PCB construction and design. All ratings are for a single TMCS1108 device on the
TMCS1108EVM, with no air flow in the specified ambient temperature conditions. Device use profiles must
satisfy both continuous conduction and short-duration transient SOA capabilities for the thermal environment
under which the system will be operated.
8.3.1 Continuous DC or Sinusoidal AC Current
The longest thermal time constants of device packaging and PCB are on the order of seconds; therefore,
any continuous DC or sinusoidal AC periodic waveform with a frequency higher than 1 Hz can be evaluated
based on the rms continuous-current level. The continuous-current capability has a strong dependence upon
the operating ambient temperature range expected in operation. Figure 8-5 shows the maximum continuous
current-handling capability of the device on the TMCS1108EVM. Current capability falls off at higher ambient
temperatures because of the reduced thermal transfer from junction-to-ambient and increased power dissipation
in the leadframe. By improving the thermal design of an application the SOA can be extended to higher currents
at elevated temperatures. Using larger and heavier copper power planes, providing air flow over the board, or
adding heat sinking structures to the area of the device can all improve thermal performance.
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Maximum Continuous RMS Current (A)
35
30
25
20
15
10
-55
-35
-15
5
25
45
65
Ambient Temperature (qC)
85
105
125
D012
Figure 8-5. Maximum Continuous RMS Current vs Ambient Temperature
8.3.2 Repetitive Pulsed Current SOA
For applications where current is pulsed between a high current and no current, the allowable capabilities are
limited by short-duration heating in the leadframe. The TMCS1108 can tolerate higher current ranges under
some conditions, however, for repetitive pulsed events, the current levels must satisfy both the pulsed current
SOA and the rms continuous current constraint. Pulse duration, duty cycle, and ambient temperate all impact the
SOA for repetitive pulsed events. Figure 8-6, Figure 8-7, Figure 8-8, and Figure 8-9 illustrate repetitive stress
levels based on test results from the TMCS1108EVM under which parametric performance and isolation integrity
was not impacted post-stress for multiple ambient temperatures. At high duty cycles or long pulse durations, this
limit approaches the continuous current SOA for a rms value defined by Equation 15.
IIN,RMS
IIN,P * D
(15)
where
•
•
•
IIN,RMS is the RMS input current level
IIN,P is the pulse peak input current
D is the pulse duty cycle
160
250
1%
5%
10%
25%
50%
75%
150
Allowable Current (A)
Allowable Current (A)
200
1%
5%
10%
25%
50%
75%
140
100
120
100
80
60
40
50
20
0
0.001
0.01
0.1
1
Current Pulse Duration (s)
10
0
0.001
D016
TA = 25°C
0.01
0.1
1
Current Pulse Duration (s)
10
D017
TA = 85°C
Figure 8-6. Maximum Repetitive Pulsed Current vs
Pulse Duration
Figure 8-7. Maximum Repetitive Pulsed Current vs
Pulse Duration
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140
120
1%
5%
10%
25%
50%
75%
100
80
60
40
80
60
40
20
20
0
0.001
1%
5%
10%
25%
50%
75%
100
Allowable Current (A)
Allowable Current (A)
120
0.01
0.1
1
Current Pulse Duration (s)
0
0.001
10
D018
0.01
0.1
1
Current Pulse Duration (s)
TA = 105°C
10
D019
TA = 125°C
Figure 8-8. Maximum Repetitive Pulsed Current vs
Pulse Duration
Figure 8-9. Maximum Repetitive Pulsed Current vs
Pulse Duration
8.3.3 Single Event Current Capability
Single higher-current events that are shorter duration can be tolerated by the TMCS1108, because the junction
temperature does not reach thermal equilibrium within the pulse duration. Figure 8-10 shows the short-circuit
duration curve for the device for single current-pulse events, where the leadframe resistance changes after
stress. This level is reached before a leadframe fusing event, but should be considered a upper limit for short
duration SOA. For long-duration pulses, the current capability approaches the continuous rms limit at the given
ambient temperature.
Fuse Current (A)
1000
100
TA = 25°C
TA = 125°C
10
0.001
0.01
0.1
Pulse Duration (s)
1
10
D004
Figure 8-10. Single-Pulse Leadframe Capability
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9 Detailed Description
9.1 Overview
The TMCS1108 is a precision Hall-effect current sensor, featuring a 100-V functional isolation working voltage, <
3% full-scale error across temperature, and device options providing both unidirectional and bidirectional current
sensing. Input current flows through a conductor between the isolated input current pins. The conductor has a
1.8-mΩ resistance at room temperature for low power dissipation and a 20-A RMS continuous current handling
capability up to 105°C ambient temperature on the TMCS1108EVM. The low-ohmic leadframe path reduces
power dissipation compared to alternative current measurement methodologies, and does not require any
external passive components, isolated supplies, or control signals on the high-voltage side. The magnetic field
generated by the input current is sensed by a Hall sensor and amplified by a precision signal chain. The device
can be used for both AC and DC current measurements and has a bandwidth of 80 kHz. There are multiple
fixed-sensitivity device variants for a wide option of linear sensing ranges, and the TMCS1108 can operate with
a low voltage supply from 3 V to 5.5 V. The TMCS1108 is optimized for high accuracy and temperature stability,
with both offset and sensitivity compensated across the entire operating temperature range.
9.2 Functional Block Diagram
VS
Hall
Element
Bias
Temperature
Compensation
---------------------Offset Cancellation
IN+
Precision
Amplifier
Output
Amplifier
VOUT
VS
IN–
GND
GND
9.3 Feature Description
9.3.1 Current Input
Input current to the TMCS1108 passes through the isolated side of the package leadframe through the IN+
and IN– pins. The current flow through the package generates a magnetic field that is proportional to the input
current, and measured by a galvanically isolated, precision, Hall sensor IC. As a result of the electrostatic
shielding on the Hall sensor die, only the magnetic field generated by the input current is measured, thus limiting
input voltage switching pass-through to the circuitry. This configuration allows for direct measurement of currents
with high-voltage transients without signal distortion on the current-sensor output. The leadframe conductor
has a nominal resistance of 1.8 mΩ at 25°C, and has a typical positive temperature coefficient as defined in
Electrical Characteristics.
9.3.2 High-Precision Signal Chain
The TMCS1108 uses a precision, low-drift signal chain with proprietary sensor linearization techniques to
provide a highly accurate and stable current measurement across the full temperature range of the device.
The device is fully tested and calibrated at the factory to account for any variations in either silicon or packaging
process variations. The full signal chain provides a fixed sensitivity voltage output that is proportional to the
current through the leadframe of the isolated input.
9.3.2.1 Lifetime and Environmental Stability
The same compensation techniques utilized in the TMCS1108 to reduce temperature drift also greatly reduce
lifetime drift due to aging, stress, and environmental conditions. Typical magnetic sensors suffer from up to 2%
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to 3% of sensitivity drift due to aging at high operating temperatures. The TMCS1108 has greatly improved
lifetime drift, as defined in the Electrical Characteristics table for total sensitivity error measured after the worstcase stress test during a three lot AEC-Q100 qualification. All other stress tests prescribed by an AEC-Q100
qualification caused lower than the specified sensitivity error, and were within the bounds specified within the
Electrical Characteristics table. Figure 9-1 shows the total sensitivity error after the worst case stress test, a
Highly Accelerated Stress Test (HAST) at 130°C and 85% relative humidity (RH), while Figure 9-2 and Figure
9-3 show the sensitivity and offset error drift after a 1000 hour, 125°C high temperature operating life stress
test as specified by AEC-Q100. This test mimics typical device lifetime operation, and shows the likely device
performance variation due to aging is vastly improved compared to typical magnetic sensors.
160
200
140
180
160
120
Unit Count
Unit Count
140
100
80
60
120
100
80
60
40
40
20
20
0
-1% -.8% -.6% -.4% -.2% 0%
.2%
.4% .6%
.8%
Sensitivity Drift (%)
0
-1% -.8% -.6% -.4% -.2% 0%
1%
.2%
Sensitivity Drift (%)
D020
Figure 9-1. Sensitivity Error After 130°C, 85% RH
HAST
.4% .6%
.8%
1%
D021
Figure 9-2. Sensitivity Error Drift After AEC-Q100
High Temperature Operating Life Stress Test
120
100
Unit Count
80
60
40
20
0
-50
-40
-30
-20
-10
0
10
20
30
IOS Drift (mA)
40
50
D022
Figure 9-3. Input-Referred Offset Drift After AEC-Q100 High Temperature Operating Life Stress Test
9.3.2.2 Frequency Response
The TMCS1108 signal chain has a spectral response atypical of a linear analog system due to its discrete time
sampling. The 250-kHz sampling interval implies an effective Nyquist frequency of 125 kHz, which limits spectral
response to below this frequency. Higher frequency content than this frequency will be aliased down to lower
spectrums.
The TMCS1108 bandwidth is defined by the –3-dB spectral response of the entire signal chain which is
constrained by the sampling frequency. Normalized gain and phase plots across frequency are shown below
in Figure 9-4 and Figure 9-5, all variants have the same bandwidth and phase response. Signal content beyond
the 3-dB bandwidth level will still have significant fundamental frequency transmission through the signal chain,
but at increasing distortion levels.
20
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4
30
3
0
2
-30
0
Phase (°)
Gain (dB)
1
-1
-2
-3
-4
-90
-120
All gains 80kHz -3dB
-150
-5
-6
10
-60
100
1k
10k
Frequency (Hz)
100k
Figure 9-4. Normalized Gain, All Variants
1M
-180
10
100
1k
Frequency (Hz)
10k
100k
Figure 9-5. Normalized Phase, All Variants
9.3.2.3 Transient Response
The TMCS1108 signal chain includes a precision analog front end followed by a sampled integrator. At the end
of each integration cycle, the signal propagates to the output. Depending on the alignment of a change in input
current relative to the sampling window, the output might not settle to the final signal until the second integration
cycle. Figure 9-6 shows a typical output waveform response to a 10-kHz sine wave input current. For a slowly
varying input current signal, the output is a discrete time representation with a phase delay of the integration
sampling window. Adding a first order filter of 100 kHz effectively smooths the output waveform with minimal
impact to phase response.
5.5
6
VOUT
Input Current
5
VOUT, 100 kHz Filter
5
4
4
3
3.5
2
3
1
2.5
0
2
-1
1.5
-2
1
-3
0.5
-4
0
0
.00005
.0001
.00015
Time (s)
.0002
Input Current (A)
Output Voltage (V)
4.5
-5
.00025
D015
Figure 9-6. Response Behavior to 10-kHz Sine Wave Input Current
Figure 9-7 shows two transient waveforms to an input-current step event, but occurring at different times during
the sampling interval. In both cases, the full transition of the output takes two sampling intervals to reach the
final output value. The timing of the current event relative to the sampling window determines the proportional
amplitude of the first and second sampling intervals.
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90
4
75
3.5
60
3
45
2.5
30
2
15
1.5
Output Voltage (V)
Input Current (A)
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IIN
V1 1
V2
0.5
0
-15
Time (4Ps/div)
Figure 9-7. Transient Response to Input-Current Step Sufficient for 1-V Output Swing
70
6
60
5
50
4
40
3
30
2
20
1
10
Output Voltage (V)
Input Current (A)
The output value is effectively an average over the sampling window; therefore, a large-enough current transient
can drive the output voltage to near the full scale range in the first sample response. This condition is likely to
be true in the case of a short-circuit or fault event. Figure 9-8 shows an input-current step twice the full scale
measurable range with two output voltage responses illustrating the effect of the sampling window. The relative
timing and size of the input current transition determines both the time and amplitude of the first output transition.
In either case, the total response time is slightly longer than one integration period.
0
IIN
V1 -1
V2
-2
0
-10
Time (4Ps/div)
Figure 9-8. Transient Response to a Large Input Current Step
9.3.3 Internal Reference Voltage
The device has an internal resistor divider from the analog supply VS that determines the zero-current output
voltage, VOUT,0A. This zero-current output level, along with sensitivity, determines the measurable input current
range of the device and allows for unidirectional or bidirectional sensing as described in Absolute Maximum
Ratings. The TMCS1108AxB variants have a zero-current output set by Equation 16, while the TMCS1108AxU
devices have a zero-current output voltage set by Equation 17.
VOUT,0A = VS × 0.5
(16)
VOUT,0A = VS × 0.1
(17)
These respective reference voltages enable a bidirectional measurable current range for the TMCS1108A2B
devices and a unidirectional measurement range for the TMCS1108A2U devices, as shown in Figure 9-9.
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5
4.5
Output Voltage (V)
4
3.5
3
2.5
2
1.5
1
A2B
A2U
0.5
0
-25 -20 -15 -10 -5
0 5 10 15 20 25 30 35 40 45
Input Current (A)
Figure 9-9. Output Voltage Relationship to Input Current for TMCS1108A2B and TMCS1108A2U
9.3.4 Current-Sensing Measurable Ranges
The TMCS1108 measurable input current range depends on the device variant, as well as the analog supply VS.
The output voltage is limited by VOUT swing to either supply or ground. The linear output swing range to both VS
and GND is calculated by Equation 18 and Equation 19.
VOUT,max = VS – SwingVS
(18)
VOUT,min = SwingGND
(19)
Rearranging the transfer function of the device to solve for input current and substituting VOUT,max and VOUT,min
yields maximum and minimum measurable input current ranges described by Equation 20 and Equation 21.
IIN,MAX+ = (VOUT,max – VOUT,0A) / S
(20)
IIN,MAX- = (VOUT,0A – VOUT,min) / S
(21)
where
• IIN,MAX+ is the maximum linear measurable positive input current.
• IIN,MAX- is the maximum linear measurable negative input current.
• S is the sensitivity of the device variant.
• VOUT,0A is the appropriate zero current output voltage.
TMCS1108AxB variants accommodate bidirectional current sensing by creating zero-current output voltage
equal to half of the supply (VS) potential, while TMCS1108AxU variants provide most of the measurable range
for positive currents.
9.4 Device Functional Modes
9.4.1 Power-Down Behavior
As a result of the inherent galvanic isolation of the device, very little consideration must be paid to powering
down the device, as long as the limits in the Absolute Maximum Ratings table are not exceeded on any pins.
The isolated current input and the low-voltage signal chain can be decoupled in operational behavior, as either
can be energized with the other shut down, as long as the isolation barrier capabilities are not exceeded.
The low-voltage power supply can be powered down while the isolated input is still connected to an active
high-voltage signal or system.
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10 Application and Implementation
Note
Information in the following applications sections is not part of the TI component specification,
and TI does not warrant its accuracy or completeness. TI’s customers are responsible for
determining suitability of components for their purposes, as well as validating and testing their design
implementation to confirm system functionality.
10.1 Application Information
The key feature sets of the TMCS1108 provide significant advantages in any application where an isolated
current measurement is required.
• Galvanic isolation provides a high isolated working voltage and excellent immunity to input voltage transients.
• Hall based measurement simplifies system level solution without the need for a power supply on the high
voltage (HV) side.
• An input current path through the low impedance conductor minimizes power dissipation.
• Excellent accuracy and low temperature drift eliminate the need for multipoint calibrations without sacrificing
system performance.
• A wide operating supply range enables a single device to function across a wide range of voltage levels.
These advantages increase system-level performance while minimizing complexity for any application where
precision current measurements must be made on isolated currents. Specific examples and design requirements
are detailed in the following section.
10.1.1 Total Error Calculation Examples
Total error can be calculated for any arbitrary device condition and current level. Error sources considered
should include input-referred offset current, power-supply rejection, input common-mode rejection, sensitivity
error, nonlinearity, and the error caused by any external fields. Compare each of these error sources in
percentage terms, as some are significant drivers of error and some have inconsequential impact to current
error. Offset (Equation 22), PSRR (Equation 23), CMRR (Equation 24), and external field error (Equation 25) are
all referred to the input, and so, are divided by the actual input current IIN to calculate percentage errors. For
calculations of sensitivity error and nonlinearity error, the percentage limits explicitly specified in the Electrical
Characteristics table can be used.
eIOS (%)
IOS
IIN
ePSRR (%)
(22)
PSRR * (VS
S
IIN
5)
(23)
eCMRR (%)
eBEXT (%)
CMRR * VCM
IIN
(24)
BEXT
G
IIN
(25)
When calculating error contributions across temperature, only the input offset current and sensitivity error
contributions vary significantly. For determining offset error over a given temperature range (ΔT), use Equation
26 to calculate total offset error current. Sensitivity error is specified for both –40°C to 85°C and –40°C to 125°C.
The appropriate specification should be used based on application operating ambient temperature range.
24
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IOS,25qC
eIOS ,'T %
§ PA ·
IOS,drift ¨
¸ u 'T
© qC ¹
IIN
(26)
To accurately calculate the total expected error of the device, the contributions from each of the individual
components above must be understood in reference to operating conditions. To account for the individual error
sources that are statistically uncorrelated, a root sum square (RSS) error calculation should be used to calculate
total error. For the TMCS1108, only the input referred offset current (IOS), CMRR, and PSRR are statistically
correlated. These error terms are lumped in an RSS calculation to reflect this nature, as shown in Equation 27
for room temperature and Equation 28 for across a given temperature range. The same methodology can be
applied for calculating typical total error by using the appropriate error term specification.
eRSS (%)
eRSS,'T (%)
eIOS
ePSRR
eIOS,'T
eCMRR
ePSRR
2
eBEXT 2
eCMRR
2
eS2
eBEXT 2
eNL 2
eS,'T 2
(27)
eNL 2
(28)
The total error calculation has a strong dependence on the actual input current; therefore, always calculate
total error across the dynamic range that is required. These curves asymptotically approach the sensitivity and
nonlinearity error at high current levels, and approach infinity at low current levels due to offset error terms with
input current in the denominator. Key figures of merit for any current-measurement system include the total error
percentage at full-scale current, as well as the dynamic range of input current over which the error remains
below some key level. Figure 10-1 illustrates the RSS maximum total error as a function of input current for a
TMCS1108A2B at room temperature and across the full temperature range with VS of 5 V.
20
RSS Max Error, 25°C
RSS Max Error, -40°C to 85°C
RSS Max Error, -40°C to 125°C
RSS Max Total Error (%)
18
16
14
12
10
8
6
4
2
0
0
5
10
15
Input Current (A)
20
25
Figure 10-1. RSS Error vs Input Current
10.1.1.1 Room Temperature Error Calculations
For room-temperature total-error calculations, specifications across temperature and drift are ignored. As an
example, consider a TMCS1108A1B with a supply voltage (VS) of 3.3 V and a worst-case common-mode
excursion of 100 V to calculate operating-point-specific parameters. Consider a measurement error due to an
external magnetic field of 30 µT, roughly the Earth's magnetic field strength. The full-scale current range of the
device in specified conditions is slightly greater than 28 A; therefore, calculate error at both 25 A and 12.5 A
to highlight error dependence on the input-current level. Table 10-1 shows the individual error components and
RSS maximum total error calculations at room temperature under the conditions specified. Relative to other
errors, the additional error from CMRR is negligible, and can typically be ignored for total error calculations.
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Table 10-1. Total Error Calculation: Room Temperature Example
ERROR COMPONENT
SYMBOL
Input offset error
eIos
PSRR error
ePSRR
CMRR error
eCMRR
External Field error
EQUATION
eIOS (%)
PSRR * (VS
S
IIN
ePSRR (%)
eBEXT (%)
% TOTAL ERROR AT
IIN = 12.5 A
0.64%
1.28%
0.88%
1.77%
0.002%
0.004%
0.11%
0.22%
5)
CMRR * VCM
IIN
eCMRR (%)
eBext
IOS
IIN
% TOTAL ERROR AT
IIN = 25 A
BEXT
G
IIN
Sensitivity error
eS
Specified in Electrical Characteristics
1.2%
1.2%
Nonlinearity error
eNL
Specified in Electrical Characteristics
0.5%
0.5%
RSS total error
eRSS
2.01%
3.32%
eRSS (%)
eIOS
ePSRR
eCMRR
2
eBEXT 2
eS2
eNL 2
10.1.1.2 Full Temperature Range Error Calculations
To calculate total error across any specific temperature range, Equation 27 and Equation 28 should be used for
RSS maximum total errors, similar to the example for room temperatures. Conditions from the example in Room
Temperature Error Calculations have been replaced with their respective equations and error components for a
–40°C to 85°C temperature range below in Table 10-2.
Table 10-2. Total Error Calculation: –40°C to 85°C Example
ERROR COMPONENT
SYMBOL
Input offset error
eIos,ΔT
IOS,25qC
eIOS ,'T %
ePSRR (%)
§ PA ·
IOS,drift ¨
¸ u 'T
© qC ¹
IIN
PSRR * (VS
S
IIN
% MAX TOTAL
ERROR AT IIN = 25 A
% MAX TOTAL
ERROR AT IIN = 12.5
A
0.80%
1.59%
0.88%
1.77%
0.002%
0.004%
0.11%
0.22%
5)
PSRR error
ePSRR
CMRR error
eCMRR
External Field error
eBext
Sensitivity error
eS,ΔT
Specified in Electrical Characteristics
1.8%
1.8%
Nonlinearity error
eNL
Specified in Electrical Characteristics
0.5%
0.5%
2.51%
3.83%
RSS total error
26
EQUATION
eRSS,ΔT
eCMRR (%)
CMRR * VCM
IIN
eBEXT (%)
eRSS,'T (%)
eIOS,'T
ePSRR
BEXT
G
IIN
eCMRR
2
eBEXT 2
eS,'T 2
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10.2 Typical Application
Inline sensing of inductive load currents, such as motor phases, provides significant benefits to the performance
of a control systems, allowing advanced control algorithms and diagnostics with minimal postprocessing. A
primary challenge to inline sensing is that the current sensor is subjected to full HV supply-level PWM transients
driving the load. The inherent isolation of an in-package Hall-effect current sensor topology helps overcome
this challenge, providing high common-mode immunity, as well as isolation between the high-voltage motor
drive levels and the low-voltage control circuitry. Figure 10-2 illustrates the use of the TMCS1108 in such an
application, driving the inductive load presented by a three phase motor.
5V
VS
V+
IN+
TMCS1108
VOUT
IN–
GND
TMCS1108
TMCS1108
V-
Figure 10-2. Inline Motor Phase Current Sensing
10.2.1 Design Requirements
For current sensing of a three-phase motor application, make sure to provide linear sensing across the expected
current range, and make sure that the device remains within working thermal constraints. A single TMCS1108
for each phase can be used, or two phases can be measured, and the third phase calculated on the motorcontroller host processor. For this example, consider a nominal supply of 5 V but a minimum of 4.9 V to include
for some supply variation. Maximum output swings are defined according to TMCS1108 specifications, and a
full-scale current measurement of ±20 A is required.
Table 10-3. Example Application Design Requirements
DESIGN PARAMETER
EXAMPLE VALUE
VS,nom
5V
VS,min
4.9 V
IIN,FS
±20 A
10.2.2 Detailed Design Procedure
The primary design parameter for using the TMCS1108 is selecting the correct sensitivity variant, and because
positive and negative current must be measured a bidirectional variant should be selected (A1B-A4B). Further
consideration of noise and integration with an ADC can be explored, but is beyond the scope of this application
design example. The TMCS1108AxB transfer function is effectively a transimpedance with a variable offset set
by VOUT,0A, which is internally set to half of the analog supply as defined by Equation 29.
VOUT = IIN × S + VOUT,0A = IIN × S + VS × .05
(29)
Design of the sensing solution focuses on maximizing the sensitivity of the device while maintaining linear
measurement over the expected current input range. The TMCS1108 has a slightly smaller linear output range to
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the supply than to ground; therefore, the measurable current range is always constrained by the positive swing
to supply, SwingVS. To account for the operating margin, consider the minimum possible supply voltage VS,min.
With the previous parameters, the maximum linear output voltage range is the range between VOUT,max and
VOUT,0A, as defined by Equation 30.
VOUT,max – VOUT,0A = VS,min – SwingVS – 0.5 × VS,min
(30)
Design parameters for this example application are shown in Table 10-4 along with the calculated output range.
Table 10-4. Example Application Design Parameters
DESIGN PARAMETER
EXAMPLE VALUE
SwingVS
0.2 V
VOUT,max
4.7 V
VOUT,0A at VS,min
2.45 V
VOUT,max – VOUT,0A
2.25 V
These design parameters result in a maximum positive linear output voltage swing of 2.25 V. To determine which
sensitivity variant of the TMCS1108 most fully uses this linear range, calculate the maximum current range by
Equation 31 for a bidirectional current (IB,MAX).
IB,max = (VOUT,max - VOUT,0A) / SA
(31)
where
•
SA is the sensitivity of the relevant A1-A4 variant.
Table 10-5 shows such calculation for each gain variant of the TMCS1108 with the appropriate sensitivities.
Table 10-5. Maximum Full-Scale Current Ranges With 2.25-V Positive Output Swing
SENSITIVITY VARIANT
SENSITIVITY
TMCS1108A1B
50 mV/A
IB,MAX
±45 A
TMCS1108A2B
100 mV/A
±22.5 A
TMCS1108A3B
200 mV/A
±11.25 A
TMCS1108A4B
400 mV/A
±5.6 A
In general, the highest sensitivity variant that provides for the desired full-scale current range is selected. For
the design parameters in this example, the TMCS1108A2B with a sensitivity of 0.1 V/A is the proper selection
because the maximum calculated ±22.5-A linear measurable range is sufficient for the desired ±20-A full-scale
current.
28
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10.2.3 Application Curve
The transfer function of the TMCS1108 linear sensing range for the nominal design parameters is shown in
Figure 10-3.
5
23 A, 4.8 V
4.5
Output Voltage (V)
4
3.5
0 A, 2.5 V
3
2.5
2
-24.5 A, 0.05 V
1.5
1
0.5
0
-25
-20
-15
-10
-5
0
5
Input Current (A)
10
15
20
25
D001
Figure 10-3. Application Example Design Transfer Curve
11 Power Supply Recommendations
The TMCS1108 only requires a power supply (VS) on the low-voltage isolated side, which powers the analog
circuitry independent of the isolated current input. VS determines the full-scale output range of the analog
output VOUT, and can be supplied with any voltage between 3 V and 5.5 V. The TMCS1108 zero-current output
voltage is derived from VS using a resistor divider; therefore, take care to optimize the power supply path for
both noise and stability across temperature to provide the highest precision measurement. To filter noise in
the power-supply path, place a low-ESR decoupling capacitor of 0.1 µF between VS and GND pins as close
as possible to the supply and ground pins of the device. To compensate for noisy or high-impedance power
supplies, add more decoupling capacitance.
The TMCS1108 power supply VS can be sequenced independently of current flowing through the input.
However, there is a typical 25 ms delay between VS reaching the recommended operating voltage and the
analog output being valid. Within this delay VOUT transfers from a high impedance state to the active drive state,
during which time the output voltage could transition between GND and VS. If this behavior must be avoided, a
stable supply voltage to VS should be provided for longer than 25 ms prior to applying input current.
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12 Layout
12.1 Layout Guidelines
The TMCS1108 is specified for a continuous current handling capability on the TMCS1108EVM, which uses 3-oz
copper pour planes. This current capability is fundamentally limited by the maximum device junction temperature
and the thermal environment, primarily the PCB layout and design. To maximize current-handling capability and
thermal stability of the device, take care with PCB layout and construction to optimize the thermal capability.
Efforts to improve the thermal performance beyond the design and construction of the TMCS1108EVM can
result in increased continuous-current capability due to higher heat transfer to the ambient environment. Keys to
improving thermal performance of the PCB include:
•
•
•
•
Use large copper planes for both input current path and isolated power planes and signals.
Use heavier copper PCB construction.
Place thermal via farms around the isolated current input.
Provide airflow across the surface of the PCB.
The TMCS1108 senses external magnetic fields, so make sure to minimize adjacent high-current traces in close
proximity to the device. The input current trace can contribute additional magnetic field to the sensor if the input
current traces are routed parallel to the vertical axis of the package. Figure 12-1 illustrates the most optimal
input current routing into the TMCS1108. As the angle that the current approaches the device deviates from 0°
to the horizontal axis, the current trace contributes some additional magnetic field to the sensor, increasing the
effective sensitivity of the device. If current must be routed parallel to the package vertical axis, move the routing
away from the package to minimize the impact to the sensitivity of the device. Terminate the input current path
directly underneath the package lead footprint, and use a merged copper input trace for both the IN+ and IN–
inputs.
IIN,}
IIN,0
IIN,0
}
}
IN+
1
8
VS
IN+
2
7
VOUT
IN±
3
6
NC
IN±
4
5
GND
IIN,}
Figure 12-1. Magnetic Field Generated by Input Current Trace
30
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In addition to thermal and magnetic optimization, make sure to consider the PCB design required creepage and
clearance for system-level isolation requirements. Maintain required creepage between solder stencils, as shown
in Figure 12-2, if possible. If not possible to maintain required PCB creepage between the two isolated sides at
board level, add additional slots or grooves to the board. If more creepage and clearance is required for system
isolation levels than is provided by the package, the entire device and solder mask can be encapsulated with an
overmold compound to meet system-level requirements.
Cu Plane
Solder Mask Creepage
VS
Cu Plane
IN+
VOUT
NC
Cu Plane
IN±
GND
Cu Plane
Figure 12-2. Layout for System Creepage Requirements
12.2 Layout Example
An example layout, shown in Figure 12-3, is from the TMCS1108EVM. Device performance is targeted for
thermal and magnetic characteristics of this layout, which provides optimal current flow from the terminal
connectors to the device input pins while large copper planes enhance thermal performance.
Figure 12-3. Recommended Board Top (Left) and Bottom (Right) Plane Layout
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13 Device and Documentation Support
13.1 Device Support
13.1.1 Development Support
For development tool support see the following:
• TMCS1108EVM
• TMCS1108 TI-TINA Model
• TMCS1108 TINA-TI Reference Design
13.2 Documentation Support
13.2.1 Related Documentation
For related documentation see the following:
•
•
•
Texas Instruments, TMCS1108EVM users's guide
Texas Instruments, Enabling Precision Current Sensing Designs with Nonratiometric Magnetic Current
Sensors
Texas Instruments, Low-Drift, Precision, In-Line Isolated Magnetic Motor Current Measurements
13.3 Receiving Notification of Documentation Updates
To receive notification of documentation updates, navigate to the device product folder on ti.com. Click on
Subscribe to updates to register and receive a weekly digest of any product information that has changed. For
change details, review the revision history included in any revised document.
13.4 Support Resources
TI E2E™ support forums are an engineer's go-to source for fast, verified answers and design help — straight
from the experts. Search existing answers or ask your own question to get the quick design help you need.
Linked content is provided "AS IS" by the respective contributors. They do not constitute TI specifications and do
not necessarily reflect TI's views; see TI's Terms of Use.
13.5 Trademarks
TI E2E™ is a trademark of Texas Instruments.
All trademarks are the property of their respective owners.
13.6 Electrostatic Discharge Caution
This integrated circuit can be damaged by ESD. Texas Instruments recommends that all integrated circuits be handled
with appropriate precautions. Failure to observe proper handling and installation procedures can cause damage.
ESD damage can range from subtle performance degradation to complete device failure. Precision integrated circuits may
be more susceptible to damage because very small parametric changes could cause the device not to meet its published
specifications.
13.7 Glossary
TI Glossary
This glossary lists and explains terms, acronyms, and definitions.
14 Mechanical, Packaging, and Orderable Information
The following pages include mechanical, packaging, and orderable information. This information is the most
current data available for the designated devices. This data is subject to change without notice and revision of
this document. For browser-based versions of this data sheet, refer to the left-hand navigation.
32
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Product Folder Links: TMCS1108
TMCS1108
www.ti.com
SBOSA36A – JANUARY 2021 – REVISED JULY 2021
PACKAGE OUTLINE
D0008B
SOIC - 1.75 mm max height
SCALE 2.800
SMALL OUTLINE INTEGRATED CIRCUIT
C
SEATING PLANE
.228-.244 TYP
[5.80-6.19]
A
.004 [0.1] C
PIN 1 ID AREA
6X .050
[1.27]
8
1
2X
.150
[3.81]
.189-.197
[4.81-5.00]
NOTE 3
4X (0 -15 )
4
5
B
8X .012-.020
[0.31-0.51]
.150-.157
[3.81-3.98]
NOTE 4
.010 [0.25]
C A B
.069 MAX
[1.75]
.005-.010 TYP
[0.13-0.25]
4X (0 -15 )
SEE DETAIL A
.010
[0.25]
.004-.010
[0.11-0.25]
0 -8
.016-.050
[0.41-1.27]
DETAIL A
.041
[1.04]
TYPICAL
4221445/C 02/2019
NOTES:
1. Linear dimensions are in inches [millimeters]. Dimensions in parenthesis are for reference only. Controlling dimensions are in inches.
Dimensioning and tolerancing per ASME Y14.5M.
2. This drawing is subject to change without notice.
3. This dimension does not include mold flash, protrusions, or gate burrs. Mold flash, protrusions, or gate burrs shall not
exceed .006 [0.15], per side.
4. This dimension does not include interlead flash.
5. Reference JEDEC registration MS-012, variation AA.
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33
TMCS1108
www.ti.com
SBOSA36A – JANUARY 2021 – REVISED JULY 2021
EXAMPLE BOARD LAYOUT
D0008B
SOIC - 1.75 mm max height
SMALL OUTLINE INTEGRATED CIRCUIT
8X (.061 )
[1.55]
8X (.055)
[1.4]
SEE
DETAILS
SYMM
SEE
DETAILS
SYMM
1
1
8
8X (.024)
[0.6]
8
SYMM
5
4
6X (.050 )
[1.27]
8X (.024)
[0.6]
(R.002 ) TYP
[0.05]
SYMM
5
4
6X (.050 )
[1.27]
(.213)
[5.4]
(R.002 )
[0.05]
TYP
(.217)
[5.5]
HV / ISOLATION OPTION
.162 [4.1] CLEARANCE / CREEPAGE
IPC-7351 NOMINAL
.150 [3.85] CLEARANCE / CREEPAGE
LAND PATTERN EXAMPLE
EXPOSED METAL SHOWN
SCALE:6X
METAL
SOLDER MASK
OPENING
EXPOSDE
METAL
SOLDER MASK
OPENING
METAL UNDER
SOLDER MASK
EXPOSED
METAL
.0028 MIN
[0.07]
ALL AROUND
.0028 MAX
[0.07]
ALL AROUND
SOLDER MASK
DEFINED
NON SOLDER MASK
DEFINED
SOLDER MASK DETAILS
4221445/C 02/2019
NOTES: (continued)
6. Publication IPC-7351 may have alternate designs.
7. Solder mask tolerances between and around signal pads can vary based on board fabrication site.
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TMCS1108
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SBOSA36A – JANUARY 2021 – REVISED JULY 2021
EXAMPLE STENCIL DESIGN
D0008B
SOIC - 1.75 mm max height
SMALL OUTLINE INTEGRATED CIRCUIT
8X (.061 )
[1.55]
8X (.055)
[1.4]
SYMM
SYMM
1
1
8
8X (.024)
[0.6]
6X (.050 )
[1.27]
8
SYMM
5
4
8X (.024)
[0.6]
SYMM
(R.002 ) TYP
[0.05]
5
4
6X (.050 )
[1.27]
(R.002 )
[0.05]
TYP
(.217)
[5.5]
(.213)
[5.4]
HV / ISOLATION OPTION
.162 [4.1] CLEARANCE / CREEPAGE
IPC-7351 NOMINAL
.150 [3.85] CLEARANCE / CREEPAGE
SOLDER PASTE EXAMPLE
BASED ON .005 INCH [0.127 MM] THICK STENCIL
SCALE:6X
4221445/C 02/2019
NOTES: (continued)
8. Laser cutting apertures with trapezoidal walls and rounded corners may offer better paste release. IPC-7525 may have alternate
design recommendations.
9. Board assembly site may have different recommendations for stencil design.
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35
PACKAGE OPTION ADDENDUM
www.ti.com
13-Nov-2023
PACKAGING INFORMATION
Orderable Device
Status
(1)
Package Type Package Pins Package
Drawing
Qty
Eco Plan
(2)
Lead finish/
Ball material
MSL Peak Temp
Op Temp (°C)
Device Marking
(3)
Samples
(4/5)
(6)
TMCS1108A1BQDR
ACTIVE
SOIC
D
8
2500
RoHS & Green
SN
Level-2-260C-1 YEAR
-40 to 125
M08A1B
TMCS1108A1BQDT
LIFEBUY
SOIC
D
8
250
RoHS & Green
SN
Level-2-260C-1 YEAR
-40 to 125
M08A1B
TMCS1108A1UQDR
ACTIVE
SOIC
D
8
2500
RoHS & Green
SN
Level-2-260C-1 YEAR
-40 to 125
M08A1U
Samples
TMCS1108A1UQDT
ACTIVE
SOIC
D
8
250
RoHS & Green
SN
Level-2-260C-1 YEAR
-40 to 125
M08A1U
Samples
TMCS1108A2BQDR
ACTIVE
SOIC
D
8
2500
RoHS & Green
SN
Level-2-260C-1 YEAR
-40 to 125
M08A2B
Samples
TMCS1108A2BQDT
LIFEBUY
SOIC
D
8
250
RoHS & Green
SN
Level-2-260C-1 YEAR
-40 to 125
M08A2B
TMCS1108A2UQDR
ACTIVE
SOIC
D
8
2500
RoHS & Green
SN
Level-2-260C-1 YEAR
-40 to 125
M08A2U
Samples
Samples
TMCS1108A2UQDT
LIFEBUY
SOIC
D
8
250
RoHS & Green
SN
Level-2-260C-1 YEAR
-40 to 125
M08A2U
TMCS1108A3BQDR
ACTIVE
SOIC
D
8
2500
RoHS & Green
SN
Level-2-260C-1 YEAR
-40 to 125
M08A3B
Samples
TMCS1108A3BQDT
ACTIVE
SOIC
D
8
250
RoHS & Green
SN
Level-2-260C-1 YEAR
-40 to 125
M08A3B
Samples
TMCS1108A3UQDR
ACTIVE
SOIC
D
8
2500
RoHS & Green
SN
Level-2-260C-1 YEAR
-40 to 125
M08A3U
Samples
TMCS1108A3UQDT
ACTIVE
SOIC
D
8
250
RoHS & Green
SN
Level-2-260C-1 YEAR
-40 to 125
M08A3U
Samples
TMCS1108A4BQDR
ACTIVE
SOIC
D
8
2500
RoHS & Green
SN
Level-2-260C-1 YEAR
-40 to 125
M08A4B
Samples
TMCS1108A4BQDT
LIFEBUY
SOIC
D
8
250
RoHS & Green
SN
Level-2-260C-1 YEAR
-40 to 125
M08A4B
TMCS1108A4UQDR
ACTIVE
SOIC
D
8
2500
RoHS & Green
SN
Level-2-260C-1 YEAR
-40 to 125
M08A4U
TMCS1108A4UQDT
LIFEBUY
SOIC
D
8
250
RoHS & Green
SN
Level-2-260C-1 YEAR
-40 to 125
M08A4U
(1)
The marketing status values are defined as follows:
ACTIVE: Product device recommended for new designs.
LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect.
NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in a new design.
PREVIEW: Device has been announced but is not in production. Samples may or may not be available.
OBSOLETE: TI has discontinued the production of the device.
(2)
RoHS: TI defines "RoHS" to mean semiconductor products that are compliant with the current EU RoHS requirements for all 10 RoHS substances, including the requirement that RoHS substance
do not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, "RoHS" products are suitable for use in specified lead-free processes. TI may
reference these types of products as "Pb-Free".
Addendum-Page 1
Samples
PACKAGE OPTION ADDENDUM
www.ti.com
13-Nov-2023
RoHS Exempt: TI defines "RoHS Exempt" to mean products that contain lead but are compliant with EU RoHS pursuant to a specific EU RoHS exemption.
Green: TI defines "Green" to mean the content of Chlorine (Cl) and Bromine (Br) based flame retardants meet JS709B low halogen requirements of
