ZXCT1107Q, ZXCT1109Q, ZXCT1110Q

A Product Line of
Diodes Incorporated
ZXCT1107Q, ZXCT1109Q, ZXCT1110Q
AUTOMOTIVE GRADE MICROPOWER CURRENT MONITOR
Description
Pin Assignments
The ZXCT1107Q/09Q/10Q are high side unipolar current sense
ZXCT1107Q
Top View
monitors. These devices eliminate the need to disrupt the ground plane
when sensing a load current.
The wide common-mode input voltage range and low quiescent current
OUT
coupled with SOT23 packages make them suitable for a range of
2
S-
3
S+
1
automotive applications.
The device is line powered and as such doesn’t need a separate supply
rail.
ZXCT1109Q
Top View
Quiescent current is only 3µA thereby minimizing current sensing error.
One external gain setting resistor increases versatility by permitting
2 S+
wide gain ranges.
OUT
The ZXCT1107Q/09Q/10Q have been qualified to AEC-Q100 Grade 1
1
and are Automotive Grade supporting PPAPs.
3
S-
Features
•
•
•
2.5V to 36V
SOT23 packages
ƒ
3-pin
ZXCT1107Q/09Q
ƒ
5-pin
ZXCT1110Q
•
Low quiescent current (3µA).
•
Extended industrial temperature range -40 to +125°C
•
Green Molding in SOT23
•
ZXCT1110Q
Top View
Wide supply and common-mode voltage range:
•
Totally Lead-Free & Fully RoHS Compliant (Notes 1 & 2)
•
Halogen and Antimony Free. “Green” Device (Note 3)
Qualified to AEC-Q100 Standards for High Reliability
•
PPAP Capable (Note 4)
Notes:
1
GND
2
OUT
3
5
S-
4
S+
Applications
Automotive Grade
•
NC
•
•
•
Automotive current measurement
Battery management
Over current monitor
1. No purposely added lead. Fully EU Directive 2002/95/EC (RoHS) & 2011/65/EU (RoHS 2) compliant.
2. See http://www.diodes.com/quality/lead_free.html for more information about Diodes Incorporated’s definitions of Halogen- and Antimony-free,
"Green" and Lead-free.
3. Halogen- and Antimony-free "Green” products are defined as those which contain <900ppm bromine, <900ppm chlorine (<1500ppm total Br + Cl) and
<1000ppm antimony compounds.
4. Automotive products are AEC-Q100 qualified and are PPAP capable. Automotive, AEC-Q100 and standard products are electrically and thermally the
same, except where specified. For more information, please refer to http://www.diodes.com/quality/product_compliance_definitions/.
Typical Application Circuit
ZXCT1107Q/ 1109Q/ 1110Q
Document number: DS37002 Rev. 1 - 2
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A Product Line of
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ZXCT1107Q, ZXCT1109Q, ZXCT1110Q
Pin Descriptions
Package
Name
OUT
SOT23
ZXCT1107Q
ZXCT1109Q
1
1
SOT25
ZXCT1110Q
3
S+
3
2
4
S-
2
3
5
GND
NC
-
-
2
1
Note:
Description
Output pin (Note 5). Current output.
This is the positive input of the current monitor and has a wide common-mode
input range. This also acts as the analog supply and provides power to internal
circuitry. The current through this pin varies with differential sense voltage.
This is the negative input of the current monitor and has a wide common-mode
input range.
Ground pin and substrate connection.
No connection
5. For the ZXCT1107Q and ZXCT1109Q pin 1 (OUT) acts as both the output pin and substrate connection. This means that for the ZXCT1107Q and
ZXCT1109Q the minimum rail voltage that can be used is 2.5V + VOUT (see applications section for more details).
Absolute Maximum Ratings
Description
Voltage on S- and S+ relative to OUT (ZXCT1107/9)
Voltage on S- and S+ relative to GND (ZXCT1110)
Rating
-0.3 to 40
-0.3 to 40
Unit
V
V
Voltage on OUT to GND (ZXCT1110)
-0.3 to VS+
V
Differential Sense Voltage, VSENSE (Notes 6 and 7)
-0.3 to +0.8
V
Maximum Current into S+ and S- (Note 7)
Storage Temperature
Maximum Junction Temperature
±8.5
-55 to +150
+150
mA
°C
°C
Package Power Dissipation (TA = +25°C)
SOT23
SOT25
ESD Ratings
300 (De-rate to Zero at +150°C)
300 (De-rate to Zero at +150°C)
mW
2500
200
1000
V
V
V
ZXCT1107Q/09Q
HBM
MM
CDM
Human Body Model
Machine Model
Charged Device Model
HBM
Human Body Model
1000
V
MM
CDM
Machine Model
Charged Device Model
150
TBC
V
V
ZXCT1110Q
Notes:
6. VSENSE = VS+ - VS7. The differential input voltage limit, VS+ - VS-, may be exceeded provided that the input current limit into S+ or S- is not exceeded.
Caution:
Stresses greater than the 'Absolute Maximum Ratings' specified above, may cause permanent damage to the device. These are stress ratings only;
functional operation of the device at conditions between maximum recommended operating conditions and absolute maximum ratings is not implied.
Device reliability may be affected by exposure to absolute maximum rating conditions for extended periods of time.
Semiconductor devices are ESD sensitive and may be damaged by exposure to ESD events. Suitable ESD precautions should be taken when
handling and transporting these devices.)
ZXCT1107Q/ 1109Q/ 1110Q
Document number: DS37002 Rev. 1 - 2
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A Product Line of
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ZXCT1107Q, ZXCT1109Q, ZXCT1110Q
Recommended Operating Conditions
Symbol
VS+
VSENSE
VOUT
TA
Note:
Parameter
Common-mode input range (Note 5)
Min
Max
ZXCT1110Q
2.5
36
ZXCT1107Q/9Q
VOUT(MAX) + 2.5
36
0
0.5
ZXCT1110Q
0
VS- - 1
ZXCT1107Q/9Q
0
VS+ - 2.5
-40
+125
Differential Sense Input voltage range (VS+-VS-)
Output voltage range (0 ≤ VSENSE ≤ 100mV)
Ambient temperature range
Unit
V
V
V
°C
5. For the ZXCT1107Q and ZXCT1109Q pin 1 (OUT) acts as both the output pin and substrate connection. This means that for the ZXCT1107Q and
ZXCT1109Q the minimum rail voltage that can be used is 2.5V + VOUT (see applications section for more details).
Electrical Characteristics (@ TA = +25°C, VS+ = 20V, VSENSE = 100mV (Note 6), RGAIN = 0, unless otherwise stated)
ZXCT1107Q, ZXCT1109Q
Symbol
IS-
Parameter
S- input current
Conditions
VSENSE = 0V (Note 6)
VSENSE = 0mV (Note 6)
VSENSE = 10mV (Note 6)
VSENSE = 30mV (Note 6)
IOUT
Output current (Note 8)
VSENSE = 100mV (Note 6)
VSENSE = 200mV (Note 6)
VSENSE = 500mV (Note 6)
IOUT -TC
CMSR
BW
Note.
Output current temperature coefficient
TA
Min
Typ
Max
Units
+25°C
-40°C
+125°C
—
—
—
19
16
35
100
—
—
nA
+25°C
-40°C
+125°C
+25°C
-40°C
+125°C
+25°C
1
—
—
37
—
—
115
3
2.2
5.5
45
42
49
124
10
—
—
54
—
—
134
-40°C
+125°C
+25°C
-40°C
+125°C
+25°C
—
—
394
—
—
787
119
129
408
396
420
810
—
—
422
—
—
832
-40°C
+125°C
+25°C
-40°C
+125°C
—
—
1.965
—
—
785
832
2.015
1.965
2.065
—
—
2.064
—
—
full range
—
370
—
ppm/ºC
—
—
—
0.1
0.13
0.05
0.4
—
—
µA/V
—
0.65
—
MHz
Common-Mode Sense rejection
VS+ = 2.5V to 36V
+25°C
-40°C
+125°C
-3dB Small Signal Bandwidth
VSENSE (AC) = 10mVPP
(Note 6) RGAIN = 2.5kΩ
+25°C
µA
mA
6. VSENSE = “VSENSE+” – “VSENSE-“
8. Output current characteristic measured with low impedance ammeter connected to GND
ZXCT1107Q/ 1109Q/ 1110Q
Document number: DS37002 Rev. 1 - 2
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ZXCT1107Q, ZXCT1109Q, ZXCT1110Q
Electrical Characteristics (@ TA = +25°C, VS+ = 20V, VSENSE = 100mV (Note 6), RGAIN = 0 unless otherwise stated)
ZXCT1110Q
Symbol
IQ
Parameter
Conditions
GND pin current
VSENSE = 0V (Note 6)
IS-
CMSR
S- input current
TA
Min
Typ
Max
+25°C
-40°C
+125°C
+25°C
-40°C
+125°C
—
—
—
—
—
—
3
2.2
5.8
19
16
35
5
—
—
100
—
—
Units
+25°C
-40°C
+125°C
+25°C
-40°C
+125°C
+25°C
—
—
—
—
—
—
3.928
0.1
0.13
0.05
0
-1.8
+2.5
4
0.4
—
—
±4
—
—
4.072
-40°C
+125°C
—
—
3.9
4.08
—
—
mA/V
—
1.8
%
µA
nA
µA/V
Common-Mode Sense rejection
VS+ = 2.5V to 36V
IOO
Output Offset current
(Notes 8 and 9)
VSENSE = 10mV (Note 6)
GT
Transconductance
VSENSE = 10mV to 150mV
(Note 6)
GE
Transconductance error
(Note 10)
VSENSE = 10mV to 150mV
(Note 6)
+25°C
-1.8
—
+25°C
—
265
—
ppm/°C
Output relative to VS-
—
+25°C
-40°C
+125°C
-1
—
—
-0.78
-0.88
-0.63
—
—
—
V
-3dB Small Signal Bandwidth
VSENSE (AC) = 10mVPP,
(Note 6)
RGAIN = 2.5kΩ
+25°C
—
0.65
—
MHz
IOUT GT-TC Transconductance temp.co
VOUTH
BW
Notes:
µA
6. VSENSE = “VSENSE+” – “VSENSE-“
8. Output current characteristic measured with low impedance ammeter connected to GND
9. Output Offset Current is defined as difference between actual output current and 40µA; measured at VSENSE =10mV.
This will include an error due to bias currents of the device.
10. For VSENSE > 10mV, the internal voltage-current converter is fully linear. This enables a true offset to be defined and used.
ZXCT1107Q/ 1109Q/ 1110Q
Document number: DS37002 Rev. 1 - 2
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A Product Line of
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ZXCT1107Q, ZXCT1109Q, ZXCT1110Q
Typical Characteristics
9.0
12
V OUT = 0V
V SENSE = 0V
TA = 125°C
10
VSENSE = 0V
VOUT = 0V
8.0
7.0
6.0
IS+ (µA)
IS+ (µA)
8
TA = 85°C
6
TA = 25°C
4
TA = -40°C
0
10
20
30
VS+ (V)
Input Current vs. VS+
1.0
0.0
-40 -25 -10 5
40
20 35 50 65 80 95 110 125
TEMPERATURE (°C)
Input Current vs. Ambient Temperature
4.0
1.8
3.5
1.6
1.2
IS- (nA)
2.5
IS+ (µA)
TA = 25°C
VOUT = 0V
VSENSE = 0V
1.4
3.0
2.0
1.5
1.0
0.8
0.6
1.0
0.4
TA = 25°C
VOUT = 0V
VSENSE = 0V
0.5
0.0
VS+ = 3.7V
4.0
2.0
TA = 0°C
0
10
20
30
VS+ (V)
IS+ Current vs. VS+
0.2
0.0
40
2500
0
10
20
30
VS+ (V)
IS- Current vs. VS+
40
450
TA = 85°C
V S+ = 20V
V OUT = 0V
400
TA = 125°C
2000
OUTPUT CURRENT (µA)
350
TA =25°C
IOUT (µA)
5.0
3.0
2
0
VS+ = 20V
1500
TA = 0°C
TA = -40°C
1000
500
300
250
200
150
100
50
0
0
100
200
300
400
500
VSENSE (mV)
Output Current vs. VSENSE
ZXCT1107Q/ 1109Q/ 1110Q
Document number: DS37002 Rev. 1 - 2
0
0.0
600
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0.5
1.0 1.5 2.0 2.5 3.0 3.5
OUTPUT VOLTAGE (V)
Output Current vs. Output Voltage
4.0
March 2014
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A Product Line of
Diodes Incorporated
ZXCT1107Q, ZXCT1109Q, ZXCT1110Q
Typical Characteristics (cont.)
700
2500
600
2000
500
1500
IOUT (µA)
IOUT (µA)
400
300
1000
200
500
100
0
0
-40 -25 -10
-40 -25 -10 5 20 35 50 65 80 95 110 125
TEMPERATURE(°C)
Output Current vs. Ambient Temperature
20 35 50 65 80 95 110 125
TEMPERATURE(°C)
Output Current vs. Ambient Temperature
700
5
2500
TA = 25°C
VOUT = 0V
600
VSENSE = 500mV
2000
IOUT (µA)
IOUT (µA)
500
400
300
1500
1000
V SENSE = 5mV
V SENSE = 150mV
V SENSE = 10mV
VSENSE = 100mV
200
500
100
0
VSENSE = 30mV
0
4.20
10
20
30
VS+ (V)
Output Current vs. VS+
0
10
20
30
VS+ (V)
Output Current vs. VS+
0.20%
TA = 125°C
VSENSE = 500mV
4.10
TA 85°C
4.05
TA = 25°C
4.00
IOUT Error [VS+ = 20V] (%)
0.15%
TA = 0°C
3.95
3.90
3.85
0
TA = -40°C
100
40
0.25%
VS+ = 20V
VOUT = 0V
4.15
DIFFERENTIAL GAIN (mA/V)
0
40
V SENSE = 50mV
200
400
500
VSENSE (mV)
Differential Gain vs. VSENSE
ZXCT1107Q/ 1109Q/ 1110Q
Document number: DS37002 Rev. 1 - 2
300
0.10% V
SENSE = 100mV
0.05%
0.00%
-0.05%
-0.10%
-0.15%
-0.20%
-0.25%
0
600
VSENSE = 150mV
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VSENSE = 30mV
TA = 25°C
VOUT = 0V
VSENSE = 50mV
10
20
30
VS+ (V)
Output Current Error vs. VS+
40
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A Product Line of
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ZXCT1107Q, ZXCT1109Q, ZXCT1110Q
Typical Characteristics (cont.)
4.00%
VSENSE = 100mV, VOUT = 0V
TA = 125°C
IOUT ERROR [VS+ = 20V] (%)
3.00%
TA = 85°C
2.00%
1.00%
TA = 25°C
0.00%
TA = 0°C
-1.00%
-2.00%
TA = -40°C
-3.00%
-4.00%
0
10
20
30
VS+ (V)
Output Current Error vs. VS+
ZXCT1107Q/ 1109Q/ 1110Q
Document number: DS37002 Rev. 1 - 2
40
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ZXCT1107Q, ZXCT1109Q, ZXCT1110Q
Typical AC Characteristics
-2
-2.5
-50
Input
-3
-60
-70
0
5
-3.5
10 15 20 25 30 35 40 45 50
TIME (µs)
Small Signal Pulse Response
Input
5
-15
Output
-16
-96
-98
-16.5
Input
SENSE VOLTAGE (mV)
-94
-18
VS+ = 0V,
GND = -20V
RGAIN = 10k
Input
-10
-19
-15
Output
5
-20
10 15 20 25 30 35 40 45 50
TIME (µs)
Small Signal Pulse Response
-15
VS+ = 0V,
GND = -20V
RGAIN = 10k
-102
5
Document number: DS37002 Rev. 1 - 2
-15.4
-104
-15.8
-16
-106
-108
-16.2
Input
-16.4
-16.6
-112
-17
10 15 20 25 30 35 40 45 50
TIME (µs)
Small Signal Pulse Response
ZXCT1107Q/ 1109Q/ 1110Q
-15.2
-15.6
Output
-110
-100
-102
0
-25
10 15 20 25 30 35 40 45 50
TIME (µs)
Large Signal Pulse Response
5
-100
-15.5
-92
-21
-98
VS+ = 0V,
GND = -20V
RGAIN = 10k
-90
-200
-25
0
-20
10 15 20 25 30 35 40 45 50
TIME (µs)
Large Signal Pulse Response
-88
Input
-20
-18
-200
-17
-5
SENSE VOLTAGE (mV)
-16
-150
-250
0
SENSE VOLTAGE (mV)
-12
-14
-100
-150
0
OUTPUT VOLTAGE (V)
Output
-50
SENSE VOLTAGE (mV)
VS+ = 0V,
GND = -20V
RGAIN = 10k
-13
-250
0
-10
0
-100
OUTPUT VOLTAGE (V)
-40
-9
Output
OUTPUT VOLTAGE (V)
-1.5
-50
SENSE VOLTAGE (mV)
-30
OUTPUT VOLTAGE (V)
SENSE VOLTAGE (mV)
-1
Output
-20
VS+ = 0V,
GND = -20V
RGAIN = 10k
-0.5
OUTPUT VOLTAGE (V)
VS+ = 0V,
GND = -3.7V
RGAIN = 10k
-10
-5
0
0
OUTPUT VOLTAGE (V)
0
-16.8
0
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5
-17
20 25 30 35 40 45 50
TIME (µs)
Small Signal Pulse Response
10 15
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A Product Line of
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ZXCT1107Q, ZXCT1109Q, ZXCT1110Q
Typical AC Characteristics (cont.)
Test Circuit for Pulse Response
100
90
80
CMRR (dB)
70
60
50
40
30
20
10
1
10
100 1k
10k 100k 1M 10M
FREQUENCY (Hz)
Common Mode Rejection Ratio CMRR
Test circuit for CMRR
30
20
GAIN (dB)
10
0
-10
-20
-30
10
TA =25°C
VS+ = 20V
VSENSE DC = 100mV
VSENSE AC = 10mVpp
RGAIN = 2.5K
100
1k
10k
100k
1M
FREQUENCY (Hz)
Small Signal Bandwidth
ZXCT1107Q/ 1109Q/ 1110Q
Document number: DS37002 Rev. 1 - 2
10M
Test circuit for Small signal bandwidth
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ZXCT1107Q, ZXCT1109Q, ZXCT1110Q
Application Information
Description
The current monitor ICs ZXCT1107Q, ZXCT1109Q and ZXCT1110Q all use a similar application circuit topology for high-side current sensing,
with small differences. The ZXCT1110Q has a separate ground pin whereas the ZXCT1107Q and ZXCT1109Q do not. The use of ZXCT1110Q
allows reduction of the absolute current measurement error in some applications by providing a reduced output offset current. The ZXCT1107Q
provides a mirror image pin assignment of the ZXCT1109Q to ease PCB layout in very small equipment designs.
The basic application circuit for each device is shown in Figure 1. Two external resistors are required. The resistor RSENSE is connected in the
path of the current to be monitored. The resistor RGAIN converts the device output current to a voltage for convenient processing by a further
device, such as a comparator, amplifier or analog-to-digital converter within a microcontroller system.
The current monitor output current is defined through the nominal transconductance of 4mA/V.
IOUT = 0.004 * VSENSE
Amp
Equation 1
Then the resistors determine the output voltage as described below.
VSENSE
RSENSE
VSUPPLY
S+
S-
GND
OUT
ZXCT1110
ILOAD
LOAD
OUTPUT
VOUT
RGAIN
GND
Figure 1 Basic Application Circuit
Calculation of Resistor Values
In order to select RSENSE, a choice of sense voltage is required. This often involves a compromise between power efficiency and accuracy for the
given temperature range. The resistor must be small enough to avoid excessive volt drop between the power supply and the load.
However, the resistor must be large enough to avoid excessive current measurement error, particularly random errors.
In a typical application, a digital system, perhaps a microcontroller, is set up to monitor the current. At a certain threshold current level, ILOADT, the
system is required to disconnect the load or report a fault. At this current level, the current measurement error must be limited to a known value.
The total percentage error comprises the inherent error in the ZXCT1107Q/1109Q/1110Q device and the tolerances of the two resistors RSENSE
and RGAIN.
The ZXCT1107Q/09Q absolute error is shown in Table 1 with error limits drawn from the table of Electrical Characteristics above.
This error varies with VSENSE.
The ZXCT1110Q is highly linear and has a transconductance of 4mA/V ±1.8% and an output of 40µA ±4µA at VSENSE=10mV. The output current
can therefore be calculated (Standard International Units) as:
-6
IOUT = (40 +/-4)*10 + (VSENSE-0.01)*(0.004 +/- 0.000072) A
The worst-case current error is then
-6
or
IOUTERROR = IOUT – IOUTIDEAL = +/- { 4*10 + (VSENSE-0.01) * 0.000072 } A
-6
IOUTERROR = +/- { 3.28*10 + VSENSE * 0.000072 } A
The percentage error, ε, is
I
I
ε = OUTERROR * 100 % = OUTERROR * 100 %
VSENSE * 0.004
IOUTIDEAL
ZXCT1107Q/ 1109Q/ 1110Q
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ZXCT1107Q, ZXCT1109Q, ZXCT1110Q
Application Information (cont.)
Calculation of Resistor Values (cont.)
Then
ε =±
3.28 * 10 −4 + VSENSE * 0.0072
%
VSENSE * 0.004
or
ε =±
0.082
± 1 .8 %
VSENSE
Equation 2
This shows that the error is reduced with increasing VSENSE. Then the minimum VSENSE required to give the error ±ε % is
0.082
VSENSE =
V
[only for ZXCT1110]
Equation 3
ε − 1.8
In the application, the effect of the external resistor tolerances must also be taken into account.
Table 1: ZXCT1107Q/ZXCT1109Q Error
VSENSE
Mean IOUT
Error Band
Percent Error
10mV
30mV
100mV
200mV
45.5 µA
124.5 µA
408 µA
809.5 µA
±8.5µA
±9.5µA
±14µA
±22.5µA
±18.7%
±7.6%
±3.4%
±2.8%
VSENSE
Mean IOUT
Error Band
Percent Error
10mV
30mV
100mV
200mV
40µA
120µA
400µA
800µA
±4µA
±5.44µA
±10.48µA
±17.68µA
±10%
±4.53%
±2.62%
±2.21%
Table 2: ZXCT1110Q Error
Note that in order to avoid additional error, VSUPPLY must be at least 1.5V greater than VOUT. This margin depends on the value of VSENSE. For
VSENSE = 100mV, this margin can be reduced to 1.0V.
RSENSE is chosen based on the threshold VSENSET of sense voltage selected as above, for the chosen threshold load current, ILOADT.
V
Equation 4
R SENSE = SENSET
ILOADT
RGAIN is chosen to give the required threshold output voltage, VOUTT. From Equation 1, the threshold output current is
IOUTT = 0.004 * VSENSET
V
R GAIN = OUTT
IOUTT
or
R GAIN =
Equation 1a
VOUTT
0.004 * VSENSET
ZXCT1107Q/ 1109Q/ 1110Q
Document number: DS37002 Rev. 1 - 2
Equation 5
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Application Information (cont.)
Design Example
A current monitor is required to provide an output voltage of 2V ±6% when the load current of a 12V supply is 2A. Resistors are available with
1% tolerance.
The sense and output resistors will contribute a total possible error of 2%, so the ZXCT11xx error must not exceed 4%. From Table 1, the error
of ZXCT1107/1109 will be 3.4% if the sense voltage is 100mV. This satisfies the total error requirement of 6%.
Equation 4 gives
RSENSE = 100mV/2A = 50mΩ
Equation 5 gives
R GAIN =
2
= 5kΩ
0.004 * 0.1
A suitable preferred value is 5.1kΩ. This gives a systematic error of +2%, which can be compensated elsewhere in the system if desired. Figure
2 shows the resulting schematic.
Figure 2. Example Circuit using ZXCT1107/ZXCT1109
Alternatively, the ZXCT1110 may be used with a reduced sense voltage if desired. From Equation 3, with ε=4%,
0.082
= 0.082/(4-1.8) = 37.2mV
VSENSE =
ε − 1.8
Equation 4 gives
RSENSE = 37.2mV/2A = 18.6mΩ
A suitable preferred value is 20mΩ. Then the sense voltage will be 2A * 20mΩ = 40mV.
Equation 5 gives
R GAIN =
2
= 12500Ω
0.004 * 0.04
A suitable preferred value is 13kΩ.
ZXCT1107Q/ 1109Q/ 1110Q
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Application Information (cont.)
The alternative example circuit using the ZXCT1110 with a sense voltage of 40mV is shown in Figure 3, giving the required overall accuracy of
±6%.
Figure 3 Example Circuit using ZXCT1110
Protection Against Load Short Circuit
In the event of a load short circuit or overload, a large proportion of the supply voltage may appear between the sense terminals. The supply may
be current limited, but there is normally a large reservoir capacitor which can deliver enough energy to damage the ZXCT11xx before the supply
voltage falls to a safe level due to current limit activation.
The ZXCT11xx is rated for a maximum sense voltage of +0.8V, but is safe if the input current is limited to ±8.5mA. In Figure 4, the resistor RPROT
limits the current and therefore protects the current monitor device against load short circuit without introducing significant current measurement
error.
Figure 4 Protection and EMC Filtering
EMC Susceptibility
In many applications, the circuit is required to operate in the presence of RF radiation. This radiation is coupled into the circuit via the supply or
load connections and will often cause significant bias shift due to rectification within the integrated circuit. The bias shift may lead to erroneous
operation of the integrated circuit. In Figure 4, a low pass filter, RPROT and C1, provides significant attenuation in the VHF and UHF regions. The
value of C1 is recommended to be in the range of 10pF to 47pF, leadless ceramic type.
ZXCT1107Q/ 1109Q/ 1110Q
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Application Information (cont.)
PCB Layout Considerations
It is necessary to take into account a small volt drop in the PCB copper and solder joints to RSENSE. Such volt drops can create noticeable error
at currents of the order of 1A and greater. The PCB must be designed to provide the maximum possible copper carrying current via the sense
resistor, and the traces from the S+ and S- pins must be connected only to the resistor pads. In this way, the effect of the copper is minimized.
If used, the capacitor C1 should be placed very close the input pins S+ and S-.
Application: High Voltage Current Monitor
The schematic of Figure 5 shows how the current monitor may be used in a high voltage application such as an Electric Vehicle system. In this
configuration the 500V PNP transistor Q1 drops a large proportion of the supply voltage. Diode D2 limits the differential input voltage to a safe
level under overload conditions. The voltage across U1 is limited by the zener diode D1. The output current of U1 is limited to about 3mA by the
D2. As RGAIN is typically a few kΩ, the output voltage is therefore limited to a few volts. An additional output clamping diode may be required for
higher gains. R1 is chosen to give a suitable bias current in D1 for the given supply voltage range.
Figure 5 400V Current Monitor
Ordering Information
Order Reference
Package
(Note 11)
Package
Code
Identification
Code
Reel
Size
Quantity
Per Reel
Tape
Width
(mm)
Qualification
Grade
(Note 12)
ZXCT1107QSA-7
SOT23
SA
1107
7”, 180mm
3000
8
Automotive Grade
ZXCT1109QSA-7
SOT23
SA
1109
7”, 180mm
3000
8
Automotive Grade
ZXCT1110QW5-7
SOT25
W5
1110
7”, 180mm
3000
8
Automotive Grade
Notes:
11.
Pad layout as shown on Diodes Inc. suggested pad layout document AP02001, which can be found on our website at
http://www.diodes.com/datasheets/ap02001.pdf
12.
ZXCT1107Q/09Q/10Q have been qualified to AEC-Q100 grade 1 and is classified as “Automotive Grade” which supports PPAP documentation.
See ZXCT1107/09/10 datasheet for commercial qualified versions.
ZXCT1107Q/ 1109Q/ 1110Q
Document number: DS37002 Rev. 1 - 2
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Marking Information
SOT 23
XXXX : Identification code
SOT25
XXXX : Identification code
Package Outline Dimensions
Please see AP02002 at http://www.diodes.com/datasheets/ap02002.pdf for latest version.
°
7
l
l
A
SOT23
H
J
K
1
K
a
M
A
1
L
L
B
C
D
SOT23
Dim
Min
Max
Typ
A
0.37
0.51
0.40
B
1.20
1.40
1.30
C
2.30
2.50
2.40
D
0.89
1.03 0.915
F
0.45
0.60 0.535
G
1.78
2.05
1.83
H
2.80
3.00
2.90
J
0.013 0.10
0.05
K
0.890 1.00 0.975
K1
0.903 1.10 1.025
L
0.45
0.61
0.55
L1
0.25
0.55
0.40
M
0.085 0.150 0.110
a
8°
All Dimensions in mm
SOT25
A
SOT25
Dim
Min
Max
Typ
A
0.35
0.50
0.38
B
1.50
1.70
1.60
C
2.70
3.00
2.80
D
0.95
⎯
⎯
H
2.90
3.10
3.00
J
0.013 0.10
0.05
K
1.00
1.30
1.10
L
0.35
0.55
0.40
M
0.10
0.20
0.15
N
0.70
0.80
0.75
0°
8°
α
⎯
All Dimensions in mm
B C
H
K
J
M
N
D
ZXCT1107Q/ 1109Q/ 1110Q
Document number: DS37002 Rev. 1 - 2
L
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Suggested Pad Layout
Please see AP02001 at http://www.diodes.com/datasheets/ap02001.pdf for the latest version.
SOT23
Y
Z
Dimensions Value (in mm)
Z
2.9
X
0.8
Y
0.9
2.0
C
1.35
E
C
E
X
SOT25
C2
Z
C2
Dimensions Value (in mm)
Z
3.20
G
1.60
X
0.55
Y
0.80
C1
G
C1
C2
Y
2.40
0.95
X
ZXCT1107Q/ 1109Q/ 1110Q
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IMPORTANT NOTICE
DIODES INCORPORATED MAKES NO WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, WITH REGARDS TO THIS DOCUMENT,
INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
(AND THEIR EQUIVALENTS UNDER THE LAWS OF ANY JURISDICTION).
Diodes Incorporated and its subsidiaries reserve the right to make modifications, enhancements, improvements, corrections or other changes
without further notice to this document and any product described herein. Diodes Incorporated does not assume any liability arising out of the
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all risks of such use and will agree to hold Diodes Incorporated and all the companies whose products are represented on Diodes Incorporated
website, harmless against all damages.
Diodes Incorporated does not warrant or accept any liability whatsoever in respect of any products purchased through unauthorized sales channel.
Should Customers purchase or use Diodes Incorporated products for any unintended or unauthorized application, Customers shall indemnify and
hold Diodes Incorporated and its representatives harmless against all claims, damages, expenses, and attorney fees arising out of, directly or
indirectly, any claim of personal injury or death associated with such unintended or unauthorized application.
Products described herein may be covered by one or more United States, international or foreign patents pending. Product names and markings
noted herein may also be covered by one or more United States, international or foreign trademarks.
This document is written in English but may be translated into multiple languages for reference. Only the English version of this document is the
final and determinative format released by Diodes Incorporated.
LIFE SUPPORT
Diodes Incorporated products are specifically not authorized for use as critical components in life support devices or systems without the express
written approval of the Chief Executive Officer of Diodes Incorporated. As used herein:
A. Life support devices or systems are devices or systems which:
1. are intended to implant into the body, or
2. support or sustain life and whose failure to perform when properly used in accordance with instructions for use provided in the
labeling can be reasonably expected to result in significant injury to the user.
B. A critical component is any component in a life support device or system whose failure to perform can be reasonably expected to cause the
failure of the life support device or to affect its safety or effectiveness.
Customers represent that they have all necessary expertise in the safety and regulatory ramifications of their life support devices or systems, and
acknowledge and agree that they are solely responsible for all legal, regulatory and safety-related requirements concerning their products and any
use of Diodes Incorporated products in such safety-critical, life support devices or systems, notwithstanding any devices- or systems-related
information or support that may be provided by Diodes Incorporated. Further, Customers must fully indemnify Diodes Incorporated and its
representatives against any damages arising out of the use of Diodes Incorporated products in such safety-critical, life support devices or systems.
Copyright © 2014, Diodes Incorporated
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