[CZ-3704]
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1. General Description
CZ-3704 is an open-type current sensor using Hall sensors, which outputs the analog voltage
proportional to the AC/DC current. Group III-V semiconductor thin film is used as the Hall sensor, which
enables the high-accuracy and high-speed current sensing. Coreless ultra-small surface mount package
realizes the space-saving. Also, the low primary conductor resistance suppresses heat generation to
achieve the 60Arms continuous current. Existing coreless current sensors have an accuracy
disadvantage from degradations caused by a disturbed magnetic field. The CZ-370x series has a built-in
stray magnetic field reduction function to suppress this effect. The CZ-370x series is also UL 61800-5-1
safety compliant, which is an excellent fit for industrial AC drives, servo motors, etc. The CZ-370x
series has a large variety of linear measurement ranges, from ±5.3A (CZ-3700), to ±180A, (CZ-3706).
This enables the designer to use the same board design across different products and helps the user to
expand the options to different current ratings.
2. Features
□ Compliant with safety standard of UL61800-5-1 (Clearance, Creepage distance ≧ 8.0mm)
□ Certified with safety standards of UL-1577 and IEC/UL60950-1
□ Maximum Primary Current : 60Arms
□ High-accuracy : 0.5%F.S.(Ta=0～90°C Typ.)
□ Quite small primary conductor resistance : 0.27mΩ Typ.
□ Fast response time : 1μs Typ.
□ Stray magnetic field reduction function
□ Small-sized surface mount package（12.7mm×10.9mm×2.25mm）
□ Differential output with VREF pin
□ Isolation Voltage：3.0kV（AC50Hz，60s）
□ Ratiometric output
3. Applications
□ AC motors
□ DC motors
□ UPS
□ General Inverters
□ Power conditioners
Also, CZ-3704 is suitable for other applications which are required isolation with small size and
suppressing heat generation.
60Arms Accurate Coreless Current Sensor
CZ-3704
Clearance/Creepage 8mm
[CZ-3704]
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4. Table of Contents
1. General Description ......................................................................................................................... 1
2. Features........................................................................................................................................... 1
3. Applications ..................................................................................................................................... 1
4. Table of Contents ............................................................................................................................. 2
5. Block Diagram and Functions ......................................................................................................... 3
6. Pin Configurations and Functions ................................................................................................... 4
7. Absolute Maximum Ratings ............................................................................................................. 5
8. Recommended Operating Conditions ............................................................................................. 5
9. Electrical Characteristics ................................................................................................................. 6
10. Characteristic Definitions ................................................................................................................. 8
11. External Circuits Example ............................................................................................................. 10
12. Board Layout for measuring thermal resistance ........................................................................... 10
13. Package .......................................................................................................................................... 11
14. Reliability Tests .............................................................................................................................. 14
15. Precautions .................................................................................................................................... 15
IMPORTANT NOTICE ................................................................................................................... 16
[CZ-3704]
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5. Block Diagram and Functions
Table 1．Explanation of circuit blocks
Circuit Block
Function
Primary Conductor
A device has the primary conductor built-in.
Hall Sensors
Hall elements which detect magnetic flux density generated from the
measured current.
Amplifier
Amplifier of Hall elements’ output.
Buffer
Output buffer with gain. This block outputs the voltage (VOUT)
proportional to the current applied to the primary conductor.
Compensation
Compensation circuit which adjusts the temperature drifts of
sensitivity and zero-current voltage.
Bias Unit
Drive circuit for Hall elements.
EEPROM Unit
Non-volatile memory for setting adjustment parameters.
Voltage Generator
Reference voltage generating circuit of VOUT.
Figure 1. Block diagram of CZ-3704
VDD
IN
Hall
Sensors
Amplifier
Buffer
Compensation
Bias Unit
EEPROM Unit
VOUT
TEST2
VSS
IP
TEST1
Primary
Conductor
VREF
TEST3
Voltage
Generator
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6. Pin Configurations and Functions
Figure 2. Pin configurations and typical output characteristics of CZ-3704
Table 2．Pin configuration and functions of CZ-3704
Pin
No.
Pin
Name
I/O
Type
Function
1
IP
I
－
Primary conductor pin ( + )
2
IN
I
－
Primary conductor pin ( - )
3
VSS
GND
Power
Ground pin (GND)
4
TEST1
―
－
Test pin (Recommended external connection : GND)
5
VREF
O
Analog
Reference output pin
6
VOUT
O
Analog
Sensor output pin
7
VDD
PWR
Power
Power supply pin (5V)
8
TEST2
―
－
Test pin (Recommended external connection : OPEN)
9
TEST3
―
－
Test pin (Recommended external connection : OPEN)
10
VSS
GND
Power
Ground pin (GND)
1
2
3
4
5
6
7
8
9
10
IIN
0
INS
−INS
IP→IN
IN→IP
VOUT - VREF
CZ-3704
(Top View)
VDD
2
VDD
2
-
[CZ-3704]
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7. Absolute Maximum Ratings
Table 3．Absolute maximum ratings
Parameter
Symbol
Min.
Max.
Units
Notes
Supply Voltage
VDD
-0.3
6.5
V
VDD pin
Analog Output Current
IOUT
-10
10
mA
VOUT pin, VREF pin
Junction Temperature
Tj
-40
150
°C
Storage Temperature
TSTG
-40
150
°C
WARNING:
Operation at or beyond these limits may result in permanent damage to the device. Normal
operation is not guaranteed at these extremes.
8. Recommended Operating Conditions
Table 4．Recommended operating conditions
Parameter
Symbol
Min.
Typ.
Max.
Units
Notes
Supply Voltage
VDD
4.5
5.0
5.5
V
VDD pin
Sensor Output Load
Capacitance 1
CLVOUT
1000
pF
Between VOUT pin and
VSS pin
Reference Output Load
Capacitance 2
CLVREF
1000
pF
Between VREF pin and
VSS pin
Sensor Output Load
Resistance 1
RLVOUT
3
kΩ
Between VOUT pin and
VSS pin
Between VOUT pin and
VDD pin
Reference Output Load
Resistance 2
RLVREF
3
kΩ
Between VREF pin and
VSS pin
Between VREF pin and
VDD pin
Operating Ambient
Temperature
Ta
-40
105
°C
Case Temperature
Note 1)
Tc
-40
130
°C
Compliant with safety
standard of UL61800-5-1
Thermal Resistance
junction to ambient
θja
32
°C /W
Board Layout is Figure 7.
Maximum Primary
Current (RMS)
IRMSmax
60
Arms
Continuous DC value or
RMS value which can be
applied to primary
conductor
WARNING:
Electrical characteristics are not guaranteed when operated at or beyond these conditions.
Note1. Continuous 60Arms current can be flowed through this IC, and even a larger current can be
flowed transiently. Using as your system complied with safety standard of UL61800-5-1, the case
temperature of this IC should be less than 130°C.
[CZ-3704]
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9. Electrical Characteristics
Table 5. Electrical Characteristics
Conditions(unless otherwise specified) : Ta=25C，VDD=5V
Parameter
Symbol
Conditions
Min.
Typ.
Max.
Units
Current Consumption
IDD
IIN＝0A, No loads
20
25
mA
Sensitivity
Note 2)
Vh
IIN=±30A
(≦5A 1ms, ＞5A 500s)
Vh=(VOUT-VREF)/1A
39.6
40.0
40.4
mV/A
Zero-Current Output
Note 2)
Vof
IIN＝0A, VOUT-VREF
-0.02
0.02
V
Reference Output
Voltage Note 6)
VREF
0.5×VDD
-0.02
0.5×VDD
0.5×VDD
+0.02
V
Linear Sensing Range
Note 3)
INS
-54
54
A
Output Saturation
Voltage H Note 4)
VsatH
RLVOUT=3kΩ
VDD-0.3
V
Output Saturation
Voltage L Note4)
VsatL
RLVOUT=3kΩ
0.3
V
Linearity Error
Note 5) Note 6)
ρ
Ta=-40～105°C
F.S.=VsatH-VsatL
±0.13
±0.15
%F.S.
Rise Response Time
Note 4)
tr
IIN 90% to VOUT 90%,
CLVOUT= CLVREF=1000pF
1
s
Fall Response Time
Note 4)
tf
IIN 10% to VOUT 10%,
CLVOUT= CLVREF=1000pF
1
s
Input Current Equivalent
Noise
INrms
IIN=0A ,DC～400kHz
30
mArms
Ratiometric Error of
Sensitivity
Vh-R
VDD=4.5V～5.5V
-1.0
1.0
%
Ratiometric Error of
Zero-Current Output
Vof-R
VDD=4.5V～5.5V
IIN=0A
-0.3
0.3
%F.S.
Stray Magnetic Field
Reduction
Ebc
Equivalent to Zero-Current
output drift
-10mT <
Stray Magnetic Field <10mT
0.01
A/mT
dV/dt Settling Time
Note 4) Note 7)
tdVdt
200V/s 200V
2
s
Primary Conductor
Resistance
RP
0.27
mΩ
Isolation Voltage
Note 8)
VINS
AC50Hz, 60s
3.0
kVrms
Isolation Resistance
Note 3)
RINS
DC1kV
500
MΩ
Retention Time of
EEPROM data
EEPRT
Tj < 105°C
10
Year
[CZ-3704]
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Table 6. Temperature drift characteristics
Conditions (unless otherwise specified) : VDD=5V
Parameter
Symbol
Conditions
Min.
Typ.
Max.
Units
Temperature Drift of
Sensitivity
Note 5) Note 6) Note 9)
Vh-d
Ta=0～90°C
-0.6
0.3
0.6
%
Ta=0～105°C
-0.6
0.9
1.4
Ta=-40～105°C
-0.9
0.9
1.7
Temperature Drift of
Zero-current Output
Note 5) Note 6) Note 9)
Vof-d
Ta=0～90°C IIN=0A
±1.3
±3.5
mV
Ta=0～105°C IIN=0A
±1.5
±4.2
Ta=-40～105°C IIN=0A
±3.7
±6.8
Temperature Drift of
Reference Output
Note 6) Note 9)
VREF-d
Ta=-40～105°C
±10
mV
Total Accuracy
Note 5) Note 6)
Etotal
Ta=0～90°C
F.S.=VsatH-VsatL
-0.4
0.5
0.8
%F.S.
Ta=0～105°C
F.S.=VsatH-VsatL
-0.4
0.8
1.1
Ta=-40～105°C
F.S.=VsatH-VsatL
-0.6
1.0
1.6
Note 2) These values can be drifted by long-term use or reflow process. Please ’14.Reliability Tests’
for the reference of drift values.
Note 3) These parameters are guaranteed by design.
Note 4) These parameters are tested in wafer condition.
Note 5) The Typical value is defined as the “average value ± 1σ”of the actual measurement result in a
certain lot. The minimum value and the maximum value are defined as “average value ± 3σ”of the
same condition.
Note 6) These values can be drifted by long-term use or reflow process.
Note 7) The threshold level of the dV/dt settling time is the convergence value ±1mV.
Note 8) This parameter is tested for 1second at 3.6kVrms in mass-production line for all devices.
Note 9) These parameters are defined as the drift from the values at Ta=25°C.
[CZ-3704]
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10. Characteristic Definitions
10.1. Sensitivity(Vh), Zero-Current Output (Vof), and Linearity Error (ρ) are defined as below:
Sensitivity(Vh) is defined as the slope of the approximate straight line calculated by the least square
method, using the data of output voltage (VOUT -VREF) when the primary current (IIN) is swept within the
range of linear sensing range (INS).
The output voltage (VOUT -VREF) when the primary current (IIN) is 0A is the Zero-Current Output (Vof).
Linearity Error (ρ) is defined as the ratio of the maximum error voltage (Vd) to the full scale (F.S.), where
Vd is the maximum difference between the output voltage (VOUT -VREF) and the approximate straight line.
Definition formula is shown as below:
ρ = Vd / F.S. × 100
Full scale (F.S.) is defined by VsatHmin - VsatLmax.
10.2. Ratiometric Error of Sensitivity is defined as below:
10.3. Ratiometric Error of Zero-Current Output is defined as below:
Figure 3. Characteristic definitions of CZ-3704
F.S.
Vd
INS
IIN[A]
VOUT-VREF[V]
Approximate straight line
by least square method
−INS
0
Vof
1
Vh
VsatHmin-
VDD
2
-VsatLmax
VDD
2
[CZ-3704]
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10.4. Total Accuracy Etotal [%F.S.] is defined as below:
：Measured Sensitivity value [mV/A]
：Sensitivity (Typ.) [mV/A]
：Measured Temperature Drift of Zero-Current Output [mV]
：Measured Linearity Error [%F.S.]
10.5. Rise Response Time tr [μs] and Fall Response Time tf [μs]
Rise response time (or fall response time) is defined as the time delay from the 90% (or 10%) of input
primary current (IIN) to the 90% (or 10%) of the output voltage (VOUT-VREF) under the pulse input of
primary current (Figure 5).
Figure 5. Definition of response time
IIN[A]
VOUT-VREF[V]
INS
-INS
F.S.
Verr
Figure 4. Total Accuracy of CZ-3704
Output of typical
sensitivity
IP→IN
IN→IP
VsatH
VDD
2
-
VsatL
VDD
2
-
Rise response time (tr)
Fall response time (tf)
IIN [A]
VOUT -VREF[V]
Time [s]
Time [s]
90% IIN
90% VOUT -VREF
tr
IIN [A]
VOUT -VREF[V]
[V]
Time [s]
Time [s]
10% IIN
tf
10% VOUT -VREF
[CZ-3704]
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11. External Circuits Example
Figure 6. External circuits example
(a) 0.1μF bypass capacitor should be placed close to CZ-3704.
(b) Add a low-pass filter if it is necessary. The C1 values should be fixed in consideration of load
conditions.
12. Board Layout for measuring thermal resistance
Table 7. Board information
Board Size
68.58mm×63.5mm
Layer number
4
Copper layer thickness
70μm
Board Thickness
1.6mm
・Top pattern(1st) ・Inner pattern(2nd/3rd VSS) ・Bottom pattern(4th)
Figure 7. Board layout for measuring thermal resistance of CZ-3704
IP
IN
VSS
TEST1
VREF
VOUT
VDD
TEST2
TEST3
VSS
IIN
IIN
ADC
5V
0.1μF
R1
R1
C1
C1
(a)
(b)
[CZ-3704]
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13. Package
13.1. Outline Dimensions
Unit : mm
The tolerances of dimensions without any mention are ±0.1mm.
( ) is a reference values.
Figure 8. Outline dimensions of CZ-3704
Terminals : Cu
Plating for Terminals : Sn-Bi
Package material : RoHS compliant, halogen-free
Table 8．Isolation characteristics of CZ-3704
Parameter
Symbol
Min.
Typ.
Max.
Units
Creepage distance
Cr
8.0
mm
Clearance distance
Cl
8.0
mm
*Flammability standard is V0. (According to UL94)
*Comparative tracking index (CTI) is 600V. Material Group is Ⅰ.
[CZ-3704]
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13.2. Standards
・IEC/UL 60950-1 – Information Technology Equipment – Edition 2. (File No.E359197)
・CSA C22.2 NO. 60950-1-07 – Information Technology Equipment – Edition 2. (File No. E359197)
・UL1577－Optical Isolators－Edition 5.(File No. E499004)
・CSA Component Acceptance Service No. 5A－Component Acceptance Service for Optocouplers and
Related Devices (File No. E499004)
13.3. Recommended Pad Dimensions
Figure 9. Recommended pad pattern
Table 9. Recommended pad dimensions
Unit:mm
If two or more trace layers are used as the current paths, please make enough number of
through-holes to flow current between the trace layers. In order to make heat dissipation better, it
is recommended that Pad on Via should be provided on the pad of the primary conductor.
L
1.59
E
11.79
W1
4.44
W2
0.64
C
0.66
P
1.27
[CZ-3704]
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13.4. Marking
Production information is printed on the package surface by laser marking. Markings consist of 11
characters excluding AKM logo.
Figure 10. Markings of CZ-3704
Table 10. Production date code table
Year(Y)
Month(M)
Day(D)
Lot number
Character
Year
Character
Month
Character
Day
Character
(L2)
Character
(L1)
Lot
number
7
2017
C
January
1
1
0
1
01
8
2018
D
February
2
2
0
2
02
9
2019
E
March
3
3
0
3
03
A
2020
F
April
4
4
0
4
04
B
2021
G
May
5
5
0
5
05
C
2022
H
June
6
6
…
…
…
D
2023
J
July
7
7
E
2024
K
August
8
8
6
7
67
F
2025
L
September
9
9
6
8
68
G
2026
M
October
0
10
6
9
69
H
2027
N
November
A
11
7
0
70
J
2028
P
December
B
12
7
1
71
K
2029
C
13
…
…
…
L
2030
D
14
N
2031
E
15
P
2032
F
16
R
2033
G
17
S
2034
H
18
T
2035
J
19
U
2036
K
20
V
2037
L
21
W
2038
N
22
X
2039
P
23
0
2040
R
24
1
2041
S
25
2
2042
T
26
3
2043
U
27
4
2044
V
28
W
29
X
30
Y
31
Production Date (Y/M/D/L2/L1)
Production Code (CZ-3704)
A
K
M
C
Z
3
7
0
Y
M
D
L2
4
L1
[CZ-3704]
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14. Reliability Tests
Table 11. Test parameters and conditions of reliability tests
No.
Test Parameter
Test Conditions
n
Test Time
1
Temperature Humidity Bias Test
【JEITA EIAJ ED-4701 102】
Ta=85C, 85%RH, continuous operation
22
500h
2
High Temperature Bias Test
【JEITA EIAJ ED-4701 101】
Ta=150C, continuous operation
22
500h
3
High Temperature Storage Test
【JEITA EIAJ ED-4701 201】
Ta=150C
22
500h
4
Low Temperature Operating Test
Ta=−40C, continuous operation
22
500h
5
Heat Cycle Test
【JEITA EIAJ ED-4701 105】
−65C⇔ +150C
30min.⇔ 30min.
Tested in vapor phase
22
200 Cycles
Tested samples are pretreated as below before each reliability test:
Desiccation: 125C/24h → Moisture Absorption: 60C/60%RH/168h
→ Reflow: 3 times (JEDEC Level2a)
Criteria：
Products whose drifts between before pretreated and after the reliability tests do not exceed the
values below are considered to be in spec.
Sensitivity Vh (Ta=25C) : Within ±1.5%
Zero-Current Output Vof (Ta=25C) : Within ±25mV
Linearity Error ρ (Ta=25C) : Within ±0.5%F.S.
EEPROM data : Unchanged
[CZ-3704]
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15. Precautions
<Storage Environment>
Products should be stored at an appropriate temperature, and at as low humidity as possible by using
desiccator (5 to 35°C). It is recommended to use the products within 4 weeks since packing was
opened. Keep products away from chlorine and corrosive gas. When stored in an inappropriate
environment, it can affect the product properties.
<Long-term Storage>
Long-term storage may result in poor lead solderability and degraded electrical performance even
under proper conditions. For those parts, which stored long-term should be checked as for
solderability before it is used.
For storage longer than 1 year, it is recommended to store in nitrogen atmosphere. Oxygen of
atmosphere oxidizes leads of products, and lead solderability get worse.
<Other Precautions>
1) This product should not be used under the environment with corrosive gas including chlorine or
sulfur.
2) This product is lead (Pb) free. All leads are plated with Sn-Bi. Do not store this product alone in high
temperature and high humidity environment. Moreover, this product should be mounted on substrate
within six months after delivery.
3) This product is damaged when it is used on the following conditions:
- Supply voltage is applied in the opposite way.
- Overvoltage which is larger than the value indicated in the specification.
4) This product will be damaged if it is used for a long time with the current (effective current) which
exceeds the current rating. Careful attention must be paid so that maximum effective current is smaller
than current rating.
5) The characteristics can be changed by the influences of nearby current and magnetic field and
electric field. Please make sure of the mounting position.
As this product contains gallium arsenide, observe the following procedures for safety.
1) Do not alter the form of this product into a gas, powder, liquid, through burning, crushing, or
chemical processing.
2) Observe laws and company regulations when discarding this product.
[CZ-3704]
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IMPORTANT NOTICE
0. Asahi Kasei Microdevices Corporation (“AKM”) reserves the right to make changes to the
information contained in this document without notice. When you consider any use or
application of AKM product stipulated in this document (“Product”), please make inquiries the
sales office of AKM or authorized distributors as to current status of the Products.
1. All information included in this document are provided only to illustrate the operation and
application examples of AKM Products. AKM neither makes warranties or representations with
respect to the accuracy or completeness of the information contained in this document nor
grants any license to any intellectual property rights or any other rights of AKM or any third party
with respect to the information in this document. You are fully responsible for use of such
information contained in this document in your product design or applications. AKM ASSUMES
NO LIABILITY FOR ANY LOSSES INCURRED BY YOU OR THIRD PARTIES ARISING FROM
THE USE OF SUCH INFORMATION IN YOUR PRODUCT DESIGN OR APPLICATIONS.
2. The Product is neither intended nor warranted for use in equipment or systems that require
extraordinarily high levels of quality and/or reliability and/or a malfunction or failure of which
may cause loss of human life, bodily injury, serious property damage or serious public impact,
including but not limited to, equipment used in nuclear facilities, equipment used in the
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equipment used in finance-related fields. Do not use Product for the above use unless
specifically agreed by AKM in writing.
3. Though AKM works continually to improve the Product’s quality and reliability, you are
responsible for complying with safety standards and for providing adequate designs and
safeguards for your hardware, software and systems which minimize risk and avoid situations
in which a malfunction or failure of the Product could cause loss of human life, bodily injury or
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4. Do not use or otherwise make available the Product or related technology or any information
contained in this document for any military purposes, including without limitation, for the design,
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5. Please contact AKM sales representative for details as to environmental matters such as the
RoHS compatibility of the Product. Please use the Product in compliance with all applicable
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occurring as a result of noncompliance with applicable laws and regulations.
6. Resale of the Product with provisions different from the statement and/or technical features set
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shall not create or extend in any manner whatsoever, any liability of AKM.
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prior written consent of AKM.
Rev.1
