CZ-37 Series

Clearance, Creepage distance ≧ 8.0mm
Ultra-high Accuracy
Coreless Current Sensor ICs
supporting 60Arms

CZ-3700, CZ-3701, CZ-3702, CZ-3703, CZ-3704, CZ-3705, CZ-3706

CZ-3720, CZ-3721, CZ-3722, CZ-3723, CZ-3724, CZ-3725, CZ-3726

Corresponding to the UL safety standard UL61800-5-1 for industrial equipment, AKM has developed the CZ-37 series coreless current sensor ICs, which achieving both creepage distance and clearance distance greater than 8 mm.

CZ-37 series has two types. One is bipolar type (CZ-370x) which is used for many applications such as phase current detection of AC motors and general Inverters. 
The other is unipolar type (CZ-372x) which is used for the applications such as PV current detection on DC side.

Applications

CZ-370x (Bipolar)

  • AC motors
  • DC motors
  • UPS's
  • General Inverter (Drives)
  • Power Conditioners (AC side)

It is suitable for the application which requires insulation and achieve small size with low heat generation.

CZ-372x (Unipolar)

  • Power conditioners (DC side)
  • Over current detection

It is suitable for the application which requires insulation and achieve small size with low heat generation. When measuring current flowing in one direction, higher signal noise ratio can be achieved compared to the bipolar detection type. 

Features

Clearance, Creepage distance≧8mm

By developing AKM's original package, both creepage distance and clearance of 8.0mm or more are achieved.
It supports a Working Voltage of 600Vrms (with reinforced insulation), making insulation design easy.

Support wide current range and 60Arms Low-heat Generation

The CZ-37 series has a low resistance of 0.27mΩ as the primary conductor resistance with AKM's original package, As a result, compared to shunt resistors and similar products of other companies, heat generation when applying the current can be greatly suppressed, and 60Arms continuous current is achieved. 
Furthermore, availability with wide current detection ranges is available. This enables to adopt common design of system boards, making it easy to roll it out to other models with different ratings.

Ultra-high accuracy

CZ-37 series is the coreless current sensor IC with ultra-high accuracy comparable to a closed-loop current sensor.
It has a built-in disturbance magnetic field suppression function, a change for conventional coreless current sensors, contributing to improvement of system efficiency and precise control in a wide range of applications.

CZ-370x (Bipolar)
CZ-372x (Unipolar)

Lineup

CZ-37 Series

Product 
Name
Linear 
Sensing 
Range
(A)
Sensitivity
(mV/A)
Temperature 
Drift of 
Sensitivity
(%) *1
Temperature 
Drift of 
Zero-Current
Output
(mV) *1
Total
Accuracy
(%F.S.)*2
Response
time
(μs)
CZ-3700 ±5.3 400 ±0.6 ±5.4

0.5
(Typ.)

-0.4~0.8
(Min. Max.)

1
CZ-3701 ±10.7 200 ±4.4
CZ-3702 ±21.5 100 ±3.8
CZ-3703 ±36 60 ±3.6
CZ-3704 ±54 40 ±3.5
CZ-3705 ±86.4 25 ±3.5
CZ-3706 ±180 12 ±3.4
Product 
Name
Linear 
Sensing 
Range 
(A)
Sensitivity
(mV/A)
Temperature 
Drift of 
Sensitivity
(%) *1
Temperature
Drift of 
Zero-Current 
Output
(mV) *1
Total 
Accuracy
(%F.S.)*2

Response 
time
(μs)
CZ-3720 -0.4 ~ 10.3
400 ±0.6 ±5.4

1.0
(Typ.)

-0.9~1.6
(Min. Max.)

1
CZ-3721 -0.8 ~ 20.6
200 ±4.4
CZ-3722 -1.7 ~ 41.3
100 ±3.8
CZ-3723 -2.9 ~ 68.8
60 ±3.6
CZ-3724 -4.4 ~ 103.4
40 ±3.5
CZ-3725 -7.1 ~ 165.8
25 ±3.5
CZ-3726 -14.9 ~ 345.2
12 ±3.4

*1 It is defined as the "average value ± 3σ" of the actual measurement result (Ta = 0 to 90 °C) in a certain lot.

*2 The typical value is defined as the “average value ± 1σ” of the actual measurement result (Ta = 0 to 90 °C) in a certain lot.

In the same manner, the minimum and maximum values are defined as the “average value ± 3σ” of the actual measurement result (Ta = 0 to 90 °C) in a certain lot.

Certified with safety standards

Related Contents

Selection Table

Supply
Voltage
(V)
Output
Voltage
(V)
Effective
Current
(Arms)
Measurement
Range
(Apeak)
Bipolar /
Unipolar
Creepage
Clearance
(mm)
Working
Voltage *
(V)
Product Name Product Series
5.0 5.0 60 ± 5.3 to ± 180
Bipolar ≧ 8 800 CZ370x CZ37 Series
0 to 345.2 Unipolar CZ372x 
3.0 50 ± 11.6 to ± 166.6 Bipolar CZ3AGx CZ3A Series
3.3 3.3 ± 12.9 to ± 129.1 CZ3A0x
5.0 5.0 40 ± 33 to ± 60 ≧ 7.2 715 CZ381x CZ38 Series
5.0 5.0 20 ± 4.5 to ± 42 Bipolar
Unipolar
≧ 5 500 CQ330x CQ3 Series
3.3 3.3 ± 8.5 to ± 44 CQ320x
5.0 5.0 ± 10.7 to ± 42 AK310x AK31 Series

* Pollution Degree II with reinforced insulation