CZ37 Series

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

Current Sensor ICs

Overview

The CZ37 series of coreless current sensor ICs has creepage and clearance distances of 8 mm or more, generates less heat, and  is ultra-accurate.
The CZ37 series and CZ3A series have the same package profile and support 5V and 3V outputs, respectively.
The CZ37 series supports 5V output, making it ideal for products with severe transmission noise.

The product lineup includes a double-pole detection model (CZ370x) that can be used for many applications such as phase current detection for AC motors and general-purpose inverters, as well as a single-pole detection model (CZ372x) that can be used for DC detection of power conditioners for photovoltaic systems.

This page contains information about the features of the CZ37 series, product details, datasheets, and product lineup information. It also provides technical information such as safety standard information and application notes.

Features

CZ37 Series

1. Clearance, Creepage distance≧8mm

By developing AKM's original package, both creepage distance and clearance of 8.0mm or more is achieved.
The CZ37 series supports a working voltage of over 550Vrms and can be used with 400V reinforced insulation.

2. Support wide current range and 60Arms Low-heat Generation

The CZ37 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.

3. Ultra-high accuracy

CZ37 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.

Applications

Bipolar

(CZ370x)

  • AC motors
  • DC motors
  • UPS (Uninterruptible Power Supply)
  • General Inverter (Drives)
  • Power Conditioners (AC side)

Unipolar

(CZ372x)

  • Power Conditioners (DC side)
  • Various overcurrent detection applications

When measuring current flowing in one direction, higher signal noise ratio can be achieved compared to the bipolar detection type.

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

Specifications

Series   CZ37 Series
Current sensor type   Coreless Current Sensor IC :
Currentier
Package size [mm] 12.7 x 10.9 x 2.25
Package Type (Mounting style)   (Small-sized)
surface mount package (SMD)
Power Supply Voltage [V] 5.0
(4.5 to 5.5)
Operating Temperature [℃] -40 to 105
Maximum Primary
Current
[Arms] 60
Working Voltage 
(pollution degree=2)
[Vrms] 558
(reinforced insulation)
Creepage / Clearance
Distance (min.)
[mm] 8.0
Primary conductor
resistance (Typ.)
[mΩ] 0.27
Isolation Voltage [kVrms] 3.0
(AC50Hz, 60s)
VREF Pin   Existence
Disturbance magnetic field
fluctuation suppression  function
  Existence
Overcurrent
detection function
  Non-existence
Ratiometric /
Non-Ratiometric
  Ratiometric
Safety Standards   IEC/UL62368-1 certified
UL1577 certified
Pb Free   Yes
Halogen Free   Yes
MSL   MSL2a
JEDEC Standard Packaging   Compliant
Packaging   TAPE
Minimum Order Quantity [pcs.] 1000
Part Status   Preview
CZ37 Series Block Diagram

Lineup


CZ37 Series 
You can download a datasheet (PDF file) below.

Product 
Name
Linear 
Sensing 
Range
Sensitivity
Temperature 
Drift of 
Sensitivity *1
Temperature 
Drift of 
Zero-Current
Output *1
Total
Accuracy *2
Response
time
Bipolar /
Unipolar
Datasheet 
Download
(PDF)
[A] [mV/A] [%] [mV] [%F.S.] [μs]
CZ3700 ±5.3 400 ±0.6 ±5.4

0.5
(Typ.)

-0.4~0.8
(Min. Max.)

1 Bipolar CZ3700 DS
CZ3701 ±10.7 200 ±4.4 CZ3701 DS
CZ3702 ±21.5 100 ±3.8 CZ3702 DS
CZ3703 ±36 60 ±3.6 CZ3703 DS
CZ3704 ±54 40 ±3.5 CZ3704 DS
CZ3705 ±86.4 25 ±3.5 CZ3705 DS
CZ3706 ±180 12 ±3.4 CZ3706 DS
CZ3720 -0.4 ~ 10.3
400 ±0.6 ±5.4

1.0
(Typ.)

-0.9~1.6
(Min. Max.)

1 Unipolar CZ3720 DS
CZ3721 -0.8 ~ 20.6
200 ±4.4 CZ3721 DS
CZ3722 -1.7 ~ 41.3
100 ±3.8 CZ3722 DS
CZ3723 -2.9 ~ 68.8
60 ±3.6 CZ3723 DS
CZ3724 -4.4 ~ 103.4
40 ±3.5 CZ3724 DS
CZ3725 -7.1 ~ 165.8
25 ±3.5 CZ3725 DS
CZ3726 -14.9 ~ 345.2
12 ±3.4 CZ3726 DS

[Notes]

*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.

Design Support

Technical Resources

You can download documents and data necessary for design. Please make use of them when designing.

Certified with safety standards

The CZ37 series has UL-60950, IEC60950, and UL-1577 certifications. You can download a detailed PDF file below.

Find other products

Search by Selection Table

You can select a product from the product specifications.
Click on the product series name to see the details.

Current 
Sensor 
Type
Package Supply
Voltage
Output
Voltage
Effective
Current
Measurement
Range
Bipolar /
Unipolar
Ratiometric/
Non-Ratiometric
Creepage
Clearance
Working
Voltage *
Product 
Name
Product
Series
(V) (V) (Arms) (Apeak) (mm) (Vrms)
Coreless SOP 5.0 5.0 60 ± 5.3 to ± 180
Bipolar Retiometric ≧ 8.0 1118 CZ370x CZ37 Series
0 to 345.2 Unipolar CZ372x 
3.0 50 ± 11.6 to ± 166.6 Bipolar Non-Ratiometric CZ3AGx CZ3A Series
3.3 3.3 ± 12.9 to ± 129.1 CZ3A0x
5.0 5.0 20 ± 4.5 to ± 42 Bipolar
Retiometric ≧ 5.0 1000 CQ330x CQ3 Series
± 20.5 to 42 Unipolar
3.3 3.3 ± 8.5 to ± 44 Bipolar CQ320x
20.9 Unipolar
Through
Hole 
DIP 5.0 5.0 50 ± 21 to ± 170 Bipolar ≧ 13.3 1330 CQ233x CQ2 Series
3.3 3.3 ± 21 to ± 85 CQ223x
5.0 5.0 ± 170 ≧ 2.7 270 CQ2366
 

* Pollution Degree II with reinforced insulation