CH701

Description

The CH701 current sensor IC is an economical and precise solution for AC or DC current sensing in 

industrial, automotive, commercial, and communications systems. The small package is ideal for 

space-constrained applications while also saving costs due to reduced board area. Typical 

applications include motor control, load detection and management, switched-mode power supplies, 

and overcurrent fault protection.

The device consists of a precise, low-offset, linear Hall sensor circuit with a copper conduction path 

located near the surface of the die. Applied current flowing through this copper conduction path 

generates a magnetic field which is sensed by the integrated Hall IC and converted into a proportional 

voltage. A precise, proportional voltage is provided by the low-offset, chopper-stabilized BCD Hall IC, 

which is programmed for accuracy after packaging. The output of the device has a positive slope 

when an increasing current flows through the primary copper conduction path (from pins 1 and 2, to 

pins 3 and 4), which is the path used for current sensing. The internal resistance of this conductive 

path is 0.8 mΩ typical, providing low power loss.

The terminals of the conductive path are electrically isolated from the sensor leads (pins 5 through 8). 

This allows the CH701 current sensor IC to be used in high-side current sense applications without the 

use of high-side differential amplifiers or other costly isolation techniques.

The CH701 is provided in a small, low-profile surface-mount SOIC8 package. The leadframe is plated 

with 100% matte tin, which is compatible with standard lead (Pb) free printed circuit board assembly 

processes. Internally, the device is Pb-free, except for flip-chip high-temperature Pb-based solder 

balls, currently exempt from RoHS. The device is fully calibrated prior to shipment from the factory.

Application

• Variable-frequency 

inverters

• Motor control

• Over-current fault 

protection

• Load detection and 

management

Features Package

• Reinforced isolation: 3000 VRMS

• Total output error: ±1.5% typical

• Primary conductor resistance: 1.2 mΩ

• Single supply: 3.3V or 5V

• Output voltage proportional to AC or DC current: ±5A, ±10A, 

±20A, ±30A, ±40A, ±50A

• -3dB bandwidth: 120 kHz

• Response time: 4 µs

• Ratio-metric output from supply voltage

• Adjustable bandwidth and resolution with a filter pin 

• Small-footprint SOIC-8 package suitable for replacing bulky 

transformers or shunt current sensing solutions 

• Integrated shield virtually eliminates capacitive coupling from 

current conductor to die, greatly suppressing output noise due 

to high dv/dt transients

• Factory-trimmed sensitivity and quiescent output voltage for 

improved accuracy

• Chopper stabilization results in extremely stable quiescent 

output voltage