FS-CAS5 Integrated current sensor

Open-loop current sensors use ampere's law (generated around an energized straight wire)

The magnetic field is proportional to the current in the wire), using the characteristics of the hall device,

By detecting the magnitude of the magnetic field intensity B generated by the primary side current, it can be detected

The amount of current in the wire. The ratio of B to I in the linear interval of hysteresis

The relationship is:

B (IP) = K * IP (K is a constant)

Hall voltage can be expressed as:

VH=(RH/d) * I * K * IP

Except that IP is a variable, the rest are constants, thus:

VH=K1 * IP (K1 is a constant)

Specific Hall chips derive the primary current by amplifying the VH to obtain the voltage.

Recommended circuit:

* The BYPASS capacitor at the Vcc end must be as close as possible to the Vc foot of the sensor

* The BYPASS capacitor at the Vout end must be as close as possible to the Vout foot of the sensor

Package form:

                                                      Standard Package (PFF)                             PSF package                            PSS package                             SMT packaging

Naming rules:

Standard (PFF) package size diagram

PSF package size diagram

PSS package size diagram

SMT package size diagram

Performance parameter definition:

Static output voltage (QVO) : The sensor output voltage VQVO in the state of no obvious magnetic field B = 0 G

-xR: VQVO and gain have a constant ratio to the supply voltage VCC; VQVO  = VCC/2 or VQVO = VCC/10

-xF: VQVO and gain do not change with the power supply voltage VCC within a certain range; VQVO = 2. 5V or VQVO = 0. 5V

Sens(Sensitivity): Sens is the slope of the reference output line VOUT = VQVO + 2 × IP/IP_MAX, which refers to the change of output with the change of current. The relationship between Sens = 2/IP_MAX is as follows

Offset with Temperature: The zero point may be offset at the operating ambient temperature due to internal component tolerances, stress and heat dissipation factors.

Sensitivity with temperature: Due to the influence of the internal temperature compensation factor, the sensitivity will change at the entire operating temperature compared to the expected value at room temperature.

Electrical Offset Voltage: The error caused by the noise caused by the amplification multiple of the HALL component and the operational amplifier itself is called the offset voltage

Zero Magnetic Offset voltage: When the primary current is caused by the maximum IP - >0, the error generated at the output end is called the zero magnetic offset voltage due to the hysteresis phenomenon of the sensor's magnetic core material

offset voltage: The offset voltage is the output voltage when the primary current is zero, ideally VQVO = VCC/2(or 2.5V). Therefore, the difference between VQVO and the ideal value is called the total zero offset voltage error. This offset error can be attributed to the zero offset voltage (due to the resolution of the QVO adjustment within the ASIC), magnetic offset, temperature drift, and temperature-induced hysteresis.

Response Time: The response time of the sensor refers to the time interval between when the applied current reaches the final 90% and the sensor output to the corresponding value of the applied current

rise time: The rise time of the sensor refers to the time interval between 10% of the sensor output and reaching the final 90%

At relatively high current, ETOT is mainly caused by sensitivity error. At relatively low currents, ETOT is mainly due to bias voltage error (VOE). In fact, when IP approaches zero, ETOT approaches infinity due to bias voltage error.

Note:

1. Incorrect cable connections may damage the sensor. After the sensor is connected to a 5V power supply, the measured current passes through the arrow direction of the sensor, and the corresponding voltage value can be measured at the output end.

2. -BR: The output voltage VOUT is directly proportional to the power supply voltage VCC, VOUT = VCC/2 + 2 × IP/ ipp (MAX), the power supply voltage changes, will cause VOUT proportional changes.

For example, the VCC ranges from 4.75V to 5.25V. The corresponding static output voltage VQVO at 0A ranges from 2.375V to 2.6255V. The output range of full scale VOUT(IPMAX) is 4.275V~4.725V.

-BF mode: zero output voltage VQVO=2.5V, gain fixed 2V, output curve: VOUT =2.5 + 2 × IP/IP(MAX)

For example, the VCC ranges from 4.75V to 5.25V. The corresponding static output voltage VQVO output at 0A is 2.5V; Full-scale VOUT(IPMAX) has a constant output of 4.5V.

Packing information:

Maximum rated parameter

General electric parameter

Dc operating parameters at VCC = 5.0V (unless otherwise specified), TA within the specified temperature range.

Isolation characteristic

* 1:60 second test for UL test only; Tested in production against UL60950-1 2nd edition.

B050 Performance parameters

Dc operating parameters at VCC = 5.0V (unless otherwise specified), TA=-40°C ~125°C

U050 Performance parameters

Dc operating parameters at VCC = 5.0V (unless otherwise specified), TA=-40°C ~125°C

B100 Performance parameters

Dc operating parameters at VCC = 5.0V (unless otherwise specified), TA=-40°C ~125°C

U100 Performance parameters

Dc operating parameters at VCC = 5.0V (unless otherwise specified), TA=-40°C ~125°C

B150 Performance parameters

Dc operating parameters at VCC = 5.0V (unless otherwise specified), TA=-40°C ~105°C

U150 Performance parameters

Dc operating parameters at VCC = 5.0V (unless otherwise specified), TA=-40°C ~105°C

B200 Performance parameters

Dc operating parameters at VCC = 5.0V (unless otherwise specified), TA=-40°C ~85°C

U200 Performance parameters

Dc operating parameters at VCC = 5.0V (unless otherwise specified), TA=-40°C ~85°C

B250 Performance parameters

Dc operating parameters at VCC = 5.0V (unless otherwise specified), TA=-40°C ~85°C

U250 Performance parameters

Dc operating parameters at VCC = 5.0V (unless otherwise specified), TA=-40°C ~85°C

Ordering information: