一款可以客户编程的汽车级开关霍尔芯片介绍-CH481

CH481是一款可以客户编程的汽车级开关霍尔芯片。

该芯片采用BCD工艺，内部集成反向电压保护和过流保护及优秀的抗雷击浪涌能力，具有高可靠性和高性能。霍尔极性可编程（锁存或单极），灵敏度在 7 到 450 Gs 内可编程，工作电压范围支持2.8V-30V。其优良的温度补偿能力，使得芯片能工作在-40~150℃环境中，并保持性能高度一致性。芯片已通过AEC-Q100认证。

主要应用：汽车车窗、天窗，座椅电机，接近开关，刹车灯感应器等

Features

• AEC-Q100 automotive qualified

• Customer-programmable operate point, Output polarity, Hysteresis (switch or latch), Output falling time for reduced EMI

• Factory-programmable TC of operate points

• Chopper stabilization for stable operate points throughout operating temperature range

• On board voltage regulator for 2.8V to 30V range

• Resistant to physical stress

• Output short-circuit protection

• Operation from unregulated supply

• Reverse-battery and freewheeling protection

• On-chip protection against Supply transients

• Wide Operating temperature range: -40 to 150 oC

• Small package sizes TO-92S, SOT-23 and SOT-89

• RoHS-compliant material meets directive 2011/65/EU

Application

- Brushless dc (direct current) motor commutation

- Motor and fan control

- Robotics control

- Speed and RPM sensing

- Tachometer, counter pickup

- Flow-rate sensing

- Automobile gear shifter

Functional Block Diagram

Absolute Maximum Ratings

1) t < 5mins, No cumulative stress

ESD Protections

1) HBM (Human Body Mode) according to AEC-Q100-002

2) MM (Machine Mode) according to AEC-Q100-003

3) CDM (charged device mode) according to AEC-Q100-011

Function Description

The CH481 exhibits programmable latch/Unipolar magnetic switching characteristics. Therefore, it requires both south and north poles or signal magnetic polar to operate properly.

The Latch mode behaves as a latch with symmetric operating and release switching points (BOP=|BRP|). This means magnetic fields with equivalent strength and opposite direction drive the output high and low.

Removing the magnetic field (B→0), it keeps the output in its previous state. This latching property defines the device as a magnetic memory.

A magnetic hysteresis BHYST keeps BOP and BRP separated by a minimal value. This hysteresis prevents output oscillation near the switching point.

The unipolar mode behaves as a unipolar with asymmetric operating and release switching points. This means While the magnetic flux density (B) is larger than operate point (Bop), the output will be turned on (Low), while the magnetic flux density(B) is lower than release point (Brp), then turn off (High) or depend the program bit, the output characteristic can be reverse.

Magnetic Activation

Typical Application

It is recommended that an external capacitor Cbypass is connected to the supply. This can reduce the noise injected into the device. Normal 0.1uF is suggested.

Typical Application Circuit

Alternative Two-Wire Application

For systems that require minimal wire count, the device output can be connected to VCC through a resistor, and the total supplied current can be sensed near the controller.