Enable / Standby control pin. Driving this pin low forces the IC into its lowest power state, disabling internal biasing blocks.
Why the confusion? This is a common practice in the electronics industry where a company (Guangdong Highway) brands a custom or semi-custom chip made by another company (Holtek) for its exclusive use in its supply chain. This is known as an "OTP" (One-Time Programmable) or "mask ROM" chip, where the software is permanently burned onto the microcontroller during manufacturing.
The HIGHWAY09A is a high-performance , typically manufactured by Holtek , designed to excel in tasks requiring robust signal processing and control. It is commonly packaged in a PDIP16 (Plastic Dual In-line Package) format, making it easy to mount on printed circuit boards (PCBs) for prototyping and mass production. highway09a pdf datasheet
In a typical integration scenario, the HIGHWAY09A acts as an intermediary buffer or driver between an upstream controller and a downstream bus line. Pull-up or pull-down resistors may be required on the control lines ( EN and CTRL ) to define a default state during system power-up sequences when the MCU GPIO pins might remain in a high-impedance (tri-state) mode. PCB Layout Recommendations
It allows for fine-tuned adjustments of motor speed and direction. Enable / Standby control pin
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Integrated Electrostatic Discharge (ESD) protection circuitry safeguards the device against voltage spikes during handling and field operation. This is a common practice in the electronics
The pinout can be used to trace signals with a multimeter.