With a focus on the three phase Brushless DC Motor control area, Holtek is delighted to announce its new Flash type controller, the HT45FM03B. Device features include 4K x 15 of Flash Program Memory, 192 bytes of RAM Data Memory, a 4.5~5.5V operating voltage range and an operating frequency of up to 20MHz. The device also includes a fully integrated system oscillator with 12/16/20MHz fixed frequency selections and an 8-channel 12-bit analog to digital converter. An internal Programmable Frequency Divider can generate audio frequencies, IR carriers as well as a range of other frequencies. These functions are complemented by fully programmable internal 8-bit and 16-bit timers. Integrated LVD and LVR functions, which can generate a reset should the power supply voltage fall below the minimum level for proper system operation, provide an additional safeguard to ensure stable operating under low power supply voltage conditions.
Being specifically directed at the Brushless Motor application area, the HT45FM03B device provides four external interrupt pins, among which three of them are used to sense the transmitted rotational signals from external Hall Effect Sensors, reducing the software loading on rotation positional sensing. Other features include three pairs of 10-bit PWM complimentary outputs complete with a Dead Time function for convenient control of three phase brushless DC motors. To ensure correct Brushless DC Motor control, it is also necessary to process some form of feedback signal which can sense and protect against situations of over-current and over-voltage. In this regard, the HT45FM03B has a fully integrated operational amplifier and a comparator which can be used to amplify the DC motor current detect signal. The combination of the operational amplifier, comparator and A/D converter can be used together to ensure smooth rotational control as well as implementing protection features.
The HT45FM03B is available in a 28-SOP package making it suitable for three phase Brushless DC Motor applications. As is the case with other Holtek 8-bit MCU devices, the HT45FM03B meets with industrial specifications and has excellent noise immunity characteristics.
