Holtek Announces New HT45R38 Addition to its C/R-F Series

03/06/2007

In order to expand its range of sensor type MCU applications, Holtek has now released its new HT45R38 C/R-F type MCU. The integrated C/R-F function within the MCU device uses an internal oscillator and timer circuits for its implementation. When the oscillator’s external effective resistor or capacitor, changes value, the oscillator output frequency will correspondingly change and change the timer value. This function, when accompanied with the internal channel decoder, to scan the different channels, allows the HT45R38 to recognise which channel’s external condition has changed.
The HT45R38 contains 4Kx15 of Program Memory, 192 bytes of Data Memory and up to 29 I/O pins. In addition to its internal C/R-F function and high current drive outputs, the device includes a fully integrated 5-channel, 12-bit resolution A/D converter. Additionally, the device includes two 8-bit PWM functions and an internal operational amplifier. The offset voltage of this operational amplifier can be adjusted down to 2mV using software, allowing it to more closely resemble that of ideal operation, allowing users to expand their range and level of application possibilities.
The device is suitable for use in application areas such as electrical home appliances or other products which require a system controller. These could include applications such as induction cookers, washing machines, hotplates, dryers to name but a few. The device would also be suitable for use in the security application area, for example door and window sensors, intruder alarms etc. For those applications that require keyboard sensing the device is also extremely appropriate for use. For products that need to drive high current loads, such as LEDs, LED matrixes or 7-segment displays etc, the internal high current drivers can be utilised, making the addition of external drive transistor circuitry unnecessary, in the process reducing the PCB size and simplifying the circuit.
The device includes an internal 8-bit MCU similar to that found in other Holtek devices. As a high noise immunity MCU, and with its internal watchdog timer and Low Voltage Reset functions, provide a combination of features to eliminate the chance of erroneous operation due to programming malfunctions or low power supply voltages. The HT45R38 is supplied in a 52-pin QFP package type.