This makes for easier implementation of the necessary constant voltage and constant current battery charge control requirements. As would be expected, a range of protection features are provided, such as over voltage protection, over current protection function in addition to internal low voltage detection and low voltage reset functions. When detecting voltage or current abnormalities, these functions work together to avoid damage to both the charger and battery under charge.

The device has a 2Kx14 Flash Program Memory, a 64 byte Data Memory, a 32 byte Data EEPROM, a high accuracy internal RC oscillator of fixed 8MHz frequency and a 4-channel 12-bit Analog to Digital Converter for voltage, current or temperature measurement.

As for timer functions, the device includes a single 10-bit Timer Module, which not only provides the usual basic timer functions but which can also generate PWM output signals for fan speed control.With regard to protection functions, the device includes LVD and LVR functions which are used to monitor the system voltage to avoid any unstable operations resulting from out of spec operating voltage. Additionally, the OCP and OVP hardware protection functions support parameter adjustment using external resistors.

Traditional chargers, which use a Flyback architecture, need an external operational amplifier, comparator, reference voltage generator and other components to implement the charge control functions. The major advantage of the HT45F5Q is in being able to integrate the aforementioned functions, extensively reducing the need for external components.

The integration also of constant voltage control, constant current feedback control, over voltage protection and over current protection into the MCU, in terms of reliability, provides these functions with the same safety and stability, as if external circuitry was used.

During the charger product manufacturing process, the internal A/D Converter can be used to read out the charger characteristics, and allow any necessary correction parameters to be written into the MCU’s internal EEPROM. This method can eliminate the usual traditional manual correction method, which can greatly enhance manufacturing productivity.

As a highly functionally integrated MCU, the need for external components is greatly reduced, resulting in the added benefits of smaller PCB areas and reduced manufacturing costs, features which combine to provide a device with an excellent price/performance ratio. The supplied 16-pin NSOP package type, with its small outline profile, is also well suited to the charger application area.

As is the case with other Holtek 8-bit MCU devices, this device meets with full industrial specification requirements and has excellent noise immunity characteristics. In terms of its safety and stability characteristics, this new devices compares excellently with other presently available charger solutions. For product development, Holtek supplies a full suite of hardware and software development tools.

Known as the HT-IDE3000, this development system includes real time emulation, full memory and register access, full trace analysis, breakpoint functions as well as other functions to ensure developers have their designs debugged and running in the shortest time possible.