The power controlling ML9077/ML9078 series of LSI ICs from the Lapis Semiconductor Group of RoHM Semiconductor are meant for small-sized electronics using dual power supplies like solar panels and coin-size batteries. The ICs provide stable power to electronic components like microcontrollers by controlling the switching between the primary/secondary (rechargeable) batteries and the solar panels as well as perform the charge control of power supplied from the solar panels to the secondary battery. Both parts feature low current of less than 80 nA (at 25°C), an operating temperature range of -20°C to 70°C, and a 12-pin WQFN (3.0 x 3.0 mm) package.
The ML9077’s key features include low current consumption of less than 80 nA (at 25°C), supplying power at low impedance, an operating voltage range of 0.0 to 3.6 V (solar cell) and 0.0 to 3.2 V (secondary battery), an operating temperature range of -20°C to 70°C, overcharge prevention of 3.1 V ±0.1 V (lithium manganese dioxide battery) and 2.6 V ±0.1 V (cobalt titanium lithium battery), secondary battery charging electric potential difference (battery voltage less solar cell voltage) of 0 V to 0.1 V, solar cell voltage >2.0 V, solar cell current < 1 mA, low voltage detecting voltage/reckless drive prevention voltage of 1.15 V ±0.1 V/1.8 V ± 0.1 V, and secondary battery electric supply potential difference (secondary battery voltage less VDO output voltage) of 0 V to 50 mV.
The ML9078’s key features include an operating voltage range of 0.0 V to 4.0 V (solar cell) and 1.1 V to 3.6 V (primary battery voltage), backflow prevention function of solar battery generation current to the primary battery, solar panel voltage limiting, low output power impedance, and power source comparison between solar panel/primary battery regulator voltage range of 1.65 V ±0.1V/3.3V ± 0.1 V (ML9078-01) and 1.5 V ±0.1 V/3.0 V ±0.1 V (ML9078-02). Both parts are available in volume production. Three versions of the ML9078 are available so that various types of solar panel and microcontrollers can be suited.