Thermometer with Four-Digit LED Display

Until recently, the Philips SAA1064 LED driver IC has been a sort of unofficial standard for driving seven-segment LED displays. It can be used to implement four-digit displays that can be driven over an I2C bus. However, no matter how it’s packaged (DIL24 or SO24) this IC is simply on the large side with its 24 pins. Its minimum supply voltage of 5 V and quiescent current of nearly 10 mA are also not exactly state of the art now. An attractive alternative for tasks of this sort is the Maxim MAX6958 IC.