I've got a "Nokia 1100" LCD, which (unless I be mistaken) is based on PCF8814, whose digital I/O range is (1.7 .. 3.3) V. The question is: is there an easy and safe way to connect it to an otherwise 3.3 V (+/- some) circuit (as in: one interfacing an SD card, or having an Arduino as its core, etc.)? (Will a few diodes suffice, for instance?) Also, the pinout for the LCD (e. g., [1]) has two pins for the "+" rail (and one more for the backlight): 6 VddI 7 Vdd The datasheet for PCF8814, however, mentions [2, p. 44] /three/ Vdd pads, with allowed Vdd1 voltage range being (1.7 .. 3.3) V (presumably meaning 3.0 V + 10% allowance), and Vdd2, Vdd3 ranges being both (2.4 .. 4.5) V. Looking at the ESD structures [2, p. 66], my guess is that the I/O voltage is Vdd1, thus 3.0 V + 10% being the upper bound. But is it connected to the LCD's Vdd or VddI? TIA. [1] http://www.circuitvalley.com/2011/09/nokia-1100-lcd-interfacing-with.html [2] http://mylcd.sourceforge.net/files/pcf8814.pdf -- FSF associate member #7257
3.3 V vs. PCF8814-based "Nokia 1100" LCD?
Started by ●June 13, 2013