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.
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