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LPC2xxx i/o are +5V tolerant; I have to interface an existing I2C +5V bus system with an LPC2xxx baseed board. Voltage on the bus is +5V, is it possible to connect pullup resistors on LPC2xxx directly to +5V? Thanks, Massimo Manca, Micron Engineering

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I've not verified it with the LPCxxx datasheet but Philips devices do it so in general. You can directly pullup to +5V because on the i2c pins there isn't a normal protection diode. Philips use there a combination of zener diodes to protect against static discharge. Have a look to the datasheet under Maxium Ratings and seek for the two i2c pins maximum voltage. This works even in times if the i2c bus is active and your LPCxxx is without power! - Henry -----Ursprüngliche Nachricht----- Von: Micron Engineering <> An: <> Datum: Dienstag, 10. August 2004 10:35 Betreff: [lpc2000] I2C pullup voltage >LPC2xxx i/o are +5V tolerant; I have to interface an existing I2C +5V >bus system with an LPC2xxx baseed board. Voltage on the bus is +5V, is >it possible to connect pullup resistors on LPC2xxx directly to +5V? >Thanks, >Massimo Manca, Micron Engineering >Yahoo! Groups Links

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