power supply of lpc2148

[shubh1994]

i am making a trainer board for lpc2148,so i want to known is it necessary to apply 3.3v on every Vdd pin of lpc2148???
or applying to any one of them will work??

 

[amayilsamy]

You must power up (3.3 V) for all Vdd pins .Thn only it will work. Or otherwise Its NOT WORK.

The pin numbers 23,43,51 Vdd (3.3 V) This is the power supply voltage for the core and I/O ports. Then only the all ports are work.

The pin number 7 VREF 63 ADC reference: This should be nominally less than or equal to the VDD voltage but should be isolated to minimize noise and error. Level on this pin is used as a reference for ADC(s) and DAC. (3.3 V) This should be nominally the same voltage as VDD but should be isolated to minimize noise and error. This voltage is only used to power the on-chip ADC(s) and DAC. Then only you can work ADC and DAC.

The pin number 63 VREF (3.3 V) ADC reference: This should be nominally less than or equal to the VDD voltage but should be isolated to minimize noise and error. Level on this pin is used as a reference for ADC(s) and DAC. Then only ADC & DAC work.


The pin number 49 VBAT RTC power supply: 3.3 V on this pin supplies the power to the RTC. Then only RTC work.

 

[shubh1994]

thankyou so much for reply!!!!
when i connected 11.0592 crystal ,lpc2148 was being programmed using flash magic at 2800 baud rate but not able to program it with 20Mhz crystal using same circuit, i am not understanding why this is happening????????
please reply soon sir.....

 

[amayilsamy]

Use 12 MHz Crystal you can set at the maximum baud rate 19200.

You can't set baud rate 2800. You can set at only these rate's 2400,4800,7200,9600,14400,19200.

And Check the same Crystal selection Flash Magic & hardware