MSP430FR2155: internal circui of P1.5

Betty Guo

Expert 7300 points

Part Number: MSP430FR2155

Hi,

For MPS430FR2155RHA, customer use P1.5 pin as power voltage measurement. below is the circuit:

the problems are :

1, The normal volatge of P1.5 should be 1.14V, measure the point B, voltage_B is 1.14V, while the voltage_A is 2.4V.

2. if remove the R26, disconnect B and A, measure the point A and B, voltage _B is 1.14V, the voltage_A still 2.4V.

quesiton is what's the internal circuit of P1.5 when it used as analog input? does it be pull up to 2.4V.

thanks.

over 3 years ago

0 Lixin Chen1 over 3 years ago

TI__Expert 7015 points

Hi, Betty,

You can find the internal circuit in Figure 6-2 (section 6.11.1 Port P1 input/output with Schmitt Trigger) of MSP430FR2155 datasheet.

What is your configuration for the P1.5? Is it configured to A5 (P1SEL0 |=BIT5; P1SEL1 |= BIT5;PM5CTL0 &= ~LOCKLPM5;)? You can find the configuration in table 6-63 in the datasheet.

Thanks,

Lixin

0 Lixin Chen1 over 3 years ago in reply to Lixin Chen1

TI__Expert 7015 points

Figure 6-2 - > Figure 6-4.

0 Lixin Chen1 over 3 years ago in reply to Lixin Chen1

TI__Expert 7015 points

If P1.5 is configured to GPIO as default, it will not be pulled to high voltage until you configure the pullup/pulldown resistor enable register PxREN.

P1IRD &= ~BIT5;

P1REN=1;

P1OUT |=BIT5;

0 Lixin Chen1 over 3 years ago in reply to Lixin Chen1

TI__Expert 7015 points

P1DIR &= ~BIT5;

P1REN=1;

P1OUT |=BIT5;

0 Betty Guo over 3 years ago in reply to Lixin Chen1

TI__Expert 7300 points

thanks Lixin, I will check with customer.

0 Lixin Chen1 over 3 years ago in reply to Betty Guo

TI__Expert 7015 points

Betty,

Please let me know if the issue is resolved or not.

Thanks,

Lixin

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MSP430FR2155: internal circui of P1.5