ADS8509: About output data at startup.

Kengo.Y

Part Number: ADS8509

Hi team,

I'd like to know the reading data at startup.
According to the datasheet, it said ". The first conversion immediately following a power-up does not produce a valid conversion result.".
Is it possible to get accurate data by keeping the RC LOW with sufficient acquisition time at startup?

At startup, the first data cannot be obtained under any conditions, right?

BR,

over 2 years ago

0 Tom Hendrick over 2 years ago

TI__Guru**** 182601 points

Hi Kengo,

The ADS8509 does not start to acquire the input until the rising BUSY signal. Stretching RC won't have an impact on that 'feature' of the device, so the first cycle from power up won't have any valid data.

0 Kengo.Y over 2 years ago in reply to Tom Hendrick

Guru 11395 points

Hi Tom,

Thank you for your reply.

BUSY also moves to HIGH when powered on.
Is this the time when BUSY goes HIGH as you said?
Or is it when it goes LOW and then HIGH?

Some devices can acquire the first data correctly when powered on.

I'd like to know details on why the first data cannot be acquired.

BR,
Kengo.

+1 Tom Hendrick over 2 years ago in reply to Kengo.Y

TI__Guru**** 182601 points

Kengo,

R/C needs to toggle, which activates the conversion cycle. After BUSY goes high, the ADS8509 goes into acquisition mode and begins normal operation.

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ADS8509: About output data at startup.