AS8510 datasheet(39/47 Pages) AMSCO

39 / 47 page

www.ams.com/AS8510

Revision 3.5

38 - 46

AS8510

Datasheet - Detailed Descr i p ti on

7.9.2 Initialization Sequence at Power ON

Figure 16. AS8510 Device Initialization Sequence at Power ON

Device initialization starts if the DVDD and AVDD supplies are switched ON and DVDD > VPORHID. The duration period of Initialization is 500

μsec

and during this period, INT pin toggles at the rate of internal low power oscillator. Toggling on INT during the period of initialization should be

ignored in the system. Device configuration and activation should be carried out only after the initialization period.

On ADC start, device enters into analog stabilization state and takes 1.5msec for oscillator and Reference to settle. After this 1.5msec period, the

first interrupt will occur after a time period of TADC.

TDATA_STATUS_RD is the time period during which the micro-controller should complete reading of data and status from the device. If reading is

carried out beyond this time period, then, ADC performance will degrade for next sample generation. Status register gets cleared automatically

only when micro-controller reads this register. Data in the channel registers is changed after TDATA_VALID duration. Ensure that data channel

registers and status registers are not read during the TDATA_INVALID duration.

Example:

Configuration registers are set as follows:

CLK_REG = 8’b0010_0000

DEC_REG_R1_I = 0100_0101

DEC_REG_R2_I = 1100_0101

FIR_CTL_REG_I = 0000_0100

ADC is configured to a data rate of 1KHz, CHOP_CLK to 2KHz, and Modulator clock to 1MHz, Decimation ratio of CIC1 = 64, and Decimation

ratio of CIC2 = 4. With these settings the various time periods as shown in the Figure 16 are as follows:

TDATA_STATUS_RD = 100

μsec

(TDATA_STATUS_RD = (1/mod_clk) * R1 * [((mod_clk/(2*chop_clk))*(1/R1)) - 2.5)

TDATA_INVALID = 8

μsec

TADC = 1msec

TDATA_VALID = TADC - TDATA_INVALID = 1msec - 8

μsec

CHOP_CLK and POR_N are internal signals of the device.

Configure

Device

Start

ADC

DVDD/AVDD

POR_N

INT

CHOP_CLK

Channel Data

0x0000

DATA1

DATA2

500µS

1.5mS

TDATA_STATUS_RD

TDATA_VALID

TDATA_INVALID

VPORHID/VPORHIA

TADC

AS8510 Fiches technique(PDF) 39 Page - ams AG

AS8510 Fiches technique(HTML) 39 Page - ams AG

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47

Fiches technique Télécharger

Lien URL