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Revision 1.18

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AS1109

Data Sheet - D e t a i l e d D e s c r i p t i o n

Figure 18. Switching into Low-Current Diagnostic Mode Timing Diagram

Shutdown Mode

The AS1109 features a shutdown mode which can be entered via 4 clock pulses during error-detection mode. To

enable the shutdown mode a 0 must be placed at SDI after the rising edge of the 3rd clock pulse.

To disable shutdown mode a 1 must be placed at SDI after the 3rd clock pulse. The shutdown/wakeup information will

be latched through if multiple AS1109 devices are in a chain. At the rising edge of the 4th clock pulse the shutdown bit

will be read out and the AS1109 will shutdown or wakeup.

Note: In shutdown mode the supply current drops down to typically 3µA.

Figure 19. Shutdown Mode Timing Diagram

Don’t

Care

Re-entering Error

Detection Mode

Global Flag Readout

SDI

OEN

LD

CLK

SDO

Load Internal all 1s

Test Pattern

(optional)

Normal Operation Current

For detailed timing information see Timing Diagrams on page 9.

2µs Low-Current

Diagnosis Mode

SDI

OEN

LD

CLK

SDO

1 = Wakeup

0 = Shutdown

1 = Wakeup

0 = Shutdown