Datasheet

ADS8331

ADS8332

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SBAS363C –DECEMBER 2009–REVISED MAY 2012

SCLK skew between converters in a daisy-chain configuration can affect the maximum frequency of SCLK. The

skew can also be affected by supply voltage and loading. It may be necessary to slow down the SCLK when the

devices are configured in daisy-chain mode.

RESET FUNCTION

The ADS8331/32 can be reset with three different methods: internal POR, software reset, and external reset

using the RESET pin.

The internal POR circuit is activated when power is initially applied to the converter. This internal circuit

eliminates the need for commands to be sent to the converter after power-on in order to set the default mode of

operation (see the Power-On Sequence Timing section for further details).

Software reset can be used to place the converter in the default mode by setting the CFR_D0 bit to '0' in the

Configuration register (see Table 5). This bit is automatically returned to '1' (default) after the converter is reset.

This reset method is useful in systems that cannot dedicate a separate control signal to the RESET pin. In these

situations, the RESET pin must be connected to VBD in order for the ADS8331/32 to operate properly.

If communication in the system becomes corrupted and a software reset cannot be issued, the RESET pin can

be used to reset the device manually. In order to reset the device and return the device to default mode, this pin

must held low for a minimum of 25ns.

After the ADS8331/32 detects a reset condition, the minimum time before the device can be reconfigured by

FS/CS going low and data clocking in on SDI is 2μs.