STAC9758 Datasheet, PDF (23/119 Pages) Integrated Device Technology – HIGH-PERFORMANCE 6-CHANNEL AC’97 2.3 CODEC WITH UNIVERSAL JACKS

STAC9758/9759
HIGH-PERFORMANCE 6-CHANNEL AC’97 2.3 CODEC WITH UNIVERSAL JACKS™
PC AUDIO
3.1.
Split Independent Power Supply Operation
In PC applications, one power supply input to the STAC9758/9759 may be derived from a supply
regulator and the other directly from the PCI power supply bus. When power is applied to the PC, the
regulated supply input to the IC will be applied some time delay after the PCI power supply. Without
proper on-chip partitioning of the analog and digital circuitry, some manufacturer's CODECs would
be subject to on-chip SCR type latch-up.
IDT’s STAC9758/9759 specifically allows power-up sequencing delays between the analog (AVddx)
and digital (VDddx) supply pins. These two power supplies can power-up independently and at differ-
ent rates with no adverse effects to the CODEC. The IC is designed with independent analog and digi-
tal circuitry that prevents on-chip SCR type latch-up. See the Reference Design for additional
connection information.
IDT™
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HIGH-PERFORMANCE 6-CHANNEL AC’97 2.3 CODEC WITH UNIVERSAL JACKS™
STAC9758/9759
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