STAC9752 Datasheet, PDF (21/95 Pages) Integrated Device Technology – TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING

STAC9752/9753
TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING
3.1.
Split Independent Power Supply Operation
In PC applications, one power supply input to the STAC9752/9753 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 STAC9752/9753 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 dif-
ferent rates with no adverse effects to the CODEC. The IC is designed with independent analog and
digital circuitry that prevents on-chip SCR type latch-up.
However, the STAC9752/9753 is not designed to operate for extended periods with only the analog
supply active.
IDT™
21
STAC9752/9753
TWO-CHANNEL, 20-BIT, AC’97 2.3 CODECS WITH HEADPHONE DRIVE, SPDIF OUTPUT MICROPHONE & JACK SENSING
REV 3.3 1206