UAC 3552A
PRELIMINARY DATA SHEET
3.3. Pin Descriptions
AUXL (36)
AUXR (37)
3.3.1. Power Supply Pins
The AUX pins provide two analog stereo inputs. Auxil-
iary input signals, e.g. the output of a conventional
receiver circuit or the output of a tape recorder can be
connected with these inputs. The input signals have to
be connected by capacitive coupling.
The UAC 3552A combines various analog and digital
functions which may be used in different modes. For
optimized performance, major parts have their own
power supply pins. All VSS power supply pins must be
connected.
FOUTL (38)
FOPL (39)
VDD (27)
FINL (40)
VSS (28)
FOUTR (41)
The VDD and VSS power supply pair are connected
internally with all digital parts of the UAC 3552A.
FOPR (42)
FINR (43)
Filter op amps are provided in the analog baseband
signal paths. These inverting op amps are freely
accessible for external use by these pins.
AVDD0 (6)
AVSS0 (3)
AVDD0 and AVSS0 are separate power supply pins
that are exclusively used for the on-chip headphone/
loudspeaker amplifiers.
The FOUTL/R pins are connected with the buffered
output of the internal switch matrix. The FOPL/R-pins
are directly connected with the inputs of the inverting
filter op amps. The FINL/R pins are connected with the
outputs of the op amps.
AVDD1 (7)
AVSS1 (2)
The AVDD1 and AVSS1 pins supply the analog audio
processing parts, except the headphone/loudspeaker
amplifiers.
OUTL (4)
OUTR (5)
The OUTL/R pins are connected to the internal output
amplifiers. They can be used for either line-out or ste-
reo headphones.
3.3.2. Analog Audio Pins
Caution: A short circuit at these pins for more than a
momentary period may result in destruction of the
internal circuits.
AGNDC (1)
Reference for analog audio signals. This pin is used as
reference for the internal op amps. This pin must be
blocked against VREF with a 3.3-µF capacitor.
XTI (8)
XTO (9)
Note: The pin has a typical DC-level of 2.25 V. It can
be used as reference input for external op amps when
no current load is applied.
The XTI pin is connected to the input of the internal
crystal oscillator; the XTO pin to its output. Both pins
should be directly connected to the crystal and two
ground-connected capacitors (see application dia-
gram).
VREF (44)
Reference ground for the internal band-gap and bias-
ing circuits. This pin should be connected to a clean
ground potential. Any external distortions on this pin
will affect the analog performance of the UAC 3552A.
DMINUS (24)
DPLUS (25)
Differential USB port pins.
16
Micronas
MICRONAS [ MICRONAS ]
