MC143416 Datasheet, PDF (7/24 Pages) Freescale Semiconductor, Inc – Dual 16-Bit Linear Codec-Filter

Pin No.
41
42
43
44
Freescale Semiconductor, Inc.
Pin Name
AVDD1
AGND1
AO0–
AO0+
Table 1. Pin Descriptions (continued)
Pin Description
Analog Positive Power Supply #1
Analog Ground #1
Output — Codec 0 Inverting Analog Output
Output — Codec 0 Non–Inverting Analog Output
PIN DESCRIPTIONS
ANALOG POWER SUPPLY
VAGREF
Analog Ground Reference (Pin 34)
This pin is used to capacitively bypass the on–chip circuit-
ry that generates the mid–supply voltage for the VAG output
pin. This pin should be bypassed to AGND with a 0.01 µF
and 10 µF capacitor using short, low inductance traces. The
VAGREF pin is only used for generating the reference voltage
for the VAG pin. This pin can be overridden by an external
voltage source, such as a resistor divider, using two 2K resis-
tors. No more than 100 na should be required to override this
circuit. All analog signal processing within this device is refer-
enced to the VAG pin. If the audio signals to be processed are
referenced to AGND, then special precautions must be uti-
lized to avoid noise between AGND and the VAG pin (such as
adding coupling capacitors). When this device is in power–
down mode, the VAGREF pin is pulled to the AVDD power
supply with a non–linear, high–impedance circuit.
VAG
Analog Common Mode Voltage (Pin 33)
This output pin provides a mid–supply analog ground. This
pin should be decoupled to AGND with a 0.01 µF ceramic ca-
pacitor. All analog signal processing within this device is ref-
erenced to this pin. If the audio signals to be processed are
referenced to AGND, then special precautions must be uti-
lized to avoid noise between AGND and the VAG pin. The
VAG pin becomes high impedance when this device is in
power–down mode.
AGND1 and AGND2
Analog Ground Pad (Pins 42 and 27, Respectively)
These pins provide the ground reference for the internal
analog circuitry.
AVDD1 and AVDD2
Analog Supply Pad (Pins 41 and 28, Respectively)
These pins are the positive power supplies for the analog
circuitry and are internally tied together.
DIGITAL POWER SUPPLY
DGND1, DGND2, and DGND3
Digital Ground Pad (Pins 20, 1, and 14, Respectively)
These pins provide the ground reference for the internal
digital circuitry.
DVDD1, DVDD2, and DVDD3
Digital Supply Pad (Pins 21, 4, and 15, Respectively)
These pins are the positive power supplies for the digital
circuitry and are internally tied together.
CONFIGURATION INPUTS
SSIMS
Mode Select (Pin 23)
This pin selects whether the chip is operating in Dual SSI,
logic 0, or in Single SSI, logic 1. In dual mode, each codec is
operated from independent serial interfaces. The timing of
each interface is dictated by the associated codec timing. In
single serial mode, the timing of the interface is derived from
the timing of the faster of the two codecs. The faster codec is
defined by bit SSI_SEL in control register 4.
SSIDS
SSI Data Size (Pin 24)
When this pin is logic 0, the 24–bit word length of the SSI is
enabled. When it is logic 1, the serial data format is adjusted
to accommodate 16–bit word length.
SSIFM
SSI Framing Mode (Pin 22)
When this pin is logic 0, Short Frame mode is selected.
This is defined as a 1–bit–wide clock pulse occurring before
the first bit (MSB) of the data stream. When the pin is logic 1,
Long Frame mode is selected. In long framing, the pulse
rises simultaneously with the first data bit (MSB) and falls af-
ter the last data bit (LSB) has been shifted out.
SPEAKER INTERFACE
SPK+ and SPK–
Speaker Positive and Negative Signal Outputs
(Pins 36 and 35, Respectively)
These pins are the outputs of the speaker driver and can
deliver 15 mW of power into a small 32 Ω speaker. The exter-
nal speaker can be dc–coupled to the SPK+ and SPK– pins.
CODEC INTERFACE
AI0+, AI1+, AI0–, and AI1–
Analog Inputs for Codec 0 and Codec 1
(Pins 38, 31, 39, and 30, Respectively)
These pins are the non–inverting and inverting inputs of
the analog input gain setting amplifier. This fully–differential
amplifier is the first stage of the A/D modulator portion of the
codec. A low to moderate gain (up to 20 dB) can be obtained
from this amplifier using external components. There is an in-
ternal 2 pF feedback capacitor to provide high frequency
roll–off above 500 kHz.
MOTOROLA
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MC143416
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