CS8421-CNZ View Datasheet(PDF) - Cirrus Logic
Part Name
Description
MFG CO.
'CS8421-CNZ' PDF : 36 Pages View PDF
CS8421
Pin Name
VD
GND
RST
BYPASS
ILRCK
ISCLK
SDIN
MCLK_OUT
TDM_IN
SDOUT
OSCLK
OLRCK
MS_SEL
GND
VL
SAOF
SAIF
SRC_UNLOCK
XTO
XTI
Thermal Pad
#
Pin Description
1 Digital Power (Input) - Digital core power supply. Typically +2.5 V.
2 Ground (Input) - Ground for I/O and core logic.
Reset (Input) - When RST is low, the CS8421 enters a low-power mode and all internal states are
3 reset. On initial power-up, RST must be held low untilthe power supply is stable and all input clocks
are stable in frequency and phase.
Sample Rate Converter Bypass (Input) - When BYPASS is high, the sample-rate converter will be
4 bypassed, and any data input through the serial audio input port will be directly output on the serial
audio output port. When BYPASS is low, the sample rate converter will operate normally.
5
Serial Audio Input Left/Right Clock (Input/Output) - Word-rate clock for the audio data on the
SDIN pin.
6 Serial Audio Bit Clock (Input/Output) - Serial-bit clock for audio data on the SDIN pin.
7 Serial Audio Input Data Port (Input) - Audio data serial input pin.
Master Clock Output (Output) - Buffered and level-shifted output for Master clock. If MCLK_OUT
8 is not required, this pin should be pulled high through a 47 kΩ resistor to turn the output off. See
“Master Clock” on page 21.
9
Serial Audio TDM Input (Input) - Time Division Multiplexing serial audio data input. Grounded
when not used. See “Time Division Multiplexing (TDM) Mode” on page 22.
10
Serial Audio Output Data Port (Output) - Audio data serial output pin. Optionally this pin may be
pulled low through a 47 kΩ resistor, but should not be pulled high.
11 Serial Audio Bit Clock (Input/Output) - Serial bit clock for audio data on the SDOUT pin.
12
Serial Audio Input Left/Right Clock (Input/Output) - Word rate clock for the audio data on the
SDOUT pin.
13
Master/Slave Select (Input) - Used to select Master or Slave for the input and output serial audio
ports at startup and reset. See Table 1 on page 19 for settings.
14 Ground (Input) - Ground for I/O and core logic.
15 Logic Power (Input) - Input/Output power supply. Typically +3.3 V or +5.0 V.
16
Serial Audio Output Format Select (Input) - Used to select the serial audio output format at star-
tup and reset. See Table 3 on page 19 for format settings.
17
Serial Audio Input Format Select (Input) - Used to select the serial audio input format at startup
and reset. See Table 2 on page 19 for format settings.
18
SRC Unlock Indicator (Output) - Indicates when the SRC is unlocked. See “SRC Locking and
Varispeed” on page 20.
19 Crystal Out (Output) - Crystal output for Master clock. See “Master Clock” on page 21.
20
Crystal/Oscillator In (Input) - Crystal or digital clock input for Master clock. See “Master Clock” on
page 21.
-
Thermal Pad - Thermal relief pad for optimized heat dissipation. This pad must be electrically con-
nected to GND. See “Power Supply, Grounding, and PCB Layout” on page 24 for more information.
DS641F4
9
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