CS53L32A
6. APPLICATIONS
6.1 GROUNDING AND POWER SUPPLY DECOUPLING
As with any high resolution converter, the CS53L32A requires careful attention to power supply and
grounding arrangements to optimize performance. Figure 6 shows the recommended power arrangement
with VA and VL connected to clean supplies. Decoupling capacitors should be located as close to the de-
vice package as possible.
6.2 OVERSAMPLING MODES
The CS53L32A operates in one of two oversampling modes. Base Rate Mode supports input sample
rates up to 50 kHz while High Rate Mode supports input sample rates up to 100 kHz. See Table 16 for
more details.
6.3 RECOMMENDED POWER-UP SEQUENCE
1) Hold RST low until the power supply, master, and left/right clocks are stable. In this state, the control
port is reset to its default settings and VQ will remain low.
2) Bring RST high. The device will remain in a low power state with VQ low and will initiate the Stand-
Alone power-up sequence. The control port will be accessible at this time. If control port operation is
desired, write the CP_EN bit prior to the completion of the Stand-Alone power-up sequence, approx-
imately 1024 LRCK cycles. Writing this bit will halt the Stand-Alone power-up sequence and initialize
the control port to its default settings. The desired register settings can be loaded while keeping the
PDN bit set to 1.
3) If Control Port mode is selected via the CP_EN bit, set the PDN bit to 0 which will initiate the power-
up sequence, which requires approximately 50 µS.
7. CONTROL PORT INTERFACE
The control port is used to load all the internal settings. The operation of the control port may be complete-
ly asynchronous with the audio sample rate. However, to avoid potential interference problems, the con-
trol port pins should remain static if no operation is required.
The control port has 2 modes: SPI and Two Wire. If Two Wire operation is desired, AD0/CS should be
tied to VL or GND. If the CS53L32A ever detects a high to low transition on AD0/CS after power-up, SPI
mode will be selected.
7.1 SPI MODE
In SPI mode, CS is the CS53L32A chip select signal, CCLK is the control port bit clock, CDIN is the input
data line from the microcontroller and the chip address is 0010000. All signals are inputs and data is
clocked in on the rising edge of CCLK. All CS53L32A registers are write-only in SPI mode.
Figure 7 shows the operation of the control port in SPI mode. To write to a register, bring CS low. The first
7 bits on CDIN form the chip address, and must be 0010000. The eighth bit is a read/write indicator (R/W),
which must be low to write. The next 8 bits form the Memory Address Pointer (MAP), which is set to the
address of the register that is to be updated. The next 8 bits are the data which will be placed into the
register designated by the MAP.
The CS53L32A has a MAP auto increment capability, enabled by the INCR bit in the MAP. If INCR is a
zero, then the MAP will stay constant for successive writes. If INCR is set to a 1, then MAP will auto in-
crement after each byte is written, allowing block writes of successive registers.
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