CDB5532U Cirrus Logic Inc, CDB5532U Datasheet - Page 43

• Manufacturer Part Number: CDB5532U
• Description: BOARD EVAL FOR CS5532U ADC
• Manufacturer: Cirrus Logic Inc

Specifications of CDB5532U

• Number Of Adc's: 2
• Number Of Bits: 24
• Sampling Rate (per Second): 3.84k
• Data Interface: Serial
• Inputs Per Adc: 1 Differential
• Input Range: ±2.5 V
• Power (typ) @ Conditions: 35mW @ 3.84kSPS
• Voltage Supply Source: Analog and Digital, Dual ±
• Operating Temperature: -40°C ~ 85°C
• Utilized Ic / Part: CS5532
• Description/function: Audio DSPs
• Operating Supply Voltage: 5 V
• Product: Audio Modules
• For Use With/related Products: C8051F320
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Contains lead / RoHS non-compliant
• Other names: 598-1159

2.12. Getting Started
This A/D converter has several features. From a
software programmer’s prospective, what should
be done first? To begin, a 4.9152 MHz or
4.096 MHz crystal takes approximately 20 ms to
start. To accommodate for this, it is recommended
that a software delay of approximately 20 ms start
the processor’s ADC initialization code. Next,
since the CS5532/34 do not provide a power-on-re-
set function, the user must first initialize the ADC
to a known state. This is accomplished by resetting
the ADC’s serial port with the Serial Port Initializa-
tion sequence. This sequence resets the serial port
to the command mode and is accomplished by
transmitting 15 SYNC1 command bytes (0xFF
hexadecimal), followed by one SYNC0 command
(0xFE hexadecimal). Once the serial port of the
ADC is in the command mode, the user must reset
all the internal logic by performing a system reset
sequence (see 2.3.2 System Reset Sequence). The
next action is to initialize the voltage reference
mode. The voltage reference select (VRS) bit in the
DS755F3
configuration register must be set based upon the
magnitude of the reference voltage between the
VREF+ and the VREF- pins.
After this, the channel-setup registers (CSRs) should
be initialized, as these registers determine how cali-
brations and conversions will be performed. Once
the CSRs are initialized, the user has three options in
calibrating the ADC: 1) don’t calibrate and use the
default settings; 2) perform self or system calibra-
tions; or 3) upload previously saved calibration re-
sults to the offset and gain registers. At this point,
the ADC is ready to perform conversions.
2.13. PCB Layout
For optimal performance, the CS5532/34 should be
placed entirely over an analog ground plane. All
grounded pins on the ADC, including the DGND
pin, should be connected to the analog ground
plane that runs beneath the chip. In a split-plane
system, place the analog-digital plane split imme-
diately adjacent to the digital portion of the chip.
CS5532/34-BS
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