CDB5532U Cirrus Logic Inc, CDB5532U Datasheet - Page 3

• 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

1. HARDWARE
1.1
The CDB5532U evaluation board provides a quick means of evaluating the CS5532 Analog-to-Digital
Converter (ADC). The CS5532 is a highly integrated ∆Σ ADC which uses charge-balance techniques to
achieve 24-bit performance. The CS5532 includes a very-low-noise, chopper-stabilized instrumentation
amplifier (6 nV/sqrt(Hz) @ 0.1 Hz) with selectable gains of 1x, 2x, 4x, 8x, 16x, 32x, and 64x. This ADC
also includes a fourth order ∆Σ modulator followed by a digital filter which provides twenty selectable out-
put word rates of 6.25 Hz, 7.5 Hz, 12.5 Hz, 15 Hz, 25 Hz, 30 Hz, 50 Hz, 60 Hz, 100 Hz, 120 Hz, 200 Hz,
240 Hz, 400 Hz, 480 Hz, 800 Hz, 960 Hz, 1.6 kHz, 1.92 kHz, 3.2 kHz and 3.84 kHz (XIN = 4.9152 MHz).
The CDB5532U is shipped with a CS5532 device soldered at U2. However, the CS5531, CS5533, or
CS5534 can be soldered in this same location. The CDB553xU software supports all four devices.
1.2
The CDB5532U evaluation board is partitioned into two main sections: analog and digital. The analog sec-
tion consists of the CS5532 and a precision voltage reference. The digital section consists of the micro-
controller, the reset circuitry, and the USB interface. The board also has power supply connections which
accommodate all of the various supply options of the CS5532.
The evaluation board’s analog section operates from either a single +5 V, dual ±2.5 V, or dual ±3 V power
supply. The evaluation board interfaces the CS5532 to an IBM
accomplish this, the board comes equipped with a microcontroller and a USB cable which physically in-
terfaces the evaluation board to the PC. The software provides easy access to the internal registers of the
CS5532, and provides a means to display and evaluate the performance of the ADC in the time domain
or the frequency domain.
1.2.1
The CS5532 is a high-precision ∆Σ ADC designed to accurately measure one or two fully-differential an-
alog voltage inputs while operating from a 4.9152 MHz crystal.
The evaluation board provides separate screw terminals to connect signals to each of the two input chan-
nels. The input screw terminals are labeled as AIN1 & AIN2, which correspond to physical input channels
1 & 2, respectively. A simple RC network on each channel filters the sensor’s output to reduce any inter-
ference picked up by the input leads. The -3 dB corner of the filter is approximately 52 kHz differential and
56 kHz common mode. Figure 7 illustrates the schematic of the analog section.
The evaluation board provides three voltage reference options for VREF+ and VREF-. The three refer-
ence options for VREF+ include: VA+, the on-board LT1019 voltage reference, and external input (J12).
Table 1 illustrates the options available. With the J17 jumper in position VA+, the reference is supplied by
the VA+ analog supply. With the J17 jumper in position LT1019, the LT1019 provides a +2.5 V reference
(the LT1019 was chosen for its low drift, typically 5 ppm/°C). By setting the J17 jumper to position VREF+,
the user can supply an external voltage reference to J12’s VREF+ input.
The three reference options for VREF- include: VA-, GND, and external input (J12). Table 2 illustrates the
options available. With the J18 jumper in position VA-, the reference is supplied by the VA- analog supply.
With the J18 jumper in position GND, the VREF- pin is connected to the board ground. By setting the J18
jumper to position VREF-, the user can supply an external voltage reference to J12’s VREF- input.
DS807DB1
Introduction
Evaluation Board Overview
Analog Section
®
compatible PC with a USB interface. To
CDB5532U
3