CDB5571 Cirrus Logic Inc, CDB5571 Datasheet - Page 20

• Manufacturer Part Number: CDB5571
• Description: DEV BOARD FOR CS5571 W/MUX
• Manufacturer: Cirrus Logic Inc
• Type: A/Dr

Specifications of CDB5571

• Number Of Adc's: 1
• Number Of Bits: 16
• Sampling Rate (per Second): 100k
• Data Interface: Serial
• Inputs Per Adc: 2 Single
• Input Range: 2.4 ~ 4.2 V
• Voltage Supply Source: Dual ±
• Operating Temperature: -40°C ~ 85°C
• Utilized Ic / Part: CS5571
• Product: Data Conversion Development Tools
• Conversion Rate: 100 KSPS
• Resolution: 16 bit
• Maximum Clock Frequency: 16 MHz
• Interface Type: SPI
• Supply Voltage (max): 3.3 V
• Supply Voltage (min): - 2.5 V
• For Use With/related Products: CS5571
• 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: 598-1275; CDB5571-1

3.7 AIN & VREF Sampling Structures
The CS5571 uses on-chip buffers on the AIN and VREF+ inputs. Buffers provide much higher input im-
pedance and therefore reduce the amount of drive current required from an external source. This helps
minimize errors.
The Buffer Enable (BUFEN) pin determines if the on-chip buffers are used or not. If the BUFEN pin is
connected to the V1+ supply, the buffers will be enabled. If the BUFEN pin is connected to the V1- pin,
the buffers are off. The converter will consume about 30 mW less power when the buffers are off, but the
input impedances of AIN, ACOM and VREF+ will be significantly less than with the buffers enabled.
3.8 Converter Performance
The CS5571 achieves excellent differential nonlinearity (DNL) as shown in figures 9 and 10. Figure 9 il-
lustrates the code widths on a typical scale of ±1 LSB. Figure 10 illustrates a zoom view of figure 9 on a
scale of ±0.1 LSB. Figure 10 also includes a DNL error histogram that indicates that the errors are equally
distributed about the perfect code size; and most codes are accurate within ±0.01 LSB.
20
+0.10
+0.08
+0.06
+0.04
+0.02
-0.02
-0.04
-0.06
-0.08
-0.10
0
1
Figure 10. CS5581 DNL Error Plot with DNL Histogram
-0.25
-0.50
-0.75
-1.00
1.00
0.75
0.50
0.25
0.00
1
Codes
Figure 9. CS5571 DNL Plot
3/25/08
10:56
Codes
65535
18k
16k
Counts per 0.01 LSB Error
14k
12k
65535
10k
8k
6k
4k
2k
0
CS5571
+0.09
+0.08
+0.07
+0.06
+0.05
+0.04
+0.03
+0.02
+0.01
0
-0.01
-0.02
-0.03
-0.04
-0.05
-0.06
-0.07
-0.08
-0.09
+0.1
-0.1
DS768PP1