CS5014 datasheet(28/40 Pages) CIRRUS

28 / 40 page

Signal to Noise + Distortion vs Signal Level

As illustrated in Figures 25 - 28, the CS5014/16’s

on-chip self-calibration provides very accurate bit

weights which yield no degradation in quantiza-

tion noise with low-level input signals. In fact,

quantization noise remains below the noise floor

in the CS5016, which dictates the converter’s sig-

nal-to-noise performance.

CS5016 Noise Considerations

All analog circuitry in the CS5016 is wideband in

order to achieve fast conversions and high

throughput. Wideband noise in the CS5016 inte-

grates to 35

µV rms in unipolar mode (70 µV rms

in bipolar mode). This is approximately 1/2 LSB

rms with a 4.5V reference in both modes. Figure

29 shows a histogram plot of output code occur-

rences obtained from 5000 samples taken from a

CS5016 in the bipolar mode. Hexadecimal code

80CD was arbitrarily selected and the analog in-

put was set close to code center. With a noiseless

converter, code 80CD would always appear. The

histogram plot of the CS5016 has a "bell" shape

with all codes other than 80CD due to internal

noise.

In a sampled data system all information about the

analog input applied to the sample/hold appears in

the baseband from dc to one-half the sampling rate.

This includes high-frequency components which

alias into the baseband. Low-pass (anti-alias) filters

Analog Input Amplitude

-100 dB -80 dB -60 dB -40 dB -20 dB

0 dB

100 dB

80 dB

60 dB

40 dB

20 dB

0 dB

1 kHz

12 kHz

24 kHz

Input

Frequencies

Figure 2

5. CS5014 S/(N+D) vs. Input Amplitude

(9Vp-p Full-Scale Input)

Analog Input Amplitude

-100 dB -80 dB -60 dB -40 dB -20 dB

0 dB

100 dB

80 dB

60 dB

40 dB

20 dB

0 dB

1 kHz

12 kHz

24 kHz

Input

Frequency

Figure 2

7. CS5016 S/(N+D) vs. Input Amplitude

(9Vp-p Full-Scale Input)

Signal

Amplitude

Relative to

Full Scale

Input Frequency

0dB

-20dB

-40dB

-60dB

-80dB

-100dB

-120dB

28 kHz

1 kHz

Sampling Rate: 56 kHz

Full Scale: 9V p-p

S/(N+D): 24.1 dB

Figure 2

6. CS5014 FFT plot with 1 kHz

-60 dB Input

Signal

Amplitude

Relative to

Full Scale

Input Frequency

0dB

-20dB

-40dB

-60dB

-80dB

-100dB

-120dB

25 kHz

Sampling Rate: 50 kHz

Full Scale: 9V p-p

S/(N+D): 9.6 dB

1 kHz

Figure 2

8. CS5016 FFT plot with 1 kHz

-80 dB Input

CS5012A, CS5014, CS5016

2-34

DS14F8

CS5012A CS5014 CS5016

DS14F9

CS5014 データシート(PDF) 28 Page - Cirrus Logic

CS5014 データシート(HTML) 28 Page - Cirrus Logic

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40

データシートダウンロード

リンク URL

CS5014 データシート(PDF) 28 Page - Cirrus Logic

CS5014 データシート(HTML) 28 Page - Cirrus Logic

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40

データシート ダウンロード

リンク URL

データシートダウンロード