Rainbow-electronics MAX1039 Manual de usuario descargar pdf (Pagina 20)

MAX1036–MAX1039

2.7V to 5.5V, Low-Power, 4-/12-Channel

2-Wire Serial 8-Bit ADCs

20 ______________________________________________________________________________________

Differential Nonlinearity

Differential nonlinearity (DNL) is the difference between

an actual step width and the ideal value of 1LSB. A

DNL error specification of less than 1LSB guarantees

no missing codes and a monotonic transfer function.

Aperture Jitter

Aperture jitter (t

) is the sample-to-sample variation in

the time between the samples.

Aperture Delay

Aperture delay (t

) is the time between the rising

edge of the sampling clock and the instant when an

actual sample is taken.

Signal-to-Noise Ratio

For a waveform perfectly reconstructed from digital sam-

ples, signal-to-noise ratio (SNR) is the ratio of full-scale

analog input (RMS value) to the RMS quantization error

(residual error). The ideal, theoretical minimum analog-

to-digital noise is caused by quantization error only and

results directly from the ADC’s resolution (N bits):

SNR = (6.02

N + 1.76)dB

INPUT VOLTAGE (LSB)

OUTPUT CODE

1...111

1...110

1...101

1...100

0...000

0...001

0...010

0...011

256

REF

1LSB =

1 253 255254

REF

2560 252

Figure 12. Unipolar Transfer Function

INPUT VOLTAGE (LSB)

OUTPUT CODE

(TWO'S COMPLEMENT)

0...111

0...110

0...101

0...100

1...000

1...001

1...010

1...011

-1-126 -125

256

REF

1LSB =

0+1-127 +125 +127+126

0...000

0...001

1...111

REF

+128-128 +124

'-' INPUT

Figure 13. Bipolar Transfer Function

3V/5V

LOGIC

= 3V/5V

GND

SUPPLIES

DGND3V/5V

GND

0.1µF

DIGITAL

CIRCUITRY

MAX1036

MAX1037

MAX1038

MAX1039

R* = 5Ω

*OPTIONAL

Figure 14. Power-Supply and Grounding Connections

1 2 ... 15 16 17 18 19 20 21 22

Comentarios a estos manuales

Sin comentarios

Rainbow-electronics MAX1039 Manual de usuario Pagina 20

Comentarios a estos manuales

Relacionado con productos y manuales para Hardware Rainbow-electronics MAX1039