MB88101A Ver la hoja de datos (PDF) - Fujitsu

Número de pieza

componentes Descripción

Fabricante

MB88101A

A/D Converter (With 4-channel Input at 12-bit Resolution)

Fujitsu 

MB88101A

(3) Definitions of A/D converter terms

• Resolution

Analog transition identifiable by the A/D converter

• Linearity error

Deviation of the straight line drawn between the zero transition point (0000 0000 0000 ↔ 0000 0000 0001)

and the full-scale transition point (1111 1111 1110 ↔ 1111 1111 1111) of the device from actual conversion

characteristics

• Differential linearity error

Deviation from the ideal input voltage required to shift output code by one LSB

Digital output

Actual converted value

1111 1111 1111

1111 1111 1110

•

•

•

•

•

•

•

•

•

0000 0000 0010

0000 0000 0001

0000 0000 0000

VOT

(1 LSB × N + VOT)

Linearity error

VNT V(N+1)T

• 1 LSB

VFST - VOT

=

4094

• Linearity error

VNT - (1 LSB × N + VOT)

=

1 LSB

• Differential linearity error =

V(N+1)T - VNT

1 LSB - 1

(LSB)

(LSB)

Ideal converted value

Analog output

VFST

• Analog input equivalent circuit

Analog input

RON1

RON2

⋅ RON1 = About 1.5 kΩ

⋅ RON2 = About 1.5 kΩ

⋅ C0 = About 60 pF

Note: The above values are reference values.

Comparator

C0

Notes: • The tolerance of output impedance of an external circuit connected to this A/D converter has an effect on

conversion time (CLK frequency). See “s TYPICAL CHARACTERISTICS”.

• If the output impedance of the external input is too high, the analog voltage sampling time may be short.

• When turning the device on, turn the power supply for the digital system first before turning VREF on.

9

Share Link: