ML2264

11

1.4 REFERENCE

determine the full scale and zero input voltages,

the analog input which produces a full scale output and

code of all zeroes. The transfer function for the A/D

converter is shown in Figure 10.

conversion. Note that the total unadjusted error increases

1.5 POWER SUPPLY AND REFERENCE DECOUPLING

A 0.1µF ceramic disc capacitor is recommended to bypass

If REF+ and REF– inputs are driven by long lines, they

should be bypassed by 0.1µF ceramic disc capacitors at

the reference input pins.

Figure 9. Operating Sequence (WR-RD Mode)

ACQUISITION

OR SAMPLING

PERIOD. ALL

COMPARATORS

AUTOZEROED.

MSB

COMPARATORS

DECIDING.

LSB

COMPARATORS

DECIDING.

WR

CONVERSION

STARTS.

ENDS. HOLD

TIME STARTS.

MSB

COMPARATOR

RESULTS ARE

LATCHED.

RD BROUGHT LOW

LATCHES LSB

COMPARATOR

RESULTS AND

BRINGS INT LOW.

(a) T/H Mode

(a) S/H Mode

ALL

COMPARATORS

AUTOZEROED.

ACQUISITION

PERIOD. MSB

COMPARATORS

ARE TRACKING

COMPARATORS

ARE SAMPLING

LSB

COMPARATORS

DECIDING.

WR

CONVERSION

STARTS.

ENDS. MSB

COMPARATOR

RESULTS ARE

LATCHED.

RD BROUGHT LOW

LATCHES LSB

COMPARATOR

RESULTS AND

BRINGS INT LOW.

Figure 10. A/D Transfer Characteristic

FULL SCALE

TRANSITION

OUTPUT

CODE

11111111

11111110

11111101

00000011

00000010

00000001

00000000

0

FS

FS – 1LSB