LTC1659

7

1659fa

TIMING DIAGRAM

DEFINITIONS

B11

MSB

B10

B1

B0

LSB

B11

CURRENT WORD

CLK

CS/LD

1659 TD

B0

PREVIOUS WORD

B11

PREVIOUS WORD

B10

B1

B0

Differential Nonlinearity (DNL): The difference between

the measured change and the ideal 1LSB change for any

two adjacent codes. The DNL error between any two codes

is calculated as follows:

DNL = (

where

two adjacent codes.

Digital Feedthrough: The glitch that appears at the ana-

log output caused by AC coupling from the digital inputs

when they change state. The area of the glitch is specified

in (nV)(sec).

Full-Scale Error (FSE): The deviation of the actual full-scale

voltage from ideal. FSE includes the effects of offset and

gain errors (see Applications Information).

Integral Nonlinearity (INL): The deviation from a straight

line passing through the endpoints of the DAC transfer

curve (Endpoint INL). Because the output cannot go

below zero, the linearity is measured between full scale

and the lowest code which guarantees the output will be

greater than zero. The INL error at a given input code is

calculated as follows:

the given input code.

Least Significant Bit (LSB): The ideal voltage difference

between two successive codes.

Resolution (n): Defines the number of DAC output states

(2n) that divide the full-scale range. Resolution does not

imply linearity.

output when the DAC is loaded with all zeros. A single

supply DAC can have a true negative offset, but the output

cannot go below zero (see Applications Information).

For this reason, single supply DAC offset is measured at

the lowest code that guarantees the output will be greater

than zero.