Definition of Terms

Resolution

Resolution is defined as the reciprocal of the

number of discrete steps in the DA output It is directly

related to the number of switches or bits within the DA For

has 10-bit resolution while the DAC1220 has 12-bit resolu-

tion

Linearity Error

Linearity error is the maximum deviation

from

a straight line passing through the endpoints of the

DA transfer characteristic It is measured after calibrating

scale Linearity error is a design parameter intrinsic to the

device and cannot be externally adjusted

Power Supply Sensitivity

Power supply sensitivity is a

measure of the effect of power supply changes on the DA

full-scale output

Settling Time

Full-scale settling time requires a zero to full-

scale or full-scale to zero output change Settling time is the

time required from a code transition until the DA output

LSB of final output value

Full-Scale Error

Full-scale error is a measure of the output

error between an ideal DA and the actual device output

and

unipolar

operation

LE

e

justable to zero as shown in

Figure 5

TLH5689 – 10

ab1

b2

(a) End point test after zero and full-scale adjust

The DAC has 1 LSB linearity error

(b) By shifting the full-scale calibration on of the DAC of

Figure (b1) we could pass the ‘‘best straight line’’ (b2)

linearity error specification

Note (a) (b1) and (b2) above illustrate the difference between ‘‘end point’’ National’s linearity test (a) and ‘‘best straight line’’ test Note that both devices in (a) and

LSB linearity error specification but the end point test is a more ‘‘real life’’ way of characterizing the DAC

Connection Diagrams

DAC102X

Dual-In-Line Package

TLH5689 – 13

DAC1020

PLCC Package

TLH5689 – 12

DAC122X

Dual-In-Line Package

TLH5689 – 11

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