DAC8564 datasheet(39/51 Pages) TI2

39 / 51 page

DAC8565

www.ti.com

SBAS411C

– JUNE 2007 – REVISED MARCH 2011

PARAMETER DEFINITIONS

With the increased complexity of many different

Full-Scale Error

specifications listed in product data sheets, this

Full-scale error is defined as the deviation of the real

section summarizes selected specifications related to

full-scale output voltage from the ideal output voltage

digital-to-analog converters.

while the DAC register is loaded with the full-scale

code (0xFFFF). Ideally, the output should be VDD – 1

STATIC PERFORMANCE

LSB. The full-scale error is expressed in percent of

Static performance parameters are specifications

full-scale range (%FSR).

such as differential nonlinearity (DNL) or integral

nonlinearity (INL). These are dc specifications and

Offset Error

provide information on the accuracy of the DAC. They

The offset error is defined as the difference between

are most important in applications where the signal

actual output voltage and the ideal output voltage in

changes slowly and accuracy is required.

the linear region of the transfer function. This

difference is calculated by using a straight line

Resolution

defined by two codes (code 485 and 64714). Since

Generally, the DAC resolution can be expressed in

the offset error is defined by a straight line, it can

different forms. Specifications such as IEC 60748-4

have a negative or positve value. Offset error is

recognize

the

numerical,

analog,

and

relative

measured in mV.

resolution. The numerical resolution is defined as the

number of digits in the chosen numbering system

Zero-Code Error

necessary to express the total number of steps of the

The zero-code error is defined as the DAC output

transfer characteristic, where a step represents both

voltage, when all '0's are loaded into the DAC

a digital input code and the corresponding discrete

analogue output value. The most commonly-used

difference between actual output voltage and ideal

definition of resolution provided in data sheets is the

output voltage (0V). It is expressed in mV. It is

numerical resolution expressed in bits.

primarily caused by offsets in the output amplifier.

Least Significant Bit (LSB)

Gain Error

The least significant bit (LSB) is defined as the

Gain error is defined as the deviation in the slope of

smallest value in a binary coded system. The value of

the real DAC transfer characteristic from the ideal

the LSB can be calculated by dividing the full-scale

transfer function. Gain error is expressed as a

output voltage by 2n, where n is the resolution of the

percentage of full-scale range (%FSR).

converter.

Full-Scale Error Drift

Most Significant Bit (MSB)

Full-scale error drift is defined as the change in

The most significant bit (MSB) is defined as the

full-scale

error

with

change

temperature.

largest value in a binary coded system. The value of

Full-scale

error

drift

expressed

units

the MSB can be calculated by dividing the full-scale

of %FSR/

°C.

output voltage by 2. Its value is one-half of full-scale.

Offset Error Drift

Relative Accuracy or Integral Nonlinearity (INL)

Offset error drift is defined as the change in offset

Relative accuracy or integral nonlinearity (INL) is

error with a change in temperature. Offset error drift

defined as the maximum deviation between the real

is expressed in

μV/°C.

transfer function and a straight line passing through

the endpoints of the ideal DAC transfer function. DNL

Zero-Code Error Drift

is measured in LSBs.

Zero-code error drift is defined as the change in

Differential Nonlinearity (DNL)

zero-code error with a change in temperature.

Zero-code error drift is expressed in

μV/°C.

Differential nonlinearity (DNL) is defined as the

maximum deviation of the real LSB step from the

Gain Temperature Coefficient

ideal 1LSB step. Ideally, any two adjacent digital

codes correspond to output analog voltages that are

The gain temperature coefficient is defined as the

exactly one LSB apart. If the DNL is less than 1LSB,

change in gain error with changes in temperature.

the DAC is said to be monotonic.

The gain temperature coefficient is expressed in ppm

of FSR/

°C.

Submit Documentation Feedback

Product Folder Link(s): DAC8565

DAC8564 数据表(PDF) 39 Page - Texas Instruments

DAC8564 数据表(HTML) 39 Page - Texas Instruments

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51

数据表下载