TLV5626

2.7-V TO 5.5-V LOW-POWER DUAL 8-BIT DIGITAL-TO-ANALOG

CONVERTER WITH INTERNAL REFERENCE AND POWER DOWN

SLAS236A –JUNE 1999 – REVISED JUNE 2000

14

POST OFFICE BOX 655303

APPLICATION INFORMATION

This offset error, not the linearity error, produces this breakpoint. The transfer function would have followed the

dotted line if the output buffer could drive below the ground rail.

For a DAC, linearity is measured between zero-input code (all inputs 0) and full-scale code (all inputs 1) after

offset and full scale are adjusted out or accounted for in some way. However, single supply operation does not

allow for adjustment when the offset is negative due to the breakpoint in the transfer function. So the linearity

is measured between full-scale code and the lowest code that produces a positive output voltage.

definitions of specifications and terminology

integral nonlinearity (INL)

The relative accuracy or integral nonlinearity (INL), sometimes referred to as linearity error, is the maximum

deviation of the output from the line between zero and full scale excluding the effects of zero code and full-scale

errors.

differential nonlinearity (DNL)

The differential nonlinearity (DNL), sometimes referred to as differential error, is the difference between the

measured and ideal 1 LSB amplitude change of any two adjacent codes. Monotonic means the output voltage

changes in the same direction (or remains constant) as a change in the digital input code.

Zero-scale error is defined as the deviation of the output from 0 V at a digital input value of 0.

Gain error is the error in slope of the DAC transfer function.

signal-to-noise ratio + distortion (S/N+D)

S/N+D is the ratio of the rms value of the measured input signal to the rms sum of all other spectral components

below the Nyquist frequency, including harmonics but excluding dc. The value for S/N+D is expressed in

decibels.

spurious free dynamic range (SFDR)

Spurious free dynamic range is the difference between the rms value of the output signal and the rms value of

the spurious signal within a specified bandwidth. The value for SFDR is expressed in decibels.