THS5651A

10BIT, 125 MSPS, CommsDAC

DIGITALTOANALOG CONVERTER

SLAS260A − FEBRUARY 2000 − REVISED SEPTEMBER 2002

21

POST OFFICE BOX 655303

• DALLAS, TEXAS 75265

APPLICATION INFORMATION

sleep mode

The THS5651A features a power-down mode that turns off the output current and reduces the supply current

to less than 5 mA over the analog supply range of 4.5 V to 5.5 V and temperature range. The power-down mode

is activated by applying a logic level 1 to the SLEEP pin (e.g., by connecting pin SLEEP to AVDD). An internal

pulldown circuit at node SLEEP ensures that the THS5651A is enabled if the input is left disconnected.

Power-up and power-down activation times depend on the value of external capacitor at node SLEEP. For a

nominal capacitor value of 0.1

µF power down takes less than 5 µs, and approximately 3 ms to power back up.

The SLEEP mode should not be used when an external control amplifier is used, as shown in Figure 22.

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.

offset error

Offset error is defined as the deviation of the output current from the ideal of zero at a digital input value of 0.

gain error

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

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

S/N+D or SINAD is the ratio of the rms value of the output 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)

SFDR is the difference between the rms value of the output signal and the rms value of the largest spurious

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

total harmonic distortion (THD)

THD is the ratio of the rms sum of the first six harmonic components to the rms value of the fundamental signal

and is expressed in decibels.

output compliance range

The maximum and minimum allowable voltage of the output of the DAC, beyond which either saturation of the

output stage or breakdown may occur.

settling time

The time required for the output to settle within a specified error band.

glitch energy

The time integral of the analog value of the glitch transient.