Applications Information
Power-On Reset (POR)
When first power is applied to VDD, the input registers
are set to zero so the DAC output is set to code zero.
To optimize DAC linearity, wait until the supplies have
settled. The MAX5214/MAX5216 output voltage range is
0 to VREF.
Power Supplies and
Bypassing Considerations
Bypass VDD with high-quality 0.1µF ceramic capacitors to a
low-impedance ground as close as possible to the device.
Minimize lead lengths to reduce lead inductance.
Connect the GND to the analog ground plane.
Layout Considerations
Digital and AC transient signals on GND can create noise
at the output. Connect GND to the star ground for the
DAC system. Refer the remote DAC loads to this system
ground for the best possible performance. Use proper
grounding techniques, such as a multilayer board with a
low-inductance ground plane, or star connect all ground
return paths back to the MAX5214/MAX5216 GND.
Carefully lay out the traces between channels to reduce
AC cross-coupling. Do not use wire-wrapped boards
and sockets. Use shielding to improve noise immunity.
Do not run analog and digital signals parallel to one
another, especially clock signals. Avoid routing digital
lines underneath the MAX5214/MAX5216 package.
Denitions
Integral Nonlinearity (INL)
INL is the deviation of the measured transfer function
from a straight line drawn between two codes once offset
and gain errors have been nullified.
Differential Nonlinearity (DNL)
DNL is the difference between an actual step height and
the ideal value of 1 LSB. If the magnitude of the DNL is
greater than -1 LSB, the DAC guarantees no missing
codes and is monotonic.
Offset Error
Offset error indicates how well the actual transfer func-
tion matches the ideal transfer function at a single point.
Typically, the point at which the offset error is specified
is at or near the zero-scale point of the transfer function.
Gain Error
Gain error is the difference between the ideal and the
actual full-scale output voltage on the transfer curve,
after nullifying the offset error. This error alters the slope
of the transfer function and corresponds to the same
percentage error in each step.
Settling Time
The settling time is the amount of time required from
the start of a transition, until the DAC output settles to
the new output value within the converter’s specified
accuracy.
Digital Feedthrough
Digital feedthrough is the amount of noise that appears
on the DAC output when the DAC digital control lines
are toggled.
Digital-to-Analog Glitch Impulse
A major carry transition occurs at the midscale point
where the MSB changes from low to high and all other
bits change from high to low, or where the MSB changes
from high to low and all other bits change from low to
high. The duration of the magnitude of the switching
glitch during a major carry transition is referred to as the
digital-to-analog glitch impulse.
Digital-to-Analog Power-Up Glitch Impulse
The digital-to-analog power-up glitch is the duration of
the magnitude of the switching glitch that occurs as the
device exits power-down mode.
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MAX5214/MAX5216 14-/16-Bit, Low-Power, Buffered Output,
Rail-to-Rail DACs with SPI Interface