MAX5115/MAX5116
Nonvolatile, Quad, 8-Bit DACs with 2-Wire Serial
Interface
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Applications Information
DAC Linearity and Offset Voltage
The output buffer can have a negative input offset volt-
age that would normally drive the output negative, but
with no negative supply, the output remains at GND
(Figure 10). Determine linearity using the end-point
method, measuring between code 10 (0A hex) and
code 240 (F0 hex) after calibrating the offset and gain
error (Figure 10).
External Voltage Reference
The MAX5115 features two reference inputs for each
DAC (REFH_ and REFL_). The MAX5116 uses a single
reference for all four DACs (REFH and REFL). REFH_
sets the full-scale voltage, while REFL_ sets the zero
code output. The MAX5115 has a 460kΩ typical input
impedance that is independent of the code. The
MAX5116 has a 115kΩ typical input impedance that is
independent of the code.
Power Sequencing
The voltage applied to REFH_ and REFL_ should not
exceed V
DD
at any time. If proper power sequencing is
not possible, connect an external Schottky diode
between REFH_, REFL_, and V
DD
to ensure compliance
with the absolute maximum ratings. Do not apply signals
to the digital inputs before the device is fully powered.
Power-Supply Bypassing and
Ground Management
Digital or AC transient signals on GND can create noise
at the analog output. Return GND to the highest-quality
ground available. Bypass V
DD
with a 0.1µF capacitor,
located as close to the device as possible. Bypass
REFH_ and REFL_ to GND with 0.1µF capacitors.
Careful PC board ground layout minimizes crosstalk
between the DAC outputs and digital inputs.
