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REF02

15 V

5 V

1.6 mA

SCL

SDA

Interface

DAC7573

LAYOUT

DAC7573

SLAS398 – SEPTEMBER 2003

APPLICATION INFORMATION (continued)

typical current required (with a 5-k

Ω load on a single DAC output) is:

600 µA + (5 V / 5 k

Ω) = 1.6 mA

The load regulation of the REF02 is typically 0.005%/mA, which results in an error of 400 µV for 1.6 mA of

current drawn from it. This corresponds to a 0.33 LSB error for a 0 V to 5 V output range.

Figure 42. REF02 Power Supply

A precision analog component requires careful layout, adequate bypassing, and clean, well-regulated power

supplies.

converters often have high-frequency glitches or spikes riding on the output voltage. In addition, digital

components can create similar high-frequency spikes as their internal logic switches states. This noise can easily

couple into the DAC output voltage through various paths between the power connections and analog output.

from the connection for digital logic until they are connected at the power-entry point. In addition, a 1 µF to 10 µF

capacitor in parallel with a 0.1 µF bypass capacitor is strongly recommended. In some situations, additional

bypassing may be required, such as a 100 µF electrolytic capacitor or even a Pi filter made up of inductors and

capacitors—all designed to essentially low-pass filter the –5 V supply, removing the high-frequency noise.

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