AD5551/AD5552

Rev. A | Page 13 of 16

REFERENCE AND GROUND

As the input impedance is code-dependent, the reference pin

should be driven from a low-impedance source. The AD5551/

AD5552 operate with a voltage reference ranging from 2 V to

the reference, references below 2 V results in reduced accuracy.

Table 6 and Table 7 outline the analog output voltage for

particular digital codes. For optimum performance, Kelvin

sense connections are provided on the AD5552.

If the application does not require separate force and sense

lines, they should be tied together close to the package to

minimize voltage drops between the package leads and the

internal die. ADR291 and ADR293 are suitable references

for this product.

POWER-ON RESET

These parts have a power-on reset function to ensure the output

is at a known state upon power-up. After power-up, the DAC

register contains all zeros, until data is loaded from the serial

register. However, the serial register is not cleared on power-up,

so its contents are undefined. When loading data initially to the

DAC, 14 bits or more should be loaded to prevent erroneous

data appearing on the output. If more than 14 bits are loaded,

only the last 14 are kept, and if fewer than 14 are loaded, bits

remain from the previous word. If the AD5551/AD5552 needs

to be interfaced with data shorter than 14 bits, the data should

be padded with zeros at the LSBs.

POWER SUPPLY AND REFERENCE BYPASSING

For accurate high-resolution performance, it is recommended

that the reference and supply pins be bypassed with a 10 μF

tantalum capacitor in parallel with a 0.1 μF ceramic capacitor.