REV. B
AD1555/AD1556
–22–
Table VIII. Status Register Data Bits
Bit
Number Name Description RESET State
DB23 (MSB) ERROR Detects One of the Following Errors 0
DB22 OVWR Read Sequence Overwrite Error 0
DB21 MFLG Modulator Flag Error MFLG
DB20 X X
DB19 ACC Accumulator Error 0
DB18 DRDY Data Ready 0
DB17 FLSTL Filter Settled 0
DB16 DRNG Output Data Not within AD1555 Range 0
DB15 X X
DB14 X X
DB13 X X
DB12 X X
DB11 PWRDN Power-Down Mode PWRDN
DB10 CSEL Select TDATA Input CSEL
DB9 X X
DB8 BW2 Filter Bandwidth Selection BW2
DB7 BW1 Filter Bandwidth Selection BW1
DB6 BW0 Filter Bandwidth Selection BW0
DB5 X X
DB4 CB4 PGA Input Select PGA4
DB3 CB3 PGA Input Select PGA3
DB2 CB2 PGA Gain Select PGA2
DB1 CB1 PGA Gain Select PGA1
DB0 (LSB) CB0 PGA Gain Select PGA0
The AD1555 has three different ground pins: AGND1, AGND2,
and AGND3 plane, depending on the configuration. AGND1
should be a star point and be connected to the analog ground
point. AGND2 should be directly tied to AGND1. A low
impedance trace should connect in the following order: AGND3,
the low side of the reference decoupling capacitor on REFCAP1,
the ground of the reference voltage, and return to AGND1.
Evaluating the AD1555/AD1556 Performance
Performances of the AD1555/AD1556 can be evaluated with
the evaluation board EVAL-AD1555/AD1556EB. The evaluation
board package includes a fully assembled and tested evaluation
board, documentation, and software for controlling the board
from a PC via the PC printer port.
