AD1555 Analog Devices, AD1555 Datasheet - Page 22

• Manufacturer Part Number: AD1555
• Description: 24-Bit, 121 dB typical SNR, Sigma-Delta A/D converter with Integrated PGA
• Manufacturer: Analog Devices

Specifications of AD1555

• Resolution (bits): 24bit
• # Chan: 2
• Sample Rate: 256kSPS
• Interface: Byte,Ser
• Analog Input Type: Diff-Bip,SE-Bip
• Ain Range: Bip 2.25V/(PGA Gain)
• Adc Architecture: Sigma-Delta Modulator
• Pkg Type: LCC

AD1555/AD1556
Bit
Number
DB23 (MSB)
DB22
DB21
DB20
DB19
DB18
DB17
DB16
DB15
DB14
DB13
DB12
DB11
DB10
DB9
DB8
DB7
DB6
DB5
DB4
DB3
DB2
DB1
DB0 (LSB)
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.
Name
X
ACC
X
X
X
X
X
X
ERROR
OVWR
MFLG
DRDY
FLSTL
DRNG
PWRDN
CSEL
BW2
BW1
BW0
CB4
CB3
CB2
CB1
CB0
Table VIII. Status Register Data Bits
Description
Detects One of the Following Errors
Read Sequence Overwrite Error
Modulator Flag Error
Accumulator Error
Data Ready
Filter Settled
Output Data Not within AD1555 Range
Power-Down Mode
Select TDATA Input
Filter Bandwidth Selection
Filter Bandwidth Selection
Filter Bandwidth Selection
PGA Input Select
PGA Input Select
PGA Gain Select
PGA Gain Select
PGA Gain Select
–22–
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.
RESET State
0
0
MFLG
X
0
0
0
0
X
X
X
X
PWRDN
CSEL
X
BW2
BW1
BW0
X
PGA4
PGA3
PGA2
PGA1
PGA0
REV. B