Datasheet

AD9557 Data Sheet
Rev. B | Page 76 of 92
REFERENCE INPUTS (REGISTER 0x0600 TO REGISTER 0x0602)
Table 72. Reference Power-Down
1
Address Bits Bit Name Description
0x0600
[7:2]
Reserved
Reserved.
1 REFB power-down Powers down REFB input receiver.
0 (default) = not powered down.
1 = powered down.
0
REFA power-down Powers down REFA input receiver.
0 (default) = not powered down.
1 = powered down.
1
When all bits are set, the reference receiver section enters a deep sleep mode.
Table 73. Reference Logic Family
Address Bits Bit Name Description
0x0601
[7:4] Reserved Reserved.
[3:2] REFB logic type Selects logic family for REFB input receiver; only REFB_P is used in CMOS mode.
00 (default) = differential.
01 = 1.2 V to 1.5 V CMOS.
10 = 1.8 V to 2.5 V CMOS.
11 = 3.0 V to 3.3 V CMOS.
[1:0]
REFA logic type The REFA logic type settings are the same as Register 0x0601[3:2] for REFB.
Table 74. Reference Priority Setting
Address Bits Bit Name Description
0x0602
[7:4] Reserved Reserved.
[3:2]
REFB priority User assigned priority level (0 to 3) of the reference associated with REFB, which ranks
that reference relative to the others.
00 (default) = 0.
01 = 1.
10 = 2.
11 = 3.
[1:0]
REFA priority The REFA priority settings are the same as in Register 0x0602[3:2] for REFB.