AD9520-2 Datasheet, PDF (72/84 Pages) Analog Devices – 12 LVPECL/24 CMOS Output Clock Generator with Integrated 2.2 GHz VCO

AD9520-2
Reg.
Addr
(Hex) Bit(s) Name
01B [7]
Enable VCO
frequency
monitor
01B [6]
01B [5]
Enable REF2
(REFIN)
frequency
monitor
Enable REF1
(REFIN)
frequency
monitor
01B [4:0] REFMON pin
control
Description
[5] [4] [3] [2]
Level or
Dynamic
[1] [0] Signal Signal at LD Pin
110 0
1 0 DYN REF2 clock (not available in differential mode).
110 0
1 1 DYN
Selected reference to PLL (differential reference when in
differential mode).
110 1
0 0 DYN
Unselected reference to PLL (not available when in differential
mode).
110 1
0 1 LVL
Status of selected reference (status of differential reference);
active low.
110 1
1 0 LVL
Status of unselected reference (not available in differential
mode); active low.
110 1
1 1 LVL
Status of REF1 frequency (active low).
111 0
0 0 LVL
Status of REF2 frequency (active low).
111 0
0 1 LVL
(Status of REF1 frequency) AND (status of REF2 frequency).
111 0
1 0 LVL
(DLD) AND (Status of selected reference) AND (status of VCO).
111 0
1 1 LVL
Status of VCO frequency (active low).
111 1
0 0 LVL
Selected reference (low = REF2, high = REF1).
111 1
0 1 LVL
DLD; active low.
111 1
1 0 LVL
Holdover active (active low).
111 1
1 1 LVL
N/A, do not use.
Enables or disables VCO frequency monitor.
[7] = 0; disable the VCO frequency monitor (default).
[7] = 1; enable the VCO frequency monitor.
Enables or disables the REF2 frequency monitor.
[6] = 0; disable the REF2 frequency monitor (default).
[6] = 1; enable the REF2 frequency monitor.
REF1 (REFIN) frequency monitor enabled; this is for both REF1 (single-ended) and REFIN (differential) inputs
(as selected by differential reference mode).
[5] = 0; disable the REF1 (REFIN) frequency monitor (default).
[5] = 1; enable the REF1 (REFIN) frequency monitor.
Selects the signal that is connected to the REFMON pin.
Level or
Dynamic
[4] [3] [2] [1] [0] Signal Signal at REFMON Pin
0 0 0 0 0 LVL
Ground, dc (default).
0 0 0 0 1 DYN
REF1 clock (differential reference when in differential mode).
0 0 0 1 0 DYN
REF2 clock (N/A in differential mode).
0 0 0 1 1 DYN
Selected reference to PLL (differential reference when in differential
mode).
0 0 1 0 0 DYN
Unselected reference to PLL (not available in differential mode).
0 0 1 0 1 LVL
Status of selected reference (status of differential reference);
active high.
0 0 1 1 0 LVL
Status of unselected reference (not available in differential mode);
active high.
0 0 1 1 1 LVL
Status REF1 frequency (active high).
0 1 0 0 0 LVL
Status REF2 frequency (active high).
0 1 0 0 1 LVL
(Status REF1 frequency) AND (status REF2 frequency).
0 1 0 1 0 LVL
(DLD) AND (status of selected reference) AND (status of VCO).
0 1 0 1 1 LVL
Status of VCO frequency (active high).
0 1 1 0 0 LVL
Selected reference (low = REF1, high = REF2).
0 1 1 0 1 LVL
DLD; active low.
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