Datasheet

AD9553
Rev. A | Page 34 of 44
Addr.
(Hex)
Register
Name
(MSB)
Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1
(LSB)
Bit 0 Default
0x1F REFA
frequency
control
REFA Divider (R
A
)[13:6] 0x40
0x20 REFA Divider (R
A
)[5:0] Enable SPI
control of R
A
Unused 0x00
0x21 Enable SPI
control of
×2
A
Select
×2
A
Enable SPI
control of
÷5
A
Select
÷5
A
Unused Unused Unused Unused 0x00
0x22 Unused Unused Unused Unused Unused Unused Unused Unused Unused
0x23 REFB
frequency
control
REFB Divider (R
B
)[13:6] 0x80
0x24 REFB Divider (R
B
)[5:0] Enable SPI
control of R
B
Unused 0x00
0x25 Enable SPI
control of
×2
B
Select
×2
B
Enable SPI
control of
÷5
B
Select
÷5
B
Unused Unused Unused Unused 0x00
0x26 Unused Unused Unused Unused Unused Unused Unused Unused Unused
0x27 DCXO
frequency
and
reference
switchover
control
XO divider (R
XO
)[13:6] 0x40
0x28 XO Divider (R
XO
)[5:0] Enable SPI
control of R
XO
Unused 0x00
0x29 Switchover mode[1:0] REFA Diff Unused Unused Unused Unused Unused 0x00
0x2A
to
0x31
Unused Unused Unused Unused Unused Unused Unused Unused Unused
0x32 OUT1 driver
control
OUT1 drive
strength
OUT1
power-
down
OUT1 Mode Control[2:0] OUT1
CMOS
polarity
Unused Use Bits[5:3]
as source for
OUT1 mode
control
0xA8
0x33 Unused Unused Unused Unused Unused Unused Unused Unused Unused 0x00
0x34 OUT2 driver
control
OUT2 drive
strength
OUT2
power-
down
OUT2 Mode Control[2:0] OUT2
CMOS
polarity
Unused Use Bits[5:3]
as source for
OUT2 mode
control
0xA8