Datasheet

AD9148 Data Sheet
Rev. B | Page 34 of 72
Register Name
Addr
(Hex) Bit Name Function Default
Coeff Q Byte 2 26 7:5 Coeff_4q[2:0]
Q-Path DAC Sinc
-1
Filter Coefficient 5 (LSB) in twos
complement format.
0
4 0 Set this bit to 0. 0
3:0 Coeff_3q[6:3]
Q-Path DAC Sinc
-1
Filter Coefficient 4 (MSB) in twos
complement format.
D
Set DAC SPI select = 0 to configure DAC 2 path.
Set DAC SPI select = 1 to configure DAC 4 path.
Coeff Q Byte 3
27
7
0
Set this bit to 0.
0
6:0 Coeff_4q[9:3]
Q-Path DAC Sinc
-1
Filter Coefficient 5 (MSB) in twos
complement format.
0
Set DAC SPI select = 0 to configure DAC 2 path.
Set DAC SPI select = 1 to configure DAC 4 path.
I Phase Adj LSB
28
7:0
Phase Word I[7:0]
See Register 0x29.
0
I Phase Adj MSB 29 1:0 Phase Word I[9:8]
Phase Word I[9:0] is used to insert a phase offset between the
I and Q data paths. The adjustment range is ±1.75°.
0
Set DAC SPI select = 0 to configure DAC 1 path.
Set DAC SPI select = 1 to configure DAC 3 path.
Q Phase Adj LSB 2A 7:0 Phase Word Q[7:0] See Register 0x2B. 0
Q Phase Adj MSB
2B
1:0
Phase Word Q[9:8]
Phase Word Q[9:0] is used to insert a phase offset between
the I and Q data paths. The adjustment range is ±1.75°.
0
Set DAC SPI select = 0 to configure DAC 2 path.
Set DAC SPI select = 1 to configure DAC 4 path.
I DC Offset LSB 2C 7:0 DC Offset I[7:0] See Register 0x2D. 0
I DC Offset MSB 2D 7:0 DC Offset I[15:8]
DC Offset I[15:0] is a value added directly to the samples
written to the IDAC. The LSB bit weight is 2
0
. The adjustment
range is ±10 mA.
Set DAC SPI select = 0 to configure DAC 1 path.
0
Set DAC SPI select = 1 to configure DAC 3 path.
Q DC Offset LSB 2E 7:0 DC Offset Q[7:0] See Register 0x2F. 0
Q DC Offset MSB
2F
7:0
DC Offset Q[15:8]
DC Offset Q[15:0] is a value added directly to the samples
written to the QDAC. The LSB bit weight is 2
0
. The adjustment
range is ±10 mA.
Set DAC SPI select = 0 to configure DAC 2 path.
0
Set DAC SPI select = 1 to configure DAC 4 path. 0