I use AD9957 in quadrature modulation mode. The hardware configuration: DAC_RSET - 10K, 18 bit Parallel data bus .
All works good, but the output level on pin 4 of Transformer T1 (schematic is attached) not more then (-12dBm), measured by HP 8935. Data on parallel bus with amplitude +- 131071.
AUX_DAC_FSC - 0x7F
Profile_0_QDUC_FSC - 0xFF
Please tell me:
1) (-12dBm) is normally level for my configuration ?
2) Can I use instead of Transformer T1, for example AD8021?