This document describes the features and characteristics of ADI's 2.7 GHz DDS-Based AgileRFTM synthesizer AD9956 Rev. A.
The AD9956 Agile RF synthesizer combines a direct‑digital‑synthesis (DDS) core with a phase‑frequency‑detector PLL. It features a 14‑bit DAC operating at up to 400 MSPS and a 48‑bit frequency‑tuning word, enabling fine‑resolution frequency hopping and linear sweep modes. The device includes a 655 MHz CML‑mode PECL‑compatible driver and operates over an extended automotive temperature range of –40 °C to +125 °C.
The datasheet provides detailed specifications, pin‑out descriptions, typical application circuits, and programming registers. It also covers absolute maximum ratings, ESD precautions, power‑down modes, and synchronization options for multi‑device operation.
| Internal DDS clock speed | 400 MSPS |
|---|---|
| DAC resolution | 14‑bit |
| Frequency tuning word | 48‑bit |
| Supply voltages | AVDD = DVDD = 1.8 V ±5%; DVDD_I/O = CP_VDD = 3.3 V ±5% |
| Power consumption (all functions on) | 400 mW |
| Phase noise (1 kHz offset) | ≤ ‑135 dBc/Hz |
| Operating temperature range | ‑40 °C to +125 °C |
The internal DDS clock runs at 400 MSPS.
AVDD and DVDD are 1.8 V ± 5 %, while DVDD_I/O and CP_VDD are 3.3 V ± 5 %.
It is rated for operation from –40 °C to +125 °C.