The AD9858 is a direct digital synthesizer (DDS) featuring a 10-bit DAC output. It has an internal clock speed of 1 GSPS and supports up to a 2 GHz input clock (selectable divide-by-2). The device integrates a 10-bit D/A converter and has a phase noise of less than 145 dBc/Hz @ 1 kHz offset. The output frequency is 100 MHz (DAC output) and it has a 32-bit programmable frequency register. It supports a simplified 8-bit parallel and SPI serial control interface and has automatic frequency sweeping capability. The device operates on a 3.3 V power supply with a typical power dissipation of 2 W. It also integrates a programmable charge pump and phase frequency detector with a fast lock circuit. The charge pump supply can be isolated up to 5 V. Additionally, the AD9858 integrates a 2 GHz mixer.
The AD9858 is a 1 GSPS direct digital synthesizer featuring a 10‑bit DAC, up to 2 GHz input clock, and integrated mixer, charge pump, and phase‑frequency detector. It supports both parallel (8‑bit) and SPI® serial control interfaces, offering fast frequency hopping and fine‑tuned 32‑bit frequency words.
The document includes functional block diagrams, electrical specifications, timing characteristics, pinout tables, and ordering information. It also lists typical applications such as VHF/UHF LO synthesis, tuners, instrumentation, cellular base‑station hopping, and radar systems, and provides absolute maximum ratings and ESD precautions.
| Internal clock speed | 1 GSPS |
|---|---|
| Maximum input clock | 2 GHz (selectable divide‑by‑2) |
| DAC resolution | 10 bits |
| Power supply voltage | 3.3 V |
| Typical power dissipation | 2 W |
| Phase noise @ 1 kHz offset | < -145 dBc/Hz |
| Operating temperature range | -40 °C to +85 °C |
The AD9858 operates with an internal clock speed of 1 GSPS.
The device is specified to operate from –40 °C to +85 °C.
The AD9858 includes a 10‑bit digital‑to‑analog converter.
Typical power dissipation is 2 W.