The AD9878 Rev. A is a low cost 3.3 V CMOS MxFE™ for broadband applications. It is compliant with DOCSIS, EURO-DOCSIS, DVB and DAVIC standards and features a 232 MHz quadrature digital upconverter, a 12-bit direct IF DAC (TxDAC+), up to a 65 MHz carrier frequency DDS, programmable sampling clock rates, an analog Tx output level adjust, dual 12-bit, 29 MSPS direct IF ADCs with video clamp input, a 10-bit, 29 MSPS sampling ADC, and an 8-bit ∑-∆ auxiliary DAC, which can be directly interfaced to AD832x family of PGA cable drivers.
The AD9878 is a single‑supply mixed‑signal front‑end designed for cable‑modem and set‑top‑box broadband applications. It integrates a transmit‑path interpolation filter, a quadrature digital upconverter, a 12‑bit transmit DAC, dual 12‑bit ADCs and a 10‑bit ADC, all clocked by an internal PLL.
The handbook contains electrical characteristics, absolute maximum ratings, pin‑out tables, register definitions, functional block diagrams, typical performance plots, PCB design guidelines, outline dimensions, and an ordering guide. It serves as a reference for designers implementing the device in RF front‑end modules.
| Supply Voltage (VAS) | 3.3 V ± 5% |
|---|---|
| Maximum Tx DAC Sample Rate | 232 MHz |
| Package | 100‑lead LQFP (ST‑100) |
| Operating Temperature Range | -40°C to +85°C |
The device is specified for an extended industrial temperature range of –40 °C to +85 °C.
The AD9878 includes dual 12‑bit ADCs and a separate 10‑bit ADC.
The transmit DAC can operate at sample rates up to 232 MHz.
It is offered in a 100‑lead low‑profile quad flat package (LQFP).