The AD9988 from Analog Devices is a Direct RF Transceiver that is designed for multi-band macro 5G and mm-Wave 5G base station radios. It integrates four transmitters, four transceivers, and digital signal processing functions, and also offers features to support time division duplex (TDD) and frequency division duplex (FDD) techniques. This transceiver supports four transmitter channels and four-receiver channels with a 4T4R configuration and has a Tx/Rx channel bandwidth of up to 1.2 GHz. It is suitable for four-antenna TDD transmitter applications, where the receiver path can be shared between receiver and observation modes.
The AD9988 includes four 12-bit, 4 GSPS rate RF digital-to-analog (DAC) cores and four 16-bit, 12 GSPS maximum sample rate, RF digital-to-analog converter (DAC) cores. It features a 16-lane 24.75 Gbps JESD204C or 15.5 Gbps JESD204B serial data port that allows up to eight lanes per transmit/receive a link, an on-chip clock multiplier, and digital signal processing capability targeted at multiband direct-to-RF radio applications. In the Tx chain, it consists of ramp-up/down converters, fine/coarse digital conversions, data router multiplexers, and a JESD204B/JESD204C link. In the Rx chain, it includes four 16-bit, 12 GSPS sampling rates, RF analog-to-digital (ADC) cores, data router multiplexers, fine/coarse digital conversions, programmable FIR filter, and pipelined buffers.
This transceiver incorporates configurable and fully bypassable digital up/down converters (DUC/DDC) with 2 independent 48-bit NCOs per DUC or DDC. It has dedicated AGC support pins for signal monitoring to ensure slow AGC control and fast detection with a low latency function for fast AGC control. The AD9988 supports programmable delay and gain per transmit data path and an adjustable coarse DDC delay for the DPD observation path. It can process either real or complex digital data (8, 12, or 16-bit).
This transceiver integrates several other auxiliary features such as an ADC clock driver with selectable divide ratios, power amplifier downstream protection circuitry, an on-chip temperature monitoring unit, programmable GPIO pins to support toggling between modes, and TDD power saving option. It is available in a 324-lead Ball Grid Array (BGA) package that measures 15 x 15 mm and requires a DC supply from 1.9 to 2.1 V. The AD9988 is ideal for use in W-CDMA, LTE, LTE-A, massive MIMO, point-to-point microwave, E-band, 5G mm-Wave, broadband communication systems, DOCSIS 3.0+ cable modem termination systems (CMTS), and wireless infrastructure applications.
