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AFE7920, AFE7921, AFE7988, AFE7989
SBAS971C –DECEMBER 2019–REVISED JUNE 2020
AFE79xx Quad-Channel RF Transceiver With Feedback Path
1 Features
between TX and RX
•
•
•
Internal PLL/VCO to generate DAC/ADC clocks
1
•
•
•
Quad RF sampling 12-GSPS transmit DACs
Quad RF sampling 3-GSPS receive ADCs
Optional external CLK at DAC or ADC rate
SerDes data interface:
Dual RF sampling 3-GSPS feedback ADCs
(AFE792x only)
–
–
–
–
–
JESD204B and JESD204C compliant
8 SerDes transceivers up to 29.5 Gbps
8b/10b and 64b/66b encoding
•
•
Maximum RF signal bandwidth:
–
TX/FB: 1200 MHz (AFE7920/88) or 400 MHz
(AFE7989) or 800MHz (AFE7921)
12-bit, 16-bit, 24-bit, and 32-bit resolution
Subclass 1 multi-device synchronization
–
RX: 600 MHz (AFE7920/88) or 400 MHz
(AFE7921/AFE7989)
•
Package: 17-mm × 17-mm FCBGA, 0.8-mm pitch
Digital Step Attenuators (DSA):
–
TX: 40 dB range, 1-dB analog and 0.125-dB
digital steps
2 Applications
•
•
•
•
•
Macro remote radio unit (RRU)
Active antenna system mMIMO (AAS)
Small cell base station
–
–
RX: 25 dB range, 0.5-dB steps
FB: 25 dB range, 0.5-dB steps
•
Single or dual-band DUC/DDCs (AFE7920/88
only) for TX and RX
Repeater
Distributed Antenna Systems (DAS)
•
•
Dual NCOs for fast frequency switching
Supports TDD operation with fast switching
3 Description
The AFE79xx is a family of high performance, wide bandwidth multi-channel transceivers, integrating four RF
sampling transmitter chains, four RF sampling receiver chains, and up to two RF sampling digitizing auxiliary
chains (feedback paths). The high dynamic range of the transmitter and receiver chains allows the device to
generate and receive 3G, 4G, and 5G signals from wireless base stations, while the wide bandwidth capability of
the AFE79xx devices is designed for multi-band 4G and 5G base stations.
Each receiver chain includes a 25-dB range DSA (Digital Step Attenuator), followed by a 3-GSPS ADC (analog-
to-digital converter). Each receiver channel has an analog peak power detector and various digital power
detectors to assist an external or internal autonomous automatic gain controller, and RF overload detectors for
device reliability protection. The single or dual digital down converters (DDC) provide up to 600 MHz of combined
signal BW. In TDD mode, the receiver channel can be configured to dynamically switch between the traffic
receiver (TDD RX) and wideband feedback receiver (TDD FB), with the capability of re-using the same analog
input for both purposes.
Each transmitter chain includes a single or dual digital up converters (DUCs) supporting up to 1200-MHz
combined signal bandwidth. The output of the DUCs drives a 12-GSPS DAC (digital to analog converter) with a
mixed mode output option to enhance 2nd or 3rd Nyquist operation. The DAC output includes a variable gain
amplifier (TX DSA) with 40-dB range and 1-dB analog and 0.125-dB digital steps.
The feedback path includes an 25-dB range DSA driving a 3-GSPS RF sampling ADC, followed by a DDC with
up to 1200-MHz bandwidth.
Device Information(1)
PART NUMBER
PACKAGE
FC-BGA
FC-BGA
FC-BGA
FC-BGA
BODY SIZE
AFE7989
AFE7920
AFE7988
AFE7921
17.00 mm × 17.00 mm
17.00 mm × 17.00 mm
17.00 mm × 17.00 mm
17.00 mm × 17.00 mm
(1) For more information, see Mechanical, Packaging, and Orderable Information.
1
An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications,
intellectual property matters and other important disclaimers. PRODUCTION DATA.