7-Bit, 75 Ω, Digital Step Attenuator
This document describes the specification for the
F1977 Digital Step Attenuator. The F1977 is part of a
family of Glitch-FreeTM DSAs optimized for the
demanding requirements of CATV and Satellite
systems. These devices are offered in a compact
5 mm x 5 mm 32 pin QFN package with 75 Ω
impedances for ease of integration.
Digital step attenuators are used in Receivers and
Transmitters to provide gain control. The F1977 is a
7-bit step attenuator optimized for these demanding
applications. The silicon design has very low insertion
loss, low distortion (+64 dBm IIP3) and pinpoint
attenuation accuracy. Most importantly, the F1977
includes IDT’s Glitch-FreeTM technology which results in
low overshoot & ringing during MSB transitions.
Lowest insertion loss for best SNR
Extremely accurate attenuation levels.
Ultra low distortion.
Glitch-FreeTM technology to protect PA or ADC
during transitions between attenuation states.
• CATV Infrastructure
• CATV Set-Top Boxes
• CATV Satellite Modems
• Data Network Equipment
• Fiber Networks
5 to 3000 MHz
• Serial & 7 bit Parallel Interface
• 31.75 dB Control Range
• 0.25 dB step
• Glitch-FreeTM for low transient overshoot
• Low Insertion Loss: 1.4 dB @ 1 GHz
• Ultra linear IIP3: +64 dBm
• Attenuation Error: -0.1 dB @ 1 GHz
• Stable Attenuator Accuracy over temperature
• Bi-directional RF use
• 3.00 V to 5.25 V supply
• 1.8 V or 3.3 V control logic
• Low Current Consumption: 325 µA typical
• -40 °C to +105 °C operating temperature
• 5 mm x 5 mm Thin QFN 32 pin package
FUNCTIONAL BLOCK DIAGRAM
F1977, Rev 1, 04/21/2016
1 © 2016 Integrated Device Technology, Inc.