DESCRIPTION
This document describes the specification for the F1951
Digital Step Attenuator. The F1951 is part of a family of
Glitch-FreeTM DSAs optimized for the demanding
requirements of communications Infrastructure. These
devices are offered in a compact 4x4 QFN package with
50 Ω impedances for ease of integration into the radio
system.
COMPETITIVE ADVANTAGE
Digital step attenuators are used in Receivers and
Transmitters to provide gain control. The F1951 is a 6-
bit step attenuator optimized for these demanding
applications. The silicon design has very low insertion
loss and low distortion (+65 dBm IP3I.). The device has
pinpoint accuracy and settles to final attenuation value
within 400 nsec. Most importantly, the F1951 includes
Renesas’ Glitch-FreeTM technology which results in less
than 0.6 dB of overshoot ringing during MSB transitions.
This is in stark contrast to competing DSAs that glitch as
much as 10 dB during MSB transitions (see p.10).
Lowest insertion loss for best SNR
Glitch-FreeTM when transitioning –
won’t damage PA or ADC
Extremely accurate with low distortion
Glitch-FreeTTMM
APPLICATIONS
Base Station 2G, 3G, 4G, TDD radiocards
Repeaters and E911 systems
Digital Pre-Distortion
Point to Point Infrastructure
Public Safety Infrastructure
WIMAX Receivers and Transmitters
Military Systems, JTRS radios
RFID handheld and portable readers
Cable Infrastructure
PART# MATRIX
Part#
F1951
F1950
F1952
Freq range
(MHz)
100 - 5000
150 - 5000
100 – 4000
Resolution /
Range (dB)
0.50 / 31.5
0.25 / 31.5
0.50 / 15.5
Control
Serial Only
Serial Only
Serial Only
IL
(dB)
-1.2
-1.3
-0.9
Pinout
HITT
PE
HITT
FEATURES
Glitch-FreeTM, < 0.6 dB transient overshoot
Spurious Free Design
3 V to 5.25 V supply
Attenuation Error < 0.2 dB @ 2 GHz
Low Insertion Loss < 1.2 dB @ 2 GHz
Excellent Linearity +65 dBm IP3I
Fast settling time, < 450 ns
Class 2 JEDEC ESD (> 2kV HBM)
Serial Interface 31.5 dB Range
Stable Integral Non-Linearity over temperature
4x4 mm Thin QFN 24 pin package
DEVICE BLOCK DIAGRAM
RF1
RF2
Bias
DEC
SPI
RSTb
VDD
SDI SDO
CLK CSb
ORDERING INFORMATION
0.8 mm height
package
Tape &
Reel
F1951NBGI8
Green
Industrial
Temp range
© 2020 Renesas Electronics Corporation
1
Aug 7, 2020
