參數(shù)資料
型號: LTC1068CG-200
廠商: LINEAR TECHNOLOGY CORP
元件分類: 運動控制電子
英文描述: Clock-Tunable, Quad Second Order, Filter Building Blocks
中文描述: QUAD SWITCHED CAPACITOR FILTER, RESISTOR PROGRAMMABLE, UNIVERSAL, PDSO28
封裝: 0.209 INCH, PLASTIC, SSOP-28
文件頁數(shù): 13/28頁
文件大?。?/td> 535K
代理商: LTC1068CG-200
13
LTC1068 Series
APPLICATIO
S I
FOR
ATIO
U
Operating Limits
The Maximum Q vs Center Frequency (f
O
) graphs, under
Typical Performance Characteristics, define an upper limit
of operating Q for each LTC1068 device 2nd order section.
These graphs indicate the power supply, f
O
and Q value
conditions under which a filter implemented with an
LTC1068 device will remain stable when operated at
temperatures of 70
°
C or less. For a 2nd order section, a
bandpass gain error of 3dB or less is arbitrarily defined as
a condition for stability.
When the passband gain error begins to exceed 1dB, the use
of capacitor C
C
will reduce the gain error (capacitor C
C
is
connected from the lowpass node to the inverting node of a
2nd order section). Please refer to Figures 4 through 7. The
value of C
C
can be best determined experimentally, and as a
guide it should be about 5pF for each 1dB of gain error and not
to exceed 15pF. When operating an LTC1068 device near the
limits defined by the Maximum Q vs Frequency graphs,
passband gain variations of 2dB or more should be expected.
W
U
U
mine the operating signal-to-noise ratio. Most of its fre-
quency contents lie within the filter passband and cannot
be reduced with post filtering. For a notch filter the noise
of the filter is centered at the notch frequency.
The total wideband noise (
μ
V
RMS
) is nearly independent of
the value of the clock. The clock feedthrough specifica-
tions are not part of the wideband noise.
For a specific filter design, the total noise depends on the
Q of each section and the cascade sequence. Please refer
to the Noise vs Q graphs under the Typical Performance
Characteristics.
Aliasing
Aliasing is an inherent phenomenon of switched-capacitor
filters and occurs when the frequency of the input signals
that produce the strongest aliased components have a
frequency, f
IN
, such as (f
SAMPLING
– f
IN
) that falls into the
filter’s passband. For an LTC1068 device the sampling
frequency is twice f
CLK
. If the input signal spectrum is not
band-limited, aliasing may occur.
Demonstration Circuit 104
DC104 is a surface mount printed circuit board for the
evaluation of Linear Technology’s LTC1068 product fam-
ily in a 28-lead SSOP package. The LTC1068 product
family consists of four monolithic clock-tunable filter
building blocks.
Demo Board 104 is available in four assembled versions:
Assembly 104-A features the low noise LTC1068CG (clock-
to-center frequency ratio = 100), assembly 104-B features
the low noise LTC1068CG-200 (clock-to-center frequency
ratio = 200), assembly 104-C features the high frequency
LTC1068CG-25 (clock-to-center frequency ratio = 25) and
assembly 104-D features the low power LTC1068CG-50
(clock-to-center frequency ratio = 50).
All DC104 boards are assembled with input, output and
power supply test terminals, a 28-lead SSOP filter device
(LTC1068CG Series), a dual op amp in an SO-8 for input
or output buffers and decoupling capacitors for the filter
and op amps. The filter and dual op amps share the power
Clock Feedthrough
Clock feedthrough is defined as the RMS value of the clock
frequency and its harmonics that are present at the filter’s
output pins. The clock feedthrough is tested with the
filter’s input grounded and depends on PC board layout
and on the value of the power supplies. With proper layout
techniques, the typical values of clock feedthrough are
listed under Electrical Characteristics.
Any parasitic switching transients during the rising and
falling edges of the incoming clock are not part of the clock
feedthrough specifications. Switching transients have fre-
quency contents much higher than the applied clock; their
amplitude strongly depends on scope probing techniques
as well as grounding and power supply bypassing. The
clock feedthrough, can be greatly reduced by adding a
simple RC lowpass network at the final filter output. This
RC will completely eliminate any switching transients.
Wideband Noise
The wideband noise of the filter is the total RMS value of
the device’s noise spectral density and is used to deter-
相關PDF資料
PDF描述
LTC1068IG Clock-Tunable, Quad Second Order, Filter Building Blocks
LTC1068IG-200 CONNECTOR ACCESSORY
LTC1068IG-25 Metal Connector Backshell; Connector Shell Size:15; For Use With:MIL-C-3899 Series III and IV Connectors; Leaded Process Compatible:No; Peak Reflow Compatible (260 C):No; Contact Plating:Cadmium Over Nickel RoHS Compliant: NA
LTC1068IG-50 STR RELIEF SZ 17 BLK ANDZ RoHS Compliant: No
LTC1068IN CONNECTOR ACCESSORY
相關代理商/技術參數(shù)
參數(shù)描述
LTC1068CG-25 制造商:LINER 制造商全稱:Linear Technology 功能描述:Clock-Tunable, Quad Second Order, Filter Building Blocks
LTC1068CG-50 制造商:LINER 制造商全稱:Linear Technology 功能描述:Clock-Tunable, Quad Second Order, Filter Building Blocks
LTC1068CG-PBF 制造商:LINER 制造商全稱:Linear Technology 功能描述:Clock-Tunable, Quad Second Order, Filter Building Blocks
LTC1068CN 功能描述:IC FILTR BUILDNG BLK QUAD 24-DIP RoHS:否 類別:集成電路 (IC) >> 接口 - 濾波器 - 有源 系列:- 產品培訓模塊:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 標準包裝:1,000 系列:- 濾波器類型:連續(xù)時間,帶通低通 頻率 - 截止或中心:150kHz 濾波器數(shù):4 濾波器階數(shù):8th 電源電壓:4.74 V ~ 11 V,±2.37 V ~ 5.5 V 安裝類型:表面貼裝 封裝/外殼:28-SOIC(0.295",7.50mm 寬) 供應商設備封裝:28-SOIC W 包裝:帶卷 (TR)
LTC1068CN#PBF 功能描述:IC FILTR BUILDNG BLK QUAD 24-DIP RoHS:是 類別:集成電路 (IC) >> 接口 - 濾波器 - 有源 系列:- 產品培訓模塊:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 標準包裝:1,000 系列:- 濾波器類型:連續(xù)時間,帶通低通 頻率 - 截止或中心:150kHz 濾波器數(shù):4 濾波器階數(shù):8th 電源電壓:4.74 V ~ 11 V,±2.37 V ~ 5.5 V 安裝類型:表面貼裝 封裝/外殼:28-SOIC(0.295",7.50mm 寬) 供應商設備封裝:28-SOIC W 包裝:帶卷 (TR)