參數(shù)資料
型號: ADG741
廠商: Analog Devices, Inc.
英文描述: CMOS Low Voltage 2ohm SPST Switches in SC70 Packages
中文描述: CMOS低電壓2ohm SPST開關(guān)在SC70封裝
文件頁數(shù): 8/8頁
文件大小: 118K
代理商: ADG741
ADG741/ADG742
–8–
REV. 0
APPLICATIONS INFORMATION
The ADG741/ADG742 belongs to Analog Devices’ new fam-
ily of CMOS switches. This series of general-purpose switches
have improved switching times, lower on resistance, higher
bandwidth, low power consumption and low leakage currents.
ADG741/ADG742 Supply Voltages
Functionality of the ADG741/ADG742 extends from 1.8 V to
5.5 V single supply, which makes it ideal for battery-powered
instruments, where important design parameters are power
efficiency and performance.
It is important to note that the supply voltage effects the input
signal range, the on resistance, and the switching times of the
part. By looking at the typical performance characteristics
and the specifications, the effects of the power supplies can
be clearly seen.
For V
DD
= 1.8 V operation, R
ON
is typically 40
over the tem-
perature range.
On Response vs. Frequency
Figure 1 illustrates the parasitic components that affect the ac
performance of CMOS switches (the switch is shown surrounded
by a box). Additional external capacitances will further degrade
some performance. These capacitances affect feedthrough,
crosstalk and system bandwidth.
S
V
IN
D
C
DS
R
ON
C
D
C
LOAD
R
LOAD
V
OUT
Figure 1. Switch Represented by Equivalent Parasitic
Components
The transfer function that describes the equivalent diagram of
the switch (Figure 1) is of the form (A)s shown below.
A
(
s
)
=
R
T
s
(
R
ON
C
DS
)
+
1
s
(
R
ON
C
T
R
T
)
+
1
where:
C
T
= C
LOAD
+ C
D
+ C
DS
R
T
= R
LOAD
/(R
LOAD
+ R
ON
)
The signal transfer characteristic is dependent on the switch
channel capacitance, C
DS
. This capacitance creates a frequency
zero in the numerator of the transfer function A(s). Because the
switch on resistance is small, this zero usually occurs at high
frequencies. The bandwidth is a function of the switch output
capacitance combined with C
DS
and the load capacitance. The
frequency pole corresponding to these capacitances appears in
the denominator of A(s).
The dominant effect of the output capacitance, C
D
, causes the
pole breakpoint frequency to occur first. Therefore, in order to
maximize bandwidth a switch must have a low input and output
capacitance and low on resistance. The On Response vs. Fre-
quency plot for the ADG741/ADG742 can be seen in TPC 6.
Off Isolation
Off isolation is a measure of the input signal coupled through an
off switch to the switch output. The capacitance, C
DS
, couples
the input signal to the output load, when the switch is off, as
shown in Figure 2.
S
V
IN
D
C
DS
C
D
C
LOAD
R
LOAD
V
OUT
Figure 2. Off Isolation Is Affected by External Load Resis-
tance and Capacitance
The larger the value of C
DS
, larger values of feedthrough will be
produced. The typical performance characteristic graph of TPC 5
illustrates the drop in off-isolation as a function of frequency. From
dc to roughly 1 MHz, the switch shows better than
75 dB isola-
tion. Up to frequencies of 10 MHz, the off isolation remains better
than
55 dB. As the frequency increases, more and more of the
input signal is coupled through to the output. Off-isolation can be
maximized by choosing a switch with the smallest C
DS
as possible.
The values of load resistance and capacitance affect off isolation
also, as they contribute to the coefficients of the poles and zeros
in the transfer function of the switch when open.
A
(
s
)
=
s
(
R
LOAD
C
DS
)
s
(
R
LOAD
)(
C
T
)
+
1
OUTLINE DIMENSIONS
Dimensions shown in inches and (mm).
C
P
6-Lead Plastic Surface Mount
(SC70)
0.007 (0.18)
0.004 (0.10)
0.012 (0.30)
0.004 (0.10)
8
0
0.012 (0.30)
0.006 (0.15)
0.004 (0.10)
0.000 (0.00)
0.039 (1.00)
0.031 (0.80)
SEATING
PLANE
0.043 (1.10)
0.031 (0.80)
3
5
4
2
6
1
0.087 (2.20)
0.071 (1.80)
PIN 1
0.094 (2.40)
0.071 (1.80)
0.026 (0.65) BSC
0.053 (1.35)
0.045 (1.15)
0.051 (1.30)
BSC
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相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
ADG741BKS 制造商:AD 制造商全稱:Analog Devices 功能描述:CMOS Low Voltage 2ohm SPST Switches in SC70 Packages
ADG741BKS-R2 制造商:Analog Devices 功能描述: 制造商:Rochester Electronics LLC 功能描述:
ADG741BKS-REEL 制造商:Rochester Electronics LLC 功能描述: 制造商:Analog Devices 功能描述:
adg741bks-reel7 制造商:Rochester Electronics LLC 功能描述: 制造商:Analog Devices 功能描述:
ADG741BKSZ5-REEL 功能描述:IC SWITCH SPST SC70-5 RoHS:是 類別:集成電路 (IC) >> 接口 - 模擬開關(guān),多路復(fù)用器,多路分解器 系列:- 標(biāo)準(zhǔn)包裝:1,000 系列:- 功能:多路復(fù)用器 電路:1 x 4:1 導(dǎo)通狀態(tài)電阻:- 電壓電源:雙電源 電壓 - 電源,單路/雙路(±):±5V 電流 - 電源:7mA 工作溫度:-40°C ~ 85°C 安裝類型:表面貼裝 封裝/外殼:16-SOIC(0.154",3.90mm 寬) 供應(yīng)商設(shè)備封裝:16-SOIC 包裝:帶卷 (TR)