參數(shù)資料
型號: AD8187ARUZ
廠商: Analog Devices Inc
文件頁數(shù): 6/20頁
文件大?。?/td> 0K
描述: IC MULTIPLEXER TRPL 2X1 24TSSOP
標(biāo)準(zhǔn)包裝: 62
功能: 多路復(fù)用器
電路: 3 x 2:1
電壓電源: 單電源
電壓 - 電源,單路/雙路(±): 3.5 V ~ 5.5 V
工作溫度: -40°C ~ 85°C
安裝類型: 表面貼裝
封裝/外殼: 24-TSSOP(0.173",4.40mm 寬)
供應(yīng)商設(shè)備封裝: 24-TSSOP
包裝: 管件
REV. A
–14–
AD8186/AD8187
AC-Coupled Inputs (DC Restore before Mux Input)
Using ac-coupled inputs presents an interesting challenge for video
systems operating from a single 5 V supply. In NTSC and PAL
video systems, 700 mV is the approximate difference between the
maximum signal voltage and black level. It is assumed that sync
has been stripped. However, given the two pathological cases
shown in Figure 7, a dynamic range of twice the maximum signal
swing is required if the inputs are to be ac-coupled. A possible
solution would be to use a dc restore circuit before the mux.
VREF
+700mV
VAVG
+5 V
VSIGNAL
GND
VINPUT = VREF + VSIGNAL
VREF ~ VAVG
VREF IS A DC VOLTAGE
SET BY THE RESISTORS
BLACK LINE WITH WHITE PIXEL
–700mV
WHITE LINE WITH BLACK PIXEL
VAVG
VREF
Figure 7. Pathological Case for
Input Dynamic Range
Tolerance to Capacitive Load
Op amps are sensitive to reactive loads. A capacitive load at the
output appears in parallel with an effective resistance of REFF =
(RL rO), where RL is the discrete resistive load, and rO is the open-
loop output impedance, approximately 15
for these muxes.
The load pole, at fLOAD = 1/(2 REFF CL), can seriously degrade
phase margin and therefore stability. The old workaround is to
place a small series resistance directly at the output to isolate the
load pole. While effective, this ruse also affects the dc and termina-
tion characteristics of a 75
system. The AD8186 and AD8187
are built with a variable compensation scheme that senses the
output reactance and trades bandwidth for phase margin, ensuring
faster settling and lower overshoot at higher capacitive loads.
Secondary Supplies and Supply Bypassing
The high current output transistors are given their own supply
pins (Pins 15, 17, 19, and 21) to reduce supply noise on-chip
and to improve output isolation. Since these secondary, high
current supply pins are not connected on-chip to the primary
analog supplies (VCC/VEE, Pins 6, 7, 9, 11, 13, and 24), some
care should be taken to ensure that the supply bypass capacitors
are connected to the correct pins. At a minimum, the primary
supplies should be bypassed. Pin 6 and Pin 7 may be a convenient
place to accomplish this. Stacked power and ground planes could
be a convenient way to bypass the high current supply pins.
IN0A
DGND
VREF
OUT 0
OUT 1
OUT 2
IN1A
IN2A
IN2B
IN1B
IN0B
VCC
VEE
VCC
OE
SEL A/
B
VEE
VCC
VEE
DVCC
MUX0
MUX1
MUX2
1
2
3
4
5
6
7
8
9
10
11
12
24
23
22
21
20
19
18
17
16
15
14
13
1 F
0.1 F
Figure 8. Detail of Primary and Secondary Supplies
Split-Supply Operation
Operating from split supplies (e.g., +3 V/–2 V or
±2.5 V) simpli-
fies the selection of the VREF voltage and load resistor termination
voltage. In this case, it is convenient to tie VREF to ground.
The logic inputs are level shifted internally to allow the digital
supplies and logic inputs to operate from 0 V and 5 V when
powering the analog circuits from split supplies. The maximum
voltage difference between DVCC and VEE must not exceed 8 V
(see Figure 9).
DVCC
(+5)
DGND
SPLIT-SUPPLY OPERATION
DIGITAL SUPPLIES
(0V)
8V MAX
ANALOG SUPPLIES
(+2.5)
(–2.5)
VCC
VEE
Figure 9. Split-Supply Operation
相關(guān)PDF資料
PDF描述
AD8189ARUZ IC MULTIPLEXER TRPL 2X1 24TSSOP
AD8190ACPZ IC SW HDMI/DVI 2:1 EQUAL 56LFCSP
AD8191AASTZ IC HDMI/DVI SWITCH 4:1 100LQFP
AD8191ASTZ IC INTERFACE HDMI/DVI 100-LQFP
AD8192ACPZ-RL7 IC SW MUX HDMI/DVI 2:1 56LFCSP
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
AD8187ARUZ-REEL 功能描述:IC MULTIPLEXER TRPL 2X1 24TSSOP 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)
AD8187ARUZ-REEL7 功能描述:IC MULTIPLEXER TRPL 2X1 24TSSOP 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)
AD8187-EVAL 制造商:Analog Devices 功能描述:Accessories, Analog multiplexer, Triple 2:1, 5.5V 制造商:Analog Devices 功能描述:TSSOP TRIPLE 2:1 G=+2 SINGLE SUPPLY MUX - Bulk
AD8187TFBS 制造商:POP 功能描述:
AD8188 制造商:AD 制造商全稱:Analog Devices 功能描述:350 MHz Single-Supply (5 V) Triple 2:1 Multiplexers