參數(shù)資料
型號(hào)： AD9878BSTZ
廠商： Analog Devices Inc
文件頁(yè)數(shù)： 21/36頁(yè)
文件大?。?/td> 0K
描述： IC FRONT-END MIXED-SGNL 100-LQFP
產(chǎn)品變化通告： AD9878BSTZ Discontinuation 21/Nov/2011
標(biāo)準(zhǔn)包裝： 1
位數(shù)： 12
通道數(shù)： 4
功率（瓦特）： 673mW
電壓 - 電源，模擬： 3.3V
電壓 - 電源，數(shù)字： 3.3V
封裝/外殼： 100-LQFP
供應(yīng)商設(shè)備封裝： 100-LQFP（14x14）
包裝： 托盤(pán)
AD9878
Rev. A | Page 28 of 36
Driving the Input
The IF ADCs have differential switched capacitor sample-and-
hold amplifier (SHA) inputs. The nominal differential input
impedance is 4.0 k||3 pF. This impedance can be used as the
effective termination impedance when calculating filter transfer
characteristics and voltage signal attenuation from nonzero source
impedances. For best performance, additional requirements must
be met by the signal source. The SHA has input capacitors that
must be recharged each time the input is sampled. This results in
a dynamic input current at the device input, and demands that
the source has low (<50 ) output impedance at frequencies up
to the ADC sampling frequency. Also, the source must have
settling of better than 0.1% in less than half the ADC clock period.
Another consideration for getting the best performance from the
ADC inputs is the dc biasing of the input signal. Ideally, the signal
should be biased to a dc level equal to the midpoint of the ADC
reference voltages, REFT12 and REFB12. Nominally, this level is
1.2 V. When ac-coupled, the ADC inputs self-bias to this voltage
and require no additional input circuitry. Figure 35 illustrates a
recommended circuit that eases the burden on the signal source
by isolating its output from the ADC input. The 33 series
termination resistors isolate the amplifier outputs from any
capacitive load, which typically improves settling time. The series
capacitors provide ac signal coupling, which ensures that the
ADC inputs operate at the optimal dc-bias voltage. The shunt
capacitor sources the dynamic currents required to charge the
SHA input capacitors, removing this requirement from the ADC
buffer. The values of CC and CS should be calculated to
determine the correct HPF and LPF corner frequencies.
AIN+
AIN–
33
CC
CS
CC
VS
33
03277-019
Figure 35. Simple ADC Drive Configuration
Receive Timing
The AD9878 sends multiplexed data to the IF10 and IF12 outputs
upon every rising edge of MCLK. RxSYNC frames the start of
each IF10 data symbol. The 10-bit and 12-bit ADCs are read
completely upon every second MCLK cycle. RxSYNC is high
for every second 10-bit ADC data if the 10-bit ADC is not in
power-down mode. The Rx timing diagram is shown in Figure 36.
tOD
tEE
tMD
REFCLK
MCLK
IF10 DATA
IF10[9:5] IF10[4:0] IF10[9:5] IF10[4:0]
M/N = 2
IF10[9:5] IF10[4:0]
IF12A
IF12B
IF12A
IF12B
RxSYNC
IF12 DATA
Rx PORT TIMING (DEFAULT MODE: MUXED IF12 ADC DATA)
M/N = 2
REFCLK
IF12A OR IF12B
IF10[9:5]
IF10[4:0]
IF10[9:5]
IF10[4:0]
IF10[9:5]
IF10[4:0]
IF12A OR IF12B
MCLK
IF10 DATA
RxSYNC
IF DATA
tMD
tEE
tOD
Rx PORT TIMING (OUTPUT DATA FROM ONLY ONE IF12 ADC)
03277-020
Figure 36. Rx Port Timing
相關(guān)PDF資料
PDF描述
AD9879BSZ IC PROCESSOR FRONT END 100MQFP
AD9901KQ IC PHASE/FREQ DISCRIMR 14-CDIP
AD9920ABBCZRL IC PROCESSOR CCD 12BIT 105CSPBGA
AD9978BCPZRL IC PROCESSOR CCD 14BIT 40-LFCSP
ADADC71KD IC ADC 16BIT HIGH RES 32-CDIP
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
AD9878-EB 制造商:Analog Devices 功能描述:EVAL KIT FOR MIXED-SGNL FRONT END FOR BROADBAND APPLICATIONS - Bulk
AD9879 制造商:AD 制造商全稱:Analog Devices 功能描述:Mixed-Signal Front End Set-Top Box, Cable Modem
AD9879_05 制造商:AD 制造商全稱:Analog Devices 功能描述:Mixed-Signal Front End Set-Top Box, Cable Modem
AD9879BS 制造商:Analog Devices 功能描述:
AD9879BSZ 功能描述:IC PROCESSOR FRONT END 100MQFP RoHS:是 類別:集成電路 (IC) >> 數(shù)據(jù)采集 - 模擬前端 (AFE) 系列:- 產(chǎn)品培訓(xùn)模塊:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 標(biāo)準(zhǔn)包裝:2,500 系列:- 位數(shù):- 通道數(shù):2 功率（瓦特）:- 電壓 - 電源，模擬:3 V ~ 3.6 V 電壓 - 電源，數(shù)字:3 V ~ 3.6 V 封裝/外殼:32-VFQFN 裸露焊盤(pán) 供應(yīng)商設(shè)備封裝:32-QFN（5x5） 包裝:帶卷 (TR)
發(fā)布緊急采購(gòu)，3分鐘左右您將得到回復(fù)。

采購(gòu)需求

(若只采購(gòu)一條型號(hào)，填寫(xiě)一行即可)

發(fā)布成功！您可以繼續(xù)發(fā)布采購(gòu)。也可以進(jìn)入我的后臺(tái)，查看報(bào)價(jià)

發(fā)布成功！您可以繼續(xù)發(fā)布采購(gòu)。也可以進(jìn)入我的后臺(tái)，查看報(bào)價(jià)

*型號(hào) *數(shù)量 廠商 批號(hào) 封裝
添加更多采購(gòu)

我的聯(lián)系方式

*
*
*