參數(shù)資料
型號: TLC2554CD
廠商: TEXAS INSTRUMENTS INC
元件分類: ADC
英文描述: 4-CH 12-BIT SUCCESSIVE APPROXIMATION ADC, SERIAL ACCESS, PDSO16
封裝: GREEN, PLASTIC, MS-012AC, SOIC-16
文件頁數(shù): 27/48頁
文件大小: 1072K
代理商: TLC2554CD
TLC2554, TLC2558
5-V, 12-BIT, 400 KSPS, 4/8 CHANNEL, LOW POWER,
SERIAL ANALOG-TO-DIGITAL CONVERTERS WITH AUTO POWER DOWN
SLAS220A –JUNE 1999
33
POST OFFICE BOX 655303
DALLAS, TEXAS 75265
PRINCIPLES OF OPERATION
Rs
ri
VS
VC
Driving Source
TLC2554/58
Ci
VI
VI = Input Voltage at AIN
VS = External Driving Source Voltage
Rs = Source Resistance
ri = Input Resistance (MUX on Resistance)
Ci = Input Capacitance
VC= Capacitance Charging Voltage
Driving source requirements:
Noise and distortion for the source must be equivalent to the resolution of the converter.
Rs must be real at the input frequency.
Figure 37. Equivalent Input Circuit Including the Driving Source
maximum conversion throughput
For a supply voltage of 5 V, if the source impedance is less than 1 k
, and the ADC analog input capacitance
Ci is less than 50 pF, this equates to a minimum sampling time tch(0.5 LSB) of 0.676
s. Since the sampling
time requires 12 SCLKs, the fastest SCLK frequency is 12/tch = 18 MHz.
The minimal total cycle time is given as:
tc
+ tcommand ) tch ) tconv ) td(EOCH–CSL) + 4
1
f (SCLK)
) 12
1
f (SCLK)
) 1.6 ms ) 0.1 ms
+ 16
1
18
MHz
) 1.7 ms + 2.59 ms
This is equivalent to a maximum throughput of 386 KSPS. The throughput can be even higher with a smaller
source impedance.
When source impedance is 100
, the minimum sampling time becomes:
tch (1 2 LSB)
+ Rt
Ci
In(8192)
+ 0.27 ms
The maximum SCLK frequency possible is 12/tch = 44 MHz. Then a 20 MHz clock (maximum SCLK frequency
for the TLC2554/2548 ) can be used. The minimal total cycle time is then reduced to:
tc
+ tcommand ) tch ) tconv ) td(EOCH–CSL) + 4
1
f (SCLK)
) 12
1
f (SCLK)
) 1.6 ms ) 0.1 ms
+ 0.8 ms ) 1.6 ms ) 0.1 ms + 2.5 ms
The maximum throughput is 1/2.5
s = 400 KSPS for this case.
相關(guān)PDF資料
PDF描述
TLC2554CDR 4-CH 12-BIT SUCCESSIVE APPROXIMATION ADC, SERIAL ACCESS, PDSO16
TLC2554IPW 4-CH 12-BIT SUCCESSIVE APPROXIMATION ADC, SERIAL ACCESS, PDSO16
TLC2558CDWR 8-CH 12-BIT SUCCESSIVE APPROXIMATION ADC, SERIAL ACCESS, PDSO20
TLC2558IPWRG4 8-CH 12-BIT SUCCESSIVE APPROXIMATION ADC, SERIAL ACCESS, PDSO20
TLC2558IDWG4 8-CH 12-BIT SUCCESSIVE APPROXIMATION ADC, SERIAL ACCESS, PDSO20
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
TLC2554CDG4 功能描述:模數(shù)轉(zhuǎn)換器 - ADC 12-bit 400 KSPS 4-Ch Serial w/Powerdown RoHS:否 制造商:Texas Instruments 通道數(shù)量:2 結(jié)構(gòu):Sigma-Delta 轉(zhuǎn)換速率:125 SPs to 8 KSPs 分辨率:24 bit 輸入類型:Differential 信噪比:107 dB 接口類型:SPI 工作電源電壓:1.7 V to 3.6 V, 2.7 V to 5.25 V 最大工作溫度:+ 85 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:VQFN-32
TLC2554CDR 功能描述:模數(shù)轉(zhuǎn)換器 - ADC 12-bit 400 KSPS 4-Ch Serial w/Powerdown RoHS:否 制造商:Texas Instruments 通道數(shù)量:2 結(jié)構(gòu):Sigma-Delta 轉(zhuǎn)換速率:125 SPs to 8 KSPs 分辨率:24 bit 輸入類型:Differential 信噪比:107 dB 接口類型:SPI 工作電源電壓:1.7 V to 3.6 V, 2.7 V to 5.25 V 最大工作溫度:+ 85 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:VQFN-32
TLC2554CDRG4 功能描述:模數(shù)轉(zhuǎn)換器 - ADC 12-bit 400 KSPS 4-Ch Serial w/Powerdown RoHS:否 制造商:Texas Instruments 通道數(shù)量:2 結(jié)構(gòu):Sigma-Delta 轉(zhuǎn)換速率:125 SPs to 8 KSPs 分辨率:24 bit 輸入類型:Differential 信噪比:107 dB 接口類型:SPI 工作電源電壓:1.7 V to 3.6 V, 2.7 V to 5.25 V 最大工作溫度:+ 85 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:VQFN-32
TLC2554CPW 功能描述:模數(shù)轉(zhuǎn)換器 - ADC 12-bit 400 KSPS 4-Ch Serial w/Powerdown RoHS:否 制造商:Texas Instruments 通道數(shù)量:2 結(jié)構(gòu):Sigma-Delta 轉(zhuǎn)換速率:125 SPs to 8 KSPs 分辨率:24 bit 輸入類型:Differential 信噪比:107 dB 接口類型:SPI 工作電源電壓:1.7 V to 3.6 V, 2.7 V to 5.25 V 最大工作溫度:+ 85 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:VQFN-32
TLC2554CPWG4 功能描述:模數(shù)轉(zhuǎn)換器 - ADC 12-bit 400 KSPS 4-Ch Serial w/Powerdown RoHS:否 制造商:Texas Instruments 通道數(shù)量:2 結(jié)構(gòu):Sigma-Delta 轉(zhuǎn)換速率:125 SPs to 8 KSPs 分辨率:24 bit 輸入類型:Differential 信噪比:107 dB 接口類型:SPI 工作電源電壓:1.7 V to 3.6 V, 2.7 V to 5.25 V 最大工作溫度:+ 85 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:VQFN-32