參數(shù)資料
型號: TLC540I
廠商: Texas Instruments, Inc.
英文描述: MOSFET N-CH 100V 41A TO-247AC
中文描述: 8位模擬到數(shù)字與串行控制和11變換器輸入端
文件頁數(shù): 9/11頁
文件大?。?/td> 164K
代理商: TLC540I
TLC540I, TLC541I
8-BIT ANALOG-TO-DIGITAL CONVERTERS
WITH SERIAL CONTROL AND 11 INPUTS
SLAS065A – OCTOBER 1983 – REVISED MARCH 1995
9
POST OFFICE BOX 655303
DALLAS, TEXAS 75265
PRINCIPLES OF OPERATION
The TLC540 and TLC541 are each complete data acquisition systems on a single chip. They include such functions
as analog multiplexer, sample and hold, 8-bit A/D converter, data and control registers, and control logic. For flexibility
and access speed, there are four control inputs [two clocks, chip select (CS), and address]. These control inputs and
a TTL-compatible 3-state output are intended for serial communications with a microprocessor or microcomputer.
With judicious interface timing, with TLC540 a conversion can be completed in 9
μ
s, while complete
input-conversion-output cycles can be repeated every 13
μ
s. With TLC541 a conversion can be completed in 17
μ
s,
while complete input-conversion-output cycles are repeated every 25
μ
s. Furthermore, this fast conversion can be
executed on any of 11 inputs or its built-in self-test and in any order desired by the controlling processor.
The system and I/O clocks are normally used independently and do not require any special speed or phase
relationships between them. This independence simplifies the hardware and software control tasks for the device.
Once a clock signal within the specification range is applied to SYSTEM CLOCK, the control hardware and software
need only be concerned with addressing the desired analog channel, reading the previous conversion result, and
starting the conversion by using I/O CLOCK. SYSTEM CLOCK will drive the conversion crunching circuitry so that
the control hardware and software need not be concerned with this task.
When CS is high, DATA OUT is in a 3-state condition and ADDRESS INPUT and I/O CLOCK are disabled. This feature
allows each of these terminals, with the exception of CS, to share a control logic point with their counterpart terminals
on additional A/D devices when additional TLC540/541 devices are used. In this way, the above feature serves to
minimize the required control logic terminals when using multiple A/D devices.
The control sequence has been designed to minimize the time and effort required to initiate conversion and obtain
the conversion result. A normal control sequence is:
1.
CS is brought low. To minimize errors caused by noise at CS, the internal circuitry waits for two rising edges
and then a falling edge of SYSTEM CLOCK after a low CS transition, before the low transition is recognized.
This technique is used to protect the device against noise when the device is used in a noisy environment.
The MSB of the previous conversion result automatically appears on DATA OUT.
2.
A new positive-logic multiplexer address is shifted in on the first four rising edges of I/O CLOCK. The MSB
of the address is shifted in first. The negative edges of these four I/O clock pulses shift out the second, third,
fourth, and fifth most significant bits of the previous conversion result. The on-chip sample and hold begins
sampling the newly addressed analog input after the fourth falling edge. The sampling operation basically
involves the charging of internal capacitors to the level of the analog input voltage.
3.
Three clock cycles are then applied to I/O CLOCK and the sixth, seventh, and eighth conversion bits are
shifted out on the negative edges of these clock cycles.
4.
The final eighth clock cycle is applied to I/O CLOCK. The falling edge of this clock cycle completes the
analog sampling process and initiates the hold function. Conversion is then performed during the next 36
system clock cycles. After this final I/O clock cycle, CS must go high or the I/O CLOCK must remain low
for at least 36 system clock cycles to allow for the conversion function.
CS can be kept low during periods of multiple conversion. When keeping CS low during periods of multiple
conversion, special care must be exercised to prevent noise glitches on I/O CLOCK. If glitches occur on I/O CLOCK,
the I/O sequence between the microprocessor/controller and the device loses synchronization. Also, if CS is taken
high, it must remain high until the end of the conversion. Otherwise, a valid falling edge of CS causes a reset condition,
which aborts the conversion in progress.
A new conversion can be started and the ongoing conversion simultaneously aborted by performing steps 1 through
4 before the 36 system clock cycles occur. Such action yields the conversion result of the previous conversion and
not the ongoing conversion.
相關(guān)PDF資料
PDF描述
TLC541I 8-BIT ANALOG-TO-DIGITAL CONVERTERS WITH SERIAL CONTROL AND 11 INPUTS
TLC542(中文) 8-Bit Analog-To-Digital Converters With Serial Control And 11 Inputs(串行控制,40ksps,12通道,8位ADC)
TLC542C 8-BIT ANALOG-TO-DIGITAL CONVERTERS WITH SERIAL CONTROL AND 11 INPUTS
TLC542I 8-BIT ANALOG-TO-DIGITAL CONVERTERS WITH SERIAL CONTROL AND 11 INPUTS
TLC545(中文) 8-Bit Analog-To-Digital Converters With Serial Control And 11 Inputs(串行控制,76ksps,20通道,8位ADC)
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TLC540IDWG4 功能描述:模數(shù)轉(zhuǎn)換器 - ADC 8Bit 75kSPS Serial Out On-Chip 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 安裝風格:SMD/SMT 封裝 / 箱體:VQFN-32
TLC540IDWR 功能描述:模數(shù)轉(zhuǎn)換器 - ADC 8Bit 75kSPS Serial Out On-Chip 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 安裝風格:SMD/SMT 封裝 / 箱體:VQFN-32
TLC540IDWRG4 功能描述:模數(shù)轉(zhuǎn)換器 - ADC 8Bit 75kSPS Serial Out On-Chip 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 安裝風格:SMD/SMT 封裝 / 箱體:VQFN-32
TLC540IFN 功能描述:模數(shù)轉(zhuǎn)換器 - ADC 8bit 11Chl A/D 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 安裝風格:SMD/SMT 封裝 / 箱體:VQFN-32