參數(shù)資料
型號: ADS1252U
英文描述: 24-Bit, 40kHz ANALOG-TO-DIGITAL CONVERTER
中文描述: 24位40kHz的模擬到數(shù)字轉(zhuǎn)換器
文件頁數(shù): 10/14頁
文件大?。?/td> 131K
代理商: ADS1252U
10
ADS1252
to DOUT mode. Data would be shifted out on the pin after
t
7
. The device communicating with the ADS1252 can pro-
vide SCLKs to the ADS1252 after the time defined by t
6
.
The normal mode of reading data from the ADS1252 would
be for the device reading the ADS1252 to latch the data on
the rising edge of SCLK (since data is shifted out of the
ADS1252 on the falling edge of SCLK). In order to retrieve
valid data, the entire DOR must be read before the
DOUT/DRDY pin reverts back to DRDY mode.
If SCLKs were not provided to the ADS1252 during the
DOUT mode, the MSB of the DOR would be present on the
DOUT/DRDY line until the time defined by t
4
. If an incom-
plete read of the ADS1252 took place while in DOUT mode
(i.e., less than 24 SCLKs were provided), the state of the last
bit read would be present on the DOUT/DRDY line until the
time defined by t
4
. If more than 24 SCLKs were provided
during DOUT mode, the DOUT/DRDY line would stay
LOW until the time defined by t
4
.
The internal data pointer for shifting data out on
DOUT/DRDY is reset on the falling edge of the time defined
by t
1
and t
4
. This ensures that the first bit of data shifted out
of the ADS1252 after DRDY mode is always the MSB of
new data.
SYNCHRONIZING MULTIPLE CONVERTERS
The normal state of SCLK is LOW. However, by holding
SCLK HIGH, multiple ADS1252s can be synchronized.
This is accomplished by holding SCLK HIGH for at least
four, but less than twenty, consecutive DOUT/DRDY cycles
(see Figure 13). After the ADS1252 circuitry detects that
SCLK has been held HIGH for four consecutive
DOUT/DRDY cycles, the DOUT/DRDY pin will pulse
LOW for 3 CLK cycles and then be held HIGH, and the
modulator will be held in a reset state. The modulator will be
released from reset and synchronization will occur on the
falling edge of SCLK. It is important to note that prior to
synchronization, the DOUT/DRDY pulse of multiple
ADS1252s in the system could have a difference in timing
up to one DRDY period. Therefore to ensure synchroniza-
tion, the SCLK should be held HIGH for at least five DRDY
cycles. The first DOUT/DRDY pulse after the falling edge
of SCLK will occur at t
14
. Valid data will not be present until
the sixth DOUT/DRDY pulse.
POWER-DOWN MODE
The normal state of SCLK is LOW. However, by holding
SCLK HIGH, the ADS1252 will enter power-down mode.
This is accomplished by holding SCLK HIGH for at least
twenty consecutive DOUT/DRDY periods (see Figure 14).
After the ADS1252 circuitry detects that SCLK has been
held HIGH for four consecutive DOUT/DRDY cycles, the
DOUT/DRDY pin will pulse LOW for 3 CLK cycles and
then be held HIGH, and the modulator will be held in a reset
state. If SCLK is held HIGH for an additional sixteen
DOUT/DRDY periods, the ADS1252 will enter power-
down mode. The part will be released from power-down
mode on the falling edge of SCLK. It is important to note
that the DOUT/DRDY pin will be held HIGH after four
DOUT/DRDY cycles, but power-down mode will not be
entered for an additional sixteen DOUT/DRDY periods. The
first DOUT/DRDY pulse after the falling edge of SCLK will
occur at t
16
. Subsequent DOUT/DRDY pulses will occur
normally. Valid data will not be present until the sixth
DOUT/DRDY pulse.
SERIAL INTERFACE
The ADS1252 includes a simple serial interface which can
be connected to microcontrollers and digital signal proces-
sors in a variety of ways. Communications with the ADS1252
can commence on the first detection of the DOUT/DRDY
pulse after power up, although data will not be valid until the
sixth conversion.
It is important to note that the data from the ADS1252 is a
24-bit result transmitted MSB-first in Offset Two’s Comple-
ment format, as shown in Table III.
TABLE III. ADS1252 Data Format (Offset Two's Comple-
ment).
DIFFERENTIAL VOLTAGE INPUT
DIGITAL OUTPUT (HEX)
+Fulll Scale
Zero
–Full Scale
7FFFFFH
000000H
800000H
FIGURE 11. DOUT/DRDY Partitioning.
DATA
DRDY Mode
DOUT Mode
DOUT Mode
DATA
DATA
t
4
t
2
t
3
t
1
DRDY Mode
DOUT/DRDY
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相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
ADS1252U 制造商:Texas Instruments 功能描述:IC 24BIT ADC 41.7KSPS SMD
ADS1252U/2K5 功能描述:模數(shù)轉(zhuǎn)換器 - ADC ResolutionPlus 24-Bit 40kHz 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
ADS1252U/2K5G4 功能描述:模數(shù)轉(zhuǎn)換器 - ADC ResolutionPlus 24-Bit 40kHz 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
ADS1252UG4 功能描述:模數(shù)轉(zhuǎn)換器 - ADC ResolutionPlus 24-Bit 40kHz 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
ADS1253 制造商:TI 制造商全稱:Texas Instruments 功能描述:24-Bit, 20kHz, Low Power ANALOG-TO-DIGITAL CONVERTER