- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄362144 > ADS7807UBE4 Low-Power, 16-Bit, Sampling CMOS ANALOG-to-DIGITAL CONVERTER PDF資料下載
參數(shù)資料
| 型號： | ADS7807UBE4 |
| 英文描述： | Low-Power, 16-Bit, Sampling CMOS ANALOG-to-DIGITAL CONVERTER |
| 中文描述： | 低功耗，16位，采樣CMOS模擬數(shù)字轉(zhuǎn)換器 |
| 文件頁數(shù)： | 18/24頁 |
| 文件大?。?/td> | 534K |
| 代理商： | ADS7807UBE4 |
ADS7807
SBAS022C
18
www.ti.com
QSPI
INTERFACING
Figure 14 shows a simple interface between the ADS7807
and any QSPI equipped microcontroller. This interface as-
sumes that the convert pulse does not originate from the
microcontroller and that the ADS7807 is the only serial
peripheral.
Before enabling the QSPI interface, the microcontroller must
be configured to monitor the slave select line. When a
transition from LOW to HIGH occurs on Slave Select (
SS
)
from
BUSY
(indicating the end of the current conversion), the
port can be enabled. If this is not done, the microcontroller
and the A/D converter may be
“
out-of-sync
”
.
Figure 15 shows another interface between the ADS7807
and a QSPI equipped microcontroller which allows the
microcontroller to give the convert pulses while also allowing
multiple peripherals to be connected to the serial bus. This
interface and the following discussion assume a master clock
for the QSPI interface of 16.78MHz. Notice that the serial
data input of the microcontroller is tied to the MSB (D7) of the
ADS7807 instead of the serial output (SDATA). Using D7
instead of the serial port offers tri-state capability which
allows other peripherals to be connected to the MISO pin.
When communication is desired with those peripherals, PCS0
and PCS1 should be left HIGH; that will keep D7 tri-stated.
In this configuration, the QSPI interface is actually set to do
two different serial transfers. The first, an 8-bit transfer, causes
PCS0 (
R/C
) and PCS1 (
CS
) to go LOW, starting a conver-
sion. The second, a 16-bit transfer, causes only PCS1 (
CS
) to
go LOW. This is when the valid data will be transferred.
For both transfers, the DT register (delay after transfer) is
used to cause a 19
μ
s delay. The interface is also set up to
wrap to the beginning of the queue. In this manner, the QSPI
is a state machine which generates the appropriate timing for
the ADS7807. This timing is thus locked to the crystal-based
timing of the microcontroller and not interrupt driven. So, this
interface is appropriate for both AC and DC measurements.
For the fastest conversion rate, the baud rate should be set
to 2 (4.19MHz SCK), DT set to 10, the first serial transfer set
to 8 bits, the second set to 16 bits, and DSCK disabled (in the
command control byte). This will allow for a 23kHz maximum
conversion rate. For slower rates, DT should be increased.
Do not slow SCK as this may increase the chance of
affecting the conversion results or accidently initiating a
second conversion during the first 8-bit transfer.
In addition, CPOL and CPHA should be set to zero (SCK
normally LOW and data captured on the rising edge). The
command control byte for the 8-bit transfer should be set to
20
H
and for the 16-bit transfer to 61
H
.
SPI
INTERFACE
The SPI interface is generally only capable of 8-bit data
transfers. For some microcontrollers with SPI interfaces, it
might be possible to receive data in a similar manner as
shown for the QSPI interface in Figure 14. The microcontroller
will need to fetch the 8 most significant bits before the
contents are overwritten by the least significant bits.
A modified version of the QSPI interface shown in Figure 15
might be possible. For most microcontrollers with SPI inter-
face, the automatic generation of the start-of-conversion
pulse will be impossible and will have to be done with
software. This will limit the interface to
‘
DC
’
applications due
to the insufficient jitter performance of the convert pulse
itself.
FIGURE 15. QSPI Interface to the ADS7807. Processor
Initiates Conversions.
FIGURE 14. QSPI Interface to the ADS7807.
QSPI is a registered trademark of Motorola.
SPI is a registered trademark of Motorola.
R/C
BUSY
SDATA
DATACLK
CS
EXT/INT
BYTE
ADS7807
PCS0/SS
MOSI
SCK
QSPI
CPOL = 0 (Inactive State is LOW)
CPHA = 1 (Data valid on falling edge)
QSPI port is in slave mode.
Convert Pulse
QSPI is a registered trademark of Motorola.
R/C
CS
DATACLK
D7 (MSB)
BYTE
ADS7807
PCS0
PCS1
SCK
MISO
QSPI
CPOL = 0
CPHA = 0
EXT/INT
+5V
QSPI is a registered trademark of Motorola.
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| ADS7807UBG4 | Low-Power, 16-Bit, Sampling CMOS ANALOG-to-DIGITAL CONVERTER |
| ADS7807UE4 | Low-Power, 16-Bit, Sampling CMOS ANALOG-to-DIGITAL CONVERTER |
| ADS7807PBG4 | Low-Power, 16-Bit, Sampling CMOS ANALOG-to-DIGITAL CONVERTER |
| ADS7807PG4 | Low-Power, 16-Bit, Sampling CMOS ANALOG-to-DIGITAL CONVERTER |
| ADS7808UBE4 | 12-Bit 10us Serial CMOS Sampling ANALOG-to-DIGITAL CONVERTER |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| ADS7807UBG4 | 功能描述:模數(shù)轉(zhuǎn)換器 - ADC Low-Power 16-Bit Sampling CMOS 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 |
| ADS7807UE4 | 功能描述:模數(shù)轉(zhuǎn)換器 - ADC Low-Power 16-Bit Sampling CMOS 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 |
| ADS7807UG4 | 功能描述:IC 16BIT 40KHZ SMPL ADC 28-SOIC 制造商:texas instruments 系列:- 包裝:管件 零件狀態(tài):在售 位數(shù):16 采樣率（每秒）:40k 輸入數(shù):1 輸入類型:單端 數(shù)據(jù)接口:SPI，并聯(lián) 配置:S/H-ADC 無線電 - S/H:ADC:1:1 A/D 轉(zhuǎn)換器數(shù):1 架構(gòu):SAR 參考類型:外部， 內(nèi)部 電壓 - 電源，模擬:5V 電壓 - 電源，數(shù)字:5V 特性:- 工作溫度:-40°C ~ 85°C 封裝/外殼:28-SOIC（0.295"，7.50mm 寬） 供應(yīng)商器件封裝:28-SOIC 基本零件編號:ADS7807 標(biāo)準(zhǔn)包裝:20 |
| ADS7808 | 制造商:BB 制造商全稱:BB 功能描述:12-Bit 10ms Serial CMOS Sampling ANALOG-to-DIGITAL CONVERTER |
| ADS7808_07 | 制造商:BB 制造商全稱:BB 功能描述:12-Bit 10us Serial CMOS Sampling ANALOG-to-DIGITAL CONVERTER |
發(fā)布緊急采購，3分鐘左右您將得到回復(fù)。