- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄364640 > ADS7822EB (Texas Instruments, Inc.) 12-Bit, High-Speed, 2.7V microPower Sampling ANALOG-TO-DIGITAL CONVERTER PDF資料下載
參數(shù)資料
| 型號(hào)： | ADS7822EB |
| 廠商： | Texas Instruments, Inc. |
| 英文描述： | 12-Bit, High-Speed, 2.7V microPower Sampling ANALOG-TO-DIGITAL CONVERTER |
| 中文描述： | 12位，高速，2.7微采樣模擬到數(shù)字轉(zhuǎn)換器 |
| 文件頁數(shù)： | 7/12頁 |
| 文件大?。?/td> | 146K |
| 代理商： | ADS7822EB |
7
ADS7822
TYPICAL PERFORMANCE CURVES
(Cont.)
At T
A
= +25
°
C, V
CC
= +2.7V, V
REF
= +2.5V, f
SAMPLE
= 75kHz, f
CLK
= 16 f
SAMPLE
, unless otherwise specified.
CHANGE IN INTEGRAL LINEARITY AND DIFFERENTIAL
LINEARITY vs REFERENCE VOLTAGE
0.20
0.15
0.10
0.05
0.00
–0.05
–0.10
D
1
2
3
4
5
Reference Voltage (V)
V
CC
= 5V
Change in Integral
Linearity (LSB)
Change in Differential
Linearity (LSB)
POWER SUPPLY REJECTION vs RIPPLE FREQUENCY
0
–10
–20
–30
–40
–50
–60
–70
–80
–90
P
1
10
100
1000
10000
Ripple Frequency (kHz)
THEORY OF OPERATION
The ADS7822 is a classic successive approximation register
(SAR) analog-to-digital (A/D) converter. The architecture is
based on capacitive redistribution which inherently includes
a sample/hold function. The converter is fabricated on a 0.6
μ
CMOS process. The architecture and process allow the
ADS7822 to acquire and convert an analog signal at up to
75,000 conversions per second while consuming very little
power.
The ADS7822 requires an external reference, an external
clock, and a single power source (V
CC
). The external refer-
ence can be any voltage between 50mV and V
CC
. The value
of the reference voltage directly sets the range of the analog
input. The reference input current depends on the conversion
rate of the ADS7822.
The external clock can vary between 10kHz (625Hz through-
put) and 1.2MHz (75kHz throughput). The duty cycle of the
clock is essentially unimportant as long as the minimum high
and low times are at least 400ns (V
CC
= 2.7V or greater).
The minimum clock frequency is set by the leakage on the
capacitors internal to the ADS7822.
The analog input is provided to two input pins: +In and –In.
When a conversion is initiated, the differential input on these
pins is sampled on the internal capacitor array. While a
conversion is in progress, both inputs are disconnected from
any internal function.
The digital result of the conversion is clocked out by the
DCLOCK input and is provided serially, most significant bit
first, on the D
OUT
pin. The digital data that is provided on the
D
OUT
pin is for the conversion currently in progress—there
is no pipeline delay. It is possible to continue to clock the
ADS7822 after the conversion is complete and to obtain the
serial data least significant bit first. See the digital timing
section for more information.
ANALOG INPUT
The +In and –In input pins allow for a differential input
signal. Unlike some converters of this type, the –In input is
not re-sampled later in the conversion cycle. When the
converter goes into the hold mode, the voltage difference
between +In and –In is captured on the internal capacitor
array.
The range of the –In input is limited to –0.2V to +1V.
Because of this, the differential input can be used to reject
only small signals that are common to both inputs. Thus, the
–In input is best used to sense a remote signal ground that
may move slightly with respect to the local ground potential.
The input current on the analog inputs depends on a number
of factors: sample rate, input voltage, source impedance, and
power down mode. Essentially, the current into the ADS7822
charges the internal capacitor array during the sample period.
After this capacitance has been fully charged, there is no
further input current. The source of the analog input voltage
must be able to charge the input capacitance (25pF) to a
12-bit settling level within 1.5 clock cycles. When the
converter goes into the hold mode or while it is in the power
down mode, the input impedance is greater than 1G
.
Care must be taken regarding the absolute analog input
voltage. To maintain the linearity of the converter, the –In
input should not drop below GND – 200mV or exceed
GND + 1V. The +In input should always remain within the
range of GND – 200mV to V
CC
+ 200mV. Outside of these
ranges, the converter’s linearity may not meet specifications.
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| ADS7822EC | CMOS Dual 4-Input NOR Gate 14-CDIP -55 to 125 |
| ADS7823E250 | 12-Bit, Sampling A/D Converter with I2C?? INTERFACE |
| ADS7823 | CONN, M HDR 2X20 NO LATCH |
| ADS7823E2K5 | 12-Bit, Sampling A/D Converter with I2C?? INTERFACE |
| ADS7823EB250 | 12-Bit, Sampling A/D Converter with I2C?? INTERFACE |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| ADS7822EB/250 | 功能描述:模數(shù)轉(zhuǎn)換器 - ADC 12-Bit Hi-Speed 2.7V MicroPower Sampling 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 |
| ADS7822EB/250 | 制造商:Texas Instruments 功能描述:IC ADC 12BIT 200KSPS MSOP-8 |
| ADS7822EB/250G4 | 功能描述:模數(shù)轉(zhuǎn)換器 - ADC 12-Bit Hi-Speed 2.7V MicroPower Sampling 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 |
| ADS7822EB/2K5 | 功能描述:模數(shù)轉(zhuǎn)換器 - ADC 12-Bit Hi-Speed 2.7V MicroPower Sampling 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 |
| ADS7822EB/2K5G4 | 功能描述:模數(shù)轉(zhuǎn)換器 - ADC 12-Bit Hi-Speed 2.7V MicroPower Sampling 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 |
發(fā)布緊急采購，3分鐘左右您將得到回復(fù)。