參數(shù)資料
型號(hào): MAX1402CAI+T
廠商: Maxim Integrated Products
文件頁數(shù): 29/38頁
文件大?。?/td> 0K
描述: IC ADC 18BIT LP 28-SSOP
產(chǎn)品培訓(xùn)模塊: Lead (SnPb) Finish for COTS
Obsolescence Mitigation Program
標(biāo)準(zhǔn)包裝: 2,000
位數(shù): 18
采樣率(每秒): 480
數(shù)據(jù)接口: QSPI?,串行,SPI?
轉(zhuǎn)換器數(shù)目: 1
功率耗散(最大): 34mW
電壓電源: 模擬和數(shù)字
工作溫度: 0°C ~ 70°C
安裝類型: 表面貼裝
封裝/外殼: 28-SSOP(0.209",5.30mm 寬)
供應(yīng)商設(shè)備封裝: 28-SSOP
包裝: 帶卷 (TR)
輸入數(shù)目和類型: 3 個(gè)差分,單極;3 個(gè)差分,雙極;5 個(gè)偽差分,單極;5 個(gè)偽差分,雙極
MAX1402
+5V, 18-Bit, Low-Power, Multichannel,
Oversampling (Sigma-Delta) ADC
4–20mA Loop-Powered Transmitters
Low power, single-supply operation, and easy interfac-
ing with optocouplers make the MAX1402 ideal for
loop-powered 4–20mA transmitters. Loop-powered
transmitters draw their power from the 4–20mA loop,
limiting the transmitter circuitry to a current budget of
4mA. Tolerances in the loop further limit this current
budget to 3.5mA. Since the MAX1402 consumes only
250A, a total of 3.25mA remains to power the remain-
ing transmitter circuitry. Figure 18 shows a block dia-
gram for a loop-powered 4–20mA transmitter.
Power Supplies
No specific power sequence is required for the
MAX1402; either the V+ or the VDD supply can come
up first. While the latchup performance of the MAX1402
is good, it is important that power be applied to the
MAX1402 before the analog input signals (AIN_) or the
CLKIN inputs, to avoid latchup. If this is not possible,
then the current flow into any of these pins should be
limited to 50mA. If separate supplies are used for the
MAX1402 and the system digital circuitry, then the
MAX1402 should be powered up first.
3-Wire and 4-Wire
RTD Configurations
Tightly matched 200A current sources compensate for
errors in 3-wire and 4-wire RTD configurations. In the 3-
wire configuration (Figure 19), the lead resistances
result in errors if only one current source is used. The
200
A will flow through RL1 developing a voltage error
between AIN1 and AIN2. An additional current source
compensates for this error by developing an equivalent
voltage across RL2 ensuring the differential voltage at
AIN1 and AIN2 is not affected by lead resistance. This
assumes both leads are of the same material and of
equal length (RL1 = RL2) and OUT1 and OUT2 have
matching tempcos (5ppm/°C). Both current sources will
flow through RL3 developing a common-mode voltage
that will not affect the differential voltage at AIN1 and
AIN2. Using one of the current sources to supply the
reference voltage ensures a more accurate ratiometric
result.
Unlike the 3-wire configuration, the 4-wire configuration
(Figure 20) has no error associated with lead resis-
tances as no current flows in the measurement leads
connected to AIN1 and AIN2. Current source OUT1
provides the excitation current for the RTD and current
source OUT2 provides current to generate the refer-
ence voltage. This reference voltage developed across
RREF ensures that the analog input voltage span
remains ratiometric to the reference voltage. RTD temp-
co errors in the analog input voltage are due to the tem-
DAC
RGAIN
ROFST
RX
VIN+
VIN-
RSENSE
4–20mA LOOP
INTERFACE
RFDBK
RY
CC
ISOLATION
BARRIER
V+
GND
V+
4
SPI
4
SPI
3
SPI
GND
SENSOR
VOLTAGE
REGULATOR
P/C
MAX1402
Figure 18. 4–20mA Transmitter
______________________________________________________________________________________
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MAX1402EAI+T 功能描述:模數(shù)轉(zhuǎn)換器 - ADC 18-Bit 5Ch 4.8ksps 2.5V Precision ADC 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
MAX1402EAI+TW 功能描述:ADC / DAC多通道 +5V 18-Bit Low-Power Multichannel Oversampling (Sigma-Delta) ADC RoHS:否 制造商:Texas Instruments 轉(zhuǎn)換速率: 分辨率:8 bit 接口類型:SPI 電壓參考: 電源電壓-最大:3.6 V 電源電壓-最小:2 V 最大工作溫度:+ 85 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:VQFN-40
MAX1402EAI+W 功能描述:ADC / DAC多通道 +5V 18-Bit Low-Power Multichannel Oversampling (Sigma-Delta) ADC RoHS:否 制造商:Texas Instruments 轉(zhuǎn)換速率: 分辨率:8 bit 接口類型:SPI 電壓參考: 電源電壓-最大:3.6 V 電源電壓-最小:2 V 最大工作溫度:+ 85 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:VQFN-40