參數(shù)資料
型號(hào)： MAX1478
廠商： Maxim Integrated Products, Inc.
英文描述： 1% Accurate, Digitally Trimmed,Rail-to-Rail Sensor Signal Conditioner
中文描述： 1%精確度、數(shù)字校準(zhǔn)、滿(mǎn)擺幅傳感器信號(hào)調(diào)理器
文件頁(yè)數(shù)： 13/20頁(yè)
文件大小： 210K
代理商： MAX1478
Selecting R
FTC
When using an external resistor, use the equation
below to determine the value for R
FTC
, and place the
resistor between ISRC and FSOTC. Since the 12-bit
FSOTC DAC provides considerable dynamic range, the
R
FTC
value need not be exact. Generally, any resistor
value within ±50% of the calculated value is accept-
able.
This approximation works best for bulk, micromachined,
silicon PRTs. Negative values for R
FTC
indicate uncon-
ventional sensor behavior that cannot be compensated
by the MAX1478 without additional external circuitry.
Selecting the PGA Gain Setting
To select the PGA gain setting, first calculate
SensorFSO, the sensor full-span output voltage at T1:
SensorFSO = S
·
V
BDRIVE
·
P
= 1.5mV/V per PSI
·
2.5V
·
10 PSI
= 0.0375V
where S is the sensor sensitivity at T1, V
BDRIVE
is the
sensor excitation voltage (initially 2.5V), and
P is the
maximum pressure differential.
Then calculate the ideal gain using the following formula
and select the nearest gain setting from Table 2:
where OUTFSO is the desired calibrated transducer
full-span output voltage, and SensorFSO is the sensor
full-span output voltage at T1.
In this example, a PGA value of 2 (gain of +95V/V) is
the best selection.
Determining Input-Referred OFFSET
The input-referred offset (IRO) register is used to null
any front-end sensor offset errors prior to amplification
by the PGA. This reduces the possibility of saturating
the PGA and maximizes the useful dynamic range of
the PGA (particularly at the higher gain values).
First, calculate the ideal IRO correction voltage using
the following formula, and select the nearest setting
from Table 1:
=
=
where IROideal is the exact voltage required to perfect-
ly null the sensor, O(T1) is the sensor offset voltage in
V/V at +25°C, and V
BDRIVE
(T1) is the nominal sensor
excitation voltage at +25°C. In this example, 30mV
must be subtracted from the amplifier front end to null
the sensor perfectly. From Table 1, select an IRO value
of 3 to set the IRO DAC to 27mV, which is nearest the
ideal value. To subtract this value, set the IRO sign bit
to 0. The residual output-referred offset error will be
corrected later with the Offset DAC.
Determining OFFTC COEF Initial Value
Generally, OFFTC COEF can initially be set to 0 since
the offset TC error will be compensated in a later step.
However, sensors with large offset TC errors may
require an initial coarse offset TC adjustment to prevent
the PGA from saturating during the compensation pro-
cedure as temperature is increased. An initial coarse
offset TC adjustment is required for sensors with an off-
set TC greater than about 10% of the FSO. If an initial
IROideal
- O T1 V
T1
( )
- 0.012V/V 2.5V
- 30mV
BDRIVE
=
]
A
OUTFSO
SensorFSO
4V
0.0375V
+106V/V
PGA
=
=
=
R
R
500ppm/ C
TCR - TCS
70k 500ppm/ C
2600ppm/ C - -2100ppm/ C
70k
FTC
ISRC
=
|
|
M
1% Accurate, Digitally Trimmed,
Rail-to-Rail Sensor Signal Conditioner
______________________________________________________________________________________
13
A
PGA
Programmable-gain amplifier gain
Input-referred offset correction DAC
value
Input-referred offset sign bit
Internal resistor selection bit
Offset-correction DAC coefficient
Offset sign bit
Offset TC compensation DAC coefficient
Offset TC sign bit
FSO trim DAC coefficient
FSO TC compensation DAC coefficient
R
ISRC
IRO
Internal (approximately 75k
) or user-
supplied resistor that programs the nomi-
nal sensor excitation current
Internal (approximately 75k
) or user-
supplied resistor that compensates
FSO TC errors
DESCRIPTION
IRO Sign
IRS
OFF COEF
OFF Sign
OFFTC COEF
OFFTC Sign
FSO COEF
FSOTC COEF
PARAMETER
R
FTC
Table 7. Compensation Components and
Values
相關(guān)PDF資料
PDF描述
MAX1478AAE 1% Accurate, Digitally Trimmed,Rail-to-Rail Sensor Signal Conditioner
MAX1479EVKIT-315 Evaluation Kit
MAX1479EVKIT-433 Evaluation Kit
MAX147ACAP +2.7Low-Power, 8-Channel, Serial 12-Bit ADCs
MAX147AEAP +2.7Low-Power, 8-Channel, Serial 12-Bit ADCs
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
MAX14780EEPA+ 功能描述:RS-422/RS-485 接口 IC PROFIBUS RS-485 Transceiver RoHS:否 制造商:Maxim Integrated 數(shù)據(jù)速率:1136 Kbps 工作電源電壓:3 V to 5.5 V 電源電流:5.9 mA 工作溫度范圍:- 40 C to + 85 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:SOIC-28 封裝:Tube
MAX14780EESA+ 功能描述:RS-422/RS-485 接口 IC PROFIBUS RS-485 Transceiver RoHS:否 制造商:Maxim Integrated 數(shù)據(jù)速率:1136 Kbps 工作電源電壓:3 V to 5.5 V 電源電流:5.9 mA 工作溫度范圍:- 40 C to + 85 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:SOIC-28 封裝:Tube
MAX14780EESA+T 功能描述:RS-422/RS-485 接口 IC PROFIBUS RS-485 Transceiver RoHS:否 制造商:Maxim Integrated 數(shù)據(jù)速率:1136 Kbps 工作電源電壓:3 V to 5.5 V 電源電流:5.9 mA 工作溫度范圍:- 40 C to + 85 C 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:SOIC-28 封裝:Tube
MAX14783EASA+ 制造商:Maxim Integrated Products 功能描述:HALF DUPLEX, DUAL VOLTAGE (3V TO 5.5V), HIGH ESD HBM (+/-35K - Rail/Tube 制造商:Maxim Integrated Products 功能描述:IC TXRX RS485/422 ESD 8SO
MAX14783EASA+T 制造商:Maxim Integrated Products 功能描述:HALF DUPLEX, DUAL VOLTAGE (3V TO 5.5V), HIGH ESD HBM (+/-35K - Tape and Reel 制造商:Maxim Integrated Products 功能描述:IC TXRX RS485/422 ESD 8SO
發(fā)布緊急采購(gòu)，3分鐘左右您將得到回復(fù)。

采購(gòu)需求

(若只采購(gòu)一條型號(hào)，填寫(xiě)一行即可)

發(fā)布成功！您可以繼續(xù)發(fā)布采購(gòu)。也可以進(jìn)入我的后臺(tái)，查看報(bào)價(jià)

發(fā)布成功！您可以繼續(xù)發(fā)布采購(gòu)。也可以進(jìn)入我的后臺(tái)，查看報(bào)價(jià)

*型號(hào) *數(shù)量 廠商 批號(hào) 封裝
添加更多采購(gòu)

我的聯(lián)系方式

*
*
*