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參數(shù)資料
| 型號(hào)： | LM9040 |
| 廠商： | National Semiconductor Corporation |
| 英文描述： | Dual Lambda Sensor Interface Amplifier |
| 中文描述： | 雙氧傳感器接口放大器 |
| 文件頁(yè)數(shù)： | 7/10頁(yè) |
| 文件大小： | 178K |
| 代理商： | LM9040 |
Cold Sensor
Typically, a Lambda sensor will have an impedance of less
than 10 k
X
when operating at temperatures between 300
§
C,
and 500
§
C. When a Lambda sensor is not at operating tem-
perature, its impedance can be more than 10 Meg
X
. Any
voltage signal that may be developed is seriously attenuat-
ed. During this high impedance condition the LM9040 will
provide a default output voltage.
TL/H/12372–19
FIGURE 9. V
OUT
with Cold Lambda Sensor
Each amplifier input has a bias charge applied across the
Differential Input impedance (Z
DIFF
) by means of charge
redistribution through the switched capacitor network. This
bias charge is a ratio of V
CC
, and is typically 447 mV for a
V
CC
value of 5.00V. This will provide an output voltage of
typically 2.025V.
While the Lambda sensor is high impedance, the 447 mV
across Z
DIFF
will be the dominant input signal. As the Lamb-
da sensor is heated, and the sensor impedance begins to
drop, the voltage signal from the sensor will become the
dominate signal.
Output Resistance
With normal operation, each output has typically 2.5 k
X
of
resistance. This resistance, along with an external capaci-
tor, form a RC low pass filter to remove any clock noise
from the output signal. An external output filter capacitor
value of 0.01
m
F is recommended. Additionally, the output
resistance will provide current limiting for the output stage
should it become shorted to Ground or V
CC
.
Any DC loading of the output will cause an error in the mea-
sured output voltage. This error will be equal to the I
#
R drop
across the output resistance:
V
ERROR
e
I
LOAD
#
2.5 k
X
Open Input Pins Defaults
In any remote sensor application it is desirable to be able to
deal with the possibility of open connections between the
sensor and the control module. The LM9040 is capable of
providing an output voltage scaled to V
CC
should either, or
both, of the wires to the Lambda sensor open. The two
inputs handle the open circuit condition differently. The
LM9040 will provide a default V
OUT
that is typically 2.025V
when V
CC
is at 5V.
For the case of an open connection of the non-inverting
input, the device would react the same as for the Cold Sen-
sor condition. The internal bias voltage across Z
IN
would
cause the output voltage to be at a value defined by V
CC
and the LM9040 DC gain. The inverting input would still be
connected to the Lambda sensor ground, so any common
mode signals would still need to be allowed for in this condi-
tion. See Figure 9.
For the case of an open connection of the inverting input,
the device output stage switches from the amplifier output
to a resistive voltage divider. In this case, the default V
OUT
is not dependent on the gain stage, and any signal on the
non-inverting input will have no effect on the output. Each
amplifier has a comparator to monitor the voltage on the
inverting input pin. When the voltage on an inverting pin
goes above typically 2.5V, the comparator will switch the
output from the amplifier output to the voltage divider stage.
To fully implement this function requires external pull-up re-
sistors for each of the inverting inputs. To minimize signal
errors due to DC currents through the 4 k
X
resistors, the
pull-up resistors need to be added in the application circuit
between the 4 k
X
input resistor and the connection to the
Lambda sensor ground point. A typical pull-up value of
51 k
X
to V
CC
is recommended. During this condition, the
effective resistance of the output stage will be 3.5 k
X
typi-
cally. See Figure 10.
TL/H/12372–20
FIGURE 10. V
OUT
with Open Inverting Input
7
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PDF描述 |
|---|---|
| LM9040M | Dual Lambda Sensor Interface Amplifier |
| LM9044 | LM9044 Lambda Sensor Interface Amplifier |
| LM9044V | LM9044 Lambda Sensor Interface Amplifier |
| LM9061 | Power MOSFET Driver with Lossless Protection |
| LM9061N | Power MOSFET Driver with Lossless Protection |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| LM9040M | 制造商:NSC 制造商全稱:National Semiconductor 功能描述:Dual Lambda Sensor Interface Amplifier |
| LM9040M/NOPB | 功能描述:IC SENSOR DUAL INTER AMP 14-SOIC RoHS:是 類別:集成電路 (IC) >> 接口 - 傳感器和探測(cè)器接口 系列:- 其它有關(guān)文件:Automotive Product Guide 產(chǎn)品培訓(xùn)模塊:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 標(biāo)準(zhǔn)包裝:74 系列:- 類型:觸控式傳感器 輸入類型:數(shù)字 輸出類型:數(shù)字 接口:JTAG，串行 電流 - 電源:100µA 安裝類型:表面貼裝 封裝/外殼:20-TSSOP（0.173"，4.40mm 寬） 供應(yīng)商設(shè)備封裝:20-TSSOP 包裝:管件 |
| LM9040MX | 功能描述:IC AMP DUAL SENSR INTERFC 14SOIC RoHS:是 類別:集成電路 (IC) >> 接口 - 傳感器和探測(cè)器接口 系列:- 其它有關(guān)文件:Automotive Product Guide 產(chǎn)品培訓(xùn)模塊:Lead (SnPb) Finish for COTS Obsolescence Mitigation Program 標(biāo)準(zhǔn)包裝:74 系列:- 類型:觸控式傳感器 輸入類型:數(shù)字 輸出類型:數(shù)字 接口:JTAG，串行 電流 - 電源:100µA 安裝類型:表面貼裝 封裝/外殼:20-TSSOP（0.173"，4.40mm 寬） 供應(yīng)商設(shè)備封裝:20-TSSOP 包裝:管件 |
| LM9040MX/NOPB | 制造商:Texas Instruments 功能描述:Lambda Sensor Interface Amplifier 14-Pin SOIC W T/R |
| LM9044 | 制造商:NSC 制造商全稱:National Semiconductor 功能描述:LM9044 Lambda Sensor Interface Amplifier |
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