参数资料
型号: MCZ33972EWR2
厂商: Freescale Semiconductor
文件页数: 15/32页
文件大小: 0K
描述: IC SWITCH DETECTION MULT 32-SOIC
标准包装: 1,000
应用: 开关监控
接口: SPI
电源电压: 8 V ~ 26 V
封装/外壳: 32-SOIC(0.295",7.50mm 宽)
供应商设备封装: 32-SOIC
包装: 带卷 (TR)
安装类型: 表面贴装
Analog Integrated Circuit Device Data
22
Freescale Semiconductor
33972
TYPICAL APPLICATIONS
INTRODUCTION
Figure 14. Analog Ratiometric Conversion
To read a potentiometer sensor, the wiper should be
grounded and brought back to the module ground, as
illustrated in Figure 14. With the wiper changing the
impedance of the sensor, the analog voltage on the input will
represent the position of the sensor.
Using the Analog feature to provide 2.0 mA of pull-up
current to an analog sensor may induce error due to the
accuracy of the current source. For this reason, a ratiometric
conversion must be considered. Using two current sources
(one for the sensor and one to set the reference voltage to the
A/D converter) will yield a maximum error (owing to the
33972) of 4%.
Higher accuracy may be achieved through module level
calibration. In this example, we use the resistor values from
Figure 14 and assume the current sources are 4% from each
other. The user may use the module end-of-line tester to
calculate the error in the A/D conversion. By placing a
2.0 k
Ω, 0.1% resistor in the end-of-line test equipment and
assuming a perfect 2.0 mA current source from the 33972, a
calculated A/D conversion may be obtained. Using the
equation yields the following:
The ADC value of 213 counts is the value with 0% error
(neglecting the resistor tolerance and AMUX input offset
voltage). Now we can calculate the count value induced by
the mismatch in current sources. From a sample device the
maximum current source was measured at 2.05 mA and
minimum current source was measured at 1.99 mA. This
yields 3% error in A/D conversion. The A/D measurement
will be as follows:
This A/D conversion is 3% low in value. The error
correction factor of 1.03 may be used to correct the value:
An error correction factor may then be stored in E2
memory and used in the A/D calculation for the specific input.
Each input used as analog measurement will have a
dedicated calibrated error correction factor.
POWER MOSFET/LED DRIVER AND MONITOR
Because of the flexible programming of the 33972 device,
it may be used to drive small loads like LEDs or MOSFET
gates. It was specifically designed to power up in the Normal
mode with the inputs tri-state. This was done to ensure the
LEDs or MOSFETs connected to the 33972 power up in the
off-state. The switch programmable inputs (SP0–SP7) have
a source-and-sink capability, providing effective MOSFET
gate control. To complete the circuit, a pull-down resistor
should be used to keep the gate from floating during the
Sleep modes. Figure 15, page 23, shows an application
where the SG0 input is used to monitor the drain-to-source
voltage of the external MOSFET. The 1.5 k
Ω resistor is used
to set the drain-to-source trip voltage. With the 2.0 mA
current source enabled, an interrupt will be generated when
the drain-to-source voltage is approximately 1.0 V.
VDD
VPWR
VDD
SI
SO
SCLK
INT
CS
AMUX
MOSI
MISO
AN0
VBAT
SP0
SP1
SP7
SG1
SG0
SG12
SG13
WAKE
VBAT
SCLK
CS
INT
16
2.0
VPWR
2.0mA
2.39k
Ω
0.1%
4.54V to 5.02V
Analog
Ports
VREF(H)
VREF(L)
Analog Sensor
or Analog Switch
R2
I2
I1
R1
VPWR
mA
2.0
VPWR
mA
16
mA
33972
MCU
ADC =
I1 x R1
I2 x R2
x 255
ADC =
2.0mA x 2.0k
Ω
x 255
2.0mA x 2.39k
Ω
ADC = 213 counts
ADC =
1.99mA x 2.0k
Ω
x255
2.05mA x 2.39k
Ω
ADC = 207 counts
ADC = 207 counts x 1.03
ADC = 213 counts
相关PDF资料
PDF描述
MCZ33975AEKR2 IC SWITCH DETECT MULT ENH 32SOIC
MCZ33993EWR2 IC MULTIPLE SWITCH DETECT 32SOIC
MCZ79076EGR2 IC IGNITION CTRL ELECTR 16-SOIC
MIC2070-2PCQS TR IC USB PWR CTRLR DUAL 16-QSOP
MIC2550ABTS TR IC USB TRANSCEIVER 14-TSSOP
相关代理商/技术参数
参数描述
MCZ33972TEW 制造商:Freescale Semiconductor 功能描述:MULTI-SW DETECT W/SUPRES - Bulk
MCZ33972TEW/R2 制造商:FREESCALE 制造商全称:Freescale Semiconductor, Inc 功能描述:Multiple Switch Detection Interface with Suppressed Wake-up
MCZ33972TEWR2 制造商:Freescale Semiconductor 功能描述:MULTI-SW DETECT W/SUPRES - Tape and Reel
MCZ33975AEK 功能描述:输入/输出控制器接口集成电路 ENHANCED MULTI SW DETECT RoHS:否 制造商:Silicon Labs 产品: 输入/输出端数量: 工作电源电压: 最大工作温度:+ 85 C 最小工作温度:- 40 C 安装风格:SMD/SMT 封装 / 箱体:QFN-64 封装:Tray
MCZ33975AEKR2 功能描述:接口 - 专用 ENHANCED MULTI SW DETECT RoHS:否 制造商:Texas Instruments 产品类型:1080p60 Image Sensor Receiver 工作电源电压:1.8 V 电源电流:89 mA 最大功率耗散: 最大工作温度:+ 85 C 安装风格:SMD/SMT 封装 / 箱体:BGA-59