參數(shù)資料
型號： MC68HC705JJ7CDW
廠商： FREESCALE SEMICONDUCTOR INC
元件分類： 微控制器/微處理器
英文描述： 8-BIT, OTPROM, 2.1 MHz, MICROCONTROLLER, PDSO20
封裝： SOIC-20
文件頁數(shù)： 153/164頁
文件大小： 1165K
代理商： MC68HC705JJ7CDW
Voltage Measurement Methods
MC68HC705JJ7 MC68HC705JP7 Advance Information Data Sheet, Rev. 4.1
Freescale Semiconductor
89
8.6 Voltage Measurement Methods
The methods for obtaining a voltage measurement can use software techniques to express these
voltages as absolute or ratiometric readings.
In most applications the external capacitor, the clock source, the reference voltage, and the charging
current may vary between devices and with changes in supply voltage or ambient temperature. All of
these variations must be considered when determining the desired resolution of the measurement. The
maximum and minimum extremes for the full scale count will be:
NFSMIN = CEXTMIN x VFSMIN x fOSCMIN / (P x ICHGMAX)
NFSMAX = CEXTMAX x VFSMAX x fOSCMAX / (P x ICHGMIN)
The minimum count should be the desired resolution, and the counting mechanism must be capable of
counting to the maximum. The final scaling of the count will be by a math routine which calculates:
VX = VREF x (NX – NOFF) / (NREF – NOFF)
Where:
VREF = Known reference voltage
VX
= Unknown voltage between VSS and VREF
NX
= Conversion count for unknown voltage
NREF = Conversion count for known reference voltage (VREF)
NOFF = Conversion count for minimum reference voltage (VSS)
When VREF is a stable voltage source such as a zener or other reference source, then the unknown
voltage will be determined as an absolute reading. If VREF is the supply source to the device (VDD), then
the unknown voltage will be determined as a ratio of VDD, or a ratiometric reading.
If the unknown voltage applied to the comparator is greater than its common-mode range (VDD –1.5 volts),
then the external capacitor will try to charge to the same level. This will cause both comparator inputs to
be above the common-mode range and the output of the comparator will be indeterminate. In this case
the comparator output flags may also be set even if the actual voltage on the positive input (+) is less than
the voltage on the negative input (–). All A/D conversion methods should have a maximum time check to
determine if this case is occurring.
Once the maximum timeout detection has been made, the state of the comparator outputs can be tested
to determine the situation. However, such tests should be carefully designed when using modes 1, 2, or
3 as these modes cause the immediate automatic discharge of the external ramping capacitor before any
software check can be made of the output state of comparator 2.
NOTE
All A/D conversion methods should include a test for a maximum elapsed
time to detect error cases where the inputs may be outside of the design
specification.
相關(guān)PDF資料
PDF描述
MC68HC705JJ7CP 8-BIT, OTPROM, 2.1 MHz, MICROCONTROLLER, PDIP20
MC68HC705JJ7S 8-BIT, UVPROM, 2.1 MHz, MICROCONTROLLER, CDIP20
MC68HC705K1DWR2 8-BIT, OTPROM, MICROCONTROLLER, PDSO16
MC68HC705K1CP 8-BIT, OTPROM, MICROCONTROLLER, PDIP16
MC68HC705K1P 8-BIT, OTPROM, 2 MHz, MICROCONTROLLER, PDIP16
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
MC68HC705JP7CDW 功能描述:IC MCU 8BIT 28-SOIC RoHS:否 類別:集成電路 (IC) >> 嵌入式 - 微控制器， 系列:HC05 其它有關(guān)文件:STM32F101T8 View All Specifications 特色產(chǎn)品:STM32 32-bit Cortex MCUs 標(biāo)準(zhǔn)包裝:490 系列:STM32 F1 核心處理器:ARM? Cortex?-M3 芯體尺寸:32-位 速度:36MHz 連通性:I²C，IrDA，LIN，SPI，UART/USART 外圍設(shè)備:DMA，PDR，POR，PVD，PWM，溫度傳感器，WDT 輸入/輸出數(shù):26 程序存儲器容量:64KB（64K x 8） 程序存儲器類型:閃存 EEPROM 大小:- RAM 容量:10K x 8 電壓 - 電源 (Vcc/Vdd):2 V ~ 3.6 V 數(shù)據(jù)轉(zhuǎn)換器:A/D 10x12b 振蕩器型:內(nèi)部 工作溫度:-40°C ~ 85°C 封裝/外殼:36-VFQFN，36-VFQFPN 包裝:托盤 配用:497-10030-ND - STARTER KIT FOR STM32497-8853-ND - BOARD DEMO STM32 UNIV USB-UUSCIKSDKSTM32-PL-ND - KIT IAR KICKSTART STM32 CORTEXM3497-8512-ND - KIT STARTER FOR STM32F10XE MCU497-8505-ND - KIT STARTER FOR STM32F10XE MCU497-8304-ND - KIT STM32 MOTOR DRIVER BLDC497-6438-ND - BOARD EVALUTION FOR STM32 512K497-6289-ND - KIT PERFORMANCE STICK FOR STM32MCBSTM32UME-ND - BOARD EVAL MCBSTM32 + ULINK-MEMCBSTM32U-ND - BOARD EVAL MCBSTM32 + ULINK2更多... 其它名稱:497-9032STM32F101T8U6-ND
MC68HC705JP7CP 制造商:Rochester Electronics LLC 功能描述: 制造商:Freescale Semiconductor 功能描述:
MC68HC705K1CDW 制造商:Motorola Inc 功能描述:
MC68HC705KJ1CDW 功能描述:8位微控制器 -MCU 8 Bit 4MHz RoHS:否 制造商:Silicon Labs 核心:8051 處理器系列:C8051F39x 數(shù)據(jù)總線寬度:8 bit 最大時鐘頻率:50 MHz 程序存儲器大小:16 KB 數(shù)據(jù) RAM 大小:1 KB 片上 ADC:Yes 工作電源電壓:1.8 V to 3.6 V 工作溫度范圍:- 40 C to + 105 C 封裝 / 箱體:QFN-20 安裝風(fēng)格:SMD/SMT
MC68HC705KJ1CP 功能描述:IC MCU 4MHZ 1.2K OTP 16-DIP RoHS:否 類別:集成電路 (IC) >> 嵌入式 - 微控制器， 系列:HC05 其它有關(guān)文件:STM32F101T8 View All Specifications 特色產(chǎn)品:STM32 32-bit Cortex MCUs 標(biāo)準(zhǔn)包裝:490 系列:STM32 F1 核心處理器:ARM? Cortex?-M3 芯體尺寸:32-位 速度:36MHz 連通性:I²C，IrDA，LIN，SPI，UART/USART 外圍設(shè)備:DMA，PDR，POR，PVD，PWM，溫度傳感器，WDT 輸入/輸出數(shù):26 程序存儲器容量:64KB（64K x 8） 程序存儲器類型:閃存 EEPROM 大小:- RAM 容量:10K x 8 電壓 - 電源 (Vcc/Vdd):2 V ~ 3.6 V 數(shù)據(jù)轉(zhuǎn)換器:A/D 10x12b 振蕩器型:內(nèi)部 工作溫度:-40°C ~ 85°C 封裝/外殼:36-VFQFN，36-VFQFPN 包裝:托盤 配用:497-10030-ND - STARTER KIT FOR STM32497-8853-ND - BOARD DEMO STM32 UNIV USB-UUSCIKSDKSTM32-PL-ND - KIT IAR KICKSTART STM32 CORTEXM3497-8512-ND - KIT STARTER FOR STM32F10XE MCU497-8505-ND - KIT STARTER FOR STM32F10XE MCU497-8304-ND - KIT STM32 MOTOR DRIVER BLDC497-6438-ND - BOARD EVALUTION FOR STM32 512K497-6289-ND - KIT PERFORMANCE STICK FOR STM32MCBSTM32UME-ND - BOARD EVAL MCBSTM32 + ULINK-MEMCBSTM32U-ND - BOARD EVAL MCBSTM32 + ULINK2更多... 其它名稱:497-9032STM32F101T8U6-ND
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