收藏本站
参数资料
型号： PIC18F6620-E/PT
厂商： Microchip Technology
文件页数： 92/165页
文件大小： 0K
描述： IC PIC MCU FLASH 32KX16 64TQFP
产品培训模块： Asynchronous Stimulus
标准包装： 160
系列： PIC® 18F
核心处理器： PIC
芯体尺寸： 8-位
速度： 25MHz
连通性： I²C，SPI，UART/USART
外围设备： 欠压检测/复位，LVD，POR，PWM，WDT
输入/输出数： 52
程序存储器容量： 64KB（32K x 16）
程序存储器类型： 闪存
EEPROM 大小： 1K x 8
RAM 容量： 3.75K x 8
电压 - 电源 (Vcc/Vdd)： 4.2 V ~ 5.5 V
数据转换器： A/D 12x10b
振荡器型： 外部
工作温度： -40°C ~ 125°C
封装/外壳： 64-TQFP
包装： 托盘
PIC18F6520/8520/6620/8620/6720/8720
DS39609B-page 30
2004 Microchip Technology Inc.
3.1
Power-on Reset (POR)
A Power-on Reset pulse is generated on-chip when
VDD rise is detected. To take advantage of the POR
circuitry, tie the MCLR pin through a 1 k
to 10 k
resistor to VDD. This will eliminate external RC
components usually needed to create a Power-on
Reset delay. A minimum rise rate for VDD is specified
(parameter D004). For a slow rise time, see Figure 3-2.
When the device starts normal operation (i.e., exits the
Reset condition), device operating parameters (volt-
age, frequency, temperature, etc.) must be met to
ensure operation. If these conditions are not met, the
device must be held in Reset until the operating
conditions are met.
FIGURE 3-2:
EXTERNAL POWER-ON
RESET CIRCUIT (FOR
SLOW VDD POWER-UP)
3.2
Power-up Timer (PWRT)
The Power-up Timer provides a fixed nominal time-out
(parameter #33) only on power-up from the POR. The
Power-up Timer operates on an internal RC oscillator.
The chip is kept in Reset as long as the PWRT is active.
The PWRT’s time delay allows VDD to rise to an accept-
able level. A configuration bit is provided to enable/
disable the PWRT.
The power-up time delay will vary from chip-to-chip due
to VDD, temperature and process variation. See DC
parameter #33 for details.
3.3
Oscillator Start-up Timer (OST)
The Oscillator Start-up Timer (OST) provides 1024
oscillator cycles (from OSC1 input) delay after the
PWRT delay is over (parameter #32). This ensures that
the crystal oscillator or resonator has started and
stabilized.
The OST time-out is invoked only for XT, LP and HS
modes and only on Power-on Reset, or wake-up from
Sleep.
3.4
PLL Lock Time-out
With the PLL enabled, the time-out sequence following
a Power-on Reset is different from other oscillator
modes. A portion of the Power-up Timer is used to
provide a fixed time-out that is sufficient for the PLL to
lock to the main oscillator frequency. This PLL lock
time-out (TPLL) is typically 2 ms and follows the
oscillator start-up time-out.
3.5
Brown-out Reset (BOR)
A configuration bit, BOREN, can disable (if clear/
programmed), or enable (if set) the Brown-out Reset
circuitry. If VDD falls below parameter D005 for greater
than parameter #35, the brown-out situation will reset
the chip. A Reset may not occur if VDD falls below
parameter D005 for less than parameter #35. The chip
will remain in Brown-out Reset until VDD rises above
BVDD. If the Power-up Timer is enabled, it will be
invoked after VDD rises above BVDD; it then will keep
the chip in Reset for an additional time delay (parame-
ter #33). If VDD drops below BVDD while the Power-up
Timer is running, the chip will go back into a Brown-out
Reset and the Power-up Timer will be initialized. Once
VDD rises above BVDD, the Power-up Timer will
execute the additional time delay.
3.6
Time-out Sequence
On power-up, the time-out sequence is as follows:
First, PWRT time-out is invoked after the POR time
delay has expired. Then, OST is activated. The total
time-out will vary based on oscillator configuration and
the status of the PWRT. For example, in RC mode with
the PWRT disabled, there will be no time-out at all.
Figures 3-3 through 3-7 depict time-out sequences on
power-up.
Since the time-outs occur from the POR pulse, the
time-outs will expire if MCLR is kept low long enough.
Bringing MCLR high will begin execution immediately
(Figure 3-5). This is useful for testing purposes, or to
synchronize more than one PIC18FXX20 device
operating in parallel.
Table 3-2 shows the Reset conditions for some Special
Function Registers, while Table 3-3 shows the Reset
conditions for all of the registers.
Note 1:
External Power-on Reset circuit is required
only if the VDD power-up slope is too slow.
The diode D helps discharge the capacitor
quickly when VDD powers down.
2:
R < 40 k
is recommended to make sure that
the voltage drop across R does not violate
the device’s electrical specification.
3:
R1 = 1 k
to 10 k will limit any current flow-
ing into MCLR from external capacitor C, in
the event of MCLR/VPP pin breakdown due to
Electrostatic Discharge (ESD) or Electrical
Overstress (EOS).
C
R1
R
D
VDD
MCLR
PIC18FXX20
相关PDF资料
PDF描述
ADG721BRM IC SWITCH DUAL SPST 8MSOP
PIC17C44-33/PT IC MCU OTP 8KX16 PWM 44TQFP
PIC17C44-25/PT IC MCU OTP 8KX16 PWM 44TQFP
ADG713BRU-REEL7 IC SWITCH QUAD SPST 16TSSOP
ADG712BR-REEL7 IC SWITCH QUAD SPST 16SOIC
相关代理商/技术参数
参数描述
PIC18F6620-I/PT 功能描述:8位微控制器 -MCU 64KB 3840 RAM 52I/O RoHS:否 制造商:Silicon Labs 核心:8051 处理器系列:C8051F39x 数据总线宽度:8 bit 最大时钟频率:50 MHz 程序存储器大小:16 KB 数据 RAM 大小:1 KB 片上 ADC:Yes 工作电源电压:1.8 V to 3.6 V 工作温度范围:- 40 C to + 105 C 封装 / 箱体:QFN-20 安装风格:SMD/SMT
PIC18F6620-I/PT 制造商:Microchip Technology Inc 功能描述:IC 8BIT FLASH MCU 18F6620 TQFP64
PIC18F6620-I/PTC01 制造商:Microchip Technology 功能描述:MCU 8-Bit PIC18 PIC RISC 64KB Flash 5V 64-Pin TQFP Tray
PIC18F6620T-I/PT 功能描述:8位微控制器 -MCU 64KB 3840 RAM 52I/O RoHS:否 制造商:Silicon Labs 核心:8051 处理器系列:C8051F39x 数据总线宽度:8 bit 最大时钟频率:50 MHz 程序存储器大小:16 KB 数据 RAM 大小:1 KB 片上 ADC:Yes 工作电源电压:1.8 V to 3.6 V 工作温度范围:- 40 C to + 105 C 封装 / 箱体:QFN-20 安装风格:SMD/SMT
PIC18F6621-E/PT 功能描述:8位微控制器 -MCU 64KB 3840 RAM 52I/O RoHS:否 制造商:Silicon Labs 核心:8051 处理器系列:C8051F39x 数据总线宽度:8 bit 最大时钟频率:50 MHz 程序存储器大小:16 KB 数据 RAM 大小:1 KB 片上 ADC:Yes 工作电源电压:1.8 V to 3.6 V 工作温度范围:- 40 C to + 105 C 封装 / 箱体:QFN-20 安装风格:SMD/SMT
发布紧急采购，3分钟左右您将得到回复。

采购需求

(若只采购一条型号，填写一行即可)

发布成功！您可以继续发布采购。也可以进入我的后台，查看报价

发布成功！您可以继续发布采购。也可以进入我的后台，查看报价

*型号 *数量 厂商 批号 封装
添加更多采购

我的联系方式

*
*
*