- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄368705 > 12C508A (Microchip Technology Inc.) Hookup/Lead Wire; Conductor Size AWG:18; No. Strands x Strand Size:65 x 36; Jacket Color:White; Conductor Material:Copper; Jacket Material:Rubber; Leaded Process Compatible:Yes; Number of Conductors:1; Outer Diameter:0.144" RoHS Compliant: Yes PDF資料下載
參數(shù)資料
| 型號： | 12C508A |
| 廠商： | Microchip Technology Inc. |
| 英文描述： | Hookup/Lead Wire; Conductor Size AWG:18; No. Strands x Strand Size:65 x 36; Jacket Color:White; Conductor Material:Copper; Jacket Material:Rubber; Leaded Process Compatible:Yes; Number of Conductors:1; Outer Diameter:0.144" RoHS Compliant: Yes |
| 中文描述： | 8引腳，8位CMOS微控制器 |
| 文件頁數(shù)： | 40/113頁 |
| 文件大?。?/td> | 1604K |
| 代理商： | 12C508A |
第1頁第2頁第3頁第4頁第5頁第6頁第7頁第8頁第9頁第10頁第11頁第12頁第13頁第14頁第15頁第16頁第17頁第18頁第19頁第20頁第21頁第22頁第23頁第24頁第25頁第26頁第27頁第28頁第29頁第30頁第31頁第32頁第33頁第34頁第35頁第36頁第37頁第38頁第39頁當前第40頁第41頁第42頁第43頁第44頁第45頁第46頁第47頁第48頁第49頁第50頁第51頁第52頁第53頁第54頁第55頁第56頁第57頁第58頁第59頁第60頁第61頁第62頁第63頁第64頁第65頁第66頁第67頁第68頁第69頁第70頁第71頁第72頁第73頁第74頁第75頁第76頁第77頁第78頁第79頁第80頁第81頁第82頁第83頁第84頁第85頁第86頁第87頁第88頁第89頁第90頁第91頁第92頁第93頁第94頁第95頁第96頁第97頁第98頁第99頁第100頁第101頁第102頁第103頁第104頁第105頁第106頁第107頁第108頁第109頁第110頁第111頁第112頁第113頁
PIC12C5XX
DS40139E-page 40
1999 Microchip Technology Inc.
8.3.1
MCLR ENABLE
This configuration bit when unprogrammed (left in the
‘1’ state) enables the external MCLR function. When
programmed, the MCLR function is tied to the internal
V
DD
, and the pin is assigned to be a GPIO. See
Figure 8-7. When pin GP3/MCLR/V
PP
is configured as
MCLR, the internal pull-up is always on.
FIGURE 8-7:
MCLR SELECT
8.4
Power-On Reset (POR)
The PIC12C5XX family incorporates on-chip Power-
On Reset (POR) circuitry which provides an internal
chip reset for most power-up situations.
The on-chip POR circuit holds the chip in reset until
V
DD
has reached a high enough level for proper opera-
tion. To take advantage of the internal POR, program
the GP3/MCLR/V
PP
pin as MCLR and tie through a
resistor to V
DD
or program the pin as GP3. An internal
weak pull-up resistor is implemented using a transistor.
Refer to Table 11-1 for the pull-up resistor ranges. This
will eliminate external RC components usually needed
to create a Power-on Reset. A maximum rise time for
V
DD
is specified. See Electrical Specifications for
details.
When the device starts normal operation (exits the
reset condition), device operating parameters (voltage,
frequency, temperature, ...) must be met to ensure
operation. If these conditions are not met, the device
must be held in reset until the operating parameters are
met.
A simplified block diagram of the on-chip Power-On
Reset circuit is shown in Figure 8-8.
GP3/MCLR/V
PP
MCLRE
INTERNAL MCLR
WEAK
The Power-On Reset circuit and the Device Reset
Timer (Section 8.5) circuit are closely related. On
power-up, the reset latch is set and the DRT is reset.
The DRT timer begins counting once it detects MCLR
to be high. After the time-out period, which is typically
18 ms, it will reset the reset latch and thus end the on-
chip reset signal.
A power-up example where MCLR is held low is
shown in Figure 8-9. V
DD
is allowed to rise and
stabilize before bringing MCLR high. The chip will
actually come out of reset T
DRT
msec after MCLR
goes high.
In Figure 8-10, the on-chip Power-On Reset feature is
being used (MCLR and V
DD
are tied together or the
pin is programmed to be GP3.). The V
DD
is stable
before the start-up timer times out and there is no
problem in getting a proper reset. However, Figure 8-
11 depicts a problem situation where V
DD
rises too
slowly. The time between when the DRT senses that
MCLR is high and when MCLR (and V
DD
) actually
reach their full value, is too long. In this situation, when
the start-up timer times out, V
DD
has not reached the
V
DD
(min) value and the chip is, therefore, not
guaranteed to function correctly. For such situations,
we recommend that external RC circuits be used to
achieve longer POR delay times (Figure 8-10).
For additional information refer to Application Notes
“
Power-Up Considerations
”
- AN522 and
“
Power-up
Trouble Shooting
” - AN607.
Note:
When the device starts normal operation
(exits the reset condition), device operating
parameters (voltage, frequency, tempera-
ture, etc.) must be meet to ensure opera-
tion. If these conditions are not met, the
device must be held in reset until the oper-
ating conditions are met.
相關PDF資料 |
PDF描述 |
|---|---|
| 12C509 | Test Prod Wire; Conductor Size AWG:18; No. Strands x Strand Size:65 x 36; Jacket Color:White; Conductor Material:Copper; Jacket Material:Rubber; Leaded Process Compatible:Yes; Number of Conductors:1 RoHS Compliant: Yes |
| 12C671 | Test Prod Wire; Conductor Size AWG:18; No. Strands x Strand Size:65 x 36; Jacket Color:White; Conductor Material:Copper; Jacket Material:Rubber; Leaded Process Compatible:Yes; Number of Conductors:1 RoHS Compliant: Yes |
| 12C672 | Test Prod Wire; Conductor Size AWG:18; No. Strands x Strand Size:65 x 36; Jacket Color:Black; Conductor Material:Copper; Jacket Material:Rubber; Leaded Process Compatible:Yes; Number of Conductors:1; Outer Diameter:0.144" RoHS Compliant: Yes |
| 12CE673 | HookUp/Lead Wire; Conductor Size AWG:18; No. Strands x Strand Size:65 x 36; Jacket Color:Black; Conductor Material:Copper; Jacket Material:Rubber; Leaded Process Compatible:Yes; Number of Conductors:1; Outer Diameter:0.144" RoHS Compliant: Yes |
| 12CGQ150 | SCHOTTKY RECTIFIER |
相關代理商/技術參數(shù) |
參數(shù)描述 |
|---|---|
| 12C508P | 制造商:Motorola Inc 功能描述: |
| 12C5B | 制造商:AMPERITE CO INC 功能描述:RELAY;TIME DELAY,12VLTG,CLOSED,,MINI |
| 12C5SB | 制造商:Olympic Controls Corporation 功能描述: |
| 12C5T | 制造商:OlympicControls Corp/Amperite Co 功能描述:Electromechanical Relay SPST-NC 3A 12VDC 12VAC Through Hole |
| 12C5XB | 制造商:OlympicControls Corp/Amperite Co 功能描述:Electromechanical Relay SPST-NC 3A 12VDC 12VAC Panel Mount |
發(fā)布緊急采購，3分鐘左右您將得到回復。