数据搜索系统,热门电子元器件搜索
  Chinese  ▼
ALLDATASHEETCN.COM

X  

M74HC4538TTR 数据表(PDF) 5 Page - STMicroelectronics

部件名 M74HC4538TTR
功能描述  Dual retriggerable monostable multivibrator
Download  18 Pages
Scroll/Zoom Zoom In 100%  Zoom Out
制造商  STMICROELECTRONICS [STMicroelectronics]
网页  http://www.st.com
标志 STMICROELECTRONICS - STMicroelectronics

M74HC4538TTR 数据表(HTML) 5 Page - STMicroelectronics

  M74HC4538TTR Datasheet HTML 1Page - STMicroelectronics M74HC4538TTR Datasheet HTML 2Page - STMicroelectronics M74HC4538TTR Datasheet HTML 3Page - STMicroelectronics M74HC4538TTR Datasheet HTML 4Page - STMicroelectronics M74HC4538TTR Datasheet HTML 5Page - STMicroelectronics M74HC4538TTR Datasheet HTML 6Page - STMicroelectronics M74HC4538TTR Datasheet HTML 7Page - STMicroelectronics M74HC4538TTR Datasheet HTML 8Page - STMicroelectronics M74HC4538TTR Datasheet HTML 9Page - STMicroelectronics Next Button
Zoom Inzoom in Zoom Outzoom out
 5 / 18 page
background image
M74HC4538
Functional description
5/18
2
Functional description
Standby state
The external capacitor Cx, is fully charged to VCC in the standby state. Hence, before
triggering, transistor Qp and Qn (connected to the Rx/Cx node) are both turned-off. The two
comparators that control the timing and the two reference voltage sources stop operating.
The total supply current is therefore only leakage current.
Trigger operation
Triggering occurs when:
A is low and B has a falling edge
B is high and A has a rising edge
After the multivibrator has been retriggered, the comparator C1 and C2 start operating and
Qn is turned on. Cx then discharges through Qn. The voltage at the node Rx/Cx external
falls.
When it reaches VREFL the output of comparator C1 becomes low. This in turn resets the
flip-flop and Qn is turned off.
At this point C1 stops functioning but C2 continues to operate.
The voltage at R/C external begins to rise with a time constant set by the external
components Rx and Cx.
Triggering the multivibrator causes Q to go high after internal delay due to the flip-flop and
the gate. Q remains high until the voltage at R/C external rises again to VREFH . At this point
C2 output goes low and G goes low. C2 stops operating. That means that after triggering
when the voltage R/C external returns to VREFH the multivibrator has returned to its
monostable state. In the case where Rx · Cx are large enough and the discharge time of the
capacitor and the delay time in the IC can be ignored, the width of the output pulse tw(out) is
as follows:
Re-triggered operation
When a second triggered pulse follows the first, its effect will depend on the state of the
multivibrator. If the capacitor Cx is being charged, the voltage level of Rx/Cx external falls to
VREFL again and Q remains high i.e. the retrigger pulse arrives in a time shorter than the
period Rx · Cx seconds, the capacitor charging time constant. If the second trigger pulse is
very close to the initial trigger pulse it is ineffective; i.e. the second trigger must arrive in the
capacitor discharge cycle to be ineffective; hence the minimum time for a second trigger to
be effective, trr (min.) depends on VCC and Cx.
Reset operation
CD is normally high. If CD is low, the trigger is not effective because Q output goes low and
trigger control flip-flop is reset. Also transistor Op is turned on and Cx is charged quickly to
VCC. Then, if CD input goes low the IC becomes waiting state both in operating and non
operating state.
Rx
Cx
72
.
0
=
t
)
OUT
(
W


类似零件编号 - M74HC4538TTR

制造商部件名数据表功能描述
logo
STMicroelectronics
M74HC4538 STMICROELECTRONICS-M74HC4538 Datasheet
288Kb / 14P
   DUAL RETRIGGERABLE MONOSTABLE MULTIVIBRATOR
M74HC4538B1R STMICROELECTRONICS-M74HC4538B1R Datasheet
288Kb / 14P
   DUAL RETRIGGERABLE MONOSTABLE MULTIVIBRATOR
M74HC4538C1R STMICROELECTRONICS-M74HC4538C1R Datasheet
288Kb / 14P
   DUAL RETRIGGERABLE MONOSTABLE MULTIVIBRATOR
M74HC4538M1R STMICROELECTRONICS-M74HC4538M1R Datasheet
288Kb / 14P
   DUAL RETRIGGERABLE MONOSTABLE MULTIVIBRATOR
More results

类似说明 - M74HC4538TTR

制造商部件名数据表功能描述
logo
STMicroelectronics
M74HC123 STMICROELECTRONICS-M74HC123 Datasheet
503Kb / 12P
   DUAL RETRIGGERABLE MONOSTABLE MULTIVIBRATOR
logo
Toshiba Semiconductor
TC74HC423AP TOSHIBA-TC74HC423AP Datasheet
435Kb / 9P
   DUAL RETRIGGERABLE MONOSTABLE MULTIVIBRATOR
logo
Fairchild Semiconductor
MM74HC423A FAIRCHILD-MM74HC423A Datasheet
108Kb / 10P
   Dual Retriggerable Monostable Multivibrator
logo
Toshiba Semiconductor
TC74HC4538AP TOSHIBA-TC74HC4538AP Datasheet
477Kb / 10P
   DUAL RETRIGGERABLE MONOSTABLE MULTIVIBRATOR
logo
Fairchild Semiconductor
MM74HC123A FAIRCHILD-MM74HC123A_01 Datasheet
133Kb / 10P
   Dual Retriggerable Monostable Multivibrator
74VHC123A FAIRCHILD-74VHC123A_07 Datasheet
468Kb / 14P
   Dual Retriggerable Monostable Multivibrator
logo
Toshiba Semiconductor
TC74HC123AP TOSHIBA-TC74HC123AP_07 Datasheet
505Kb / 14P
   Dual Retriggerable Monostable Multivibrator
logo
National Semiconductor ...
MM54HC123A NSC-MM54HC123A Datasheet
198Kb / 6P
   Dual Retriggerable Monostable Multivibrator
logo
Microsemi Corporation
TSC347 MICROSEMI-TSC347 Datasheet
600Kb / 4P
   Dual Retriggerable Monostable Multivibrator
logo
ON Semiconductor
74VHC123A ONSEMI-74VHC123A Datasheet
467Kb / 16P
   Dual Retriggerable Monostable Multivibrator
May 2007 Rev. 1.2
logo
Fairchild Semiconductor
74VHC123ASJX FAIRCHILD-74VHC123ASJX Datasheet
469Kb / 14P
   Dual Retriggerable Monostable Multivibrator
More results


Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18


数据表 下载

Go To PDF Page


链接网址




隐私政策
ALLDATASHEETCN.COM
ALLDATASHEET是否为您带来帮助?  [ DONATE ] 

关于 Alldatasheet   |   广告服务   |   联系我们   |   隐私政策   |   链接交换   |   制造商名单
All Rights Reserved©Alldatasheet.com


Mirror Sites
English : Alldatasheet.com  |   English : Alldatasheet.net  |   Chinese : Alldatasheetcn.com  |   German : Alldatasheetde.com  |   Japanese : Alldatasheet.jp
Russian : Alldatasheetru.com  |   Korean : Alldatasheet.co.kr  |   Spanish : Alldatasheet.es  |   French : Alldatasheet.fr  |   Italian : Alldatasheetit.com
Portuguese : Alldatasheetpt.com  |   Polish : Alldatasheet.pl  |   Vietnamese : Alldatasheet.vn
Indian : Alldatasheet.in  |   Mexican : Alldatasheet.com.mx  |   British : Alldatasheet.co.uk  |   New Zealand : Alldatasheet.co.nz
Family Site : ic2ic.com  |   icmetro.com