- 您現(xiàn)在的位置：買賣IC網(wǎng) > PDF目錄360473 > 74HCT5555 (NXP Semiconductors N.V.) Programmable delay timer with oscillator PDF資料下載
參數(shù)資料
| 型號： | 74HCT5555 |
| 廠商： | NXP Semiconductors N.V. |
| 英文描述： | Programmable delay timer with oscillator |
| 中文描述： | 與振蕩器可編程延遲計時器 |
| 文件頁數(shù)： | 4/23頁 |
| 文件大?。?/td> | 142K |
| 代理商： | 74HCT5555 |
September 1993
4
Philips Semiconductors
Product specification
Programmable delay timer with oscillator
74HC/HCT5555
Fig.3 Functional diagram.
handbook, full pagewidth
MGA644
RTC
CTC
MONOSTABLE
CIRCUITRY
Q
RS
OSC
CON
MR
A
B
1
14
15
4
5
6
9
7
2
3
10
S
11
S
12
S
13
S3
POWER-ON
RESET
RTR/RTR
OUTPUT
STAGE
Q
24 - STAGE COUNTER
CD
CP
0
1
2
FUNCTIONAL DESCRIPTION
The oscillator configuration allows the
design of RC or crystal oscillator
circuits. The device can operate from
an external clock signal applied to the
RS input (R
TC
and C
TC
must not be
connected). The oscillator frequency
is determined by the external timing
components (R
T
and C
T
), within the
frequency range 1 Hz to 4 MHz
(32 kHz to 20 MHz with crystal
oscillator).
In the HCT version the MR input is
TTL compatible but the RS input has
CMOS input switching levels. The RS
input can be driven by TTL input
levels if RS is tied to V
CC
via a pull-up
resistor.
The counter divides the frequency to
obtain a long pulse duration. The
24-stage is digitally programmed via
the select inputs (S
0
to S
3
). Pin S
3
can
also be used to select the test mode,
which is a convenient way of
functionally testing the counter.
The “5555” is triggered on either the
positive-edge, negative-edge or both.
Trigger pulse applied to input A for
positive-edge triggering
Trigger pulse applied input B for
negative-edge triggering
Trigger pulse applied to inputs A
and B (tied together) for both
positive-edge and negative
triggering.
The Schmitt trigger action in the
trigger inputs, transforms slowly
changing input signals into sharply
defined jitter-free output signals and
provides the circuit with excellent
noise immunity.
The OSC CON input is used to select
the oscillator mode, either
continuously running (OSC CON =
HIGH) or triggered start mode (OSC
CON = LOW). The continuously
running mode is selected where a
start-up delay is an undesirable
feature and the triggered start mode
is selected where very low power
consumption is the primary concern.
The start of the programmed time
delay occurs when output Q goes
HIGH (in the triggered start mode, the
previously disabled oscillator will
start-up). After the programmed time
delay, the flip-flop stages are reset
and the output returns to its original
state.
An internal power-on reset is used to
reset all flip-flop stages.
The output pulse can be terminated
by the asynchronous overriding
master reset (MR), this results in all
flip-flop stages being reset. The
output signal is capable of driving a
power transistor. The output time
delay is calculated using the following
formula (minimum time delay is
100 ns):
1
f
i
Once triggered, the output width may
be extended by retriggering the
gated, active HIGH-going input A or
the active LOW-going input B. By
repeating this process, the output
pulse period (Q = HIGH, Q = LOW)
can be made as long as desired. This
mode is selected by RTR/RTR =
HIGH. A LOW on RTR/RTR makes,
once triggered, the outputs (Q, Q)
independent of further transitions of
inputs A and B.
--
division ratio (s).
×
相關(guān)PDF資料 |
PDF描述 |
|---|---|
| 74HC5555 | Programmable delay timer with oscillator |
| 74HCT563 | 4-Bit Synchronous Up/Down Counters (Dual Clock With Clear) 16-SOIC -40 to 85 |
| 74HC563 | Octal D-type transparent latch; 3-state; inverting |
| 74HC563PW | Octal D-type transparent latch; 3-state; inverting |
| 74HC563DB | Octal D-type transparent latch; 3-state; inverting |
相關(guān)代理商/技術(shù)參數(shù) |
參數(shù)描述 |
|---|---|
| 74HCT5555D | 功能描述:計時器和支持產(chǎn)品 PROG DELAY TIMER W/OSC RoHS:否 制造商:Micrel 類型:Standard 封裝 / 箱體:SOT-23 內(nèi)部定時器數(shù)量:1 電源電壓-最大:18 V 電源電壓-最小:2.7 V 最大功率耗散: 最大工作溫度:+ 85 C 最小工作溫度:- 40 C 封裝:Reel |
| 74HCT5555D,112 | 功能描述:計時器和支持產(chǎn)品 PROG DELAY TIMER RoHS:否 制造商:Micrel 類型:Standard 封裝 / 箱體:SOT-23 內(nèi)部定時器數(shù)量:1 電源電壓-最大:18 V 電源電壓-最小:2.7 V 最大功率耗散: 最大工作溫度:+ 85 C 最小工作溫度:- 40 C 封裝:Reel |
| 74HCT5555D,118 | 功能描述:計時器和支持產(chǎn)品 PROG DELAY TIMER W/SCH TRIGGER RoHS:否 制造商:Micrel 類型:Standard 封裝 / 箱體:SOT-23 內(nèi)部定時器數(shù)量:1 電源電壓-最大:18 V 電源電壓-最小:2.7 V 最大功率耗散: 最大工作溫度:+ 85 C 最小工作溫度:- 40 C 封裝:Reel |
| 74HCT5555D-T | 制造商:NXP Semiconductors 功能描述:Programmable Timer Single 16-Pin SO T/R |
| 74HCT5555N | 功能描述:計時器和支持產(chǎn)品 PROG DELAY TIMER W/SCH TRIGGER RoHS:否 制造商:Micrel 類型:Standard 封裝 / 箱體:SOT-23 內(nèi)部定時器數(shù)量:1 電源電壓-最大:18 V 電源電壓-最小:2.7 V 最大功率耗散: 最大工作溫度:+ 85 C 最小工作溫度:- 40 C 封裝:Reel |
發(fā)布緊急采購，3分鐘左右您將得到回復(fù)。