HEF4541B [NXP]
Programmable timer; 可编程定时器型号: | HEF4541B |
厂家: | NXP |
描述: | Programmable timer |
文件: | 总9页 (文件大小:147K) |
中文: | 中文翻译 | 下载: | 下载PDF数据表文档文件 |
INTEGRATED CIRCUITS
DATA SHEET
For a complete data sheet, please also download:
• The IC04 LOCMOS HE4000B Logic
Family Specifications HEF, HEC
• The IC04 LOCMOS HE4000B Logic
Package Outlines/Information HEF, HEC
HEF4541B
MSI
Programmable timer
January 1995
Product specification
File under Integrated Circuits, IC04
Philips Semiconductors
Product specification
HEF4541B
MSI
Programmable timer
disables the oscillator to provide no active power
DESCRIPTION
dissipation.
The HEF4541B is a programmable timer which consists of
a 16-stage binary counter, an integrated oscillator to be
used with external timing components, an automatic
power-on reset and output control logic. The frequency of
the oscillator is determined by the external components
Rt and Ct within the frequency range 1 Hz to 100 kHz. This
oscillator may be replaced by an external clock signal at
input RS, the timer advances on the positive-going
transition of RS. A LOW on the auto reset input (AR) and
a LOW on the master reset input (MR) enables the internal
power-on reset. A HIGH level at input MR resets the
counter independent on all other inputs. Resetting
A HIGH at input AR turns off the power-on reset to provide
a low quiescent power dissipation of the timer. The
16-stage counter divides the oscillator frequency by
28, 210, 213 or 216 depending on the state of the address
inputs (A0, A1). The divided oscillator frequency is
available at output O. The phase input (PH) features a
complementary output signal. If the mode select input
(MODE) is LOW or HIGH the timer can be used
respectively as a single transition timer or 2n frequency
divider.
Fig.1 Functional diagram.
HEF4541BP(N): 14-lead DIL; plastic
(SOT27-1)
HEF4541BD(F):
14-lead DIL; ceramic (cerdip)
(SOT73)
HEF4541BT(D):
14-lead SO; plastic
(SOT108-1)
( ): Package Designator North America
FAMILY DATA, IDD LIMITS category MSI
Fig.2 Pinning diagram.
See Family Specifications
January 1995
2
Philips Semiconductors
Product specification
HEF4541B
MSI
Programmable timer
Fig.3 Logic diagram.
3
January 1995
Philips Semiconductors
Product specification
HEF4541B
MSI
Programmable timer
PINNING
FUNCTION TABLE
A0, A1
MODE
AR
address inputs
INPUTS
MODE
mode select input
AR MR PH
MODE
auto reset input
H
L
L
L
X
X
X
X
X
X
X
H
auto reset disabled
auto reset enabled (1)
master reset active
normal operation selected
division to output
single-cycle mode (2)
output initially LOW,
after reset
MR
master reset input
PH
phase input
X
X
H
L
RTC
CTC
RS
external resistor connection (Rt)
external capacitor connection (Ct)
external resistor connection (RS) or
external clock input
X
X
L
L
X
L
L
X
FREQUENCY SELECTION TABLE
NUMBER OF
X
L
H
X
output initially HIGH,
after reset
fosc
-------
- = 2 n
fout
A0
A1
COUNTER STAGES n
Notes
1. For correct power-on reset, the supply voltage should
be above 8.5 V. For VDD < 8.5 V, disable the autoreset
L
L
L
H
L
13
10
8
8 192
1 024
256
and connect AR to VDD
.
H
H
2. The timer is initialized on a reset pulse and the output
changes state after 2n-1 counts and remains in that
state (latched). Reset of this latch is obtained by
master reset or by a LOW to HIGH transition on the
MODE input.
H
16
65 536
H = HIGH state (the more positive voltage)
L = LOW state (the less positive voltage)
X = state is immaterial
RC oscillator
Timing component limitations
The oscillator frequency is mainly determined by
RtCt, provided Rt << RS and RSC2 << RtCt. The function of
RS is to minimize the influence of the forward voltage
across the input protection diodes on the frequency. The
stray capacitance C2 should be kept as small as possible.
In consideration of accuracy, Ct must be larger than the
inherent stray capacitance. Rt must be larger than the
LOCMOS ‘ON’ resistance in series with it, which typically
is 500 Ω at VDD = 5 V, 300 Ω at VDD = 10 V and 200 Ω at
VDD = 15 V.
Typical formula for oscillator
frequency:
The recommended values for these components to
maintain agreement with the typical oscillation formula are:
Ct ≥ 100 pF, up to any typical value,
1
fosc = ---------------------------------
2, 3 × Rt × Ct
10 kΩ ≤ Rt ≤ 1 MΩ.
Fig.4 External component connection for RC
oscillator; RS ≈ 2 Rt.
January 1995
4
Philips Semiconductors
Product specification
HEF4541B
MSI
Programmable timer
Ct curve at Rt = 56 kΩ; RS = 120 kΩ.
− − − Rt curve at Ct = 1 nF; RS = 2 Rt.
Fig.5 RC oscillator frequency as a function of Rt and Ct at VDD = 5 to 15 V; Tamb = 25 °C.
January 1995
5
Philips Semiconductors
Product specification
HEF4541B
MSI
Programmable timer
Rt = 56 kΩ; Ct = 1 nF; RS = 0.
− − − Rt = 56 kΩ; Ct = 1 nF; RS = 120 kΩ.
Fig.6 Frequency deviation (∆f) as a function of ambient temperature; referenced at : fosc at Tamb = 25 °C and
VDD = 10 V.
January 1995
6
Philips Semiconductors
Product specification
HEF4541B
MSI
Programmable timer
DC CHARACTERISTICS
VSS = 0 V
Tamb (°C)
+ 25
VDD VOL VOH
SYMBOL
−40
+ 85
V
V
V
MIN. MAX. MIN. TYP. MAX. MIN. MAX.
Supply current
5
−
−
−
80
750
−
−
−
20
80 −
230 µA
700 µA
power-on reset
10
15
ID
250
600 −
enabled (note)
1600
500 1300 −
1500 µA
Supply voltage for automatic
reset initialization (note)
Output current
VDD
−
−
−
−
−
−
−
−
−
8,5
0,4
5
−
−
−
−
−
−
−
−
−
−
−
−
−
−
−
−
−
−
−
−
−
−
−
−
V
5
10
15
5
4,6
0,5
0,3
mA
mA
mA
mA
mA
mA
mA
HIGH; CTC, RTC
9,5 −IOH
13,5
1,4
1,2
0,95
3,2
4,8
4,0
2,5 −IOH
1,4
1,2
0,95
0,20
0,68
2,30
Output current
LOW; CTC, RTC
5
0,4
0,33
1,00
3,20
0,27
0,85
2,70
10 0,5
15 1,5
IOL
Note
1. All inputs at 0 V or VDD; except input AR = input MR = 0 V (power-on reset active).
AC CHARACTERISTICS
VSS = 0 V; Tamb = 25 °C; input transition times ≤ 20 ns
VDD
V
TYPICAL FORMULA FOR P (µW)(1)
2
Dynamic power dissipation
per package
5
1 300 fi + foCLVDD
2
10
15
5
5 300 fi + foCLVDD
12 000 fi + foCLVDD
2
(P)
2
2
2
2
Total power dissipation
when using the
1 300 fosc
5 300 fosc
12 000 fosc
+
+
+
foCLVDD
foCLVDD
foCLVDD
+ 2CtVDD fosc
+ 10 VDD
+ 100 VDD
+ 400 VDD
2
10
15
+ 2CtVDD fosc
2
on-chip oscillator (P)
+ 2CtVDD fosc
Notes
1. where:
fi
= input frequency (MHz)
fo = output frequency (MHz)
CL = load capacitance (pF)
VDD = supply voltage (V)
Ct = timing capacitance (pF)
fosc = oscillator frequency (MHz)
January 1995
7
Philips Semiconductors
Product specification
HEF4541B
MSI
Programmable timer
AC CHARACTERISTICS
VSS = 0 V; Tamb = 25 °C; CL = 50 pF; input transition times ≤ 20 ns
VDD
TYPICAL EXTRAPOLATION
FORMULA
SYMBOL MIN. TYP. MAX.
V
Propagation delays
RS → O
28 selected
5
10
15
375
150
110
750 ns
300 ns
220 ns
348 ns
139 ns
102 ns
+
+
+
(0,55 ns/pF) CL
(0,23 ns/pF) CL
(0,16 ns/pF) CL
tPHL
tPLH
;
;
;
;
HIGH to LOW
LOW to HIGH
RS → O
210 selected
5
10
15
425
165
120
850 ns
330 ns
240 ns
398 ns
154 ns
112 ns
+
+
+
(0,55 ns/pF) CL
(0,23 ns/pF) CL
(0,16 ns/pF) CL
tPHL
tPLH
HIGH to LOW
LOW to HIGH
RS → O
2
13 selected
5
10
15
510 1020 ns
483 ns
179 ns
127 ns
+
+
+
(0,55 ns/pF) CL
(0,23 ns/pF) CL
(0,16 ns/pF) CL
tPHL
tPLH
HIGH to LOW
LOW to HIGH
190
135
380 ns
270 ns
RS → O
216 selected
5
10
15
5
575 1150 ns
548 ns
199 ns
142 ns
+
+
+
(0,55 ns/pF) CL
(0,23 ns/pF) CL
(0,16 ns/pF) CL
tPHL
tPLH
HIGH to LOW
LOW to HIGH
210
150
30
15
12
30
15
12
16
30
36
90
90
90
8
420 ns
300 ns
ns
Minimum clock
60
30
24
60
30
24
8
pulse width; LOW
10
15
5
tWRSL
tWMRH
fmax
ns
ns
Minimum reset
ns
pulse width; HIGH
10
15
5
ns
ns
Maximum clock
pulse frequency
MHz
10
15
5
15
18
MHz
MHz
kHz
kHz
kHz
kHz
kHz
kHz
Oscillator frequency
Oscillator frequency
Rt = 5 kΩ
10
15
5
fosc
Ct = 1 nF
RS = 10 kΩ
Rt = 56 kΩ
Ct = 1 nF
10
15
fosc
8
8
RS = 120 kΩ
January 1995
8
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