HEF4541BP ,Programmable timerINTEGRATED CIRCUITSDATA SHEETFor a complete data sheet, please also download:• The IC04 LOCMOS HE40 ..
HEF4541BT ,Programmable timerINTEGRATED CIRCUITSDATA SHEETFor a complete data sheet, please also download:• The IC04 LOCMOS HE40 ..
HEF4543BD ,BCD to 7-segment latch/decoder/driverINTEGRATED CIRCUITSDATA SHEETFor a complete data sheet, please also download:• The IC04 LOCMOS HE40 ..
HEF4543BF ,BCD to 7-segment latch/decoder/driverINTEGRATED CIRCUITSDATA SHEETFor a complete data sheet, please also download:• The IC04 LOCMOS HE40 ..
HEF4543BP ,BCD to 7-segment latch/decoder/driverINTEGRATED CIRCUITSDATA SHEETFor a complete data sheet, please also download:• The IC04 LOCMOS HE40 ..
HEF4543BT ,BCD to 7-segment latch/decoder/driverINTEGRATED CIRCUITSDATA SHEETFor a complete data sheet, please also download:• The IC04 LOCMOS HE40 ..
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HEF4541BP
Programmable timer
Philips Semiconductors Product specification
Programmable timer HEF4541B
MSI
DESCRIPTIONThe 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 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
disables the oscillator to provide no active power
dissipation.
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 by8,210,213 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.
FAMILY DATA, IDD LIMITS category MSISee Family Specifications
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
Philips Semiconductors Product specification
Programmable timer HEF4541B
MSI
Philips Semiconductors Product specification
Programmable timer HEF4541B
MSI
PINNING
FREQUENCY SELECTION TABLEA0,A1 address inputs
MODE mode select input auto reset input master reset input phase input
RTC external resistor connection (Rt)
CTC external capacitor connection (Ct) external resistor connection (RS)or
external clock input
FUNCTION TABLE
Notes For correct power-on reset, the supply voltage should
be above 8.5 V. For VDD < 8.5 V, disable the autoreset
and connect AR to VDD. 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 = HIGH state (the more positive voltage)
L = LOW state (the less positive voltage)= state is immaterial
RC oscillator
Timing component limitationsThe oscillator frequency is mainly determined by
RtCt, provided Rt << RS and RSC2 << RtCt. The function of 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, 300Ω at VDD= 10 V and 200Ωat
VDD = 15 V.
The recommended values for these components to
maintain agreement with the typical oscillation formula are:≥ 100 pF, up to any typical value, kΩ≤Rt≤ 1MΩ.
Philips Semiconductors Product specification
Programmable timer HEF4541B
MSI
Philips Semiconductors Product specification
Programmable timer HEF4541B
MSI
