Datasheet HEF4538BU, HEF4538BT, HEF4538BPB, HEF4538BP, HEF4538BDB Datasheet (Philips)

DATA SH EET

Product specification
File under Integrated Circuits, IC04

January 1995

INTEGRATED CIRCUITS

HEF4538B
MSI

Dual precision monostable
multivibrator

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

January 1995 2

Philips Semiconductors Product specification

Dual precision monostable multivibrator

HEF4538B

MSI

DESCRIPTION

The HEF4538B is a dual retriggerable-resettable
monostable multivibrator. Each multivibrator has an active
LOW trigger/retrigger input (I0), an active HIGH
trigger/retrigger input (I1), an overriding active LOW direct
reset input (CD), an output (O) and its complement (O),
and two pins (CTC,

(1)

RCTC) for connecting the external
timing components Ctand Rt. Typical pulse width variation
over temperature range is ± 0,2%.

The HEF4538B may be triggered by either the positive or
the negative edges of the input pulse and will produce an

accurate output pulse with a pulse width range of 10 µs to
infinity. The duration and accuracy of the output pulse are
determined by the external timing components C

t

and Rt.
The output pulse width (T) is equal to Rt× Ct. The linear
design techniques in LOCMOS guarantee precise control
of the output pulse width.

A LOW level at CDterminates the output pulse
immediately. Schmitt-trigger action in the trigger inputs
makes the circuit highly tolerant to slower rise and fall
times.

Fig.1 Functional diagram.

PINNING

Note

1. Always connected to ground.

FAMILY DATA, I

DD

LIMITS category MSI

See Family specifications.

HEF4538BP(N): 16-lead DIL; plastic (SOT38-1)
HEF4538BD(F): 16-lead DIL; ceramic (cerdip) (SOT74)
HEF4538BT(D): 16-lead SO; plastic (SOT109-1)
( ): Package Designator North America

I

0A,I0B

input (HIGH to LOW triggered)

I

1A

, I

1B

input (LOW to HIGH triggered)

CDA, C

DB

direct reset input (active LOW)

O

A

, O

B

output

OA, O

B

complementary output (active LOW)

C

TC A

, C

TC B

external capacitor connections

(1)

RC

TC A

, RC

TC B

external capacitor/ resistor
connections

Fig.2 Pinning diagram.

January 1995 3

Philips Semiconductors Product specification

Dual precision monostable multivibrator

HEF4538B

MSI

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Fig.3 Logic diagram.

January 1995 4

Philips Semiconductors Product specification

Dual precision monostable multivibrator

HEF4538B

MSI

FUNCTION TABLE

Notes

1. H = HIGH state (the more positive voltage)
L = LOW state (the less positive voltage)
X = state is immaterial

= positive output pulse
= negative output pulse
= positive-going transition
= negative-going transition

INPUTS OUTPUTS

I

0

I

1

C

D

O O

LH
HH
XXLLH

Fig.4 Connection of the external timing

components Rtand Ct.

DC CHARACTERISTICS

V

SS

=0V

Note

1. Only one monostable is switching: current present during output pulse (output O is HIGH).

V

DD

V

SYMBOL

T

amb

(°C)

− 40 + 25 + 85

TYP. MAX. TYP. MAX. TYP. MAX.

Supply current 5 55 µA

active state 10 I

D

150 µA

(see note) 15 220 µA

Input leakage

current 15 ± I

IN

300 1000 nA

(pins 2 and 14)

January 1995 5

Philips Semiconductors Product specification

Dual precision monostable multivibrator

HEF4538B

MSI

AC CHARACTERISTICS

V

SS

=0V; T

amb

=25°C; CL= 50 pF; input transition times ≤ 20 ns

V

DD

V

SYMBOL MIN. TYP. MAX.

TYPICAL EXTRAPOLA TION

FORMULA

Propagation delays

I0, I1→ O 5 200 460 ns 173 ns + (0,55 ns/pF) C

L

HIGH to LOW 10 t

PHL

90 180 ns 79 ns + (0,23 ns/pF) C

L

15 60 120 ns 52 ns + (0,16 ns/pF) C

L

I0, I1→ O 5 220 440 ns 193 ns + (0,55 ns/pF) C

L

LOW to HIGH 10 t

PLH

85 190 ns 74 ns + (0,23 ns/pF) C

L

15 60 120 ns 52 ns + (0,16 ns/pF) C

L

CD→ O 5 125 250 ns 98 ns + (0,55 ns/pF) C

L

HIGH to LOW 10 t

PHL

55 110 ns 44 ns + (0,23 ns/pF) C

L

15 40 80 ns 32 ns + (0,16 ns/pF) C

L

CD→ O 5 125 250 ns 98 ns + (0,55 ns/pF) C

L

LOW to HIGH 10 t

PLH

55 110 ns 44 ns + (0,23 ns/pF) C

L

15 40 80 ns 32 ns + (0,16 ns/pF) C

L

Recovery times 5 20 40 ns

CD→ I0,I

1

10 t

RCD

10 20 ns

15 5 10 ns

Retrigger times 5 0 ns

O,

O → I0,I

1

10 t

RO

0ns

15 0 ns

Minimum I

0

59045ns

pulse width; LOW 10 t

WI0L

30 15 ns

15 24 12 ns

Minimum I

1

55025ns

pulse width; HIGH 10 t

WI1H

24 12 ns

15 20 10 ns

Minimum C

D

55525ns

pulse width; LOW 10 t

WCDL

25 12 ns

15 20 10 ns

Output O or

O 5 218 230 242 µs

R

t

= 100 kΩ

Ct= 0,002 µF

pulse width 10 t

WO

213 224 235 µs

15 211 223 234 µs

Output O or O 5 10,3 10,8 11,3 ms

R

t

= 100 kΩ

Ct= 0,1 µF

pulse width 10 t

WO

10,2 10,7 11,2 ms

15 10,1 10,6 11,1 ms

Output O or O 5 1,01 1,09 1,11 s

R

t

= 100 kΩ

Ct=10µF

pulse width 10 t

WO

0,99 1,04 1,09 s

15 0,99 1,04 1,09 s

January 1995 6

Philips Semiconductors Product specification

Dual precision monostable multivibrator

HEF4538B

MSI

AC CHARACTERISTICS

V

SS

=0V; T

amb

=25°C; CL= 50 pF; input transition times ≤ 20 ns

Note

1. The maximum permissible resistance R

t

, which holds the specified accuracy of tWO, depends on the leakage current

of the capacitor Ctand the leakage of the HEF4538B.

V

DD

V

SYMBOL MIN. TYP. MAX.

Change in output O 5 ± 0,2 %

pulse width over 10 ∆t

WO

± 0,2 %

temperature (T

amb

)15 ±0,2 %

Change in output O

pulse width over ∆t

WO

± 1,5 %

V

DD

range 5 to 15 V

Pulse width variation 5 ± 1%

R

t

= 100 kΩ

Ct= 2 nF to 10 µF

between circuits 10 ∆t

WO

± 1%

in same package 15 ± 1%

External timing

resistor R

t

5 −

(1)

kΩ

External timing

capacitor C

t

2000 − no limits pF

Input capacitance

(pin 2 or 14) C

IN

15 pF

January 1995 7

Philips Semiconductors Product specification

Dual precision monostable multivibrator

HEF4538B

MSI

Fig.5 Waveforms showing minimum I0, I1, O and CDpulse widths, recovery times and propagation delays.

Fig.6 Timing diagram.

(1) Positive edge triggering.
(2) Positive edge re-triggering (pulse lengthening).
(3) Negative edge triggering.
(4) Reset (pulse shortening).
(5) T = Rt× Ct.

January 1995 8

Philips Semiconductors Product specification

Dual precision monostable multivibrator

HEF4538B

MSI

Fig.7 Typical normalized change in output pulse width as a function of ambient temperature; 0% at

VDD= 10 V and T

amb

=25°C.

(a) Rt= 100 kΩ; Ct= 100 nF.. (b) Rt= 100 kΩ; Ct= 2 nF.

Fig.8 Typical normalized change in output pulse

width as a function of the supply voltage at
T

amb

=25°C; 0% at

VDD=10V;Rt= 100 kΩ.

Fig.9 Total supply current as a function of the

output duty factor; Rt= 100 kΩ;
Ct= 100 nF; CL= 50 pF. One monostable
multivibrator switching only.