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
HEF4894B
12-stage shift-and-store register
LED driver
Product specification
File under Integrated Circuits, IC04
January 1995
Philips Semiconductors
Product specification
12-stage shift-and-store register LED driver
APPLICATIONS
•
Automotive
•
Industrial
GENERAL DESCRIPTION
The HEF4894B is a 12 stage serial
shift register having a storage latch
associated with each stage for
strobing data from the serial input to
parallel LED driver outputs O
0
to
O
11
. Data is shifted on positive-going
clock transitions. The data in each
shift register stage is transferred to
the storage register when the strobe
(STR) input is HIGH. Data in the
storage register appears at the
outputs whenever the output enable
(EO) signal is HIGH.
Two serial outputs (O
s
and O
s
’) are
available for cascading a number of
HEF4894B devices. Data is available
at O
s
on positive-going clock edges to
allow high-speed operation in
cascaded systems in which the clock
rise time is fast. The same serial
information is available at O
s
’ on the
next negative-going clock edge and
provides cascading HEF4894B
devices when the clock rise time is
slow.
ORDERING AND PACKAGE INFORMATION
TYPE
NUMBER
HEF4894BT
HEF4894BP
PINNING
PIN
1
2
3
D
CP
SYMBOL
STR
PACKAGES
PINS
20
20
PIN POSITION
SO
DIL
MATERIAL
plastic
plastic
HEF4894B
CODE
SO20/SOT163A
DIL20/SOT146
NAME AND FUNCTION
strobe input
data input
clock input
parallel outputs (open drain)
ground
serial outputs
output enable input
positive supply voltage
4, 5, 6, 7, 8, 9, 18, O
0
to O
11
17, 16, 15, 14, 13
10
11, 12
19
20
FAMILY DATA
V
ss
O
s
, O
s
’
EO
V
DD
See Family Specifications except for:
Rating for DC current into any open-drain output: 40 mA.
I
DD
LIMITS category MSI:
see Family Specifications.
Preliminary pin assignment.
Fig.1 Pinning diagram.
Fig.2 Functional diagram.
January 1995
2
Philips Semiconductors
Product specification
12-stage shift-and-store register LED driver
HEF4894B
Fig.3 Logic diagram.
FUNCTION TABLE
INPUTS
CP
↑
↓
↑
Fig.4 One D-latch.
↑
↑
↓
Notes
1. H = HIGH state (the more positive voltage)
2. L = LOW state (the less positive voltage)
3. X = state is immaterial
4.
↑
= positive-going transition
5.
↓
= negative-going transition
6. Z = high impedance OFF state
7. nc = no change
8. O
11
’ = the information in the twelfth shift register stage.
At the positive clock edge the information in the 10
th
register stage is
transferred to the 11
th
register stage and the O
s
output.
EO
L
L
H
H
H
H
STR
X
X
L
H
H
H
D
X
X
X
L
H
H
PARALLEL
OUTPUTS
O
0
Z
Z
nc
Z
L
nc
O
n
Z
Z
nc
O
n
−
1
O
n
−
1
nc
SERIAL
OUTPUTS
O
S
O
10
’
nc
O
10
’
O
10
’
O
10
’
nc
O
S
’
nc
O
11
nc
nc
nc
O
11
January 1995
3
Philips Semiconductors
Product specification
12-stage shift-and-store register LED driver
HEF4894B
PARAMETER
Propagation delay
CP to O
n
OFF to LOW
Propagation delay
CP to O
n
LOW to OFF
Propagation delay
STR to O
n
OFF to LOW
Propagation delay
STR to O
n
LOW to OFF
Output transition
time; O
s
, O
s
’
HIGH to LOW
Output transition
time; O
s
, O
s
’
LOW to HIGH
Note
V
DD
(V)
5
10
15
5
10
15
5
10
15
5
10
15
5
10
15
5
10
15
SYMBOL
TYP.
240
MAX.
480
160
110
340
150
120
280
140
110
200
100
70
170
80
60
170
80
60
UNIT
TYPICAL EXTRAPOLATION
FORMULA
see note 1
t
PZL
80
55
170
ns
t
PLZ
75
60
140
ns
see note 1
t
PZL
70
55
100
ns
see note 1
t
PLZ
40
35
85
ns
see note 1
35 ns
+
(1.0 ns/pF) C
L
t
THL
40
30
85
ns
19 ns
+
(0.42 ns/pF) C
L
16 ns
+
(0.28 ns/pF) C
L
35 ns
+
(1.0 ns/pF) C
L
t
TLH
40
30
ns
19 ns
+
(0.42 ns/pF) C
L
16 ns
+
(0.28 ns/pF) C
L
1. Definition of symbol equivalent to 3-state outputs.
AC CHARACTERISTICS
V
SS
= 0 V; T
amb
= 25
°C;
C
L
= 50 pF; input transition times
≤
20 ns.
PARAMETER
output enable time
EO to O
n
OFF to LOW
output disable time
EO to O
n
LOW to OFF
minimum clock pulse width
LOW
minimum strobe pulse width
HIGH
V
DD
(V)
5
10
15
5
10
15
5
10
15
5
10
15
t
WSTRH
t
WCPL
t
PLZ
SYMBOL
t
PZL
MIN.
−
−
−
−
−
−
60
30
24
80
60
24
TYP.
100
55
50
80
40
30
30
15
12
40
30
12
MAX.
200
110
100
160
80
60
−
−
−
−
−
−
ns
ns
ns
ns
UNIT
January 1995
5
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