DATA SH EET
Product specification
File under Integrated Circuits, IC04 January 1995
INTEGRATED CIRCUITS
HEF4894B
12-stage shift-and-store register
LED driver
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
12-stage shift-and-store register LED driver HEF4894B
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 O0to
O11. 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 (Osand Os’) are
available for cascading a number of
HEF4894B devices. Data is available
at Oson 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 Os’ on the
next negative-going clock edge and
provides cascading HEF4894B
devices when the clock rise time is
slow.
ORDERING AND PACKAGE INFORMATION
PINNING
FAMILY DATA
See Family Specifications except for:
Rating for DC current into any open-drain output: 40 mA.
IDD LIMITS category MSI: see Family Specifications.
TYPE
NUMBER PACKAGES
PINS PIN POSITION MATERIAL CODE
HEF4894BT 20 SO plastic SO20/SOT163A
HEF4894BP 20 DIL plastic DIL20/SOT146
PIN SYMBOL NAME AND FUNCTION
1 STR strobe input
2 D data input
3 CP clock input
4, 5, 6, 7, 8, 9, 18,
17, 16, 15, 14, 13 O0to O11 parallel outputs (open drain)
10 Vss ground
11, 12 Os,O
s
’ serial outputs
19 EO output enable input
20 VDD positive supply voltage
Fig.1 Pinning diagram.
Preliminary pin assignment.
Fig.2 Functional diagram.
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Philips Semiconductors Product specification
12-stage shift-and-store register LED driver HEF4894B
Fig.3 Logic diagram.
Fig.4 One D-latch.
FUNCTION TABLE
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. O11’ = the information in the twelfth shift register stage.
At the positive clock edge the information in the 10th register stage is
transferred to the 11th register stage and the Osoutput.
INPUTS PARALLEL
OUTPUTS SERIAL
OUTPUTS
CP EO STR D O0OnOSOS’
↑LXX Z ZO
10’nc
↓LXX Z ZncO
11
↑HLXncncO
10’nc
↑HHL ZO
n
−1O
10’nc
↑HHH LO
n
−1O
10’nc
↓HHHncncncO
11
January 1995 4
Philips Semiconductors Product specification
12-stage shift-and-store register LED driver HEF4894B
DC CHARACTERISTICS
VSS =0 V.
AC CHARACTERISTICS
VSS = 0 V; Tamb =25°C; input transition times ≤20 ns.
AC CHARACTERISTICS
VSS = 0 V; Tamb =25°C; CL= 50 pF; input transition times ≤20 ns.
PARAMETER VDD
(V) SYMBOL
Tamb (°C)
UNIT CONDITIONS−40 +25 +85
MIN. MAX. MIN. MAX. MIN. MAX.
output voltage 5 VOL −0.75 −0.75 −1.5 V VI=V
SS or VDD;
LOW; On10 −0.75 −0.75 −1.5 Io < 20 mA
15 −0.75 −0.75 −1.5
output leakage 5 IOZH −2−2−15 µAV
o
= 15 V
current; HIGH; On10 −2−2−15
15 −2−2−15
PARAMETER VDD
(V) TYPICAL FORMULA FOR P
(µW)
Dynamic power 5 1200 fi+∑(foCL)×VDD2where:
dissipation per package 10 5550 fi+∑(foCL)×VDD2Rload =∞
(P) 15 15000 fi+∑(foCL)×VDD2fi= input frequency (MHz),
fo= output frequency (MHz),
CL= load capacitance (pF),
∑(foCL) = sum of outputs
VDD = supply voltage (V)
PARAMETER VDD
(V) SYMBOL TYP. MAX. UNIT TYPICAL EXTRAPOLATION
FORMULA
Propagation delay 5 160 320 132 ns +(0.55 ns/pF) CL
CP to Os10 tPHL 65 130 ns 53 ns +(0.23 ns/pF) CL
HIGH to LOW 15 45 90 37 ns + (0.16 ns/pF) CL
Propagation delay 5 130 260 102 ns +(0.55 ns/pF) CL
CP to Os10 tPLH 55 110 ns 44 ns + (0.23 ns/pF) CL
LOW to HIGH 15 40 80 32 ns + (0.16 ns/pF) CL
Propagation delay 5 120 240 92 ns +(0.55 ns/pF) CL
CP to Os’10t
PHL 50 100 ns 39 ns + (0.23 ns/pF) CL
HIGH to LOW 15 40 80 32 ns + (0.16 ns/pF) CL
Propagation delay 5 130 260 102 ns +(0.55 ns/pF) CL
CP to Os’10t
PLH 60 120 ns 49 ns + (0.23 ns/pF) CL
LOW to HIGH 15 45 90 37 ns +(0.16 ns/pF) CL
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Philips Semiconductors Product specification
12-stage shift-and-store register LED driver HEF4894B
Note
1. Definition of symbol equivalent to 3-state outputs.
AC CHARACTERISTICS
VSS = 0 V; Tamb =25°C; CL= 50 pF; input transition times ≤20 ns.
Propagation delay 5 240 480
CP to On10 tPZL 80 160 ns see note 1
OFF to LOW 15 55 110
Propagation delay 5 170 340
CP to On10 tPLZ 75 150 ns see note 1
LOW to OFF 15 60 120
Propagation delay 5 140 280
STR to On10 tPZL 70 140 ns see note 1
OFF to LOW 15 55 110
Propagation delay 5 100 200
STR to On10 tPLZ 40 100 ns see note 1
LOW to OFF 15 35 70
Output transition 5 85 170 35 ns +(1.0 ns/pF) CL
time; Os,O
s
’10t
THL 40 80 ns 19 ns + (0.42 ns/pF) CL
HIGH to LOW 15 30 60 16 ns +(0.28 ns/pF) CL
Output transition 5 85 170 35 ns +(1.0 ns/pF) CL
time; Os,O
s
’10t
TLH 40 80 ns 19 ns + (0.42 ns/pF) CL
LOW to HIGH 15 30 60 16 ns +(0.28 ns/pF) CL
PARAMETER VDD
(V) SYMBOL MIN. TYP. MAX. UNIT
output enable time 5 tPZL −100 200 ns
EO to On10 −55 110
OFF to LOW 15 −50 100
output disable time 5 tPLZ −80 160 ns
EO to On10 −40 80
LOW to OFF 15 −30 60
minimum clock pulse width 5 tWCPL 60 30 −ns
LOW 10 30 15 −
15 24 12 −
minimum strobe pulse width 5 tWSTRH 80 40 −ns
HIGH 10 60 30 −
15 24 12 −
PARAMETER VDD
(V) SYMBOL TYP. MAX. UNIT TYPICAL EXTRAPOLATION
FORMULA
January 1995 6
Philips Semiconductors Product specification
12-stage shift-and-store register LED driver HEF4894B
set-up time 5 tsu 60 30 −ns
D to CP 10 20 10 −
15 15 5 −
hold time 5 thold 5−15 −ns
D to CP 10 20 5 −
15 20 5 −
Maximum clock pulse frequency 5 fmax 510 −MHz
10 11 22 −
15 14 28 −
PARAMETER VDD
(V) SYMBOL MIN. TYP. MAX. UNIT
Fig.5 Timing diagram.
January 1995 7
Philips Semiconductors Product specification
12-stage shift-and-store register LED driver HEF4894B
APPLICATION INFORMATION
An example of applications for the HEF4894B is:
•Serial-to-parallel converting LED driver
Fig.6 LED driver register.
