English
Language : 

MC14557_04 Datasheet, PDF (1/8 Pages) ON Semiconductor – 1-to-64 Bit Variable Length Shift Register
MC14557B
1−to−64 Bit Variable Length
Shift Register
The MC14557B is a static clocked serial shift register whose length
may be programmed to be any number of bits between 1 and 64. The
number of bits selected is equal to the sum of the subscripts of the
enabled Length Control inputs (L1, L2, L4, L8, L16, and L32) plus
one. Serial data may be selected from the A or B data inputs with the
A/B select input. This feature is useful for recirculation purposes. A
Clock Enable (CE) input is provided to allow gating of the clock or
negative edge clocking capability.
The device can be effectively used for variable digital delay lines or
simply to implement odd length shift registers.
• 1−64 Bit Programmable Length
• Q and Q Serial Buffered Outputs
• Asynchronous Master Reset
• All Inputs Buffered
• No Limit On Clock Rise and Fall Times
• Supply Voltage Range = 3.0 Vdc to 18 Vdc
• Capable of Driving Two Low−power TTL Loads or one Low−power
Schottky TTL Load Over the Rated Temperature Range
• Pb−Free Packages are Available
MAXIMUM RATINGS (Voltages Referenced to VSS)
Symbol
Parameter
Value
Unit
VDD
DC Supply Voltage Range
−0.5 to +18.0
V
Vin, Vout Input or Output Voltage Range
−0.5 to VDD + 0.5
V
(DC or Transient)
Iin, Iout
Input or Output Current
(DC or Transient) per Pin
±10
mA
PD
Power Dissipation,
per Package (Note 2)
500
mW
TA
Ambient Temperature Range
Tstg
Storage Temperature Range
TL
Lead Temperature
(8−Second Soldering)
−55 to +125
°C
−65 to +150
°C
260
°C
Maximum ratings are those values beyond which device damage can occur.
Maximum ratings applied to the device are individual stress limit values (not
normal operating conditions) and are not valid simultaneously. If these limits are
exceeded, device functional operation is not implied, damage may occur and
reliability may be affected.
1. Vin and Vout should be constrained to the range VSS v (Vin or Vout) v VDD.
Unused inputs must always be tied to an appropriate logic voltage level (e.g.,
either VSS or VDD). Unused outputs must be left open.
2. Temperature Derating:
Plastic “P and D/DW” Packages: – 7.0 mW/°C From 65°C To 125°C
*For additional information on our Pb−Free strategy and soldering details, please
download the ON Semiconductor Soldering and Mounting Techniques
Reference Manual, SOLDERRM/D.
http://onsemi.com
MARKING DIAGRAMS
16
1
PDIP−16
P SUFFIX
CASE 648
16
MC14557BCP
AWLYYWW
1
1
SO−16 WB
DW SUFFIX
CASE 751G
16
14557
AWLYYWW
1
SOEIAJ−16
F SUFFIX
CASE 966
16
MC14557B
ALYW
1
A
= Assembly Location
WL, L = Wafer Lot
YY, Y = Year
WW, W = Work Week
ORDERING INFORMATION
See detailed ordering and shipping information in the package
dimensions section on page 6 of this data sheet.
© Semiconductor Components Industries, LLC, 2004
1
June, 2004 − Rev. 5
Publication Order Number:
MC14557B/D