Fairchild DM74LS503N 8-bit successive approximation register (with expansion control) Datasheet

Revised March 2000
DM74LS503
8-Bit Successive Approximation Register
(with Expansion Control)
General Description
Features
The DM74LS503 register has an active LOW Enable (E)
input that is used in cascading two or more packages for
longer word lengths. A HIGH signal on E, after a START
operation, forces Q7 HIGH and prevents the device from
accepting serial data. With the E input of an DM74LS503
connected to the CC output of a preceding (more significant) device, the DM74LS503 will be inhibited until the preceding device is filled, causing its CC output to go LOW.
This LOW signal then enables the DM74LS503 to accept
the serial data on subsequent clocks.
■ Performs serial-to-parallel conversion
■ Expansion control for longer words
■ Storage and control for successive approximation A to D
conversion
■ Low power Schottky version of 2503
Ordering Code:
Order Number
DM74LS503N
Package Number
N16E
Package Description
16-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300 Wide
Connection Diagram
Logic Symbol
VCC = Pin 16
GND = Pin 8
Pin Descriptions
Pin Names
D
Description
Serial Data Input
S
Start Input (Active LOW)
CP
Clock Pulse Input (Active Rising Edge)
E
Conversion Enable Input (Active LOW)
CC
Conversion Complete Output (Active LOW)
Q0–Q7
Parallel Register Outputs
Q7
Complement of Q7 Output
© 2000 Fairchild Semiconductor Corporation
DS010190
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DM74LS503 8-Bit Successive Approximation Register
March 1989
DM74LS503
Logic Diagrams
Note: Cell logic is repeated for register stages Q5 to Q1.
Connection for Longer Word Lengths
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2
Supply Voltage
Note 1: The “Absolute Maximum Ratings” are those values beyond which
the safety of the device cannot be guaranteed. The device should not be
operated at these limits. The parametric values defined in the Electrical
Characteristics tables are not guaranteed at the absolute maximum ratings.
The “Recommended Operating Conditions” table will define the conditions
for actual device operation.
7V
Input Voltage
7V
0°C to +70°C
Operating Free Air Temperature Range
−65°C to +150°C
Storage Temperature Range
Recommended Operating Conditions
Symbol
Parameter
Min
Nom
Max
4.75
5
5.25
Units
VCC
Supply Voltage
VIH
HIGH Level Input Voltage
V
VIL
LOW Level Input Voltage
0.8
V
IOH
HIGH Level Output Voltage
−0.4
mA
8
mA
70
°C
2
IOL
LOW Level Output Current
TA
Free Air Operating Temperature
0
tS (H)
Setup Time HIGH or LOW
16
tS (L)
S to CP
16
tH (H)
Hold Time HIGH or LOW
0
tH (L)
S to CP
0
tS (H)
Setup Time HIGH or LOW
8
tS (L)
D to CP
8
tH (H)
Hold Time HIGH or LOW
10
tH (L)
D to CP
10
tW (H)
CP Pulse Width HIGH or LOW
46
tW (L)
V
ns
ns
ns
ns
ns
46
Electrical Characteristics
Over recommended operating free air temperature range (unless otherwise noted)
Symbol
Parameter
Conditions
VI
Input Clamp Voltage
VCC = Min, II = −18 mA
VOH
HIGH Level
VCC = Min, IOH = Max,
Output Voltage
VIL = Max
VOL
II
Min
Typ
(Note 2)
Max
Units
−1.5
V
2.7
V
LOW Level
VCC = Min, IOL = Max, VIH = Min
0.5
Output Voltage
IOL = 4 mA, VCC = Min
0.4
Input Current @ Max
VCC = Max, VI = 7V
Input Voltage
VI = 10V
V
0.1
mA
IIH
HIGH Level Input Current
VCC = Max, VI = 2.7V
20
µA
IIL
LOW Level Input Current
VCC = Max, VI = 0.4V
−0.8
mA
IOS
Short Circuit Output Current
VCC = Max (Note 3)
ICC
Supply Current
VCC = Max
−20
−100
mA
65
mA
Note 2: All typicals are at VCC = 5V, TA = 25°C.
Note 3: Not more than one output should be shorted at a time, and the duration should not exceed one second.
Switching Characteristics
VCC = +5.0V, TA = +25°C
Symbol
RL = 2 kΩ, CL = 15 pF
Parameter
Min
Max
fMAX
Maximum Count Frequency
tPLH
Propagation Delay
15
35
MHz
tPHL
CP to Qn or CC
25
tPLH
Propagation Delay
20
tPHL
E to Q7
24
3
Units
ns
ns
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DM74LS503
Absolute Maximum Ratings(Note 1)
DM74LS503 8-Bit Successive Approximation Register
Physical Dimensions inches (millimeters) unless otherwise noted
16-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300 Wide
Package Number N16E
Fairchild does not assume any responsibility for use of any circuitry described, no circuit patent licenses are implied and
Fairchild reserves the right at any time without notice to change said circuitry and specifications.
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FAIRCHILD’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT
DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT OF FAIRCHILD
SEMICONDUCTOR CORPORATION. As used herein:
2. A critical component in any component of a life support
device or system whose failure to perform can be reasonably expected to cause the failure of the life support
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1. Life support devices or systems are devices or systems
which, (a) are intended for surgical implant into the
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to perform when properly used in accordance with
instructions for use provided in the labeling, can be reasonably expected to result in a significant injury to the
user.
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