DM74LS503中文资料
? 2000 Fairchild Semiconductor Corporation DS010190
https://www.wendangku.net/doc/be8701584.html,
March 1989Revised March 2000
DM74LS503 8-Bit Successive Approximation Register
DM74LS503
8-Bit Successive Approximation Register (with Expansion Control)
General Description
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 DM74LS503connected to the CC output of a preceding (more signifi-cant) device, the DM74LS503 will be inhibited until the pre-ceding 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. Features
s Performs serial-to-parallel conversion s Expansion control for longer words
s Storage and control for successive approximation A to D conversion s Low power Schottky version of 2503
Ordering Code:
Connection Diagram Logic Symbol
V CC = Pin 16GND = Pin 8
Pin Descriptions
Order Number Package Number
Package Description
DM74LS503N
N16E
16-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300 Wide
Pin Names Description
D 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–Q7Parallel Register Outputs Q7
Complement of Q7 Output
https://www.wendangku.net/doc/be8701584.html, 2
D M 74L S 503
Logic Diagrams
Note: Cell logic is repeated for register stages Q5 to Q1.
Connection for Longer Word Lengths
https://www.wendangku.net/doc/be8701584.html,
DM74LS503
Absolute Maximum Ratings (Note 1)
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.
Recommended Operating Conditions
Electrical Characteristics
Over recommended operating free air temperature range (unless otherwise noted)Note 2: All typicals are at V CC = 5V, T A = 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
V CC = +5.0V, T A = +25°C
Supply Voltage 7V Input Voltage
7V
Operating Free Air Temperature Range 0°C to +70°C Storage Temperature Range
?65°C to +150°C
Symbol Parameter
Min Nom Max Units V CC Supply Voltage
4.755
5.25
V V IH HIGH Level Input Voltage 2
V V IL LOW Level Input Voltage 0.8V I OH HIGH Level Output Voltage ?0.4mA I OL LOW Level Output Current 8mA T A Free Air Operating Temperature 070
°C t S (H)Setup Time HIGH or LOW 16ns t S (L)S to CP
16t H (H)Hold Time HIGH or LOW 0ns t H (L)S to CP
0t S (H)Setup Time HIGH or LOW 8ns t S (L) D to CP
8t H (H)Hold Time HIGH or LOW 10ns t H (L) D to CP
10t W (H)CP Pulse Width HIGH or LOW
46ns
t W (L)
46
Symbol Parameter
Conditions
Min
Typ Max Units (Note 2)
V I Input Clamp Voltage V CC = Min, I I = ?18 mA ?1.5
V V OH HIGH Level V CC = Min, I OH = Max, 2.7
V Output Voltage V IL = Max
V OL LOW Level V CC = Min, I OL = Max, V IH = Min
0.5V Output Voltage I OL = 4 mA, V CC = Min 0.4I I Input Current @ Max V CC = Max, V I = 7V 0.1mA Input Voltage
V I = 10V
I IH HIGH Level Input Current V CC = Max, V I = 2.7V 20μA I IL LOW Level Input Current V CC = Max, V I = 0.4V ?0.8mA I OS Short Circuit Output Current V CC = Max (Note 3)?20?100mA I CC
Supply Current
V CC = Max
65
mA
Symbol Parameter
R L = 2 k ?, C L = 15 pF Units Min Max
f MAX Maximum Count Frequency 15
MHz t PLH Propagation Delay 35ns t PHL CP to Qn or CC 25t PLH Propagation Delay 20ns
t PHL
E to Q7
24
https://www.wendangku.net/doc/be8701584.html,
4
D M 74L S 503 8-B i t S u c c e s s i v e A p p r o x i m a t i o n R e g i s t e r
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.LIFE SUPPORT POLICY
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:1.Life support devices or systems are devices or systems which, (a) are intended for surgical implant into the body, or (b) support or sustain life, and (c) whose failure to perform when properly used in accordance with instructions for use provided in the labeling, can be rea-sonably expected to result in a significant injury to the user. 2. A critical component in any component of a life support device or system whose failure to perform can be rea-sonably expected to cause the failure of the life support device or system, or to affect its safety or effectiveness.
https://www.wendangku.net/doc/be8701584.html,