900,000+ Datasheet PDF Search and Download

Datasheet4U offers most rated semiconductors datasheets pdf

National Semiconductor Electronic Components Datasheet


16 Bit Data Transceiver

No Preview Available !

74ETL16245 pdf
May 1994
54 74ETL16245 16-Bit Data
Transceiver with Incident Wave Switching
General Description
The 54 74ETL16245 contains sixteen non-inverting bidirec-
tional buffers with TRI-STATE outputs designed with inci-
dent wave switching live insertion support and enhanced
noise margin for TTL backplane applications
Both the A and B ports include a bus hold circuit to latch the
output to the value last forced on that pin
The B port of this device includes 25X series output resis-
tors which minimize undershoot and ringing
Y Supports the VME64 ETL specification
Y Functionally and pin compatible with industry standard
TTL 16245 SSOP pinout
Y Improved TTL-compatible input threshold range
Y High drive TTL-compatible outputs (IOH e b60 mA
IOL e 90 mA)
Y Supports 25X incident wave switching on the A port
Y BiCMOS design significantly reduces power dissipation
Y Distributed VCC and GND pin configuration minimizes
high-speed switching noise
Y 25X series-dampening resistor on B-port
Y Available in 48-pin SSOP and ceramic flatpak
Y Guaranteed output skew
Y Guaranteed simultaneous switching noise level and
dynamic threshold performance
Y Guaranteed latchup protection
Logic Symbol
Connection Diagram
Pin Assignment for
SSOP and Flatpak
TL F 11654 – 1
Pin Description
Pin Names
Transmit Receive Input
Output Enable Input (Active LOW)
Backplane Bus Data
Local Bus Data
TRI-STATE is a registered trademark of National Semiconductor Corporation
C1995 National Semiconductor Corporation TL F 11654
TL F 11654 – 2
RRD-B30M105 Printed in U S A

No Preview Available !

74ETL16245 pdf
Functional Description
The device uses byte-wide Direction (DIR) control and Out-
put Enable (OE) controls The DIR inputs determine the di-
rection of data flow through the device The OE inputs dis-
able the A and the B ports
The part contains active circuitry which keeps all outputs
disabled when VCC is less than 2 2V to aid in live insertion
Logic Diagrams (Positive Logic)
Truth Table (Each 8-bit Section)
A Data to B Bus
B Data to A Bus
TL F 11654–3
ETL’s Improved Noise Immunity
TTL input thresholds are typically determined by tempera-
ture-dependent junction voltages which result in worst case
input thresholds between 0 8V and 2 0V By contrast ETL
provides greater noise immunity because its input thresh-
olds are determined by current mode input circuits similar to
those used for ECL or BTL ETL’s worst case input thresh-
olds between 1 4V and 1 6V are compensated for temper-
ature voltage and process variations
TL F 11654 – 4
Incident Wave Switching
When TTL logic is used to drive fully loaded backplanes the
combination of low backplane bus characteristic imped-
ance wide TTL input threshold range and limited TTL drive
generally require multiple waveform reflections before a val-
id signal can be received across the backplane The VME
International Trade Association (VITA) defined ETL to pro-
vide incident wave switching which increases the data trans-
fer rate of a VME backplane and extends the life of VME
applications TTL compatibility with existing VME back-
planes and modules was maintained
Improved Input Threshold Characteristics of ETL
ABTC Worst Case VOUT – VIN
TL F 11654–5
ETL Worst Case VOUT – VIN
TL F 11654 – 6

Part Number 74ETL16245
Description 16 Bit Data Transceiver
Maker National - National
Total Page 10 Pages
PDF Download
74ETL16245 pdf
Download PDF File
74ETL16245 pdf
View for Mobile

Featured Datasheets

Part Number Description Manufacturers PDF
74ETL16245 16 Bit Data Transceiver 74ETL16245

Part Number Start With

0  1  2  3  4  5  6  7  8  9  A  B  C  D  E  F  G  H  I  J  K  L  M  N  O  P  Q  R  S  T  U  V  W  X  Y  Z

site map

webmaste! click here

contact us

Buy Components