Document
DM74ALS245A Octal 3-STATE Bus Transceiver
September 1986 Revised February 2000
DM74ALS245A Octal 3-STATE Bus Transceiver
General Description
This advanced low power Schottky device contains 8 pairs of 3-STATE logic elements configured as octal bus transceivers. These circuits are designed for use in memory, microprocessor systems and in asynchronous bidirectional data buses. Two way communication between buses is controlled by the (DIR) input. Data transmits either from the A bus to the B bus or from the B bus to the A bus. Both the driver and receiver outputs can be disabled via the (G) enable input which causes outputs to enter the high impedance mode so that the buses are effectively isolated.
Features
s Advanced oxide-isolated, ion-implanted Schottky TTL process s Non-inverting logic output s Glitch free bus during power up and down s 3-STATE outputs independently controlled on A and B buses s Low output impedance to drive terminated transmission lines to 133Ω s Switching response specified into 500Ω/50 pF s Specified to interface with CMOS at VOH = VCC − 2V s PNP inputs to reduce input loading s Switching specifications guaranteed over full temperature and VCC range
Ordering Code:
Order Number DM74ALS245AWM DM74ALS245ASJ DM74ALS245AMSA DM74ALS245AN Package Number M20B M20D MSA20 N20A Package Description 20-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-013, 0.300 Wide 20-Lead Small Outline Package (SOP), EIAJ TYPE II, 5.3mm Wide 20-Lead Shrink Small Outline Package (SSOP), EIAJ TYPE II, 5.3mm Wide 20-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300 Wide
Devices also available in Tape and Reel. Specify by appending the suffix letter “X” to the ordering code.
Connection Diagram
Function Table
Control Inputs G L L H DIR L H X B Data to A Bus A Data to B Bus Hi-Z Operation
H = HIGH Logic Level L = LOW Logic Level X = Either HIGH or LOW Logic Level
© 2000 Fairchild Semiconductor Corporation
DS006213
www.fairchildsemi.com
DM74ALS245A
Absolute Maximum Ratings(Note 1)
Supply Voltage Input Voltage Control Inputs I/O Ports Operating Free Air Temperature Range Storage Temperature Range Typical θJA N Package M Package 53.0°C/W 72.0°C/W 7V 5.5V 0°C to +70°C −65°C to +150°C
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
Recommended Operating Conditions
Symbol VCC VIH VIL IOH IOL TA Supply Voltage HIGH Level Input Voltage LOW Level Input Voltage HIGH Level Output Current LOW Level Output Current Operating Free Air Temperature 0 Parameter Min 4.5 2 0.8 −15 24 70 Typ 5 Max 5.5 Units V V V mA mA °C
Electrical Characteristics
over recommended operating free air temperature range. All.