74LS645

DM74LS645 FAIRCHILD

Document overview

• Manufacturer or author: Provided By www.digicamel.com(FREE DATASHEET DOWNLOAD SITE)
• PDF pages: 5

Technical content

Features

■ Bi-directional bus transceivers in high-density 20-pin packages ■ Hysteresis at bus inputs improves noise margins ■ 3-STATE outputs Ordering Code: Devices also available in Tape and Reel. Specify by appending the suffix letter “X” to the ordering code. Connection Diagram Function Table H = HIGH Level L = LOW Level X = Irrelevant Order Number Package Number Package Description DM74LS645WM M20B 20-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-013, 0.300 Wide DM74LS645N N20A 20-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300 Wide Control Inputs DM74LS645 G DIR L L B data to A bus L H A data to B bus H X Isolation

www.fairchildsemi.com 2 DM74LS645 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 Note 2: Voltage values are with respect to the network ground terminal.

Electrical Characteristics

over recommended operating free air temperature range (unless otherwise noted) Note 3: For conditions shown as Min or Max, use the appropriate value specified under Recommended Operating Conditions. Note 4: All typicals are at VCC = 5V, TA = 25°C. Note 5: Not more than one output should be shorted at a time, and the duration should not exceed one second. Supply Voltage 7V Input Voltage 7V Operating Free Air Temperature Range 0°C to +70°C Storage Temperature Range −55°C to +150°C Symbol Parameter Min Nom Max Units V CC Supply Voltage (Note 2) 4.75 5 5.25 V VIH HIGH Level Input Voltage 2 V VIL LOW Level Input Voltage 0.6 V IOH HIGH Level Output Current −15 mA IOL LOW Level Output Current 24 mA TA Free Air Operating Temperature 0 70 °C Symbol Parameter Conditions (Note 3) Min Typ Max Units (Note 4) VI Input Clamp Voltage V CC = Min, II = 18 mA −1.5 V H YS Hysteresis (VT+ − V−)V CC = Min 0.2 0.4 V A or B Input VOH HIGH Level Output Voltage V CC = Min, VIH = 2V, I OH = −3 mA 2.4 3.4 V VIL = Max I OH = Max 2 VOL LOW Level Output Voltage V CC = Min, VIH = 2V, I OL = 12 mA 0.25 0.4 V VIL = Max I OL = 24 mA 0.35 0.5 IOZH Off-State Output Current, V CC = Max, G at 2V, 20 µA HIGH Level Voltage Applied V O = 2.7V IOZL Off-State Output Current, V CC = Max, G at 2V −400 µA LOW Level Voltage Applied V O = 0.4V II Input Current at V CC = Max A or B V I = 5.5V 0.1 mA Maximum Input Voltage DIR or G V I = 7V 0.1 IIH HIGH Level Input Current V CC = Max, VIH = 2.7 20 µA IIL LOW Level Input Current V CC = Max, VIL = 0.4V −0.4 mA IOS Short Circuit Output Current (Note 5) VCC = Max −40 −225 mA ICC Total Supply Outputs HIGH V CC = Max, 48 70 Current Outputs LOW Outputs Open 62 90 mA Outputs at Hi-Z 64 95

3 www.fairchildsemi.com DM74LS645 Switching Characteristics at VCC = 5V and TA = 25°C From (Input) R L = 667Ω Symbol Parameter To (Output) C L = 45 pF C L = 5 pF Units M i nM a xM i nM a x tPLH Propagation Delay Time A to B 15 ns LOW-to-HIGH Level Output tPHL Propagation Delay Time A to B 15 ns HIGH-to-LOW Level Output tPLH Propagation Delay Time B to A 15 ns LOW-to-HIGH Level Output tPHL Propagation Delay Time B to A 15 ns HIGH-to-LOW Level Output tPZL Output Enable Time G to A 40 ns to LOW Level tPZH Output Enable Time G to A 40 ns to HIGH Level tPZL Output Enable Time G to B 40 ns to LOW Level tPZH Output Enable Time G to B 40 ns to HIGH Level tPLZ Output Disable Time G to A 25 ns to LOW Level tPHZ Output Disable Time G to A 25 ns to HIGH Level tPLZ Output Disable Time G to B 25 ns to LOW Level tPHZ Output Disable Time G to B 25 ns to HIGH Level

www.fairchildsemi.com 4 DM74LS645 Physical Dimensions inches (millimeters) unless otherwise noted 20-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-013, 0.300 Wide Package Number M20B

5 www.fairchildsemi.com DM74LS645 Octal Bus Transceiver Physical Dimensions inches (millimeters) unless otherwise noted (Continued) 20-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300 Wide Package Number N20A 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. www.fairchildsemi.com