Revised March 2000 DM74AS257 • DM74AS258 3-STATE Quad 1 of 2 Line Data Selector/Multiplexers General Description Features These data selectors/multiplexers contain inverters and drivers to supply full on-chip data selection to the four 3STATE outputs that can interface directly with data lines of bus-organized systems. A 4-bit word selected from one of two sources is routed to the four outputs. The DM74AS257 presents true data whereas the DM74AS258 presents inverted data to minimize propagation delay time. ■ Switching specifications at 50 pF This 3-STATE output feature means that n-bit (paralleled) data selectors with up to 300 sources can be implemented for data buses. It also permits the use of standard TTL registers for data retention throughout the system. ■ Switching specifications guaranteed over full temperature and VCC range ■ Advanced oxide-isolated, ion-implanted Schottky TTL process ■ Functionally and pin for pin compatible with Schottky, low power Schottky, and advanced low power Schottky TTL counterpart ■ Improved AC performance over Schottky, low power Schottky, and advanced low power Schottky counterparts ■ 3-STATE buffer-type output drive bus lines directly ■ Expand any data input point ■ Multiplex dual data buses ■ General four functions of two variables (one variable is common) ■ Source programmable counters Ordering Code: Order Number DM74AS257M Package Number Package Description M16A 16-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-012, 0.150 Narrow DM74AS257N N16E 16-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300 Wide DM74AS258M M16A 16-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-012, 0.150 Narrow DM74AS258N N16E 16-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 INPUTS OUTPUT Y OUTPUT SELECT A B AS257 AS258 H X X X Z Z L L L X L H L L H X H L L H X L L H L H X H H L CONTROL H = HIGH Level L = LOW Level X = Don't Care Z = High Impedance (OFF) © 2000 Fairchild Semiconductor Corporation DS006107 www.fairchildsemi.com DM74AS257 • DM74AS258 3-STATE Quad 1 of 2 Line Data Selector/Multiplexers September 1986 DM74AS257 • DM74AS258 Logic Diagrams DM74AS257 www.fairchildsemi.com DM74AS258 2 Supply Voltage, VCC 7V Input Voltage 7V Voltage Applied to Disabled Output 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. 5.5V 0°C to +70°C Operating Free Air Temperature Range −65°C to +150°C Storage Temperature Range Typical θJA N Package 75.0°C/W Recommended Operating Conditions Symbol Parameter Min Nom Max 4.5 5 5.5 Units VCC Supply Voltage VIH HIGH Level Input Voltage V VIL LOW Level Input Voltage 0.8 V IOH HIGH Level Output Current −15 mA IOL LOW Level Output Current 48 mA TA Free Air Operating Temperature 70 °C 2 V 0 Electrical Characteristics over recommended operating free air temperature range. All typical values are measured at VCC = 5V, TA = 25°C. Symbol VIK Parameter Input Clamp VOL HIGH Level VCC = 4.5V, IOH = Max Output Voltage IOH = −2 mA, VCC = 4.5V to 5.5V LOW Level Output Voltage II Input Current @ 2.4 VCC = 5.5V, VIH = 7V VCC = 5.5V, VIH = 2.7V HIGH Level VCC = 5.5V, VIL = 0.4V LOW Level Output Drive Current VCC = 5.5V, VO = 2.25V IOZH Off-State Output Current, VCC = 5.5V HIGH Level Voltage Applied VO = 2.7V IOZL ICCH ICCL ICCZ Off-State Output Current, VCC = 5.5V LOW Level Voltage Applied VO = 0.4V Supply DM74AS257 Current DM74AS258 Supply DM74AS257 VCC = 5.5V Current DM74AS258 Outputs Open Supply DM74AS257 Current DM74AS258 −1.2 V V 0.5 A, B, G 0.1 Select 0.2 A, B, G 20 Select 40 −1 −0.5 All Others IO (Note 2) Units V Select Input Current Max 3.2 0.35 Input Current IIL Typ VCC − 2 VCC = 4.5V, IOL = Max Max Input Voltage IIH Min VCC = 4.5V, II = −18 mA Voltage VOH Conditions −30 Outputs HIGH Outputs LOW Outputs Disabled V mA µA mA −112 mA −50 µA −50 µA 12.9 19.7 mA 8.8 13.5 mA 19 30.6 mA 15.8 24.6 mA 19.7 31.9 mA 15.5 25.2 mA Note 2: The output conditions have been chosen to produce a current that closely approximates one half of the true short-circuit output current, IOS. 3 www.fairchildsemi.com DM74AS257 • DM74AS258 Absolute Maximum Ratings(Note 1) DM74AS257 • DM74AS258 DM74AS257 Switching Characteristics over recommended operating free air temperature range Symbol tPLH Parameter From To Data Any Propagation Delay Time, LOW-to-HIGH Level Output tPHL Conditions VCC = 4.5V to 5.5V, CL = 50 pF, Y RL = 500Ω Propagation Delay Time, HIGH-to-LOW Level Output tPLH Propagation Delay Time, Select LOW-to-HIGH Level Output tPHL Any Y Propagation Delay Time, HIGH-to-LOW Level Output tPZH Output Enable Time to HIGH Level tPZL OUTPUT Any Control Y Output Enable Time to LOW Level tPHZ Output Disable Time, from HIGH Level tPLZ OUTPUT Any Control Y Output Disable Time, from LOW Level Min Max Units 1 5.5 ns 1 6 ns 2 11 ns 2 10 ns 2 7.5 ns 2 9.5 ns 1.5 6.5 ns 2 7 ns Min Max Units 1 5 ns 1 4 ns 2 9.5 ns 2 10 ns 2 8 ns 2 10 ns 1.5 6 ns 2 6.5 ns DM74AS258 Switching Characteristics over recommended operating free air temperature range Symbol tPLH Parameter Propagation Delay Time, From To Data Any LOW-to-HIGH Level Output tPHL Conditions CL = 50 pF, Y RL = 500Ω Propagation Delay Time, HIGH-to-LOW Level Output tPLH Propagation Delay Time, Select LOW-to-HIGH Level Output tPHL Any Y Propagation Delay Time, HIGH-to-LOW Level Output tPZH Output Enable Time to HIGH Level tPZL OUTPUT Any Control Y Output Enable Time to LOW Level tPHZ Output Disable Time, from HIGH Level tPLZ OUTPUT Any Control Y Output Disable Time, from LOW Level www.fairchildsemi.com VCC = 4.5V to 5.5V, 4 DM74AS257 • DM74AS258 Physical Dimensions inches (millimeters) unless otherwise noted 16-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-012, 0.150 Narrow Package Number M16A 5 www.fairchildsemi.com DM74AS257 • DM74AS258 3-STATE Quad 1 of 2 Line Data Selector/Multiplexers Physical Dimensions inches (millimeters) unless otherwise noted (Continued) 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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