Revised July 2003 74AC138 • 74ACT138 1-of-8 Decoder/Demultiplexer General Description Features The AC/ACT138 is a high-speed 1-of-8 decoder/demultiplexer. This device is ideally suited for high-speed bipolar memory chip select address decoding. The multiple input enables allow parallel expansion to a 1-of-24 decoder using just three AC/ACT138 devices or a 1-of-32 decoder using four AC/ACT138 devices and one inverter. ■ ICC reduced by 50% ■ Demultiplexing capability ■ Multiple input enable for easy expansion ■ Active LOW mutually exclusive outputs ■ Outputs source/sink 24 mA ■ ACT138 has TTL-compatible inputs Ordering Code: Order Number Package Number 74AC138SC M16A 16-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-012, 0.150" Narrow M16D 16-Lead Small Outline Package (SOP), EIAJ TYPE II, 5.3mm Wide 74AC138SJ 74AC138MTC MTC16 74AC138PC Package Description 16-Lead Thin Shrink Small Outline Package (TSSOP), JEDEC MO-153, 4.4mm Wide N16E 16-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300" Wide 74ACT138SC M16A 16-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-012, 0.150" Narrow 74ACT138SJ M16D 16-Lead Small Outline Package (SOP), EIAJ TYPE II, 5.3mm Wide 74ACT138PC N16E 16-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300" Wide Device also available in Tape and Reel. Specify by appending suffix letter “X” to the ordering code. Connection Diagram Logic Symbols IEEE/IEC Pin Descriptions Pin Names Description A0–A2 Address Inputs E1–E2 Enable Inputs E3 Enable Input O0–O7 Outputs FACT is a trademark of Fairchild Semiconductor Corporation. © 2003 Fairchild Semiconductor Corporation DS009925 www.fairchildsemi.com 74AC138 • 74ACT138 1-of-8 Decoder/Demultiplexer November 1988 74AC138 • 74ACT138 Truth Table Inputs Outputs E1 E2 E3 A0 A1 A2 O0 O1 O2 O3 O4 O5 O6 H X X X X X H H H H H H H H X H X X X X H H H H H H H H X X L X X X H H H H H H H H L L H L L L L H H H H H H H L L H H L L H L H H H H H H L L H L H L H H L H H H H H L L H H H L H H H L H H H H L L H L L H H H H H L H H H L L H H L H H H H H H L H H L L H L H H H H H H H H L H L L H H H H H H H H H H H L H = HIGH Voltage Level L = LOW Voltage Level O7 X = Immaterial Functional Description Logic Diagram The AC/ACT138 high-speed 1-of-8 decoder/demultiplexer accepts three binary weighted inputs (A0, A1, A2) and, when enabled, provides eight mutually exclusive activeLOW outputs (O0–O7). The AC/ACT138 features three Enable inputs, two active-LOW (E1, E2) and one activeHIGH (E3). All outputs will be HIGH unless E1 and E2 are LOW and E3 is HIGH. This multiple enable function allows easy parallel expansion of the device to a 1-of-32 (5 lines to 32 lines) decoder with just four AC/ACT138 devices and one inverter (see Figure 1). The AC/ACT138 can be used as an 8-output demultiplexer by using one of the active LOW Enable inputs as the data input and the other Enable inputs as strobes. The Enable inputs which are not used must be permanently tied to their appropriate active-HIGH or active-LOW state. Please note that this diagram is provided only for the understanding of logic operations and should not be used to estimate propagation delays. FIGURE 1. Expansion to 1-of-32 Decoding www.fairchildsemi.com 2 Recommended Operating Conditions −0.5V to +7.0V Supply Voltage (VCC) DC Input Diode Current (IIK) VI = −0.5V −20 mA VI = VCC + 0.5V +20 mA DC Input Voltage (VI) Supply Voltage (VCC) −0.5V to VCC + 0.5V VO = VCC + 0.5V +20 mA 0V to VCC −40°C to +85°C Minimum Input Edge Rate (∆V/∆t) AC Devices DC Output Source VIN from 30% to 70% of VCC ±50 mA VCC @ 3.3V, 4.5V, 5.5V 125 mV/ns Minimum Input Edge Rate (∆V/∆t) DC VCC or Ground Current ±50 mA per Output Pin (ICC or IGND) Storage Temperature (TSTG) 0V to VCC Operating Temperature (TA) −0.5V to VCC + 0.5V or Sink Current (IO) 4.5V to 5.5V Output Voltage (VO) −20 mA DC Output Voltage (VO) 2.0V to 6.0V ACT Input Voltage (VI) DC Output Diode Current (IOK) VO = −0.5V AC ACT Devices −65°C to +150 °C VIN from 0.8V to 2.0V Junction Temperature (TJ) VCC @ 4.5V, 5.5V 140°C PDIP 125 mV/ns Note 1: Absolute maximum ratings are those values beyond which damage to the device may occur. The databook specifications should be met, without exception, to ensure that the system design is reliable over its power supply, temperature, and output/input loading variables. Fairchild does not recommend operation of FACT circuits outside databook specifications. DC Electrical Characteristics for AC Symbol VIH Parameter Minimum HIGH Level Input Voltage VIL VOH TA = +25°C VCC (V) Typ 3.0 1.5 TA = −40°C to +85°C Guaranteed Limits 2.1 2.1 4.5 2.25 3.15 3.15 5.5 2.75 3.85 3.85 Maximum LOW Level 3.0 1.5 0.9 0.9 Input Voltage 4.5 2.25 1.35 1.35 5.5 2.75 1.65 1.65 Minimum HIGH Level 3.0 2.99 2.9 2.9 Output Voltage 4.5 4.49 4.4 4.4 5.5 5.49 5.4 5.4 3.0 2.56 2.46 4.5 3.86 3.76 5.5 4.86 4.76 Units Conditions VOUT = 0.1V V or VCC − 0.1V VOUT = 0.1V V or VCC − 0.1V V IOUT = −50 µA VIN = VIL or VIH VOL IOH = −12 mA V IOH = −24 mA IOH = −24 mA (Note 2) Maximum LOW Level 3.0 0.002 0.1 0.1 Output Voltage 4.5 0.001 0.1 0.1 5.5 0.001 0.1 0.1 3.0 0.36 0.44 4.5 0.36 0.44 5.5 0.36 0.44 5.5 ±0.1 ±1.0 µA VI = VCC, GND 75 mA VOLD = 1.65V Max −75 mA VOHD = 3.85V Min 40.0 µA VIN = VCC or GND V IOUT = 50 µA VIN = VIL or VIH IIN Maximum Input (Note 4) Leakage Current IOLD Minimum Dynamic IOHD Output Current (Note 3) 5.5 ICC (Note 4) Maximum Quiescent Supply Current 5.5 5.5 4.0 IOL = 12 mA V IOL = 24 mA 0 IOL = 24 mA (Note 2) Note 2: All outputs loaded; thresholds on input associated with output under test. Note 3: Maximum test duration 2.0 ms, one output loaded at a time. Note 4: IIN and ICC @ 3.0V are guaranteed to be less than or equal to the respective limit @ 5.5V VCC. 3 www.fairchildsemi.com 74AC138 • 74ACT138 Absolute Maximum Ratings(Note 1) 74AC138 • 74ACT138 DC Electrical Characteristics for ACT Symbol Parameter Minimum HIGH Level VIH VIL VOH TA = +25°C VCC (V) Typ 4.5 1.5 TA = −40°C to +85°C Guaranteed Limits 2.0 2.0 Input Voltage 5.5 1.5 2.0 2.0 Maximum LOW Level 4.5 1.5 0.8 0.8 Units V or VCC − 0.1V VOUT = 0.1V V Input Voltage 5.5 1.5 0.8 0.8 Minimum HIGH Level 4.5 4.49 4.4 4.4 Output Voltage 5.5 5.49 5.4 5.4 3.86 3.76 Conditions VOUT = 0.1V or VCC − 0.1V V IOUT = −50 µA V IOH = −24 mA VIN = VIL or VIH 4.5 5.5 VOL IOH = −24 mA (Note 5) 4.86 4.76 Maximum LOW Level 4.5 0.001 0.1 0.1 Output Voltage 5.5 0.001 0.1 0.1 4.5 0.36 0.44 5.5 0.36 0.44 5.5 ±0.1 ±1.0 µA VI = VCC, GND V IOUT = 50 µA V IOL 24 mA VIN = VIL or VIH IIN Maximum Input Leakage Current ICCT Maximum IOL.= 24 mA (Note 5) 1.5 mA VI = VCC − 2.1V IOLD Minimum Dynamic 5.5 75 mA VOLD = 1.65V Max IOHD Output Current (Note 6) 5.5 −75 mA VOHD = 3.85V Min ICC Maximum Quiescent 40.0 µA VIN = VCC or GND 5.5 ICC/Input Supply Current 0.6 5.5 4.0 Note 5: All outputs loaded; thresholds on input associated with output under test. Note 6: Maximum test duration 2.0 ms, one output loaded at a time. AC Electrical Characteristics for AC Symbol tPLH tPHL tPLH tPHL tPLH tPHL Parameter VCC TA = +25°C (V) CL = 50 pF TA = −40°C to +85°C CL = 50 pF (Note 7) Min Typ Max Min Max Propagation Delay 3.3 1.5 8.5 13.0 1.5 15.0 An to On 5.0 1.5 6.5 9.5 1.5 10.5 Propagation Delay 3.3 1.5 8.0 12.5 1.5 14.0 An to On 5.0 1.5 6.0 9.0 1.5 10.5 Propagation Delay 3.3 1.5 11.0 15.0 1.5 16.0 E1 or E2 to On 5.0 1.5 8.0 11.0 1.5 12.0 Propagation Delay 3.3 1.5 9.5 13.5 1.5 15.0 E1 or E2 to On 5.0 1.5 7.0 9.5 1.5 10.5 Propagation Delay 3.3 1.5 11.0 15.5 1.5 16.5 E3 to On 5.0 1.5 8.0 11.0 1.5 12.5 Propagation Delay 3.3 1.5 8.5 13.0 1.5 14.0 E3 to On 5.0 1.5 6.0 8.0 1.0 9.5 Note 7: Voltage Range 3.3 is 3.3V ± 0.3V Voltage Range 5.0 is 5.0V ± 0.5V www.fairchildsemi.com 4 Units ns ns ns ns ns ns Symbol tPLH Parameter Propagation Delay An to On tPHL Propagation Delay An to On tPLH Propagation Delay E1 or E2 to On tPHL Propagation Delay E1 or E2 to On tPLH Propagation Delay E3 to On Propagation Delay tPHL E3 to On VCC TA = +25°C (V) CL = 50 pF TA = −40°C to +85°C CL = 50 pF Units (Note 8) Min Typ Max Min Max 5.0 1.5 7.0 10.5 1.5 11.5 ns 5.0 1.5 6.5 1.5 11.5 ns 5.0 2.5 8.0 11.5 2.0 12.5 ns 5.0 2.0 7.5 11.5 2.0 12.5 ns 5.0 2.5 8.0 12.0 2.0 13.0 ns 5.0 2.0 6.5 10.5 1.5 11.5 ns 10.5 Note 8: Voltage Range 5.0 is 5.0V ± 0.5V Capacitance Typ Units CIN Symbol Input Capacitance Parameter 4.5 pF VCC = OPEN CPD Power Dissipation Capacitance 60.0 pF VCC = 5.0V 5 Conditions www.fairchildsemi.com 74AC138 • 74ACT138 AC Electrical Characteristics for ACT 74AC138 • 74ACT138 Physical Dimensions inches (millimeters) unless otherwise noted 16-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-012, 0.150" Narrow Package Number M16A www.fairchildsemi.com 6 74AC138 • 74ACT138 Physical Dimensions inches (millimeters) unless otherwise noted (Continued) 16-Lead Small Outline Package (SOP), EIAJ TYPE II, 5.3mm Wide Package Number M16D 7 www.fairchildsemi.com 74AC138 • 74ACT138 Physical Dimensions inches (millimeters) unless otherwise noted (Continued) 16-Lead Thin Shrink Small Outline Package (TSSOP), JEDEC MO-153, 4.4mm Wide Package Number MTC16 www.fairchildsemi.com 8 74AC138 • 74ACT138 1-of-8 Decoder/Demultiplexer 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. 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: 2. A critical component in any component of a life support device or system whose failure to perform can be reasonably expected to cause the failure of the life support device or system, or to affect its safety or effectiveness. 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 reasonably expected to result in a significant injury to the user. www.fairchildsemi.com 9 www.fairchildsemi.com