Revised September 2000 74F138 1-of-8 Decoder/Demultiplexer General Description Features The F138 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 F138 devices or a 1-of-32 decoder using four F138 devices and one inverter. ■ Demultiplexing capability ■ Multiple input enable for easy expansion ■ Active LOW mutually exclusive outputs Ordering Code: Order Number Package Number Package Description 74F138SC M16A 16-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-012, 0.150 Narrow 74F138SJ M16D 16-Lead Small Outline Package (SOP), EIAJ TYPE II, 5.3mm Wide 74F138PC 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. Logic Symbols Connection Diagram IEEE/IEC © 2000 Fairchild Semiconductor Corporation DS009478 www.fairchildsemi.com 74F138 1-of-8 Decoder/Demultiplexer April 1988 74F138 Unit Loading/Fan Out Pin Names U.L. Input IIH/IIL HIGH/LOW Output IOH/IOL Description A0–A2 Address Inputs 1.0/1.0 20 µA/−0.6 mA E1, E2 Enable Inputs (Active LOW) 1.0/1.0 20 µA/−0.6 mA E3 Enable Input (Active HIGH) 1.0/1.0 20 µA/−0.6 mA O0–O7 Outputs (Active LOW) 50/33.3 −1 mA/20 mA Truth Table Inputs Outputs E1 E2 E3 A0 A1 A2 O0 O1 O2 O3 O4 O5 O6 O7 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 X = Immaterial Functional Description The F138 high-speed 1-of-8 decoder/demultiplexer accepts three binary weighted inputs (A0, A1, A2) and, when enabled, provides eight mutually exclusive active LOW outputs (O0–O7). The F138 features three Enable inputs, two active LOW (E1, E2) and one active HIGH (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 F138 devices and one inverter (See Figure 1). The F138 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. FIGURE 1. Expansion to 1-of-32 Decoding www.fairchildsemi.com 2 74F138 Logic Diagram Please note that this diagram is provided only for the understanding of logic operations and should not be used to estimate propagation delays. 3 www.fairchildsemi.com 74F138 Absolute Maximum Ratings(Note 1) Recommended Operating Conditions Storage Temperature −65°C to +150°C Ambient Temperature under Bias −55°C to +125°C Free Air Ambient Temperature Junction Temperature under Bias −55°C to +150°C Supply Voltage 0°C to +70°C +4.5V to +5.5V −0.5V to +7.0V VCC Pin Potential to Ground Pin Input Voltage (Note 2) −0.5V to +7.0V Input Current (Note 2) −30 mA to +5.0 mA Voltage Applied to Output in HIGH State (with VCC = 0V) Standard Output −0.5V to VCC 3-STATE Output −0.5V to +5.5V Note 1: Absolute maximum ratings are values beyond which the device may be damaged or have its useful life impaired. Functional operation under these conditions is not implied. Current Applied to Output Note 2: Either voltage limit or current limit is sufficient to protect inputs. in LOW State (Max) twice the rated IOL (mA) ESD Last Passing Voltage (Min) 4000V DC Electrical Characteristics Symbol Min Parameter Typ Max VCC Conditions Input HIGH Voltage VIL Input LOW Voltage 0.8 V VCD Input Clamp Diode Voltage −1.2 V Min V Min 0.5 V Min IOL = 20 mA 5.0 µA Max VIN = 2.7V 7.0 µA Max VIN = 7.0V 50 µA Max VOUT = VCC V 0.0 3.75 µA 0.0 −0.6 mA Max VIN = 0.5V −150 mA Max VOUT = 0V VOH VOL 2.0 Units VIH Output HIGH 10% VCC 2.5 Voltage 5% VCC 2.7 Output LOW 10% VCC V Recognized as a HIGH Signal Recognized as a LOW Signal IIN = −18 mA IOH = −1 mA IOH = −1 mA Voltage IIH Input HIGH Current IBVI Input HIGH Current Breakdown Test ICEX Output HIGH Leakage Current VID Input Leakage 4.75 Test IOD Output Leakage Circuit Current IID = 1.9 µA All Other Pins Grounded VIOD = 150 mV All Other Pins Grounded IIL Input LOW Current IOS Output Short-Circuit Current ICCH Power Supply Current 13 20 mA Max VO = HIGH ICCL Power Supply Current 13 20 mA Max VO = LOW −60 AC Electrical Characteristics Symbol Parameter TA = +25°C TA = 0°C to +70°C VCC = +5.0V VCC = +5.0V CL = 50 pF CL = 50 pF Min Typ Max Min Max tPLH Propagation Delay 3.5 5.6 7.5 3.5 8.5 tPHL An to On 4.0 6.1 8.0 4.0 9.0 tPLH Propagation Delay 3.5 5.4 7.0 3.5 8.0 tPHL E1 or E2 to On 3.0 5.3 7.0 3.0 7.5 tPLH Propagation Delay 4.0 6.2 8.0 4.0 9.0 tPHL E3 to On 3.5 5.6 7.5 3.5 8.5 www.fairchildsemi.com 4 Units ns ns ns 74F138 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 74F138 Physical Dimensions inches (millimeters) unless otherwise noted (Continued) 16-Lead Small Outline Package (SOP), EIAJ TYPE II, 5.3mm Wide Package Number M16D www.fairchildsemi.com 6 74F138 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 7 www.fairchildsemi.com