Revised February 2001 74LCX138 Low Voltage 1-of-8 Decoder/Demultiplexer with 5V Tolerant Inputs General Description Features The LCX138 is a high-speed 1-of-8 decoder/demultiplexer. This device is ideally suited for high-speed memory chip select address decoding. The multiple input enables allow parallel expansion to a 1-of-24 decoder using just three LCX138 devices or a 1-of-32 decoder using four LCX138 devices and one inverter. ■ 5V tolerant inputs The 74LCX138 is fabricated with advanced CMOS technology to achieve high speed operation while maintaining CMOS low power dissipation. ■ Implements patented noise/EMI reduction circuitry ■ 2.3V–3.6V VCC specifications provided ■ 6.0 ns tPD max (VCC = 3.3V), 10 µA ICC max ■ Power down high impedance inputs and outputs ■ ±24 mA output drive (VCC = 3.0V) ■ Latch-up performance exceeds 500 mA ■ ESD performance: Human body model > 2000V Machine model > 200V Ordering Code: Order Number 74LCX138M 74LCX138SJ 74LCX138MTC Package Number Package Description 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 MTC16 16-Lead Thin Shrink Small Outline Package (TSSOP), JEDEC MO-153, 4.4mm Wide Devices also available in Tape and Reel. Specify by appending suffix letter “X” to the ordering code. Connection Diagram Pin Descriptions Pin Names © 2001 Fairchild Semiconductor Corporation DS012417 Description A0–A2 Address Inputs E1–E2 Enable Inputs E3 Enable Input O0–O7 Outputs www.fairchildsemi.com 74LCX138 Low Voltage 1-of-8 Decoder/Demultiplexer with 5V Tolerant Inputs March 1995 74LCX138 Functional Description All outputs will be HIGH unless E1 and E2 are LOW and E3 is HIGH. The LCX138 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. The LCX138 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 LCX138 features three Enable inputs, two active-LOW (E1, E2) and one active-HIGH (E3). 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 O7 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 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. www.fairchildsemi.com 2 Symbol Parameter Value Conditions VCC Supply Voltage −0.5 to +7.0 VI DC Input Voltage −0.5 to +7.0 VO DC Output Voltage IIK DC Input Diode Current −50 VI < GND IOK DC Output Diode Current −50 VO < GND +50 VO > VCC Units V V −0.5 to VCC + 0.5 Output in HIGH or LOW State (Note 2) V mA mA IO DC Output Source/Sink Current ±50 mA ICC DC Supply Current per Supply Pin ±100 mA IGND DC Ground Current per Ground Pin ±100 mA TSTG Storage Temperature −65 to +150 °C Recommended Operating Conditions (Note 3) Symbol VCC Parameter Supply Voltage Min Max Operating 2.0 3.6 Data Retention 1.5 3.6 VI Input Voltage VO Output Voltage HIGH or LOW State IOH/IOL Output Current VCC = 3.0V − 3.6V ±24 VCC = 2.7V − 3.0V ±12 VCC = 2.3V − 2.7V ±8 TA Free-Air Operating Temperature ∆t/∆V Input Edge Rate, VIN = 0.8V–2.0V, VCC = 3.0V Units V 0 5.5 V 0 VCC V mA −40 85 °C 0 10 ns/V 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. Note 2: IO Absolute Maximum Rating must be observed. Note 3: Unused inputs must be held HIGH or LOW. They may not float. DC Electrical Characteristics Symbol Parameter Conditions VCC (V) VIH VIL VOH VOL HIGH Level Input Voltage LOW Level Input Voltage HIGH Level Output Voltage LOW Level Output Voltage IOH = −100 µA TA = −40°C to +85°C Min 2.3 − 2.7 1.7 2.7 − 3.6 2.0 V 2.3 − 2.7 0.7 2.7 − 3.6 0.8 2.3 − 3.6 VCC − 0.2 IOH = -8 mA 2.3 1.8 IOH = −12 mA 2.7 2.2 IOH = −18 mA 3.0 2.4 IOH = −24 mA 3.0 2.2 IOL = 100 µA 2.3 − 3.6 Units Max V V 0.2 IOL = 8mA 2.3 0.6 IOL = 12 mA 2.7 0.4 IOL = 16 mA 3.0 0.4 V IOL = 24 mA 3.0 0.55 II Input Leakage Current 0 ≤ VI ≤ 5.5V 2.3 − 3.6 ±5.0 µA IOFF Power-Off Leakage Current VI or VO = 5.5V 0 10 µA ICC Quiescent Supply Current VI = V CC or GND 2.3 − 3.6 10 3.6V ≤ VI ≤ 5.5V 2.3 − 3.6 ±10 VIH = VCC −0.6V 2.3 − 3.6 500 ∆ICC Increase in ICC per Input 3 µA µA www.fairchildsemi.com 74LCX138 Absolute Maximum Ratings(Note 1) 74LCX138 AC Electrical Characteristics TA = −40°C to +85°C, RL = 500Ω Symbol Parameter VCC = 3.3V ± 0.3V VCC = 2.7V VCC = 2.5V ± 0.2V CL = 50pF CL = 50pF CL = 30pF Min Max Min Max Min Max tPHL Propagation Delay 1.5 6.0 1.5 7.0 1.5 7.2 tPLH An to Qn 1.5 6.0 1.5 7.0 1.5 7.2 tPHL Propagation Delay 1.5 6.5 1.5 7.5 1.5 8.4 tPLH E3 to Qn 1.5 6.5 1.5 7.5 1.5 8.4 tPHL Propagation Delay 1.5 6.0 1.5 7.0 1.5 7.2 tPLH E1 or E2 to Qn 1.5 6.0 1.5 7.0 1.5 7.2 tOSHL Output to Output Skew (Note 4) 1.0 tOSLH Units ns ns ns ns 1.0 Note 4: Skew is defined as the absolute value of the difference between the actual propagation delay for any two separate outputs of the same device. The specification applies to any outputs switching in the same direction, either HIGH-to-LOW (tOSHL) or LOW-to-HIGH (tOSLH). Dynamic Switching Characteristics Symbol VOLP VOLV VCC TA = 25°C (V) Typical CL = 50 pF, VIH = 3.3V, VIL = 0V 3.3 0.8 CL = 30 pF, VIH = 2.5V, VIL = 0V 2.5 0.6 CL = 50 pF, VIH = 3.3V, VIL = 0V 3.3 −0.8 CL = 30 pF, VIH = 2.5V, VIL = 0V 2.5 −0.6 Parameter Quiet Output Dynamic Peak VOL Quiet Output Dynamic Valley VOL Conditions Units V V Capacitance Typical Units CIN Symbol Input Capacitance Parameter VCC = Open, VI = 0V or VCC 7 pF COUT Output Capacitance VCC = 3.3V, VI = 0V or VCC 8 pF CPD Power Dissipation Capacitance VCC = 3.3V, VI = 0V or VCC, f = 10 MHz 25 pF www.fairchildsemi.com Conditions 4 74LCX138 AC Loading and Waveforms Generic for LCX Family FIGURE 1. AC Test Circuit (CL includes probe and jig capacitance) Test Switch tPLH, tPHL Open tPZL, tPLZ 6V at VCC = 3.3 ± 0.3V VCC x 2 at VCC = 2.5 ± 0.2V tPZH,tPHZ GND Waveform for Inverting and Non-Inverting Functions 3-STATE Output Low Enable and Disable Times for Logic Propagation Delay, Pulse Width and trec Waveforms Setup Time, Hold TIme and Recovery TIme for Logic 3-STATE Output High Enable and Disable Times for Logic trise and tfall Symbol VCC 3.3V ± 0.3V 2.7V 2.5V ± 0.2V Vmi 1.5V 1.5V VCC/2 Vmo 1.5V 1.5V VCC/2 Vx VOL + 0.3V VOL + 0.3V VOL + 0.15V Vy VOH − 0.3V VOH − 0.3V VOH − 0.15V FIGURE 2. Waveforms (Input Pulse Characteristics; f = 1MHz, tr = tf = 3ns) 5 www.fairchildsemi.com 74LCX138 Schematic Diagram Generic for LCX Family www.fairchildsemi.com 6 74LCX138 Physical Dimensions inches (millimeters) unless otherwise noted 16-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-012, 0.150 Narrow Package Number M16A 7 www.fairchildsemi.com 74LCX138 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 8 16-Lead Thin Shrink Small Outline Package (TSSOP), JEDEC MO-153, 4.4mm Wide Package Number MTC16 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 74LCX138 Low Voltage 1-of-8 Decoder/Demultiplexer with 5V Tolerant Inputs Physical Dimensions inches (millimeters) unless otherwise noted (Continued)