Revised October 2006 FSTU3257 Quad 2:1 Multiplexer/Demultiplexer Bus Switch with 2V Undershoot Protection General Description Features The Fairchild Switch FSTU3257 is a quad 2:1 high-speed CMOS TTL-compatible multiplexer/demultiplexer bus switch. The low on resistance of the switch allows inputs to be connected to outputs without adding propagation delay or generating additional ground bounce noise. ■ Undershoot hardened to 2V (A and B Ports) When OE is LOW, the select pin connects the A Port to the selected B Port output. The A and B Ports are “undershoot hardened” with Undershoot Hardened Circuit (UHC®¥) protection to support an extended range of 2.0V below ground. Fairchild’s integrated UHC senses undershoot at the I/O and responds by preventing voltage differentials from developing and turning on the switch. When OE is HIGH, the switch is OPEN and a high-impedance state exists between the two ports. ■ Soft enable turn-on to minimize bus to bus charge sharing during enable ■ 4: switch connection between two ports. ■ Minimal propagation delay through the switch. ■ Low lCC. ■ Zero bounce in flow-through mode. ■ Control inputs compatible with TTL level. ■ See Applications Note AN-5008 for details Ordering Code: Order Number Package Number FSTU3257M M16A Package Description 16-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-012, 0.150" Narrow FSTU3257QSC MQA16 16-Lead Quarter Size Outline Package (QSOP), JEDEC MO-137, 0.150" Wide FSTU3257MTC MTC16 16-Lead Thin Shrink Small Outline Package (TSSOP), JEDEC MO-153, 4.4mm Wide Device also available in Tape and Reel. Specify by appending suffix letter “X” to the ordering code. Logic Diagram Connection Diagram Pin Descriptions Truth Table Pin Name Description S OE Function OE Bus Switch Enable X H Disconnect S Select Input L L A B1 A Bus A H L A B2 B1–B2 Bus B UHC®¥ is a registered trademark of Fairchild Semiconductor Corporation. © 2005 Fairchild Semiconductor Corporation DS500302 www.fairchildsemi.com FSTU3257 Quad 2:1 Multiplexer/Demultiplexer Bus Switch with 2V Undershoot Protection August 1999 FSTU3257 Absolute Maximum Ratings(Note 1) Recommended Operating Conditions (Note 4) 0.5V to 7.0V 2.0V to 7.0V 0.5V to 7.0V 50mA Supply Voltage (VCC) DC Switch Voltage (VS) (Note 2) DC Input Control Pin Voltage (VIN)(Note 3) DC Input Diode Current (lIK) VIN 0V DC Output (IOUT) Power Supply Operating (VCC) 128mA DC VCC/GND Current (ICC/IGND) Storage Temperature Range (TSTG) 4.0V to 5.5V Input Voltage (VIN) 0V to 5.5V Output Voltage (VOUT) 0V to 5.5V Input Rise and Fall Time (tr, tf) / 100mA 65qC to 150 qC Switch Control Input 0nS/V to 5nS/V Switch I/O ESD 0nS/V to DC 40 qC to 85 qC Free Air Operating Temperature (TA) Human Body Model 5kV 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 rating. The Recommended Operating Conditions tables will define the conditions for actual device operation. Note 2: VS is the voltage observed/applied at either the A or B Ports across the switch. Note 3: The input and output negative voltage ratings may be exceeded if the input and output diode current ratings are observed. Note 4: Unused control inputs must be held HIGH or LOW. They may not float. DC Electrical Characteristics VCC Symbol Parameter (V) 40 qC to 85 qC TA Min Typ (Note 5) Max 1.2 Units Conditions 18mA VIK Clamp Diode Voltage VIH HIGH Level Input Voltage 4.0–5.5 VIL LOW Level Input Voltage 4.0–5.5 0.8 V II Input Leakage Current 5.5 r1.0 PA 0d VIN d5.5V IOZ OFF-STATE Leakage Current 5.5 r1.0 PA 0 dA, B dVCC RON Switch On Resistance 4.5 4 7 : VIN 0V, IIN 64mA (Note 6) 4.5 4 7 : VIN 0V, IIN 30mA 4.5 8 15 : VIN 2.4V, IIN 15mA 4.0 11 20 : VIN 2.4V, IIN 15mA VCC or GND, IOUT 4.5 2.0 V IIN V ICC Quiescent Supply Current 5.5 3 PA VIN ' ICC Increase in ICC per Input 5.5 2.5 mA One input at 3.4V VIKU Voltage Undershoot 5.5 2.0 V 0 Other inputs at VCC or GND 0.0 mA t IIN t 50 mA OE Note 5: Typical values are at VCC 5.0V and T A 5.5V 25qC Note 6: Measured by the voltage drop between A and B pins at the indicated current through the switch. On resistance is determined by the lower of the voltages on the two (A or B) pins. www.fairchildsemi.com 2 TA Symbol CL Parameter VCC 4.5 – 5.5V Min tPHL,tPLH Max Prop Delay Bus to Bus (Note 7) Prop Delay, Select to Bus A 40 qC to 85qC, 50pF, RU 7.0 RD 500: VCC Min Units No. 0.25 0.25 30.0 35.0 7.0 30.0 35.0 Output Enable Time, OE to Bus A, B 7.0 30.0 35.0 ns ns 1.5 8.4 9.8 1.5 8.8 9.8 ns Output Disable Time, Output Enable Time, OE to Bus A, B Figure Max tPZH, tPZL Output Enable Time, Select to Bus B tPHZ, tPLZ Output Disable Time, Select to Bus B Conditions 4.0V VI OPEN Figures 2, 3 VI 7V for tPZL VI OPEN for tPZH VI 7V for tPLZ VI OPEN for tPHZ Figures 2, 3 Figures 2, 3 Note 7: This parameter is guaranteed by design but is not tested. The bus switch contributes no propagation delay other than the RC delay of the typical On resistance of the switch and the 50pF load capacitance, when driven by an ideal voltage the source (zero output impedance). Capacitance (Note 8) Symbol Parameter Typ Control Pin Input Capacitance CIN A Port CI/O B Port CI/O ON State Note 8: TA Input/Output Capacitance Input/Output Capacitance ON State (A or B Port) 25qC, f Max 3 Units pF 7.5 pF 5.5 pF 14 pF Conditions VCC 5.0V VCC, OE VCC 5.0V 5.0V Switch ON 1 MHz, Capacitance is characterized but not tested. Undershoot Characteristic (Note 9) Symbol Parameter Output Voltage During Undershoot VOUTU Min Typ 2.5 VOH 0.3 Max Units Conditions V Figure 1 Note 9: This is intended to characterize the device’s protective capabilities by maintaining output signal integrity during an input transient voltage undershoot event. FIGURE 1. Device Test Conditions Parameter Value VIN See Waveform V R1 - R2 100K : VTRI 11.0 V VCC 5.5 V Transient Input Voltage (VIN) Waveform Units 3 www.fairchildsemi.com FSTU3257 AC Electrical Characteristics FSTU3257 AC Loading and Waveforms Note: Input driven by 50: source terminated in 50: Note: CL includes load and stray capacitance Note: Input PRR 1.0 MHz, tW 500 ns FIGURE 2. AC Test Circuit FIGURE 3. AC Waveforms www.fairchildsemi.com 4 FSTU3257 Physical Dimensions inches (millimeters) unless otherwise noted 16-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-012, 0.150" Narrow Package Number M16A 16-Lead Quarter Size Outline Package (QSOP), JEDEC MO-137, 0.150" Wide Package Number MQA16 5 www.fairchildsemi.com FSTU3257 Quad 2:1 Multiplexer/Demultiplexer Bus Switch with 2V Undershoot Protection 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 Technology Description The Fairchild Switch family derives from and embodies Fairchild’s proven switch technology used for several years in its 74LVX3L384 (FST3384) bus switch product. 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 www.fairchildsemi.com 6