Revised July 2002 FST33X257 24:12 Multiplexer/Demultiplexer Bus Switch General Description Features The Fairchild Switch FST33X257 is a 24:12 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. ■ 4Ω switch connection between two ports When OEx is LOW, the select pin connects the A Port to the selected B Port output. When OEx is HIGH, the switch is OPEN and a high-impedance state exists between the two ports. ■ Control inputs compatible with TTL level ■ Minimal propagation delay through the switch ■ Low lCC ■ Zero bounce in flow-through mode Ordering Code: Order Number Package Number Package Description FST33X257QSP MQA48A 48-Lead Quarter Size Very Small Outline Package (QVSOP), JEDEC MO-154, 0.150" Wide Device also available in Tape and Reel. Specify by appending suffix letter “X” to the ordering code. © 2002 Fairchild Semiconductor Corporation DS500724 www.fairchildsemi.com FST33X257 24:12 Multiplexer/Demultiplexer Bus Switch May 2002 FST33X257 Logic Diagram Connection Diagram Pin Descriptions Pin Name Description OEx Bus Switch Enable Sx Select Input A Bus A B1–B2 Bus B Truth Table www.fairchildsemi.com 2 Sx OEx Function X H Disconnect L L A = B1 H L A = B2 Supply Voltage (VCC) −0.5V to +7.0V Recommended Operating Conditions (Note 3) DC Switch Voltage (VS) −0.5V to +7.0V Power Supply Operating (VCC) DC Input Voltage (VIN)(Note 2) −0.5V to +7.0V Input Voltage (VIN) 0V to 5.5V 0V to 5.5V DC Input Diode Current (lIK) VIN < 0V −50 mA Output Voltage (VOUT) DC Output (IOUT) Sink Current 128 mA Input Rise and Fall Time (tr, tf) +/− 100 mA DC VCC /GND Current (ICC /IGND) Storage Temperature Range (TSTG) 4.0V to 5.5V Switch Control Input −65°C to +150 °C 0 ns/V to 5 ns/V Switch I/O 0 ns/V to DC −40 °C to +85 °C Free Air Operating Temperature (TA) 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: The input and output negative voltage ratings may be exceeded if the input and output diode current ratings are observed. Note 3: Unused control inputs must be held HIGH or LOW. They may not float. DC Electrical Characteristics Symbol Parameter VCC (V) TA = −40 °C to +85 °C Typ (Note 4) Min Units −1.2 VIK Clamp Diode Voltage VIH HIGH Level Input Voltage 4.0–5.5 VIL LOW Level Input Voltage 4.0–5.5 0.8 II Input Leakage Current 5.5 ±1.0 0 10 4.5 Conditions Max 2.0 V IIN = −18 mA V V µA 0 ≤ VIN ≤ 5.5V VIN = 5.5V IOZ OFF-STATE Leakage Current 5.5 ±1.0 µA RON Switch On Resistance 4.5 4 7 Ω 0 ≤ A, B ≤ VCC VIN = 0V, IIN = 64 mA (Note 5) 4.5 4 7 Ω VIN = 0V, IIN = 30 mA 4.5 8 15 Ω VIN = 2.4V, IIN = 15 mA 4.0 11 20 Ω VIN = 2.4V, IIN = 15 mA ICC Quiescent Supply Current (Note 6) 5.5 3 µA VIN = VCC or GND, IOUT = 0 ∆ ICC Increase in ICC per Input 5.5 2.5 mA One Input at 3.4V (Note 7) Other Inputs at VCC or GND Note 4: Typical values are at VCC = 5.0V and TA = +25°C Note 5: 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. Note 6: Per VCC pin. Note 7: Per TTL driven input, control pins only. 3 www.fairchildsemi.com FST33X257 Absolute Maximum Ratings(Note 1) FST33X257 AC Electrical Characteristics TA = −40 °C to +85°C, Symbol CL = 50 pF, RU = RD = 500Ω Parameter VCC = 4.5 – 5.5V Min tPHL, tPLH Propagation Delay Bus to Bus (Note 8) Max Units VCC = 4.0V Min Max 0.25 1.0 4.7 5.2 tPZH, tPZL Output Enable Time, Select to Bus B 1.0 5.2 5.7 Output Enable Time, OE to Bus A, B 1.0 5.1 5.6 1.0 5.2 5.5 1.5 5.5 5.5 VI = OPEN ns Output Disable Time, Output Enable Time, Figures 1, 2 VI = 7V for tPZL ns tPHZ, tPLZ Output Disable Time, Select to Bus B Figure Number 0.25 Propagation Delay, Select to Bus A Conditions VI = OPEN for tPZH VI = 7V for tPLZ ns VI = OPEN for tPHZ Figures 1, 2 Figures 1, 2 OE to Bus A, B Note 8: 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 9) Symbol Parameter CI/O Typ Control Pin Input Capacitance Max Units 3 pF A Port Input/Output Capacitance 7 pF B Port 5 pF CIN Note 9: TA = +25°C, f = 1 MHz, Capacitance is characterized but not tested. AC Loading and Waveforms Note: Input driven by 50 Ω source terminated in 50 Ω Note: CL includes load and stray capacitance Note: Input PRR = 1.0 MHz, tW = 500 ns FIGURE 1. AC Test Circuit FIGURE 2. AC Waveforms www.fairchildsemi.com 4 Conditions VCC = 5.0V VCC, OE = 5.0V FST33X257 24:12 Multiplexer/Demultiplexer Bus Switch 48-Lead Quarter Size Very Small Outline Package (QVSOP), JEDEC MO-154, 0.150" Wide Package Number MQA48A 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 5 www.fairchildsemi.com