Revised February 2000 DM74ALS5245 Octal 3-STATE Transceiver General Description Features This octal bus transceiver is designed for asynchronous two-way communication between data buses. The inputs include hysteresis which provides improved noise rejection. Data is transmitted either from the A bus to the B bus or from the B bus to the A bus depending on the logic level of the direction control (DIR) input. The device can be disabled via the enable input (G) which causes the outputs to enter the high impedance mode so the buses are effectively isolated. ■ Input Hysteresis ■ Low output noise generation ■ High input noise immunity ■ Advanced oxide-isolated, ion implanted Schottky TTL process ■ Switching specification guaranteed over the full temperature and VCC range ■ PNP inputs to reduce input loading Ordering Code: Order Number Package Number DM74ALS5245WM M20B Package Description DM74ALS5245SJ M20D 20-Lead Small Outline Package (SOP), EIAJ TYPE II, 5.3mm Wide DM74ALS5245N N20A 20-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300 Wide 20-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-013, 0.300 Wide Devices also available in Tape and Reel. Specify by appending the suffix letter “X” to the ordering code. Connection Diagram Function Table Control Inputs Operation DIR G L = LOW Logic Level L L L H A Data to B Bus H X High Impedance H = HIGH Logic Level © 2000 Fairchild Semiconductor Corporation DS009175 B Data to A Bus X = Don't Care (Either LOW or HIGH Logic Level) www.fairchildsemi.com DM74ALS5245 Octal 3-STATE Transceiver October 1986 DM74ALS5245 Absolute Maximum Ratings(Note 1) Supply Voltage 7V Input Voltage Control Inputs 7V I/O Ports 5.5V 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 Characteristic tables are not guaranteed at the absolute maximum ratings. The “Recommended Operating Conditions” table will define the conditions for actual device operation. 0°C to +70°C Operating Free-Air Temperature Range −65°C to +150°C Storage Temperature Range Typical θJA N Package 56.0°C/W M Package 74.0°C/W Recommended Operating Conditions Symbol Parameter Min Max Units 4.5 5.5 V LOW Level Input Voltage 0.8 V IOH HIGH Level Output Current −15 mA IOL LOW Level Output Current 24 mA TA Free Air Operating Temperature Range 70 °C VCC Supply Voltage VIH HIGH Level Input Voltage VIL 2 V 0 Electrical Characteristics over recommended free air temperature range. All typical values are measured at VCC = 5V, TA = 25°C. Symbol Parameter Test Conditions VIK Input Clamp Voltage VCC = Min, II = −18 mA HYS Hysteresis (VT+ − VT−) VCC = Min VOH HIGH Level VCC = 4.5V to 5.5V IOH = −0.4 mA Output Voltage VCC = Min IOH = −3 mA LOW Level VCC = Min Output Voltage II Input Current at VCC = Max Maximum Input Voltage Typ Max −1.5 0.2 IOH = Max VOL Min Units V 0.32 V 3.2 V VCC − 2 2.4 2 IOL = 12 mA 0.25 0.4 IOL = 24 mA 0.35 0.5 I/O Ports, VI = 5.5V 100 Control Inputs, VI = 7V 100 V µA IIH HIGH Level Input Current VCC = Max, VI = 2.7V 20 IIL LOW Level Input Current VCC = Max, VI = 0.4V −100 µA IO Output Drive Current VCC = Max, VO = 2.25V −112 mA ICC Supply Current VCC = Max VOLP VOLV VIHD VILD −30 Outputs HIGH 30 45 Outputs LOW 36 55 Outputs Disabled 38 58 Quiet Output Maximum VCC = 5.0V, TA = 25°C Dynamic VOL (Figures 1, 2; (Note 2)(Note 3)) Quiet Output Minimum VCC = 5.0V, TA = 25°C Dynamic VOL (Figures 1, 2; (Note 2)(Note 3)) Minimum High Level VCC = 5.0V, TA = 25°C Dynamic Input Voltage (Note 2)(Note 4) Maximum Low Level VCC = 5.0V, TA = 25°C Dynamic Input Voltage (Note 2)(Note 4) µA mA 0.5 V −0.2 V 1.6 V 1.0 V Note 2: Plastic DIP package. Note 3: n = number of device outputs; n−1 outputs switching, each driven 0V to 3V one output @ GND. Note 4: n = number of device outputs; n outputs switching, n−1 inputs switching 0V to 3V. Input under test switching 3V to threshold (VILD); 0V to threshold (VIHD); f = 1 MHz. www.fairchildsemi.com 2 over recommended operating free air temperature range Symbol tPLH tPHL Parameter From (Input) Conditions Propagation Delay Time VCC = 4.5V to 5.5V, LOW-to-HIGH Level Output R1 = R2 = 500Ω, Propagation Delay Time CL = 50 pF HIGH-to-LOW Level Output tPZH Output Enable Time to HIGH Level Output tPZL Output Enable Time to LOW Level Output tPHZ Output Disable Time from HIGH Level Output tPLZ Min Max Units A or B to B or A 3 10 ns A or B to B or A 3 10 ns G to A or B 5 20 ns G to A or B 5 20 ns G to A or B 2 10 ns G to A or B 4 15 ns To (Output) Output Disable Time from LOW Level Output 3 www.fairchildsemi.com DM74ALS5245 Switching Characteristics DM74ALS5245 ALS Noise Characteristics VOLP/VOLV and VOHP/VOHV: The setup of a noise characteristics measurement is critical to the accuracy and repeatability of the tests. The following is a brief description of the setup used to measure the noise characteristics of ALS. • Determine the quiet output pin that demonstrates the greatest noise levels. The worst case pin will usually be the furthest from the ground pin. Monitor the output voltages using a 50Ω coaxial cable plugged into a standard SMB type connector on the test fixture. Do not use an active FET probe. • Measure VOLP and VOLV on the quiet output during the HL transition. Measure VOHP and VOHV on the quiet output during the LH transition. Equipment: Word Generator Printed Circuit Board Test Fixture Dual Trace Oscilloscope Procedure: • Verify that the GND reference recorded on the oscilloscope has not drifted to ensure the accuracy and repeatability of the measurements. 1. Verify Test Fixture Loading: Standard Load 50 pF, 500Ω. 2. Deskew the word generator so that no two channels have greater than 150 ps skew between them. This requires that the oscilloscope be deskewed first. Swap out the channels that have more than 150 ps of skew until all channels being used are within 150 ps. It is important to deskew the word generator channels before testing. This will ensure that the outputs switch simultaneously. VILD and VIHD: • Monitor one of the switching outputs using a 50Ω coaxial cable plugged into a standard SMB type connector on the test fixture. Do not use an active FET probe. • First increase the input LOW voltage level, VIL, until the output begins to oscillate. Oscillation is defined as noise on the output LOW level that exceeds VIL limits, or on output HIGH levels that exceed VIH limits. The input LOW voltage level at which oscillation occurs is defined as VILD. 3. Terminate all inputs and outputs to ensure proper loading of the outputs and that the input levels are at the correct voltage. 4. Set VCC to 5.0V. • Next decrease the input HIGH voltage level on the word generator, VIH until the output begins to oscillate. Oscillation is defined as noise on the output LOW level that exceeds V IL limits, or on output HIGH levels that exceed VIH limits. The input HIGH voltage level at which oscillation occurs is defined as VIHD. 5. Set the word generator to toggle all but one output at a frequency of 1 MHz. Greater frequencies will increase DUT heating and affect the results of the measurement. 6. Set the word generator input levels at 0V LOW and 3V HIGH. Verify levels with a digital volt meter. • Verify that the GND reference recorded on the oscilloscope has not drifted to ensure the accuracy and repeatability of the measurements. FIGURE 1. Quiet Output Noise Voltage Waveforms Note 5: VOHV and VOHP are measured with respect to VOH reference. VOLV and VOLP are measured with respect to ground reference. Note 6: Input pulses have the following characteristics: f = 1 MHz, tr = 3 ns, tf = 3 ns, skew < 150 ps. FIGURE 2. Simultaneous Switching Test Circuit www.fairchildsemi.com 4 DM74ALS5245 Physical Dimensions inches (millimeters) unless otherwise noted 20-Lead Small Outline Integrated Circuit (SOIC), JEDEC MS-013, 0.300 Wide Package Number M20B 5 www.fairchildsemi.com DM74ALS5245 Physical Dimensions inches (millimeters) unless otherwise noted (Continued) 20-Lead Small Outline Package (SOP), EIAJ TYPE II, 5.3mm Wide Package Number M20D www.fairchildsemi.com 6 DM74ALS5245 Octal 3-STATE Transceiver Physical Dimensions inches (millimeters) unless otherwise noted (Continued) 20-Lead Plastic Dual-In-Line Package (PDIP), JEDEC MS-001, 0.300 Wide Package Number N20A 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. 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