MC74F3893A QUAD FUTUREBUS BACKPLANE TRANSCEIVER (3 STATE + OPEN COLLECTOR) The MC74F3893A is a quad backplane transceiver and is intended to be used in very high speed bus systems. The MC74F3893A interfaces to “Backplane Transceiver Logic” (BTL). BTL features a reduced (1 V) voltage swing for lower power consumption and a series diode on the drivers to reduce capacitive loading (< 5 pF). Incident wave switching is employed, therefore BTL propagation delays are short. Although the voltage swing is much less for BTL, so is its receiver threshold region, therefore noise margins are excellent. BTL offers low power consumption, low ground bounce, reduced EMI and crosstalk, low capacitive loading, superior noise margin and short propagation delays. This results in a high bandwidth, reliable backplane. The MC74F3893A has four TTL outputs (Rn) on the receiver side with a common Receive Enable input (RE). It has four data inputs (Dn) which are also TTL. These data inputs are NANDed with the Data Enable input (DE). The four I/O pins (Bus side) are futurebus compatible, sink a minimum of 100 mA, and are designed to drive heavily loaded backplanes with load impedances as low as 10 ohms. All outputs are designed to be glitch-free during power up and power down. • Quad Backplane Transceiver • Drives Heavily Loaded Backplanes with Equivalent Load Impedances Down to 10 ohms • Futurebus Drivers Sink 100 mA • Reduced Voltage Swing (1 Volt) Produces Less Noise and Reduces Power Consumption • High Speed Operation Enhances Performance of Backplane Buses and Facilitates Incident Wave Switching • Compatible with IEEE 896 and IEEE 1194.1 Futurebus Standards • Built-In Precision Band-Gap (BG) Reference Provides Accurate Receiver Threshold and Improved Noise Immunity • Glitch-Free Power Up/Power Down Operation On All Outputs • Pin and Function Compatible with NSC DS3893A and Signetics 74F3893 • Separate Bus Ground Returns for Each Driver to Minimize Ground Noise • MOS and TTL Compatible High Impedance Inputs PINOUT: 20-LEAD PLCC (TOP VIEW) I/O0 BUS I/O1 GND I/O2 I/O3 18 17 15 14 16 BUS GND 19 13 BUS GND BG GND 20 12 RE VCC 1 11 DE D0 2 10 R3 R0 3 9 D3 4 5 6 D1 R1 LOGIC GND 7 8 D2 R2 FAST AND LS TTL DATA 4-273 QUAD FUTUREBUS BACKPLANE TRANSCEIVER (3 STATE + OPEN COLLECTOR) FAST SCHOTTKY TTL FN SUFFIX PLASTIC CASE 775-02 8 19 4 3 ORDERING INFORMATION MC74FXXXXAFN Plastic LOGIC SYMBOL 2 4 7 9 D0 D1 D2 D3 11 DE 12 RE I/O0 I/O1 I/O2 I/O3 R0 R1 18 17 15 14 3 5 R2 R3 8 10 MC74F3893A LOGIC DIAGRAM D0 R0 D1 2 18 I/O0 3 4 17 I/O1 5 R1 12 D2 R2 D3 R3 DE 7 15 RE I/O2 8 9 14 I/O3 10 11 VCC = PIN 1: LOGIC GND = PIN 6 BUS GND = PIN 13,16, 19: BG GND = PIN 20 FUNCTION TABLE Inputs Input/Output Outputs DE RE Dn I/On Rn H H L L L H H L L H Transmit to Bus H L H H L H Dn H Z Z Receiver 3-State, Transmit to Bus L L L L X X H L L H Receive, I/On = Inputs Operating Mode H = HIGH voltage level: L = LOW voltage level: X = Don’t care: Z = HIGH impedance “Off” state. RECOMMENDED OPERATING CONDITIONS Limits Symbol Parameter Min Typ Max Unit VCC Supply Voltage 4.5 5.0 5.5 V VIH High-Level Input Voltage 2.0 — — V VIL Low-Level Input Voltage — — 0.8 V IIK Input Clamp Current — — –18 mA VTH Bus Input Threshold I/On Only 1.475 1.550 1.625 V IOH Output Current High Rn Only — — –3.0 mA IOL Output Current Low — — 100 mA TA Operating Ambient Temperature Range 0 — 70 °C Dn, DE, RE FAST AND LS TTL DATA 4-274 MC74F3893A DC CHARACTERISTICS (Over Recommended Operating Free-Air Temperature Range Unless otherwise specified) Limits Symbol VOH VOHB VOL High-Level Output Voltage High-Level Output Bus Voltage Output LOW Voltage VOLB Low Level Output Bus Voltage VOCB Driver Output Positive Clamp Voltage VIK II IIH IIHB IIL IILB Test Conditions (Note 1) Min Typ (2) Max Unit Rn 2.5 — — V VCC = MIN: VIL = 1.3 V; RE = 0.8 V: IOH = MAX I/On 1.9 — — V VCC = MAX: DN = DE = 0.8 V: VT = 2.0 V: RT = 10Ω: RE = 2.0 V IOH = MAX Rn — 0.35 0.5 V VCC = MIN: VIN = 1.8 V; RE = 0.8 V: IOL = 6.0 mA 0.75 1.0 1.2 0.75 1.0 1.1 — — 2.9 Parameter I/On V I/On Dn = DE = VIH: IOL = 100 mA Dn = DE = VIH: IOL = 80 mA V VCC = MAX or 0 V: DN = DE = 0.8 V: RE = 2.0 V I/On = 1.0 mA — — 3.2 Input Clamp Diode Voltage — –0.73 –1.2 V VCC = MIN, II = IIK Input Current at Maximum Input Voltage — — 100 µA VCC = MAX: VI = 7.0 V: DE = RE = Dn = VCC High Level Input Current Dn, RE, DE — — 20 µA VCC = MAX: DE = RE = Dn = 2.5 V I/On — — 100 µA VCC = 0 V: DN = DE = 0.8 V: I/On = 1.2 V: RE = 0 V: RE — — –100 Dn — — –200 DE — — –500 I/On –250 — 100 µA — — 20 µA — — –20 –80 — –200 mA Dn = 1.2 V: VO = 0 V: RE = 0.8 V — 55 80 mA VCC = MAX: (RE = VIH or VIL) High-Level I/O Bus Current (Power Off) Low-Level Input Current Low-Level I/O Bus Current (Power On) IOZH Off-State Output Current, HighLevel Voltage Applied IOZL Off-State Output Current, Low-Level Voltage Applied IOS Output Short Circuit Current (Note 3) ICC Supply Current (Total ) Rn µA I/On = 10 mA VCC = MAX: DE = 4.5 V VI = 0.5V: Dn = 4.5 V VCC = MAX: Dn = DE = 0.8 V: I/On = 0.75 V : RE = 0 V: VO = 2.5V: RE = 2.0 V VCC = MAX: VO = 0.5 V: RE = 2.0 V VCC = MAX: NOTES: 1. For conditions shown as MIN or MAX, use the appropriate value specified under recommended operating conditions for the applicable device type. 2. All typical values are at VCC = 5.0 V, TA = + 25°C. 3. Not more than one output should be shorted at a time. For testing IOS, the use of high-speed test apparatus and/or sample-and-hold techniques are preferable in order to minimize internal heating and more accurately reflect operational values. Otherwise, prolonged shorting of a High output may raise the chip temperature well above normal and thereby cause invalid readings in other parameter tests. In any sequence of parameter tests, IOS tests should be performed last. FAST AND LS TTL DATA 4-275 MC74F3893A AC ELECTRICAL CHARACTERISTICS for Receiver and Receiver Enable Symbol Parameter 74F 74F TA = +25°C VCC=+5.0V, VT=+2.0V CD = 30 pF RT = 10 Ω TA = 0°C to +70°C VCC=+5.0V ±10%,VT=+2.0V CD = 30 pF RT = 10 Ω Min Typ Max Min Max Unit tPLH tPHL Propagation Delay Dn to I/On — — — — — — 1.0 1.0 7.0 7.0 ns tPLH tPHL Propagation Delay DE to I/On — — — — — — 1.0 1.0 7.0 7.0 ns tTLH tTHL Dn to I/On Transition Time 10% to 90%, 90% to 10% — — — — — — 1.0 1.0 5.0 5.0 ns tDskew Skew Between Receivers in Same Package — 1.0 — — — ns AC ELECTRICAL CHARACTERISTICS for Receiver Symbol Parameter 74F 74F TA = +25°C VCC=+5.0V CL = 50 pF RL = 1.0K Ω TA = 0°C to +70°C VCC=+5.0V ±10% CL = 50 pF RL = 1.0K Ω Min Typ Max Min Max Unit tPLH tPHL Propagation Delay I/On to Rn — — — — — — 2.0 2.0 8.0 8.0 ns tDskew Skew Between Receivers in Same Package — 1.0 — — — ns AC ELECTRICAL CHARACTERISTICS for Receiver Enable 74F 74F TA = +25°C VCC=+5.0V CL = 50 pF RL = 500 Ω TA = 0°C to +70°C VCC=+5.0V ±10% CL = 50 pF RL = 500 Ω Min Typ Max Min Max Unit tPZH tPZL Output Enable to High or Low Level RE to Rn — — — — — — 2.0 2.0 12.0 12.0 ns tPHZ tPLZ Output Disable From High or Low Level RE to Rn — — — — — — 1.0 1.0 8.0 8.0 ns Symbol Parameter FAST AND LS TTL DATA 4-276 FAST AND LS TTL DATA 4-277