54LVXC4245 8-Bit Dual Supply Configurable Voltage Interface Transceiver with TRI-STATE ® Outputs General Description Features The LVXC4245 is a 24-pin dual-supply, 8-bit configurable voltage interface transceiver suited for real time configurable I/O applications. The VCCA pin accepts a 5V supply level. The “A” port is a dedicated 5V port. The VCCB pin accepts a 3V-to-5V supply level. The “B” port is configured to track the VCCB supply level respectively. A 5V level on the VCC pin will configure the I/O pins at a 5V level and a 3V VCC will configure the I/O pins at a 3V level. This device will allow the VCCB voltage source pin and I/O pins on the “B” port to float when OE is HIGH. This feature is necessary to buffer data to and from a socket that permits live insertion and removal during normal operation. Bidirectional interface between 5V and 3V-to-5V buses Control inputs compatible with TTL level Outputs source/sink up to 24 mA Available in Cerpack and CDIP packages Implements patented EMI reduction circuitry Flexible VCCB operating range Allows B port and VCCB to float simultaneously when OE is HIGH n Functionally compatible with the 54 series 245 n Standard Microcircuit Drawing (SMD) 5962-9862001 n n n n n n n Ordering Code Order Number Package Number Package Description 54LVXC4245W-QML W24C 24-Lead Ceramic Flatpack 54LVXC4245J-QML J24F 24-Lead Ceramic Dual-in-line Logic Symbol Connection Diagram Pin Assignment for Cerpack and CDIP DS101033-1 Pin Descriptions Pin Names Description OE Output Enable Input T/R Transmit/Receive Input A0–A7 Side A Inputs or TRI-STATE Outputs B0–B7 Side B Inputs or TRI-STATE Outputs DS101033-2 TRI-STATE ® is a registered trademark of National Semiconductor Corporation © 1999 National Semiconductor Corporation DS101033 www.national.com 54LVXC4245 8-Bit Dual Supply Configurable Voltage Interface Transceiver with TRI-STATE Outputs March 1999 Truth Table Inputs OE Outputs T/R L L Bus B Data to Bus A L H Bus A Data to Bus B H X HIGH-Z State Logic Diagram DS101033-4 www.national.com 2 Absolute Maximum Ratings (Note 1) Recommended Operating Conditions (Note 2) If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/ Distributors for availability and specifications. Supply Voltage (VCCA,VCCB) DC Input Voltage (VI) @ OE, T/R DC Input/Output Voltage (VI/O) @ An @ Bn DC Input Diode Current (IIK) @ OE, T/R DC Output Diode Current (IOK) DC Output Source or Sink Current (IO) DC VCC or Ground Current Per Output Pin (ICC or IGND) and Max Current Storage Temperature Range (TSTG) Supply Voltage VCCA VCCB Input Voltage (VI) @ OE , T/R Input/Output Voltage (VI/O) @ An @ Bn Free Air Operating Temperature (TA) Minimum Input Edge Rate (∆V/∆t) VIN from 30% to 70% of VCC VCC @ 3V, 4.5V, 5.5V −0.5V to +7.0V −0.5V to VCCA +0.5V −0.5V to VCCA +0.5V −0.5V to VCCB +0.5V ± 20 mA ± 50 mA ± 50 mA 4.5V to 5.5V 2.7V to 5.5V 0V to VCCA 0V to VCCA 0V to VCCB −55˚C to +125˚C 8 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. ± 50 mA ± 200 mA Note 2: The A port unused pins (inputs and I/O’s) must be held HIGH or LOW. They may not float. −65˚C to +150˚C DC Electrical Characteristics Symbol Parameter VCCA (V) VCCB (V) TA = −55˚C to +125˚C Units Conditions Guaranteed Limits VIHA An 4.5 2.7 2.0 Input Voltage OE 4.5 3.6 2.0 or T/R 5.5 5.5 2.0 ≥ VCC − 0.1V Bn 4.5 2.7 2.0 4.5 3.6 2.0 4.5 5.5 3.85 VIHB VILA VOHB V VOUT ≤ 0.1V Maximum Low Level An 4.5 2.7 0.8 Input Voltage OE 4.5 3.6 0.8 or T/R 5.5 5.5 0.8 ≥ VCC − 0.1V Bn 4.5 2.7 0.8 4.5 3.6 0.8 4.5 5.5 1.65 VILB VOHA V VOUT ≤ 0.1V Minimum High Level 4.5 2.7 4.4 5.5 5.5 5.4 4.5 3.0 3.7 4.5 4.5 3.7 4.5 2.7 2.6 5.5 5.5 5.4 4.5 2.7 2.2 4.5 3.0 2.4 4.5 3.0 2.2 IOH = −12 mA IOH = −12 mA IOH = −24 mA 4.5 4.5 3.7 IOH = −24 mA 3 V IOH = −100 µA IOH = −100 µA IOH = −24 mA Minimum High Level Output Voltage V IOH = −24 mA IOH = −100 µA IOH = −100 µA www.national.com DC Electrical Characteristics (Continued) TA = −55˚C to +125˚C VCCA (V) VCCB (V) Maximum Low Level 4.5 2.7 0.1 Output Voltage 5.5 5.5 0.1 4.5 3.0 0.4 4.5 4.5 0.4 4.5 2.7 0.1 5.5 5.5 0.1 4.5 2.7 0.3 4.5 3.0 0.3 4.5 3.0 0.4 4.5 4.5 0.4 ± 1.0 ± 1.0 ± 5.0 ± 5.0 µA Symbol Parameter Units Conditions Guaranteed Limits VOLA VOLB IIN IOZA IOZB ∆ICC ICCA1 Maximum Input Leakage 5.5 3.6 Current @ OE, T/R 5.5 5.5 IOL = 24 mA IOL = 24 mA VI = VCCA, GND 5.5 3.6 5.5 ± 5.0 ± 5.0 µA 5.5 OE = VCCA VO = VCCB, GND VI = VCC − 2.1V 5.5 µA Maximum All Inputs 5.5 5.5 1.5 mA ICC/Input Bn 5.5 3.6 0.5 mA 5.5 Open 40 µA 5.5 3.6 40 µA 5.5 5.5 40 Bn = VCCB or GND OE = GND, T/R = GND An = VCCA or GND 5.5 3.6 10 µA 5.5 5.5 40 Bn = VCCB or GND OE = GND, T/R = VCCA V (Note 3) V (Note 3) V (Note 3) V (Note 3) Quiescent VCCA Quiescent VCCA Quiescent VCCB Quiet Output Maximum 5.0 3.3 1.5 Dynamic VOL 5.0 5.0 1.5 5.0 3.3 0.8 5.0 5.0 1.5 VOLPB VOLVA IOL = 100 µA IOL = 100 µA IOL = 12 mA IOL = 12 mA Maximum TRI-STATE 3.6 5.5 Supply Current VOLPA V Output Leakage @ Bn 5.5 Output Leakage @ An Supply Current ICCB IOL = 100 µA IOL = 100 µA IOL = 24 mA IOL = 24 mA VI = VIL, VIH OE = VCCA VO = VCCA, GND VI = VIL, VIH, Maximum TRI-STATE Supply Current as B Port Floats ICCA2 V Quiet Output Minimum 5.0 3.3 -1.1 Dynamic VOL 5.0 5.0 -1.2 5.0 3.3 -0.7 5.0 5.0 -1.1 VOLVB Note 3: Max number of outputs defined as (n). Data inputs are driven 0V to VCC level; one output at GND. www.national.com 4 VI = VCCB − 0.6V An = VCCA or GND Bn = Open, OE = VCCA T/R = VCCA, VCCB = Open An = VCCA or GND AC Electrical Characteristics Symbol CL = 50 pF VCCA = 4.5V to 5.5V VCCB = 4.5V to 5.5V TA = −55˚C to +125˚C Parameter CL = 50 pF VCCA = 4.5V to 5.5V VCCB = 2.7V to 3.6V TA = −55˚C to +125˚C Min Max Min Max tPHL Propagation 1.0 8.0 1.0 9.5 tPLH Delay A to B 1.0 8.0 1.0 9.5 tPHL Propagation 1.0 8.0 1.0 9.5 tPLH Delay B to A 1.0 8.0 1.0 9.5 tPZL Output Enable 1.0 9.5 1.0 12.0 tPZH Time OE to B 1.0 9.5 1.0 12.0 tPZL Output Enable 1.0 11.5 1.0 13.0 tPZH Time OE to A 1.0 11.5 1.0 13.0 tPHZ Output Disable 1.0 7.0 1.0 7.5 tPLZ Time OE to B 1.0 7.0 1.0 7.5 tPHZ Output Disable 0.5 7.0 0.5 7.0 tPLZ Time OE to A 0.5 7.0 0.5 7.0 tOSHL Output to Output tOSLH Skew (Note 4) 1.5 1.5 Units ns ns ns ns ns ns ns Data to Output 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). Parameter guaranteed by design. Capacitance Symbol Parameter CIN Input Capacitance CI/O Input/Output Capacitance CPD Power Dissipation Capacitance A→B B→A Max Units 10 pF 50 pF Conditions VCC = Open VCCA = 5V, VCCB = 3.3V VCCA = 5V 12 pF 50 pF VCCB = 3.3V Note 5: CPD is measured at 10 MHz. 5 www.national.com Configurable I/O Application for mixed or unknown Voltages “A” port is a dedicated 5V port to interface 5V ICs. The “B” port is configurable and accepts a 3V-to-5V supply level. This configurable ″B″ port provides maximum flexibility for interfacing to unknown supply voltages, for interfacing to supply voltages which may change in the future, or for providing flexibility when supplying systems to multiple customers with varying power supply requirements. Figure 1 shows how the LVXC4245 fits into a system with a 3V subsystem and a 5V subsystem. LVXC4245 is designed to solve 3V/5V interfacing issues when CMOS devices cannot tolerate I/O levels above their applied VCC. If an I/O pin of 3V ICs is driven by 5V ICs, the P-Channel transistor in 3V ICs will conduct causing current flow from I/O bus to the 3V power supply. The resulting high current flow can cause destruction of 3V ICs through latchup effects. To prevent this problem, a current limiting resistor is used typically under direct connection of 3V ICs and 5V ICs, but it causes speed degradation. In a better solution, the LVXC4245 configures two different output levels to handle the dual supply interface issues. The DS101033-3 FIGURE 1. LVXC4245 Fits into a System with 3V Subsystem and 5V Subsystem www.national.com 6 Configurable I/O Application for mixed or unknown Voltages In the first case, when interfacing to non-TTL inputs such as ACMOS or HCMOS where full 5V signal swings are needed, the LVXC4245 can act as an amplifier to translate 0 volt to 3 volt signals up to 0 volt to 5 volt levels as shown in Figure 2. (Continued) Additionally, the LVXC4245 solves two other unique problems: when interfacing to non-TTL compatible signals or when interfacing to components or busses which are pulled up to 5V. DS101033-5 FIGURE 2. LVXC4245 amplifies 3V signals for interfacing to non-TTL inputs. sumption. The LVXC4245 can be used to translate the 3 volt signals to 5 volt levels and eliminate the power consumed by the pull-up resistors. In the second case, when interfacing to busses which use resistive pull-ups to 5V, it is desirable to avoid connecting 3V devices directly to the bus to avoid excessive power con- DS101033-6 FIGURE 3. LVXC4245 for interfacing to 5V busses with pull-ups minimizes power consumption. 7 www.national.com Physical Dimensions inches (millimeters) unless otherwise noted 24-Lead Ceramic Flatpack Package Number W24C 24-Lead Ceramic Dual-in-line Package Number J24F www.national.com 8 LIFE SUPPORT POLICY NATIONAL’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 NATIONAL SEMICONDUCTOR CORPORATION. As used herein: 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 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. National Semiconductor Corporation Americas Tel: 1-800-272-9959 Fax: 1-800-737-7018 Email: [email protected] www.national.com National Semiconductor Europe Fax: +49 (0) 1 80-530 85 86 Email: [email protected] Deutsch Tel: +49 (0) 1 80-530 85 85 English Tel: +49 (0) 1 80-532 78 32 Français Tel: +49 (0) 1 80-532 93 58 Italiano Tel: +49 (0) 1 80-534 16 80 2. A critical component is 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. 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