54LVXC3245 8-Bit Dual Supply Configurable Voltage Interface Transceiver with TRI-STATE ® Outputs General Description Features The LVXC3245 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 3V supply level. The A port is a dedicated 3V 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 sockets that require live insertion and removal during normal operation. Bidirectional interface between 3V and 3V-to-5V buses Control inputs compatible with TTL level Outputs source/sink up to 24 mA Available in Cerpack and CDIP package 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) 5962-9861901 n n n n n n n Ordering Code Order Number Package Number Package Description 54LVXC3245W-QML W24A 24-Lead (0.300" Wide) Ceramic Flatpack 54LVXC3245J-QML J24F 24-Lead Ceramic Dual-in-line Logic Symbol Connection Diagram Pin Assignment for CDIP and Cerpack DS101032-1 Pin Descriptions Pin Names Description OE Output Enable Input T/R Transmit/Receive Input A0–A7 Side A Inputs or 3-STATE Outputs B0–B7 Side B Inputs or 3-STATE Outputs DS101032-2 TRI-STATE ® is a registered trademark of National Semiconductor Corporation © 1999 National Semiconductor Corporation DS101032 www.national.com 54LVXC3245 8-Bit Dual Supply Configurable Voltage Interface Transceiver with TRI-STATE ® Outputs February 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 H = High Voltage Level L = Low Voltage Level X = Immaterial Logic Diagram DS101032-4 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 Curr. (IIK) @ OE, T/R DC Output Diode (IOK)Current 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 @ 3.0V, 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 2.7V to 3.6V 3.0V 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 −65˚C to +150˚C Note 2: The A port unused pins (inputs or I/Os) must be held HIGH or LOW. They may not float. DC Electrical Characteristics Symbol VIHA VOHB Units Conditions Guaranteed Limits Minimum High An, 2.7 3.0 2.0 OE 3.0 3.6 2.0 Voltage T/R 3.6 5.5 2.0 Bn 2.7 3.0 2.0 3.0 3.6 2.0 3.6 5.5 3.85 Maximum Low An, 2.7 3.0 0.8 Level Input OE 3.0 3.6 0.8 Voltage T/R 3.6 5.5 0.8 Bn 2.7 3.0 0.8 3.0 3.6 0.8 3.6 5.5 1.65 VILB VOHA TA = −55˚C to +125˚C VCCB (V) Level Input VIHB VILA VCCA (V) Parameter Minimum High Level 2.7 3.0 2.6 Output Voltage 3.6 5.5 3.5 2.7 3.0 2.2 3.0 3.0 2.4 3.0 3.0 2.2 2.7 3.0 2.9 3.6 5.5 5.4 2.7 3.0 2.4 3.0 3.0 2.2 3.0 4.5 3.7 3 V VOUT ≤ 0.1V or ≥VCC − 0.1V V VOUT ≤ 0.1V or ≥VCC − 0.1V V IOH = −100 µA IOH = −100 µA IOH = −12 mA IOH = −12 mA V IOH = −24 mA IOH = −100 µA IOH = −100 µA IOH = −12 mA IOH = −24 mA IOH = −24 mA www.national.com DC Electrical Characteristics Symbol VOLA VCCA (V) Parameter TA = −55˚C to +125˚C VCCB (V) Units Conditions Guaranteed Limits 2.7 3.0 0.1 3.6 5.5 0.1 2.7 3.0 0.3 3.0 3.0 0.3 3.0 3.0 0.4 2.7 3.0 0.1 3.6 5.5 0.1 2.7 3.0 0.3 3.0 3.0 0.4 3.0 4.5 0.4 ± 1.0 ± 1.0 µA ± 5.0 ± 5.0 µA VI = VIL, VIH, OE = VCCA VO = VCCA, GND Maximum Input 3.6 3.6 Leakage Current @ 3.6 5.5 V IOL = 100 µA IOL = 100 µA IOL = 12 mA IOL = 12 mA Maximum Low Level Output Voltage VOLB IIN (Continued) V IOL = 24 mA IOL = 100 µA IOL = 100 µA IOL = 12 mA IOL = 24 mA IOL = 24 mA VI = VCCA, GND OE , T/R IOZA Maximum 3-STATE 3.6 3.6 Output Leakage 3.6 5.5 @ An IOZB Maximum 3-STATE 3.6 3.6 3.6 5.5 ± 5.0 ± 5.0 µA Output Leakage VI = VIL, VIH, OE = VCCA VO = VCCB, GND mA VI = VCCB–2.1V VI = VCC–0.6V @ Bn ∆ICC ICCA1 Maximum Bn 3.6 5.5 1.5 ICC/Input All Inputs 3.6 3.6 0.5 3.6 Open 10 µA µA An = VCCA or GND, Bn = VCCB or GND, OE = GND, T/R = GND µA An = VCCA or GND, Bn = VCCB or GND, OE = GND, T/R = VCCA V (Note 3) V (Note 3) V (Note 3) V (Note 3) Quiescent VCCA Supply Current as B Port Floats ICCA2 ICCB VOLPA VOLPB VOLVA VOLVB Quiescent VCCA 3.6 3.6 10 Supply Current 3.6 5.5 10 Quiescent VCCB 3.6 3.6 10 Supply Current 3.6 5.5 40 Quiet Output 3.3 3.3 1.0 Maximum Dynamic 3.3 5.0 1.1 VOL 3.3 3.3 0.9 3.3 5.0 1.6 Quiet Output 3.3 3.3 -0.7 Minimum Dynamic 3.3 5.0 -0.8 VOL 3.3 3.3 -0.6 3.3 5.0 -1.1 An = VCCA or GND Bn = Open, OE = VCCA, T/R = VCCA, VCCB = Open Note 3: Max number of outputs defined as (n). Data inputs are driven 0V to VCC level; one output at GND. Note 4: Max number of Data Inputs (n) switching. (n–1) inputs switching 0V to VCC level. Input-under-test switching: VCC level to threshold (VIHD), 0V to threshold (VILD), f = 1 MHz. www.national.com 4 AC Electrical Characteristics Symbol Parameter TA = −55˚C to +125˚C CL = 50 pF TA = −55˚C to +125˚C CL = 50 pF VCCA = 2.7V–3.6V VCCB = 4.5V–5.5V VCCA = 2.7V–3.6V VCCB = 3.0V–3.6V Units Min Max Min Max tPHL Propagation Delay 1.0 9.0 1.0 9.5 tPLH A to B 1.0 9.0 1.0 9.5 tPHL Propagation Delay 1.0 9.0 1.0 9.0 tPLH B to A 1.0 9.0 1.0 9.0 tPZL Output Enable Time 1.0 9.0 1.0 10.0 tPZH OE to B 1.0 9.0 1.0 10.0 tPZL Output Enable Time 1.0 11.0 1.0 11.0 tPZH OE to A 1.0 11.0 1.0 11.0 tPHZ Output Disable Time 1.0 7.5 1.0 8.0 tPLZ OE to B 1.0 7.5 1.0 8.0 tPHZ Output Disable Time 1.0 7.0 1.0 7.0 tPLZ OE to A 1.0 7.0 1.0 7.0 tOSHL Output to Output tOSLH Skew (Note 5) 1.5 ns ns ns ns ns ns 1.5 ns Data to Output Note 5: 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 Max Units CIN Symbol Input Capacitance Parameter 10.0 pF CI/O Input/Output Capacitance 12.0 pF CPD Power Dissipation 50 pF Capacitance Conditions VCC = Open VCCA = 3.3V VCCB = 5.0V VCCB = 5.0V VCCA = 3.3V Note 6: CPD is measured at 10 MHz. 5 www.national.com Configurable I/O Application for mixed or unknown Voltages “A” port is a dedicated 3V port to interface 3V 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 LVXC3245 fits into a system with a 3V subsystem and a 5V subsystem. LVXC3245 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 LVXC3245 configures two different output levels to handle the dual supply interface issues. The DS101032-3 FIGURE 1. LVXC3245 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 LVXC3245 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 LVXC3245 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. DS101032-5 FIGURE 2. LVXC3245 amplifies 3V signals for interfacing to non-TTL inputs. sumption. The LVXC3245 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- DS101032-6 FIGURE 3. LVXC3245 for interfacing to 5V busses with pull-ups minimizes power consumption. 7 www.national.com 8 Physical Dimensions inches (millimeters) unless otherwise noted 24-Lead (0.300" Wide) Ceramic Flatpack Package Number W24C 24-Lead Ceramic Dual-in-line Package Number J24F 9 www.national.com 54LVXC3245 8-Bit Dual Supply Configurable Voltage Interface Transceiver with TRI-STATE ® Outputs 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: 2. A critical component is any component of a life support 1. Life support devices or systems are devices or sysdevice or system whose failure to perform can be reatems which, (a) are intended for surgical implant into sonably expected to cause the failure of the life support the body, or (b) support or sustain life, and whose faildevice or system, or to affect its safety or effectiveness. ure 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. 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