74LCX257 LOW VOLTAGE CMOS QUAD 2 CHANNEL MULTIPLEXER WITH 5V TOLERANT INPUTS AND OUTPUTS (3-STATE) 5V TOLERANT INPUTS AND OUTPUTS HIGH SPEED: t = 6.0 ns (MAX.) at V = 3V PD CC POWER DOWN PROTECTION ON INPUTS AND OUTPUTS SYMMETRICAL OUTPUT IMPEDANCE: SOP TSSOP I = I = 24mA (MIN) at V = 3V OH OL CC PCI BUS LEVELS GUARANTEED AT 24 mA Table 1: Order Codes BALANCED PROPAGATION DELAYS: t t PLH PHL PACKAGE T & R OPERATING VOLTAGE RANGE: SOP 74LCX257MTR V (OPR) = 2.0V to 3.6V (1.5V Data CC Retention) TSSOP 74LCX257TTR PIN AND FUNCTION COMPATIBLE WITH 74 SERIES 257 It is composed of four independent 2 channel LATCH-UP PERFORMANCE EXCEEDS multiplexers with common SELECT and ENABLE 500mA (JESD 17) (OE) INPUT. The 74LCX257 is a non-inverting ESD PERFORMANCE: multiplexer. When the ENABLE INPUT is held HBM > 2000V (MIL STD 883 method 3015) Hig, all outputs become in high impedance MM > 200V state. If SELECT INPUT is heldLo, data is selected, when SELECT INPUT isHig, data is chosen. DESCRIPTION It has same speed performance at 3.3V than 5V The 74LCX257 is a low voltage CMOS QUAD 2 AC/ACT family, combined with a lower power CHANNEL MULTIPLEXER (3-STATE) fabricated consumption. with sub-micron silicon gate and double-layer 2 All inputs and outputs are equipped with metal wiring C MOS technology. It is ideal for low protection circuits against static discharge, giving power and high speed 3.3V applications it can be them 2KV ESD immunity and transient excess interfaced to 5V signal environment for both inputs voltage. and outputs. Figure 1: Pin Connection And IEC Logic Symbols Rev. 4 September 2004 1/13 Obsolete Product(s) - Obsolete Product(s)74LCX257 Figure 2: Input And Output Equivalent Circuit Table 2: Pin Description PIN N SYMBOL NAME AND FUNCTION 1 SELECT Common Data Select Inputs 2, 5, 11, 14 1A to 4A Data Inputs From Source A 3, 6, 10, 13 1B to 4B Data Inputs From Source B 4, 7, 9, 12 1Y to 4Y 3 State Multiplexer Outputs 15 OE 3 State Output Enable Inputs (Active LOW) 8 GND Ground (0V) 16 V Positive Supply Voltage CC Table 3: Truth Table INPUTS OUTPUT OE SELECT A B Y H XXX Z LLL X L LL H X H LH X L L LH X H H X : Dont Care Z : High Impedance 2/13 Obsolete Product(s) - Obsolete Product(s)