74VHCT126A ,QUAD BUS BUFFERS (3-STATE)74VHCT126AQUAD BUS BUFFERS (3-STATE)
74VHCT126A
QUAD BUS BUFFERS (3-STATE)
1/12December 2004 HIGH SPEED: tPD = 3.8 ns (TYP.) at VCC = 5V LOW POWER DISSIPATION:
ICC = 2 μA (MAX.) at TA=25°C COMPATIBLE WITH TTL OUTPUTS:
VIH = 2V (MIN.), VIL = 0.8V (MAX) POWER DOWN PROTECTION ON INPUTS
& OUTPUTS SYMMETRICAL OUTPUT IMPEDANCE:OH | = IOL = 8 mA (MIN) BALANCED PROPAGATION DELAYS: PLH ≅ t PHL OPERATING VOLTAGE RANGE:
VCC(OPR) = 4.5V to 5.5V PIN AND FUNCTION COMPATIBLE WITH
74 SERIES 126 IMPROVED LATCH-UP IMMUNITY LOW NOISE: VOLP = 0.8V (MAX.)
DESCRIPTIONThe 74VHCT126A is an advanced high-speed
CMOS QUAD BUS BUFFERS fabricated with
sub-micron silicon gate and double-layer metal
wiring C2 MOS technology.
The device requires the 3-STATE control input G
to be set low to place the output in to the high
impedance state.
Power down protection is provided on all inputs
and outputs and 0 to 7V can be accepted on
inputs with no regard to the supply voltage. This
device can be used to interface 5V to 3V since all
inputs are equipped with TTL threshold.
All inputs and outputs are equipped with
protection circuits against static discharge, giving
them 2KV ESD immunity and transient excess
voltage.
74VHCT126AQUAD BUS BUFFERS (3-STATE)
Figure 1: Pin Connection And IEC Logic Symbols
Table 1: Order Codes Rev. 5
74VHCT126A2/12
Figure 2: Input Equivalent Circuit Table 2: Pin Description
Table 2: Truth Table X : Don‘ t Care
Z : High Impedance
Table 3: Absolute Maximum Ratings Absolute Maximum Ratings are those values beyond which damage to the device may occur. Functional operation under these conditions is
not implied
1) Output in OFF State
2) High or Low State
Table 4: Recommended Operating Conditions 1) Output in OFF State
2) High or Low State
3) VIN from 0.8V to 2V
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Table 5: DC Specifications
Table 6: AC Electrical Characteristics (Input tr = tf = 3ns)
(*) Voltage range is 5.0V ± 0.5V
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Table 7: Capacitive Characteristics 1) CPD is defined as the value of the IC’s internal equivalent capacitance which is calculated from the operating current consumption without
load. (Refer to Test Circuit). Average operating current can be obtained by the following equation. ICC(opr) = CPD x VCC x fIN + ICC/4 (per circuit)
Table 8: Dynamic Switching Characteristics 1) Worst case package.
2) Max number of outputs defined as (n). Data inputs are driven 0V to 3.0V, (n-1) outputs switching and one output at GND.
3) Max number of data inputs (n) switching. (n-1) switching 0V to 3.0V. Inputs under test switching: 3.0V to threshold (VILD), 0V to threshold
(VIHD), f=1MHz.
74VHCT126A5/12
Figure 3: Test Circuit CL =15/50pF or equivalent (includes jig and probe capacitance)
RL = R1 = 1KΩ or equivalent
RT = ZOUT of pulse generator (typically 50Ω)
Figure 4: Waveform - Propagation Delays (f=1MHz; 50% duty cycle)
74VHCT126A6/12
Figure 5: Waveform - Output Enable And Disable Time (f=1MHz; 50% duty cycle)
