Document
HD74HC125/HD74HC126
Quad. Bus Buffer Gates (with 3-state outputs)
Description
The HD74HC125, HD74HC126 require the 3-state control input C to be taken high to put the output into the high impedance condition, whereas the HD74HC125, HD74HC126 requires the control input to be low to put the output into high impedance.
Features
• • • • • High Speed Operation: tpd = 8 ns typ (CL = 50 pF) High Output Current: Fanout of 15 LSTTL Loads Wide Operating Voltage: VCC = 2 to 6 V Low Input Current: 1 µA max Low Quiescent Supply Current: ICC (static) = 4 µA max (Ta = 25°C)
Function Table
Inputs C HC125 H L L X : Z : HC126 L H H A X L H Output Y HC125 Z L H HC126 Z L H
Irrelevent Off (high-impedance) state of a 3-state output.
HD74HC125/HD74HC126
Pin Arrangement
HD74HC125
1C 1A 1Y 2C 2A 2Y GND
1 2 3 4 5 6 7 (Top view)
14 13 12 11 10 9 8
VCC 4C 4A 4Y 3C 3A 3Y
HD74HC126
1C 1A 1Y 2C 2A 2Y GND
1 2 3 4 5 6 7 (Top view)
14 13 12 11 10 9 8
VCC 4C 4A 4Y 3C 3A 3Y
2
HD74HC125/HD74HC126
Absolute Maximum Ratings
Item Supply voltage range Input voltage Output voltage Output current DC current drain per VCC, GND DC input diode current DC output diode current Power dissipation per package Storage temperautre Symbol VCC VIN VOUT I OUT I CC, I GND I IK I OK PT Tstg Rating –0.5 to +7.0 –0.5 to VCC + 0.5 –0.5 to VCC + 0.5 ±35 ±75 ±20 ±20 500 –65 to +150 Unit V V V mA mA mA mA mW °C
3
HD74HC125/HD74HC126
DC Characteristics
Ta = 25°C Item Input voltage Symbol VIH Ta = –40 to +85°C Max — — — 0.5 1.35 1.8 — — — — — 0.1 0.1 0.1 0.33 0.33 ±5.0 ±1.0 40 µA µA µA I OL = 6 mA I OL = 7.8 mA Vin = VIH or VIL, Vout = VCC or GND Vin = VCC or GND Vin = VCC or GND, Iout = 0 µA V I OH = –6 mA I OH = –7.8 mA Vin = VIH or VIL I OL = 20 µA V Vin = VIH or VIL I OH = –20 µA V Unit V Test Conditions
VCC (V) Min Typ Max Min 2.0 4.5 6.0 1.5 — 3.15 — 4.2 — — — — — — — — — — 0.5 1.5 3.15 4.2 —
VIL
2.0 4.5 6.0
1.35 — 1.8 — 1.9 4.4 5.9 4.13 5.63 — — —
Output voltage
VOH
2.0 4.5 6.0 4.5 6.0
1.9 2.0 — 4.4 4.5 — 5.9 6.0 — 4.18 — 5.68 — — — — — — — — — — —
VOL
2.0 4.5 6.0 4.5 6.0
0.0 0.1 0.0 0.1 0.0 0.1 — — — — —
0.26 — 0.26 — ±0.5 — ±0.1 — 4.0 —
Off-state output current Input current Quiescent supply current
I OZ Iin I CC
6.0 6.0 6.0
4
HD74HC125/HD74HC126
AC Characteristics (CL = 50 pF, Input tr = tf = 6 ns)
Ta = 25°C Item Symbol Ta = –40 to +85°C Max 125 25 21 190 38 33 190 38 33 75 15 13 10 pF ns ns ns Unit ns Test Conditions
VCC (V) Min Typ Max Min 2.0 4.5 6.0 — — — — — — — — — — — — — — 8 — — 9 — — 14 — — 4 — 5 100 — 20 17 — —
Propagation delay t PLH time t PHL
Output enable time
t ZH t ZL
2.0 4.5 6.0
150 — 30 26 — —
Output disable time
t HZ t LZ
2.0 4.5 6.0
150 — 30 26 60 12 10 10 — — — — — —
Output rise/fall time
t TLH t THL
2.0 4.5 6.0
Input capacitance
Cin
—
5
Cautions
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