M74HC138
3 TO 8 LINE DECODER (INVERTING)
■ HIGH SPEED: tPD = 13ns (TYP.) at VCC = 6V
■ LOW POWER DISSIPATION: ICC = 4µA(MAX.) at TA=25°C
■ HIGH NOISE IMMUNITY: VNIH = VNIL = 28 % VCC (MIN.)
■ SYMMETRICAL OUTPUT IMPEDANCE: |IOH| = IOL = 4mA (MIN)
■ BALANCED PROPAGATION DELAYS: tPLH ≅ tPHL
■ WIDE OPERATING VOLTAGE RANGE: VCC (OPR) = 2V to 6V
■ PIN AND FUNCTION COMPATIBLE WITH 74 SERIES 138
DESCRIPTION
The M74HC138 is an high speed CMOS 3 TO 8 LINE DECODER fabricated
with silicon gate C2MOS technology.
If the device is enabled, 3 binary select inputs (A, B, and C)
determine which one of the outputs will go low. If enable input G1
is held low or either G2A or G2B is held high, the decoding
function is inhibited and all the 8 outputs go high. Three enable
inputs are provided to ease cascade connection and application of
address decoders for memory systems.
All inputs are equipped with protection circuits against static
discharge and transient excess voltage.
ABSOLUTE MAXIMUM RATINGS
| Symbol | Parameter | Value | Unit |
| VCC | Supply Voltage | -0.5 to +7 | V |
| VI | DC Input Voltage | -0.5 to VCC + 0.5 | V |
| VO | DC Output Voltage | -0.5 to VCC + 0.5 | V |
| IIK | DC Input Diode Current | ± 20 | mA |
| IOK | DC Output Diode Current | ± 20 | mA |
| IO | DC Output Current | ± 25 | mA |
| ICC or IGND | DC VCC or Ground Current | ± 50 | mA |
| PD | Power Dissipation | 500(*) | mW |
| Tstg | Storage Temperature | -65 to +150 | °C |
| TL | Lead Temperature (10 sec) | 300 | °C |
Absolute Maximum Ratings are those values beyond which damage to
the device may occur. Functional operation under these conditions
is not implied
(*) 500mW at 65 °C; derate to 300mW by 10mW/°C from 65°C to 85°C
PIN CONNECTION AND IEC LOGIC SYMBOLS
INPUT AND OUTPUT EQUIVALENT CIRCUIT
LOGIC DIAGRAM
