Texas Instruments SN5427, SN54LS27, SN7427, SN74LS27 Triple 3-Input Positive-NOR Gates
Datasheet and Technical Specifications
Product Overview
This document details the Texas Instruments SN5427, SN54LS27, SN7427, and SN74LS27 integrated circuits, which are triple 3-input positive-NOR gates. These devices offer dependable Texas Instruments quality and reliability.
Key Features:
- Three independent 3-input positive-NOR gates per package.
- SN5427 and SN54LS27 are characterized for operation over the full military temperature range of -55°C to 125°C.
- SN7427 and SN74LS27 are characterized for operation from 0°C to 70°C.
- Available in multiple package options including Plastic "Small Outline" Packages, Ceramic Chip Carriers, Flat Packages, and Plastic and Ceramic DIPs.
Logic Symbol and Diagram
Logic Symbol: The logic symbol for each gate is a triangle with a bubble at the output, signifying a NOR function. It features three inputs (A, B, C) and one output (Y).
Logic Diagram: The internal logic diagram illustrates the implementation of the 3-input NOR gate using standard logic gate symbols.
Positive Logic Equation: Y = A + B + C or Y = Ā · B · C
Function Table
| INPUTS | OUTPUT | ||
|---|---|---|---|
| A | B | C | Y |
| H | X | X | L |
| X | H | X | L |
| X | X | H | L |
| L | L | L | H |
Note: H = High Level, L = Low Level, X = Don't Care.
Internal Schematics
The document provides internal schematics detailing the transistor-level circuitry for both the '27 (TTL) and 'LS27 (Schottky TTL) versions of the NOR gates.
Absolute Maximum Ratings
| Parameter | Value | Unit |
|---|---|---|
| Supply voltage, VCC (Note 1) | 7 | V |
| Input voltage: '27 | 5.5 | V |
| Input voltage: 'LS27 | 7 | V |
| Operating free-air temperature: SN54' | -55 to 125 | °C |
| Operating free-air temperature: SN74' | 0 to 70 | °C |
| Storage temperature range | -65 to 150 | °C |
NOTE 1: Voltage values are with respect to network ground terminal.
Recommended Operating Conditions
SN5427 / SN7427
| Parameter | SN5427 | SN7427 | UNIT | ||||
|---|---|---|---|---|---|---|---|
| MIN | NOM | MAX | MIN | NOM | MAX | ||
| VCC Supply voltage | 4.5 | 5 | 5.5 | 4.75 | 5 | 5.25 | V |
| VIH High-level input voltage | 2 | 2 | V | ||||
| VIL Low-level input voltage | 0.8 | 0.8 | V | ||||
| IOH High-level output current | -0.8 | -0.8 | mA | ||||
| IOL Low-level output current | 16 | 16 | mA | ||||
| TA Operating free-air temperature | -55 | 125 | 0 | 70 | °C | ||
SN54LS27 / SN74LS27
| Parameter | SN54LS27 | SN74LS27 | UNIT | ||||
|---|---|---|---|---|---|---|---|
| MIN | TYP | MAX | MIN | TYP | MAX | ||
| VCC Supply voltage | 4.5 | 5 | 5.5 | 4.75 | 5 | 5.25 | V |
| VIH High-level input voltage | 2 | 2 | V | ||||
| VIL Low-level input voltage | 0.7 | 0.8 | V | ||||
| IOH High-level output current | -0.4 | -0.4 | mA | ||||
| IOL Low-level output current | 4 | 8 | mA | ||||
| TA Operating free-air temperature | -55 | 125 | 0 | 70 | °C | ||
Electrical Characteristics
SN5427 / SN7427
| PARAMETER | TEST CONDITIONS † | SN5427 | SN7427 | UNIT | ||||
|---|---|---|---|---|---|---|---|---|
| MIN | TYP | MAX | MIN | TYP | MAX | |||
| VIK | VCC = MIN, II = -12 mA | -1.5 | -1.5 | V | ||||
| VOH | VCC = MIN, IOH = -0.8 mA | 2.4 | 3.4 | 2.4 | 3.4 | V | ||
| VOL | VCC = MIN, IOL = 16 mA | 0.2 | 0.4 | 0.2 | 0.4 | V | ||
| IIH | VCC = MAX, VI = 5.5 V | 1 | 1 | mA | ||||
| IIL | VCC = MAX, VI = 0.4 V | -1.6 | -1.6 | mA | ||||
| IOS § | VCC = MAX | -20 | -18 | -55 | mA | |||
| ICCH | VCC = MAX, VI = 0 V | 10 | 16 | 10 | 16 | mA | ||
| ICCL | VCC = MAX, See Note 2 | 16 | 26 | 16 | 26 | mA | ||
† For conditions shown as MIN or MAX, use the appropriate value specified under recommended operating conditions.
‡ All typical values are at VCC = 5 V, TA = 25°C.
§ Not more than one output should be shorted at a time.
NOTE 2: One input at 4.5 V, all others at GND.
SN54LS27 / SN74LS27
| PARAMETER | TEST CONDITIONS † | SN54LS27 | SN74LS27 | UNIT | ||||
|---|---|---|---|---|---|---|---|---|
| MIN | TYP | MAX | MIN | TYP | MAX | |||
| VIK | VCC = MIN, II = -18 mA | -1.5 | -1.5 | V | ||||
| VOH | VCC = MIN, IOH = -0.4 mA | 2.5 | 3.4 | 2.7 | 3.4 | V | ||
| VOL | VCC = MIN, IOL = 4 mA | 0.25 | 0.4 | 0.25 | 0.4 | V | ||
| IIH | VCC = MAX, VI = 7 V | 0.1 | 0.1 | mA | ||||
| IIL | VCC = MAX, VI = 2.7 V | -20 | -20 | mA | ||||
| IOS § | VCC = MAX | -20 | -100 | -100 | mA | |||
| ICCH | VCC = MAX, VI = 0 V | 2 | 4 | 2 | 4 | mA | ||
| ICCL | VCC = MAX, See Note 2 | 3.4 | 6.8 | 3.4 | 6.8 | mA | ||
† For conditions shown as MIN or MAX, use the appropriate value specified under recommended operating conditions.
‡ All typical values are at VCC = 5 V, TA = 25°C.
§ Not more than one output should be shorted at a time, and the duration of the short-circuit should not exceed one second.
NOTE 2: One input at 4.5 V, all others at GND.
Switching Characteristics
Switching characteristics are provided for VCC = 5 V, TA = 25°C.
SN5427 / SN7427
| PARAMETER | FROM (INPUT) | TO (OUTPUT) | TEST CONDITIONS | MIN | TYP | MAX | UNIT |
|---|---|---|---|---|---|---|---|
| tPLH | A, B or C | Y | RL = 400 Ω, CL = 15 pF | 10 | 15 | ns | |
| tPHL | A, B or C | Y | 7 | 11 | ns |
NOTE 3: Load circuits and voltage waveforms are shown in Section 1.
SN54LS27 / SN74LS27
| PARAMETER | FROM (INPUT) | TO (OUTPUT) | TEST CONDITIONS | MIN | TYP | MAX | UNIT |
|---|---|---|---|---|---|---|---|
| tPLH | A, B or C | Y | RL = 2 kΩ, CL = 15 pF | 10 | 15 | ns | |
| tPHL | A, B or C | Y | 10 | 15 | ns |
NOTE 3: Load circuits and voltage waveforms are shown in Section 1.
Package Options and Materials
Texas Instruments offers these devices in various package types and packaging materials. The following table summarizes some of the available options:
Package Types:
- LCCC (Leadless Ceramic Chip Carrier)
- CDIP (Ceramic Dual In-line Package)
- CFP (Ceramic Flat Pack)
- SOIC (Small Outline Integrated Circuit)
- SOP (Small Outline Package)
- PDIP (Plastic Dual-In-line Package)
Detailed information on package dimensions, tape and reel specifications, and tube packaging is provided in the mechanical data sections.
Mechanical Data and Package Outlines
The document includes detailed mechanical drawings for various package types, specifying dimensions in millimeters and inches. These drawings illustrate the physical characteristics of each package for PCB layout and integration.
- SOIC (Small Outline Integrated Circuit): A surface-mount package, typically 1.75 mm maximum height.
- CDIP (Ceramic Dual In-line Package): A through-hole package, typically 5.08 mm maximum height, often hermetically sealed for reliability.
- CFP (Ceramic Flat Pack): A surface-mount ceramic package.
- PDIP (Plastic Dual-In-line Package): A through-hole plastic package.
These sections also include land pattern examples and solder mask details to aid in printed circuit board design.
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