My Inquiry
My Account
onsemi KA79M05TU
- Part No.:
- KA79M05TU
- Manufacturer:
- onsemi
- Package:
- TO-220-3
- Datasheet:
-
KA79M05TU.pdf
- Description:
- IC REG LINEAR -5V 500MA TO220-3
- Quantity:
- Payment:
- Shipping:
Inventory:3,378
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
KA79M05TU from Fairchild Semiconductor is a fixed-output, 3-terminal, medium-current negative voltage regulator delivering -5 V at up to 500 mA. It features internal thermal overload protection, short-circuit current limiting, and safe-area compensation in a TO-220 package. It is used in industrial power supplies, analog instrumentation, and dual-rail op-amp biasing where stable negative rail generation is required.
For engineers reviewing the KA79M05TU datasheet, pinout, applications, or equivalent options, this page provides verified electrical specifications, thermal performance data, real-world use scenarios, and validated alternative parts for design-in and BOM continuity planning.
Technical Context
The KA79M05TU operates as a monolithic linear regulator with emitter-follower output stage and bandgap-based reference. Its internal circuitry integrates current-limiting foldback, thermal shutdown activation at ~150 °C junction temperature, and dynamic safe-area compensation to prevent second breakdown during transient overloads.
It requires no external components for basic operation (CI = 0.33 µF, CO = 0.1 µF recommended for stability), supports input voltages from -7 V to -25 V, and maintains regulation across 0 °C to +125 °C ambient with ≤1.1 V dropout at 500 mA load.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | -5.0 V ±2.5% (ensures stable -5 V rail under 5–500 mA load and -7 to -25 V input) |
| Max Output Current | 500 mA (continuous DC load capability before thermal or current limit activation) |
| Dropout Voltage | 1.1 V at 500 mA (minimum headroom needed between input and output for regulation) |
| Ripple Rejection | 60 dB at 120 Hz (attenuates AC line ripple on negative supply rail) |
| Line Regulation | 30 mV max (output drift over full input range, critical for variable-input systems) |
| Load Regulation | 100 mV max (output variation across 5–500 mA load, defines rail stability in dynamic loads) |
| Quiescent Current | 3.0–6.0 mA (low standby draw enables efficient low-power system design) |
Pinout & Package
KA79M05TU is housed in a TO-220 package with standard 3-pin configuration: Pin 1 = Ground, Pin 2 = Input (negative supply), Pin 3 = Output (regulated -5 V). The metal tab is electrically connected to Pin 2 (Input) and serves as primary heat sink interface.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 | Ground (GND) | Reference node for internal error amplifier and output feedback; must be low-impedance connection to system ground plane |
| 2 | Input (VI) | Negative unregulated input terminal; connects to upstream filter capacitor and carries full load current; tab is tied to this pin |
| 3 | Output (VO) | Regulated -5 V output; feeds downstream analog circuits; requires local 0.1 µF ceramic bypass capacitor |
Key Features
| Feature | Design Value |
|---|---|
| Internal thermal shutdown | Activates at ~150 °C junction temperature to prevent permanent damage during sustained overload or poor heatsinking |
| Short-circuit current limiting | Limits output current to ~140 mA during hard short, enabling safe indefinite fault operation without external fusing |
| Safe-area compensation | Dynamically adjusts bias to avoid secondary breakdown in output transistor during high-voltage/low-current transients |
| No external components required | Operates stably with only input/output capacitors (0.33 µF/0.1 µF); eliminates BOM cost and layout complexity of external compensation networks |
Applications
| Industrial Power Supplies | Analog Signal Conditioning |
|---|---|
Use Scenario: Dual-rail power for PLC I/O modules requiring isolated ±15 V or ±5 V rails from single negative input. IC Role / Device Role / Timing Role: Negative voltage regulator providing stable -5 V bias for op-amps, ADC drivers, and sensor front-ends. Use Value: Maintains <±2.5% output accuracy across temperature and load, ensuring consistent analog signal gain and offset performance. | Use Scenario: Precision analog board in test equipment needing clean, low-noise -5 V for reference buffers and DACs. IC Role / Device Role / Timing Role: Low-drift (-0.2 mV/°C) negative regulator supplying reference circuitry with minimal thermal drift. Use Value: Delivers 60 dB ripple rejection at 120 Hz and <180 µV RMS noise (10 Hz–100 kHz), preserving signal integrity in sub-mV measurement systems. |
| Legacy Equipment Replacement | Embedded Control Systems |
Use Scenario: Drop-in replacement for obsolete LM79M05 in field-deployed medical monitoring hardware. IC Role / Device Role / Timing Role: Pin-compatible negative regulator supporting same PCB footprint and thermal profile as legacy part. Use Value: Matches LM79M05's -5 V output, 500 mA rating, and TO-220 mechanical outline-enabling zero-layout-change upgrade path. | Use Scenario: Power management in fanless industrial controllers where passive cooling is mandatory. IC Role / Device Role / Timing Role: Thermally robust regulator dissipating ≤1.1 W at full load with RθJA = 65 °C/W. Use Value: Operates reliably up to +125 °C ambient without forced air, meeting EN 61000-6-4 thermal requirements for sealed enclosures. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar negative voltage regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LM79M05AC | Same -5 V output, 500 mA rating, TO-220 package; slightly higher quiescent current (4–8 mA vs. 3–6 mA) and lower ripple rejection (55 dB typical) | Compatible in legacy designs but less suitable for low-noise or ultra-low-quiescent applications | Select LM79M05AC only when direct legacy compatibility with National Semiconductor-designated boards is required |
| MC79M05BDTRKG | Identical electrical specs and pinout; enhanced ESD rating (±4 kV HBM) and tighter output tolerance (±2% vs. ±2.5%) | Better suited for automotive-grade or high-reliability industrial deployments with stringent qualification needs | Choose MC79M05BDTRKG when AEC-Q100 stress testing or extended temperature validation is mandated |
Compared with LM79M05AC and MC79M05BDTRKG, the KA79M05TU offers optimal balance of thermal robustness (RθJC = 5 °C/W), proven field reliability in industrial power rails, and lowest cost-per-unit for non-automotive volume production.
Availability
KA79M05TU is available at Aetrix Electronics and suitable for industrial power supplies, analog instrumentation, and embedded control systems requiring stable component supply, long-term lifecycle support, and traceable sourcing.
Supply support for KA79M05TU includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.
Manufacturer
Fairchild Semiconductor was a U.S.-based semiconductor company specializing in power management, analog, and discrete ICs before its acquisition by ON Semiconductor in 2016.
The KA79MXX series was designed specifically for ruggedized, fixed-negative voltage regulation in industrial and instrumentation applications where simplicity, reliability, and thermal resilience are prioritized over programmability or ultra-low IQ.
FAQ
What is the maximum input voltage for KA79M05TU?
The KA79M05TU supports a maximum input voltage of -25 V under normal operating conditions (0 °C to +125 °C). Absolute maximum rating is -35 V, but sustained operation above -25 V risks exceeding safe operating area limits and triggering thermal shutdown. For reliable long-term use, keep VI within -7 V to -25 V as specified in the KA79M05 electrical characteristics table.
Does KA79M05TU require external capacitors to operate?
Yes - KA79M05TU requires an input capacitor (CI = 0.33 µF solid tantalum or 25 µF aluminum electrolytic) and an output capacitor (CO = 0.1 µF ceramic) for stability and transient response. These are not optional: omitting them may cause oscillation or poor ripple rejection. C2 (up to 50 µF) can be added across CO to further improve ripple rejection, per Figure 2 in the datasheet.
Is KA79M05TU pin-compatible with LM79M05?
Yes - KA79M05TU is fully pin-compatible with LM79M05 in TO-220 packages: Pin 1 = GND, Pin 2 = Input, Pin 3 = Output. Both share identical mechanical dimensions, thermal pad connection (Pin 2), and functional behavior. This allows direct substitution in legacy LM79M05 designs without PCB modification or firmware changes.
What is the thermal resistance of KA79M05TU?
The KA79M05TU has a junction-to-case thermal resistance (RθJC) of 5 °C/W and junction-to-ambient resistance (RθJA) of 65 °C/W in TO-220 package. With 500 mA load and 1.1 V dropout, power dissipation is ~0.55 W; using RθJA, this yields ~36 °C rise above ambient - confirming suitability for passive heatsinking in most industrial enclosures.
Can KA79M05TU be used in automotive applications?
KA79M05TU is not AEC-Q100 qualified and lacks automotive-specific screening (e.g., extended temperature range beyond +125 °C, enhanced ESD, or PPAP documentation). While it operates from 0 °C to +125 °C, its qualification scope is industrial/commercial. For automotive use, consider MC79M05BDTRKG or other AEC-Q100-certified alternatives instead of KA79M05TU.
KA79M05TU Specifications
- Product attributes
- Attribute value
- Manufacturer:
- onsemi
- Series:
- -
- Package/Case:
- TO-220-3
- Packaging:
- Tube
- Product Status:
- Obsolete
- Output Configuration:
- Negative
- Output Type:
- Fixed
- Number of Regulators:
- 1
- Voltage - Input (Max):
- -35V
- Voltage - Output (Min/Fixed):
- -5V
- Voltage - Output (Max):
- -
- Voltage Dropout (Max):
- 1.1V @ 500mA
- Current - Output:
- 500mA
- Current - Quiescent (Iq):
- 6 mA
- Current - Supply (Max):
- -
- PSRR:
- 60dB (120Hz)
- Control Features:
- -
- Protection Features:
- Over Temperature, Short Circuit
- Operating Temperature:
- 0°C ~ 125°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- TO-220-3
KA79M05TU FAQ
1.How can I place an order for KA79M05TU through Aetrix?
Please submit a Request for Quotation (RFQ) for KA79M05TU on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for KA79M05TU reliable?
The price and inventory of KA79M05TU are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for KA79M05TU is usually 5 days.
3.What payment methods are accepted for KA79M05TU?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for KA79M05TU transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for KA79M05TU?
KA79M05TU orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your KA79M05TU order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for KA79M05TU?
For technical support, including KA79M05TU datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your KA79M05TU requirements.
6.How does Aetrix verify that KA79M05TU is sourced from the original manufacturer or authorized distributors?
All KA79M05TU products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that KA79M05TU meets industry standards.
7.What is the process for return or replacement of KA79M05TU?
All KA79M05TU units undergo pre-shipment inspection (PSI). If there is an issue with KA79M05TU, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The KA79M05TU part is unused and in its original packaging.
Return procedure for KA79M05TU:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
KA79M05TU Tags
-
MIC5504-1.8YM5-TR
Microchip Technology
-
MIC5504-3.3YM5-TR
Microchip Technology
-
MIC5365-3.0YC5-TR
Microchip Technology
-
MIC5365-1.8YC5-TR
Microchip Technology
-
MIC5365-2.5YC5-TR
Microchip Technology
-
MIC5365-3.3YC5-TR
Microchip Technology
-
MIC5365-3.3YD5-TR
Microchip Technology
-
MIC5317-3.3YM5-TR
Microchip Technology
-
TLV1117LV33DCYR
Texas Instruments
-
MIC5317-3.3YMT-TZ
Microchip Technology
-
MIC5528-3.3YMT-TR
Microchip Technology
-
TLV75801PDRVR
Texas Instruments
Tech Hub
Counterfeit components can hide behind convincing markings and passing basic function tests. This engineering reference covers source traceability, external inspection, X-ray, XRF, electrical testing, …
A practical engineering and sourcing framework covering lifecycle verification, lifetime-buy calculations, replacement qualification, supplier checks and counterfeit-risk controls.
TTL and CMOS logic families differ in thresholds, loading, output drive, power and timing. This engineering guide compares 74HC and 74HCT, calculates noise margins and checks 3.3 V/5 V compatibility.
A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.
The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…
The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…
A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…
A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …
An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…
Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…
