My Inquiry
My Account
Texas Instruments LM3578AM/NOPB
- Part No.:
- LM3578AM/NOPB
- Manufacturer:
- Texas Instruments
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
LM3578AM/NOPB.pdf
- Description:
- IC REG BUCK BOOST 750MA 8SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:2,914
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
LM3578AM/NOPB from Texas Instruments is a monolithic switching regulator controller IC featuring an integrated NPN output transistor, dual comparator inputs (inverting and non-inverting), internal 1.0 V reference, and oscillator programmable up to 100 kHz via single external capacitor. It supports buck, boost, and inverting DC-DC topologies with up to 750 mA output current, 0.9 V collector saturation voltage, and operates from 2 V to 40 V supply. Used in industrial power supplies requiring stable mid-current regulation.
For engineers reviewing the LM3578AM/NOPB datasheet, LM3578AM/NOPB pinout, LM3578AM/NOPB application, or LM3578AM/NOPB equivalent, key selection criteria include its 0–90% duty cycle range, ground- or VIN-referenced current limit sensing, thermal shutdown, and ambient temperature rating of 0°C to +70°C - critical for cost-sensitive non-automotive embedded power designs.
Technical Context
The LM3578AM/NOPB implements a pulse-width modulation (PWM) architecture with a dedicated oscillator section whose frequency is set by a single external timing capacitor (e.g., 3900 pF yields ~24 kHz). Its comparator stage provides independent inverting and non-inverting inputs, each internally biased to 1.0 V, enabling direct feedback without external op-amps in inverting configurations.
It integrates a high-current NPN output transistor with separate collector and emitter terminals, allowing flexible placement in buck (emitter-grounded), boost (collector-grounded), or inverting (collector-to-VIN) topologies. Current limiting operates cycle-by-cycle using a 110 mV sense threshold referenced either to ground or VIN, with built-in thermal shutdown and under-voltage lockout functionality.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Supply Voltage Range | 2 V to 40 V - supports wide-input industrial rails including 5 V, 12 V, and 24 V systems. |
| Output Current Capability | Up to 750 mA pulsed - sufficient for medium-power DC-DC stages without external pass transistor. |
| Collector Saturation Voltage | ≤0.9 V at 750 mA - minimizes conduction loss in buck/boost switch node, improving efficiency at moderate loads. |
| Oscillator Frequency Range | Typical 24 kHz (max 100 kHz) - balances EMI control and inductor size; set by single CT capacitor (e.g., 3900 pF). |
| Reference Voltage | 1.0 V ±50 mV - precise internal bias enables accurate output voltage setting with standard resistor dividers. |
| Current Limit Threshold | 110 mV ±30 mV - allows scalable overcurrent protection using low-value sense resistors (e.g., 0.15 Ω = 733 mA trip). |
| Ambient Temperature Range | 0°C to +70°C - commercial-grade rating suitable for indoor industrial, consumer, and test equipment applications. |
Pinout & Package
LM3578AM/NOPB is housed in an 8-pin SOIC package (Package Number D0008A), with thermal pad exposed on underside per TI's SOIC-8 thermal design guidelines. Pin functions are validated per TI SNVS767E Rev. April 2013.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 - Inverting Input (INV) | Comparator inverting input | Internally biased to 1.0 V; accepts feedback signal for error amplification in buck/boost loops. |
| 2 - Non-Inverting Input (NINV) | Comparator non-inverting input | Also internally biased to 1.0 V; enables polarity-inverting configurations without external op-amp. |
| 3 - Ground (GND) | Power and signal reference | Common return for internal circuitry, current limit sense (if ground-referenced), and oscillator timing. |
| 4 - Current Limit (CL) | Overcurrent sense input | Triggers cycle-by-cycle shutdown when pulled 110 mV below GND or above VIN - selectable reference. |
| 5 - Emitter (EMIT) | NPN transistor emitter terminal | Connected to ground in buck mode; must not drop >1 V below GND (0.6 V above 100°C junction). |
| 6 - Collector (COLL) | NPN transistor collector terminal | Switching node in boost/inverting topologies; rated to 50 V sustaining voltage (BVCEO(SUS)). |
| 7 - Timing Capacitor (CT) | Oscillator timing node | Connects external capacitor (e.g., 3900 pF) to set switching frequency; blanking/reset pulses generated internally. |
| 8 - Supply (VIN) | Power input | Supplies internal logic and oscillator; also serves as current limit reference point when CL is VIN-referenced. |
Key Features
| Feature | Design Value |
|---|---|
| Dual comparator inputs with 1.0 V reference | Eliminates need for external op-amp in inverting regulators - reduces BOM count and layout area. |
| Programmable oscillator (1 Hz–100 kHz) | Single CT capacitor sets frequency - simplifies EMI tuning and inductor selection across wide load ranges. |
| Ground- or VIN-referenced current limit | Enables flexible overcurrent protection topology - supports both low-side and high-side sense configurations. |
| Thermal shutdown and UVLO | Prevents latch-up during overload or brownout - ensures robust operation in unregulated input environments. |
| Separate collector/emitter pins | Supports all three basic switching topologies (buck, boost, inverting) with one IC - improves design reuse. |
Applications
| Industrial DC Power Supply | Motor Speed Control |
|---|---|
Use Scenario: 24 V input converted to regulated 5 V or 12 V for PLC I/O modules and sensor interfaces. IC Role / Device Role / Timing Role: PWM controller managing external inductor/diode switch node; regulates output via feedback to INV/NINV pins. Use Value: Delivers stable 750 mA output with <10 mV ripple using minimal external components - reduces board space vs. integrated DC-DC modules. | Use Scenario: Variable-speed control of small DC motors in factory automation actuators and HVAC dampers. IC Role / Device Role / Timing Role: Generates adjustable-duty-cycle drive waveform; current limit protects motor windings during stall conditions. Use Value: 0–90% duty cycle range and 110 mV current limit threshold enable precise torque control without external current-sense amplifiers. |
| Lamp Flasher Circuit | RS-232 Line Driver Power Supply |
Use Scenario: Intermittent flashing of incandescent or LED indicator lamps in instrumentation panels. IC Role / Device Role / Timing Role: Oscillator-driven switch controlling lamp current; timing capacitor sets flash rate (e.g., 1–5 Hz). Use Value: Built-in oscillator eliminates need for 555 timer or microcontroller - lowers system cost and firmware complexity. | Use Scenario: Generating ±12 V rails from single 5 V supply for RS-232 transceivers in embedded serial gateways. IC Role / Device Role / Timing Role: Inverting regulator configuration producing negative voltage; level-shift accuracy ensures tight output tolerance. Use Value: Dual-input comparator enables direct feedback from negative rail without level-shifting circuitry - improves regulation accuracy to ±3%. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar switching regulator controller applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LM2578AM/NOPB | Wider ambient range (−40°C to +85°C); higher max junction temp (125°C) | Suitable for extended-temperature industrial or outdoor enclosures | Select when operating beyond 70°C ambient or requiring automotive-adjacent reliability. |
| MC34063AP1G | Higher max switching frequency (100 kHz vs. 24 kHz typical); integrated current sense amplifier | Better suited for compact, high-frequency designs with tighter EMI constraints | Choose when board space is limited and inductor size must be minimized - but requires additional compensation components. |
Compared with LM2578AM/NOPB and MC34063AP1G, the LM3578AM/NOPB offers lower component count for inverting/buck-boost topologies due to dual comparator inputs and no need for external level shifters, while trading off maximum frequency and extended temperature capability.
Availability
LM3578AM/NOPB is available at Aetrix Electronics and suitable for industrial DC power supplies, motor speed control circuits, lamp flasher modules, and RS-232 line driver power generation requiring stable component supply and long-term manufacturability.
Supply support for LM3578AM/NOPB 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
Texas Instruments is a global semiconductor leader delivering analog, embedded processing, and logic solutions with emphasis on reliability, longevity, and broad technical documentation support.
The LM3578A product line was designed specifically for cost-effective, discrete-based switching regulator implementations in commercial-grade industrial and consumer electronics - prioritizing simplicity, topology flexibility, and minimal external component count.
FAQ
What is the maximum switching frequency supported by the LM3578AM/NOPB?
The LM3578AM/NOPB oscillator supports frequencies up to 100 kHz, with a typical value of 24 kHz when using a 3900 pF timing capacitor. The actual frequency is determined by fOSC = 8×10−5/CT, where CT is in farads. Operation above 24 kHz may reduce efficiency due to increased switching losses and requires careful layout to manage EMI.
Can the LM3578AM/NOPB be used in an inverting regulator configuration?
Yes, the LM3578AM/NOPB is explicitly designed for inverting regulator use. Its dual comparator inputs (INV and NINV), each biased to 1.0 V, allow direct negative feedback without external op-amps. Figure 34 in TI SNVS767E shows a verified −15 V output from +5 V input using LM3578AM/NOPB - confirming full inverting topology support.
What is the purpose of the separate collector and emitter pins on the LM3578AM/NOPB?
The separate collector (Pin 6) and emitter (Pin 5) pins on the LM3578AM/NOPB provide physical routing flexibility for all three fundamental switching topologies: buck (emitter grounded), boost (collector grounded), and inverting (collector tied to VIN). This eliminates the need for external transistor buffers in medium-current applications and enables direct connection to external catch diodes or inductors.
How does the current limit function work on the LM3578AM/NOPB?
The LM3578AM/NOPB current limit activates when the voltage at Pin 4 (CL) deviates by 110 mV from either ground or VIN - selectable via external resistor network. It operates cycle-by-cycle, turning off the output transistor until the next oscillator period. This protects against short-circuits and overloads without latching, and supports both low-side (ground-referenced) and high-side (VIN-referenced) sensing schemes.
Is thermal shutdown included in the LM3578AM/NOPB?
Yes, the LM3578AM/NOPB includes internal thermal shutdown that disables the output transistor when junction temperature exceeds 150°C. Recovery occurs automatically once temperature falls below the hysteresis threshold. This feature is documented in the Absolute Maximum Ratings and Functional Description sections of TI SNVS767E, ensuring safe operation under sustained overload or poor heatsinking conditions.
LM3578AM/NOPB Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- -
- Package/Case:
- 8-SOIC (0.154", 3.90mm Width)
- Packaging:
- Tube
- Product Status:
- Active
- Function:
- Step-Up, Step-Down, Step-Up/Step-Down
- Output Configuration:
- Positive or Negative
- Topology:
- Buck, Boost, Buck-Boost
- Output Type:
- -
- Number of Outputs:
- 1
- Voltage - Input (Min):
- 2V
- Voltage - Input (Max):
- 40V
- Voltage - Output (Min/Fixed):
- -
- Voltage - Output (Max):
- -
- Current - Output:
- 750mA (Switch)
- Frequency - Switching:
- 20kHz
- Synchronous Rectifier:
- No
- Operating Temperature:
- 0°C ~ 70°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-SOIC
LM3578AM/NOPB FAQ
1.How can I place an order for LM3578AM/NOPB through Aetrix?
Please submit a Request for Quotation (RFQ) for LM3578AM/NOPB 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 LM3578AM/NOPB reliable?
The price and inventory of LM3578AM/NOPB are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM3578AM/NOPB is usually 5 days.
3.What payment methods are accepted for LM3578AM/NOPB?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM3578AM/NOPB transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM3578AM/NOPB?
LM3578AM/NOPB orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM3578AM/NOPB 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 LM3578AM/NOPB?
For technical support, including LM3578AM/NOPB datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM3578AM/NOPB requirements.
6.How does Aetrix verify that LM3578AM/NOPB is sourced from the original manufacturer or authorized distributors?
All LM3578AM/NOPB 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 LM3578AM/NOPB meets industry standards.
7.What is the process for return or replacement of LM3578AM/NOPB?
All LM3578AM/NOPB units undergo pre-shipment inspection (PSI). If there is an issue with LM3578AM/NOPB, 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 LM3578AM/NOPB part is unused and in its original packaging.
Return procedure for LM3578AM/NOPB:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LM3578AM/NOPB Tags
-
TPS562201DDCR
Texas Instruments
-
MC34063ABD-TR
STMicroelectronics
-
TPS561201DDCR
Texas Instruments
-
MC33063ADR
Texas Instruments
-
MC34063ADR
Texas Instruments
-
TPS560200DBVR
Texas Instruments
-
AP3012KTR-G1
Diodes Incorporated
-
TLV61048DBVR
Texas Instruments
-
AZ34063UMTR-G1
Diodes Incorporated
-
TPS562200DDCR
Texas Instruments
-
AP62300TWU-7
Diodes Incorporated
-
MC34063EBD-TR
STMicroelectronics
Tech Hub
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…
An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…
Operational amplifier guide covering op amp basics, feedback, ideal vs real op amps, common configurations, buffer circuits, offset, bias current, gain-bandwidth, slew rate, rail-to-rail limits and sel…
Jumper cables guide covering safe connection order, red and black clamp placement, final ground connection, cable gauge, length, clamp quality, copper vs CCA cables, jump starter comparison and battery…
