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Texas Instruments LM3100MH
- Part No.:
- LM3100MH
- Manufacturer:
- Texas Instruments
- Package:
- 20-PowerTSSOP (0.173", 4.40mm Width)
- Datasheet:
-
LM3100MH.pdf
- Description:
- IC REG BUCK ADJ 1.5A 20HTSSOP
- Quantity:
- Payment:
- Shipping:
Inventory:1,424
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Product details
Overview
LM3100MH from Texas Instruments is a synchronous step-down DC-DC voltage regulator with integrated dual 40 V N-channel MOSFETs, delivering up to 1.5 A output current across 4.5 V–36 V input range, featuring 0.8 V ±1.5% internal reference and constant-on-time (COT) control for fast transient response in industrial power supplies and automotive body electronics.
For engineers reviewing the LM3100MH datasheet, LM3100MH pinout, LM3100MH application, or LM3100MH equivalent, this page delivers verified technical context, HTSSOP-20 package mapping, confirmed COT regulation behavior, soft-start and thermal shutdown implementation details, and validated alternative options for buck converter design-in.
Technical Context
The LM3100MH employs a Constant ON-Time (COT) hysteretic control architecture where high-side switch on-time is inversely proportional to VIN and set by external RON resistor - enabling near-constant switching frequency up to 1 MHz without loop compensation. Regulation compares FB pin voltage against a precision 0.8 V internal reference.
It integrates dual N-channel synchronous switches (RDS-UP-ON = 0.35 Ω max, RDS-DN-ON = 0.2 Ω max), valley current limit at 1.9 A, bootstrap gate drive (BST/SW with 0.033 µF capacitor), and independent VCC LDO (6 V, 65 mA) with UVLO at 3.75 V. Thermal shutdown activates at 165°C with 20°C hysteresis.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Input Voltage Range | 4.5 V to 36 V - supports direct conversion from 12/24 VDC systems and multi-cell Li-ion batteries. |
| Output Current | 1.5 A continuous - sufficient for point-of-load regulation in embedded controllers and telematics modules. |
| Reference Voltage | 0.8 V ±1.5% - enables precise adjustable output down to 0.8 V using external RFB1/RFB2 divider. |
| Switching Frequency | Up to 1 MHz - programmable via RON resistor; maintains stability across line/load variations. |
| Current Limit Threshold | 1.9 A valley detection - protects against overload while allowing peak inductor current up to ~2.2 A. |
| VCC Regulator | 6 V ±1.2 V, 65 mA - powers internal circuitry and gate drivers; requires ≥680 nF ceramic CVCC. |
| Soft-Start Current | 8 µA internal source - controls ramp rate of output voltage via external CSS capacitor. |
Pinout & Package
LM3100MH is housed in a thermally enhanced HTSSOP-20 package (6.50 mm × 4.40 mm) with exposed thermal pad (EP) tied to GND. Pin count and layout match TI's PWP package designation.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1,9,10,12,19,20 | N/C | No connection - must remain unconnected per datasheet. |
| 2,3 | SW | Switching node - connects to inductor; carries high di/dt; critical for EMI and layout. |
| 4,5 | VIN | Main input supply - accepts 4.5–36 V; decoupled with CIN near pins. |
| 6 | BST | Bootstrap capacitor terminal - requires 0.033 µF ceramic cap to SW for high-side gate drive. |
| 7 | GND | Analog ground - reference for internal comparators and control logic. |
| 8 | SS | Soft-start - internal 8 µA current source charges external CSS to control VOUT ramp rate. |
| 11 | TST | Test mode enable - tie to GND for normal operation; floating or high disables regulation. |
| 13 | FB | Feedback input - regulated at 0.8 V; connects to RFB1/RFB2 divider for output voltage setting. |
| 14 | EN | Enable - active-high; >1.26 V enables regulator; <1.1 V forces shutdown. |
| 15 | RON | On-time control - resistor from VIN sets tON and thus switching frequency. |
| 16 | VCC | Internal LDO output - 6 V supply for gate drivers and bias circuits; requires ≥680 nF CVCC. |
| 17,18 | PGND | Power ground - source connection for synchronous rectifier; ties to power ground plane. |
| EP (DAP) | Exposed Pad | Thermal interface - must be soldered to GND plane for thermal performance (RθJC = 6.5°C/W). |
Key Features
| Feature | Design Value |
|---|---|
| No loop compensation required | COT architecture eliminates need for external compensation network - reduces BOM count and layout sensitivity. |
| Stable with ceramic output capacitors | Does not rely on output capacitor ESR for stability - enables use of low-ESR, high-reliability MLCCs. |
| Ultra-fast load transient response | Fixed on-time + comparator-based control achieves sub-microsecond recovery from load steps. |
| Integrated dual N-channel switches | 40 V rated, RDS-ON ≤0.35 Ω (high-side) and ≤0.2 Ω (low-side) - eliminates external MOSFETs and drivers. |
| Valley current limiting | Detects re-circulating current during off-time - provides accurate overcurrent protection without sense resistors. |
Applications
| Industrial PLC Power Supply | Automotive Body Control Module |
|---|---|
Use Scenario: Provides 3.3 V or 5 V rail for microcontroller, CAN transceiver, and sensor interfaces in DIN-rail mounted programmable logic controllers. IC Role / Device Role / Timing Role: Primary synchronous buck regulator converting 24 VDC field bus to stable low-voltage logic supply. Use Value: 1.5 A capability supports multiple peripherals; wide VIN range accommodates brownout and surge conditions per IEC 61000-4-5. |
Use Scenario: Powers infotainment head unit subsystems including display backlight drivers and audio amplifiers in 12 V automotive platforms. IC Role / Device Role / Timing Role: Point-of-load regulator stepping down battery voltage to 3.3 V/5 V rails under cold-crank (4.5 V) and load-dump (36 V) conditions. Use Value: Integrated 40 V switches and thermal shutdown ensure robustness across automotive temperature range (–40°C to 125°C). |
| Telecom Remote Radio Unit | Industrial Camera System |
Use Scenario: Generates 0.8 V core voltage for FPGA or DSP in outdoor small-cell base stations powered from 48 V PoE-derived supply. IC Role / Device Role / Timing Role: High-efficiency buck converter operating at 1 MHz to minimize filter size in space-constrained RF enclosures. Use Value: Programmable frequency avoids noise coupling into sensitive RF front-end; ceramic-capacitor compatibility simplifies thermal design. |
Use Scenario: Supplies 1.8 V or 2.5 V to high-speed image sensors and MIPI CSI-2 interface in factory automation vision systems. IC Role / Device Role / Timing Role: Low-noise, fast-transient regulator maintaining tight voltage tolerance (<±2%) during burst-mode sensor readout. Use Value: 0.8 V reference and ±1.5% accuracy enable precise output setting; valley current limit prevents damage during short-circuit events. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar synchronous buck regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LM5115MHX/NOPB | External MOSFET driver (no integrated FETs); supports higher VIN (75 V) and current (5 A+); requires compensation network. | Better suited for high-power, high-input designs where efficiency at light load or board area is secondary. | Select when >1.5 A output or >36 V input is required; avoid if minimizing component count is priority. |
| TPS5430DDAR | Non-synchronous buck (integrated high-side FET only); lower max frequency (500 kHz); requires external Schottky diode. | Lower cost and simpler layout but reduced efficiency at medium-to-heavy loads due to diode conduction loss. | Choose for cost-sensitive, lower-current (<3 A) applications where thermal margin allows diode losses. |
Compared with LM5115MHX/NOPB and TPS5430DDAR, the LM3100MH offers the optimal balance of integration (dual FETs), wide input range, and no-compensation COT control - making it ideal for compact, fast-response 1.5 A buck designs where layout simplicity and transient performance are critical.
Availability
LM3100MH is available at Aetrix Electronics and suitable for industrial PLC power supplies, automotive body control modules, telecom remote radio units, and industrial camera systems requiring stable component supply and long-term production continuity.
Supply support for LM3100MH 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 company specializing in analog, embedded processing, and power management ICs, with leadership in high-reliability power conversion solutions.
The LM3100MH belongs to TI's Simple Switcher® family of integrated DC-DC regulators, designed specifically for ease of use, minimal external components, and robust operation in harsh industrial and automotive environments.
FAQ
What is the maximum input voltage rating for the LM3100MH?
The LM3100MH has an absolute maximum input voltage rating of 40 V on the VIN pin, with recommended operating range from 4.5 V to 36 V. Transient spikes up to 40 V are tolerated per datasheet Absolute Maximum Ratings, but sustained operation above 36 V may trigger VCC UVLO or degrade reliability. The LM3100MH is commonly used in 24 V industrial and 12 V automotive systems where load dump events reach 36 V.
How does the LM3100MH achieve stable regulation without external compensation components?
The LM3100MH uses a Constant ON-Time (COT) hysteretic control scheme that compares the FB pin voltage to a 0.8 V internal reference and initiates fixed-duration on-times - eliminating the need for traditional Type II/III compensation networks. This architecture inherently stabilizes the loop with ceramic output capacitors and delivers ultra-fast transient response. The LM3100MH does not require ESR-based damping, unlike many voltage-mode or current-mode controllers.
What is the purpose of the RON pin on the LM3100MH, and how is it configured?
The RON pin on the LM3100MH sets the high-side switch on-time via an external resistor connected between VIN and RON. This resistor determines the switching frequency - higher RON values yield longer on-times and lower frequencies. For example, a 100 kΩ resistor with VIN = 18 V yields ~1.38 µs on-time. The LM3100MH datasheet specifies minimum RON to ensure tON ≥ 200 ns at maximum VIN for reliable current limit operation.
Can the LM3100MH operate with all-ceramic output capacitors?
Yes, the LM3100MH is explicitly designed to be stable with ceramic and other low-ESR output capacitors - a key differentiator from many COT regulators that require ESR for phase margin. Its control architecture does not depend on output capacitor ESR for stability, enabling use of high-reliability, low-profile MLCCs. Typical designs use ≥10 µF ceramic COUT, often paralleled for ripple reduction, without risk of oscillation.
What thermal protection features are built into the LM3100MH?
The LM3100MH includes thermal shutdown that activates at a typical junction temperature of 165°C, disabling the buck switch and grounding the SS pin to halt output voltage ramp-up. It features 20°C hysteresis, so normal operation resumes only after junction temperature falls below ~145°C. Combined with the HTSSOP-20 package's 6.5°C/W junction-to-case thermal resistance and exposed pad (EP) tied to GND, the LM3100MH sustains 1.5 A output in ambient temperatures up to 85°C with proper PCB copper area.
LM3100MH Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- SIMPLE SWITCHER®
- Package/Case:
- 20-PowerTSSOP (0.173", 4.40mm Width)
- Packaging:
- Tube
- Product Status:
- Obsolete
- Function:
- Step-Down
- Output Configuration:
- Positive
- Topology:
- Buck
- Output Type:
- Adjustable
- Number of Outputs:
- 1
- Voltage - Input (Min):
- 4.5V
- Voltage - Input (Max):
- 36V
- Voltage - Output (Min/Fixed):
- 0.8V
- Voltage - Output (Max):
- 7.2V
- Current - Output:
- 1.5A
- Frequency - Switching:
- Up to 1MHz
- Synchronous Rectifier:
- Yes
- Operating Temperature:
- -40°C ~ 125°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 20-HTSSOP
LM3100MH FAQ
1.How can I place an order for LM3100MH through Aetrix?
Please submit a Request for Quotation (RFQ) for LM3100MH 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 LM3100MH reliable?
The price and inventory of LM3100MH are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM3100MH is usually 5 days.
3.What payment methods are accepted for LM3100MH?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM3100MH transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM3100MH?
LM3100MH orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM3100MH 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 LM3100MH?
For technical support, including LM3100MH datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM3100MH requirements.
6.How does Aetrix verify that LM3100MH is sourced from the original manufacturer or authorized distributors?
All LM3100MH 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 LM3100MH meets industry standards.
7.What is the process for return or replacement of LM3100MH?
All LM3100MH units undergo pre-shipment inspection (PSI). If there is an issue with LM3100MH, 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 LM3100MH part is unused and in its original packaging.
Return procedure for LM3100MH:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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