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Texas Instruments LM5576MHX
- Part No.:
- LM5576MHX
- Manufacturer:
- Texas Instruments
- Package:
- 20-PowerTSSOP (0.173", 4.40mm Width)
- Datasheet:
-
LM5576MHX.pdf
- Description:
- IC REG BUCK ADJ 3A 20HTSSOP
- Quantity:
- Payment:
- Shipping:
Inventory:3,322
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Product details
Overview
LM5576MHX from Texas Instruments is a 75V input, 3A synchronous step-down switching regulator with integrated 170mΩ N-channel MOSFET, emulated current-mode control, and adjustable 50–500kHz switching frequency. It delivers regulated DC output as low as 1.225V and supports industrial power bus conversion in harsh environments.
For engineers reviewing the LM5576MHX datasheet, LM5576MHX pinout, LM5576MHX application, or LM5576MHX equivalent, key selection considerations include its ultra-wide 6–75V input range, cycle-by-cycle current limiting, thermal shutdown at 165°C, and HTSSOP-20EP package with exposed thermal pad for high-power density designs.
Technical Context
The LM5576MHX implements emulated current-mode control using a reconstructed ramp signal derived from VIN–VOUT and diode current sampling-eliminating leading-edge spikes and enabling stable operation at very low duty cycles. Its dual-mode VCC regulator maintains ~7V bias supply across 6–75V input, reducing internal dissipation above 9V.
Frequency is set via single RT resistor (50–500kHz), and SYNC pin enables master-slave synchronization of multiple units or external clock locking. Protection includes cycle-by-cycle current limit, thermal shutdown, remote shutdown via SD pin, and bootstrap UVLO.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Input Voltage Range | 6 V to 75 V - supports direct connection to industrial 24/48/72V buses without pre-regulation |
| Output Current | 3 A continuous - sufficient for powering FPGA I/O banks, PLC modules, or motor control logic rails |
| Feedback Reference | 1.225 V ±1.5% - enables precise low-voltage regulation down to 1.225V with minimal external components |
| Switch RDS(on) | 170 mΩ typical - reduces conduction loss and thermal stress in high-current buck stages |
| Switching Frequency | 50 kHz to 500 kHz - adjustable via RT resistor to balance efficiency vs. size of magnetics and EMI filtering |
| Junction Temp Limit | 165 °C with 25 °C hysteresis - ensures automatic recovery after thermal overload without latch-up |
| Thermal Resistance | RθJA = 40 °C/W - requires PCB thermal pad connection to ground plane for full 3A capability |
Pinout & Package
LM5576MHX is housed in a thermally enhanced HTSSOP-20EP (PWP) package measuring 6.5 mm × 4.4 mm with an exposed die attach pad for direct PCB thermal coupling.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| VIN (pins 3,4) | High-voltage input supply | Accepts 6–75V unregulated input; dual-mode VCC regulator draws bias here |
| SW (pins 17,18) | Switch node | Drives external Schottky diode and buck inductor; connects to BST capacitor |
| BST (pin 20) | Bootstrap supply input | Requires 0.022 µF ceramic cap to SW for high-side gate drive; UVLO at 3.8 V |
| PGND (pins 13,14) | Power ground return | Low-side reference for IS sense resistor and PRE switch; separate from AGND |
| IS (pins 15,16) | Diode current sense | Measures recirculating diode current for DC level reconstruction in emulated ramp |
| FB (pin 7) | Feedback input | Connects to resistor divider; regulates output by comparing to 1.225 V internal reference |
| RT (pin 8) | Oscillator frequency set | Single resistor to AGND sets switching frequency from 50–500 kHz |
| SYNC (pin 5) | Frequency synchronization I/O | Enables multi-device synchronization or external clock lock; pulldown-driven interface |
| SD (pin 2) | Shutdown/standby control | Three-state logic: <0.7 V = shutdown, 0.7–1.225 V = standby, >1.225 V = active |
| SS (pin 11) | Soft-start timing | 10 µA internal current source charges external capacitor to control output voltage ramp rate |
Key Features
| Feature | Design Value |
|---|---|
| Emulated current-mode control | Eliminates need for current-sense resistor and blanking circuit; enables stable sub-10% duty cycle operation at high VIN/VOUT ratios |
| Integrated 75V/170mΩ MOSFET | Reduces BOM count and layout complexity while maintaining 3A output capability without external switch |
| Adjustable soft-start | External capacitor on SS pin allows programmable startup time to prevent inrush current in capacitive loads |
| Thermal shutdown with hysteresis | 165°C trip with 25°C hysteresis prevents thermal cycling and enables safe auto-recovery after overload |
| Multi-device synchronization | SYNC pin allows up to five LM5576MHX units to phase-lock without external timing IC or complex clock distribution |
Applications
| Industrial Power Supply | Telecom Remote Radio Unit |
|---|---|
Use Scenario: Converting 48V telecom bus to 3.3V/5V for baseband processing and RF front-end biasing in outdoor macrocells. IC Role / Device Role / Timing Role: Primary buck controller delivering isolated, ripple-controlled DC rails with fault reporting via SD pin. Use Value: 75V absolute max rating withstands lightning-induced transients on long cable runs; SYNC enables interleaved operation for lower input ripple. | Use Scenario: Powering programmable logic controllers (PLCs) and distributed I/O modules in factory automation cabinets with 24V/48V field wiring. IC Role / Device Role / Timing Role: Main DC-DC converter generating 5V/12V system rails from unregulated industrial bus with brownout immunity. Use Value: Wide 6–75V input accommodates battery backup, rectified AC, or degraded bus conditions; thermal pad ensures reliability in sealed enclosures. |
| Railway Signaling System | Test & Measurement Equipment |
Use Scenario: Regulating 72V train battery supply to 15V analog sensor excitation and 3.3V microcontroller core voltage in onboard diagnostics units. IC Role / Device Role / Timing Role: High-reliability buck regulator with overtemperature and short-circuit protection for safety-critical subsystems. Use Value: Cycle-by-cycle current limit and 165°C thermal shutdown meet EN 50155 shock/vibration and thermal endurance requirements. | Use Scenario: Providing stable, low-noise 12V and ±15V rails for precision ADC drivers and op-amp signal chains in portable analyzers. IC Role / Device Role / Timing Role: Programmable-frequency buck stage minimizing conducted EMI in sensitive measurement front-ends. Use Value: 50–500kHz frequency adjustment allows EMI notch placement away from critical harmonics; COMP pin enables custom loop compensation. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar buck regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LM5164MHX | 4.5–65V input, 1A output, integrated FET, 100kHz–2.2MHz frequency range | Limited to lower current and narrower input range; better suited for space-constrained, medium-power applications | Choose LM5164MHX when board area is constrained and 1A output suffices; not suitable for 3A industrial loads. |
| TPS54360BDDAR | 3.5–60V input, 3.5A output, integrated FET, 100kHz–2.5MHz frequency, higher 1.5% ref accuracy | Higher max input voltage (60V vs. 75V); lacks SYNC pin and emulated current mode; uses traditional current sensing | Choose TPS54360BDDAR for cost-sensitive designs needing 3.5A and tighter reference tolerance, but accept no multi-device sync capability. |
Compared with LM5576MHX, LM5164MHX offers higher frequency flexibility but sacrifices input voltage headroom and output current, while TPS54360BDDAR provides higher current and accuracy but omits synchronization and emulated current-mode benefits critical for high-VIN stability.
Availability
LM5576MHX is available at Aetrix Electronics and suitable for industrial power supplies, railway signaling systems, and telecom remote radio units requiring stable component supply across extended temperature and voltage ranges.
Supply support for LM5576MHX 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 specializing in analog, embedded processing, and power management technologies with decades of automotive and industrial qualification expertise.
The LM5576 product line targets high-input-voltage DC-DC conversion in harsh environments-designed specifically for industrial, telecom, and transportation applications where wide VIN, robust protection, and thermal resilience are mandatory.
FAQ
What is the maximum input voltage rating for the LM5576MHX?
The LM5576MHX has an absolute maximum input voltage rating of 76 V across VIN pins. Its recommended operating range is 6 V to 75 V, making it suitable for direct connection to 48V and 72V industrial and telecom power buses. Exceeding 76 V risks permanent damage, especially during transient events-careful input filtering and layout are essential to suppress ringing.
How does the LM5576MHX achieve stable regulation at very low duty cycles?
The LM5576MHX uses emulated current-mode control, reconstructing the inductor current ramp from VIN–VOUT and diode current sampling instead of measuring switch current directly. This eliminates leading-edge spikes and propagation delays, enabling reliable PWM operation below 10% duty cycle-critical for high-input, low-output voltage conversions like 72V-to-3.3V.
Can multiple LM5576MHX ICs be synchronized, and how?
Yes, multiple LM5576MHX ICs can be synchronized by connecting their SYNC pins together. The device with the highest programmed oscillator frequency automatically becomes the master, pulling the shared SYNC line low to reset others' ramp cycles. No external clock generator is needed-this self-synchronizing architecture simplifies multi-rail designs and reduces EMI through phase interleaving.
What thermal design considerations apply to the LM5576MHX HTSSOP-20EP package?
The LM5576MHX HTSSOP-20EP package features an exposed thermal pad (EP) that must be soldered to a large PCB copper pour tied to the PGND net. With RθJA = 40 °C/W, achieving full 3A output requires this thermal path-failure to connect EP results in excessive junction temperature rise and premature thermal shutdown. TI recommends ≥200 mm² of 2-oz copper under the pad with ≥4 thermal vias.
Does the LM5576MHX require an external current-sense resistor?
No, the LM5576MHX does not require an external current-sense resistor. It uses internal diode current sensing via the IS pins and emulates the current ramp using a combination of sample-and-hold DC level and a voltage-controlled current source into the RAMP pin. This eliminates external sensing components and associated noise susceptibility while retaining cycle-by-cycle current limiting.
LM5576MHX Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- SIMPLE SWITCHER®
- Package/Case:
- 20-PowerTSSOP (0.173", 4.40mm Width)
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Obsolete
- Function:
- Step-Down
- Output Configuration:
- Positive
- Topology:
- Buck
- Output Type:
- Adjustable
- Number of Outputs:
- 1
- Voltage - Input (Min):
- 6V
- Voltage - Input (Max):
- 75V
- Voltage - Output (Min/Fixed):
- 1.225V
- Voltage - Output (Max):
- 70V
- Current - Output:
- 3A
- Frequency - Switching:
- 50kHz ~ 500kHz
- Synchronous Rectifier:
- No
- Operating Temperature:
- -40°C ~ 125°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 20-HTSSOP
LM5576MHX FAQ
1.How can I place an order for LM5576MHX through Aetrix?
Please submit a Request for Quotation (RFQ) for LM5576MHX 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 LM5576MHX reliable?
The price and inventory of LM5576MHX are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM5576MHX is usually 5 days.
3.What payment methods are accepted for LM5576MHX?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM5576MHX transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM5576MHX?
LM5576MHX orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM5576MHX 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 LM5576MHX?
For technical support, including LM5576MHX datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM5576MHX requirements.
6.How does Aetrix verify that LM5576MHX is sourced from the original manufacturer or authorized distributors?
All LM5576MHX 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 LM5576MHX meets industry standards.
7.What is the process for return or replacement of LM5576MHX?
All LM5576MHX units undergo pre-shipment inspection (PSI). If there is an issue with LM5576MHX, 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 LM5576MHX part is unused and in its original packaging.
Return procedure for LM5576MHX:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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