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Texas Instruments LM21212MHX-2/NOPB
- Part No.:
- LM21212MHX-2/NOPB
- Manufacturer:
- Texas Instruments
- Package:
- 20-PowerTSSOP (0.173", 4.40mm Width)
- Datasheet:
-
LM21212MHX-2/NOPB.pdf
- Description:
- IC REG BUCK ADJ 12A 20HTSSOP
- Quantity:
- Payment:
- Shipping:
Inventory:2,240
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Product details
Overview
LM21212MHX-2/NOPB from Texas Instruments is a monolithic synchronous buck regulator delivering up to 12 A continuous output current with 0.6 V to VIN adjustable output voltage, integrated 7-mΩ high-side and 4.3-mΩ low-side MOSFETs, and resistor-adjustable switching frequency from 300 kHz to 1.55 MHz. It operates from 2.95 V to 5.5 V input and supports prebiased startup and output voltage tracking in networking and FPGA power applications.
For engineers reviewing the LM21212MHX-2/NOPB datasheet, LM21212MHX-2/NOPB pinout, LM21212MHX-2/NOPB application, or LM21212MHX-2/NOPB equivalent, this device serves as a high-current, voltage-mode-controlled point-of-load regulator requiring precise enable threshold control, thermal-aware layout, and external compensation for stability across ceramic output capacitors.
Technical Context
The LM21212MHX-2/NOPB implements voltage-mode PWM control with trailing-edge modulation, enabling stable loop response across wide output voltage ranges and compatibility with any output capacitance type. Its internal error amplifier delivers 95 dB open-loop gain and 11 MHz gain-bandwidth product, supporting robust transient performance under dynamic load steps.
It integrates dual overcurrent protection thresholds (15–19 A rising, 12 A falling), programmable soft-start via external capacitor on SS/TRK, and precision power-good monitoring with 15 µs deglitch timing. Thermal shutdown activates at 165°C with 10°C hysteresis, and the exposed-pad HTSSOP-20 package provides 24°C/W junction-to-ambient thermal resistance.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Current | 12 A continuous - supports high-power FPGAs and ASICs without external current sharing. |
| Input Voltage Range | 2.95 V to 5.5 V - compatible with standard 3.3 V and 5 V intermediate buses. |
| Output Voltage Range | 0.6 V to VIN - enables low-voltage core rails (e.g., 1.2 V, 0.9 V) with ±1% reference accuracy. |
| Switching Frequency | 300 kHz to 1.55 MHz - adjustable via FADJ resistor; higher frequencies allow smaller inductors and faster transient response. |
| HS/LS RDS(on) | 7 mΩ / 4.3 mΩ - minimizes conduction loss at full load, enabling >95% peak efficiency at 5 VIN/1.2 VOUT. |
| Enable Threshold | 1.35 V typical with 110 mV hysteresis - ensures clean, glitch-immune power sequencing in multi-rail systems. |
| Thermal Shutdown | 165°C with 10°C hysteresis - protects die during overload or poor PCB thermal design while allowing recovery at ~155°C. |
Pinout & Package
LM21212MHX-2/NOPB is housed in a thermally enhanced 20-pin HTSSOP package (6.50 mm × 4.40 mm) with an exposed pad electrically and thermally connected to PGND. The exposed pad must be soldered to the PCB ground plane to achieve specified thermal performance (θJA = 24°C/W).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 FADJ | Frequency adjust input | Connects to AGND via resistor to set switching frequency between 300 kHz and 1.55 MHz. |
| 2 SS/TRK | Soft-start and tracking control | Internal 2 µA current source charges external capacitor for controlled ramp-up; also accepts external voltage for rail tracking. |
| 3 EN | Enable input | Active-high logic input with 1.35 V threshold and 110 mV hysteresis; internally pulled up if left floating. |
| 4 AVIN | Analog supply input | Powers internal bias circuitry; recommended to filter with RC network from PVIN to reduce noise coupling into control loop. |
| 5–7 PVIN | Power switch input | High-current input pins tied together at package; require low-ESR bulk capacitance placed adjacent to minimize switching loop inductance. |
| 8–10 PGND | Power ground return | Low-impedance return path for high-side/low-side switch currents; must be connected to exposed pad and local ground plane. |
| 11–16 SW | Switch node outputs | Connects directly to inductor; multiple pins reduce trace inductance and improve current sharing in high-frequency operation. |
| 17 PGOOD | Open-drain power-good flag | Asserts low during OVP/UVP, EN disable, or prebiased startup fault; requires external pullup to valid logic rail. |
| 18 COMP | Error amplifier output | Connects to external RC compensation network; drives voltage loop stability and transient response. |
| 19 FB | Feedback input | Inverting input of error amplifier; senses output voltage via resistive divider; 0.6 V reference sets VOUT = 0.6 × (1 + R1/R2). |
| 20 AGND | Analog ground reference | Quiet ground for reference, error amplifier, and bias circuits; must be separated from noisy PGND except at single-point connection. |
| EP | Exposed thermal pad | Electrically tied to PGND; mandatory solder connection to PCB ground plane for thermal dissipation and EMI reduction. |
Key Features
| Feature | Design Value |
|---|---|
| Integrated power switches | 7-mΩ high-side and 4.3-mΩ low-side MOSFETs eliminate external discrete FETs and gate drivers, reducing BOM count and layout complexity. |
| Prebiased startup support | Does not sink current during startup when output is precharged, preventing output voltage collapse and enabling seamless hot-swap operation. |
| Voltage tracking capability | SS/TRK pin accepts external ramp signal to coordinate power-up sequence with other rails, satisfying FPGA or processor supply sequencing requirements. |
| Comprehensive fault protection | Integrated OVP (105–120% VFB), UVP (82–97% VFB), OCP (15–19 A), OTP (165°C), and UVLO (2.7 V) ensure system reliability without external supervision ICs. |
| Adjustable soft-start | External capacitor on SS/TRK sets output ramp rate; prevents inrush current and allows synchronization with other regulators via shared ramp signal. |
Applications
| Networking Power Supply | FPGA Core Rail |
|---|---|
|
Use Scenario: Point-of-load regulation for 10G/25G Ethernet PHYs and packet processors requiring tight voltage tolerance and fast transient response. IC Role / Device Role / Timing Role: Primary buck regulator generating 1.0 V or 1.2 V core supply from 3.3 V or 5 V backplane bus. Use Value: Integrated 7-mΩ/4.3-mΩ FETs and 12 A capability deliver >94% efficiency at full load, minimizing board-level heat generation in dense switch fabric designs. |
Use Scenario: Powering high-performance Xilinx or Intel FPGA core voltages with strict sequencing and margining requirements. IC Role / Device Role / Timing Role: Voltage-mode synchronous buck controller providing regulated VCCINT with tracking and soft-start coordination. Use Value: SS/TRK pin enables precise voltage ramp matching to auxiliary rails (e.g., VCCAUX, VCCIO), satisfying FPGA power-on timing specifications per vendor datasheets. |
| Industrial CPU Module | Test Equipment Power |
|
Use Scenario: Compact, fanless CPU modules for edge computing where thermal headroom is limited and long-term reliability is critical. IC Role / Device Role / Timing Role: Main SoC core supply delivering 0.85 V–1.1 V at up to 12 A with thermal shutdown and power-good signaling. Use Value: Exposed-pad HTSSOP-20 package with 24°C/W θJA enables operation up to 125°C junction temperature without heatsinks, simplifying mechanical design. |
Use Scenario: Programmable power supplies in automated test equipment requiring stable, low-noise output with remote monitoring. IC Role / Device Role / Timing Role: High-accuracy, digitally monitored DC-DC stage with PGOOD flag and precision enable for system-level interlock control. Use Value: ±1% reference and 0.1% line/load regulation ensure voltage stability across varying input and load conditions, meeting Class II calibration tolerances. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar synchronous buck regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TPS544B25RQF | Current-mode control, 4.5–18 V input, 12 A, 0.6 V reference, no integrated low-side FET (external sync rectifier required) | Requires external MOSFET and more complex compensation; better suited for higher-input industrial systems | Select when input exceeds 5.5 V or when current-mode loop dynamics are preferred for ultra-fast transient response. |
| MP2451DT-LF-Z | 3–36 V input, 0.6–30 V output, 0.6 A max, no integrated power FETs, fixed 500 kHz frequency | Lower current rating and no internal switches limit use to sub-1 A auxiliary rails only | Consider only for low-power auxiliary supplies where footprint and cost outweigh performance needs; not a functional replacement for LM21212MHX-2/NOPB. |
Compared with TPS544B25RQF and MP2451DT-LF-Z, LM21212MHX-2/NOPB offers superior integration (dual internal FETs), tighter input range optimization (2.95–5.5 V), and higher output current (12 A), making it uniquely suitable for compact, high-efficiency 3.3 V/5 V bus-derived core supplies where layout area and thermal management are constrained.
Availability
LM21212MHX-2/NOPB is available at Aetrix Electronics and suitable for networking infrastructure, FPGA power delivery, and industrial CPU module applications requiring stable component supply, long-term lifecycle assurance, and traceable sourcing.
Supply support for LM21212MHX-2/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 specializing in analog, embedded processing, and power management technologies with over 90 years of innovation in high-reliability power conversion solutions.
The LM21212MHX-2/NOPB belongs to TI's high-current synchronous buck regulator product line, designed specifically for efficient, space-constrained point-of-load regulation in FPGA, ASIC, and microprocessor applications operating from low-voltage intermediate buses.
FAQ
What is the maximum continuous output current supported by the LM21212MHX-2/NOPB?
The LM21212MHX-2/NOPB supports up to 12 A of continuous output current under recommended operating conditions (TJ ≤ 125°C, proper PCB thermal design). This rating assumes adequate copper area, vias under the exposed pad, and airflow per TI's thermal guidelines in SNVS715B. Derating applies above 85°C ambient.
Does the LM21212MHX-2/NOPB support startup into a prebiased output?
Yes, the LM21212MHX-2/NOPB supports startup into a prebiased output. During startup, it does not sink current from the output rail, allowing smooth voltage ramp-up past the precharged level. This behavior is confirmed in Section 8.3.4 and Figure 14 of the LM21212-2 datasheet (SNVS715B).
How is the switching frequency adjusted on the LM21212MHX-2/NOPB?
The switching frequency of the LM21212MHX-2/NOPB is adjusted using an external resistor connected between the FADJ pin and AGND. Frequency scales from 300 kHz to 1.55 MHz as resistance decreases; for example, 95.3 kΩ yields ~500 kHz, and 22.6 kΩ yields ~1.5 MHz. Full details are in Section 7.4 and Figure 22 of SNVS715B.
What is the purpose of the SS/TRK pin on the LM21212MHX-2/NOPB?
The SS/TRK pin on the LM21212MHX-2/NOPB serves dual functions: (1) soft-start control via internal 2 µA current source charging an external capacitor, and (2) output voltage tracking by accepting an external ramp signal. This enables coordinated power-up with other rails, satisfying FPGA and processor sequencing requirements per TI's application notes.
Can the LM21212MHX-2/NOPB operate with ceramic output capacitors only?
Yes, the LM21212MHX-2/NOPB is explicitly designed to be stable with any output capacitance type, including all-ceramic configurations. Its voltage-mode control architecture and wide-bandwidth error amplifier (11 MHz GBW) allow robust compensation using standard Type II or III networks, as validated in TI's WEBENCH® simulations and application reports.
LM21212MHX-2/NOPB Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- -
- Package/Case:
- 20-PowerTSSOP (0.173", 4.40mm Width)
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Function:
- Step-Down
- Output Configuration:
- Positive
- Topology:
- Buck
- Output Type:
- Adjustable
- Number of Outputs:
- 1
- Voltage - Input (Min):
- 2.95V
- Voltage - Input (Max):
- 5.5V
- Voltage - Output (Min/Fixed):
- 0.6V
- Voltage - Output (Max):
- 5.5V
- Current - Output:
- 12A
- Frequency - Switching:
- 300kHz ~ 1.55MHz
- Synchronous Rectifier:
- Yes
- Operating Temperature:
- -40°C ~ 125°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 20-HTSSOP
LM21212MHX-2/NOPB FAQ
1.How can I place an order for LM21212MHX-2/NOPB through Aetrix?
Please submit a Request for Quotation (RFQ) for LM21212MHX-2/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 LM21212MHX-2/NOPB reliable?
The price and inventory of LM21212MHX-2/NOPB are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM21212MHX-2/NOPB is usually 5 days.
3.What payment methods are accepted for LM21212MHX-2/NOPB?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM21212MHX-2/NOPB transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM21212MHX-2/NOPB?
LM21212MHX-2/NOPB orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM21212MHX-2/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 LM21212MHX-2/NOPB?
For technical support, including LM21212MHX-2/NOPB datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM21212MHX-2/NOPB requirements.
6.How does Aetrix verify that LM21212MHX-2/NOPB is sourced from the original manufacturer or authorized distributors?
All LM21212MHX-2/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 LM21212MHX-2/NOPB meets industry standards.
7.What is the process for return or replacement of LM21212MHX-2/NOPB?
All LM21212MHX-2/NOPB units undergo pre-shipment inspection (PSI). If there is an issue with LM21212MHX-2/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 LM21212MHX-2/NOPB part is unused and in its original packaging.
Return procedure for LM21212MHX-2/NOPB:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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