My Inquiry
My Account
Texas Instruments LM26420XMHX/NOPB
- Part No.:
- LM26420XMHX/NOPB
- Manufacturer:
- Texas Instruments
- Package:
- 20-PowerTSSOP (0.173", 4.40mm Width)
- Datasheet:
-
LM26420XMHX/NOPB.pdf
- Description:
- IC REG BUCK ADJ 2A DL 20HTSSOP
- Quantity:
- Payment:
- Shipping:
Inventory:3,808
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
LM26420XMHX/NOPB from Texas Instruments is a dual-channel synchronous buck DC/DC converter delivering 2 A per channel at 2.5 V and 1.2 V outputs, operating from 3 V to 5.5 V input, with 2.2 MHz fixed switching frequency and integrated 75-mΩ PMOS/50-mΩ NMOS power switches - used in FPGA core voltage regulation and CPU I/O power delivery.
For engineers reviewing the LM26420XMHX/NOPB datasheet, LM26420XMHX/NOPB pinout, LM26420XMHX/NOPB application, or LM26420XMHX/NOPB equivalent, key selection criteria include dual-output sequencing capability, 180° phase-shifted operation for reduced input ripple, independent precision enable (1.04 V threshold) and open-drain power good indicators, and compliance with CISPR25 Class 5 conducted emissions.
Technical Context
The LM26420XMHX/NOPB implements current-mode PWM control with internal compensation, enabling stable regulation across 0.8 V–4.5 V output range using only external resistive feedback. Its 30 ns minimum on-time supports high-frequency conversion down to 0.8 V output while maintaining 93% peak efficiency.
It integrates independent UVLO (2.628 V rising, 330 mV hysteresis), thermal shutdown (165°C), overvoltage protection (15% above VREF), and cycle-by-cycle current limiting (3.3 A typical). Regulators operate 180° out of phase to minimize input capacitor RMS current and reduce EMI.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Input Voltage Range | 3 V to 5.5 V - supports USB-powered and single-cell Li-ion systems without pre-regulation. |
| Switching Frequency | 2.2 MHz (±15%) - enables use of compact 1–2.2 µH inductors and low-ESR ceramic capacitors. |
| Output Voltage Accuracy | ±1.5% over line/load/temp - ensures tight regulation for FPGA VCCINT and processor core rails. |
| Feedback Reference | 0.8 V ±1.5% - sets output via resistor divider; enables 0.8 V–4.5 V programmability. |
| Max Output Current | 2 A per channel - sufficient for dual-core SoC core and I/O supply with margin. |
| Efficiency | Up to 93% at 5 V input / 1.2 V–2.5 V outputs - reduces thermal load in space-constrained designs. |
| Enable Threshold | 1.04 V with 150 mV hysteresis - allows precise sequencing using resistor dividers off upstream supplies. |
Pinout & Package
LM26420XMHX/NOPB is packaged in a thermally enhanced 20-pin HTSSOP (6.50 mm × 4.40 mm) with exposed die attach pad (DAP) connected to system ground for optimal thermal performance.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| VINC | Control circuit supply | Provides clean bias for internal logic; requires RC filter (1–10 Ω + 0.22–1 µF) to suppress noise coupling. |
| EN1 / EN2 | Independent enable inputs | Logic-high (>1.04 V) activates respective buck channel; hysteresis prevents chatter during ramp-up. |
| VIND1 / VIND2 | Power input for Buck 1/2 | Separate input pins allow independent input sources or local decoupling per channel. |
| SW1 / SW2 | Switch node outputs | Drive external inductors; require low-inductance layout and Kelvin connection to minimize ringing. |
| FB1 / FB2 | Feedback inputs | Connect to resistor dividers; 0.4–100 nA bias current enables high-impedance networks. |
| PG1 / PG2 | Open-drain Power Good | Assert low when output is within ±7.5% of target; requires external pull-up (10–100 kΩ) for sequencing. |
| PGND1 / PGND2 | Power ground returns | Separate ground paths for each buck stage reduce cross-talk and improve EMI performance. |
| AGND | Analog ground reference | Reference point for feedback and control circuits; must be tied to PGND at single point near DAP. |
| DAP | Thermal & electrical ground | Exposed pad must be soldered to large copper pour for thermal dissipation and low-impedance GND return. |
Key Features
| Feature | Design Value |
|---|---|
| 180° phase-shifted operation | Reduces input capacitor RMS current by ~30%, lowering required capacitance and EMI filtering burden. |
| Internal soft-start (600 µs) | Prevents inrush current and output overshoot; supports ratiometric startup when EN1/EN2 tied. |
| CISPR25 Class 5 compliance | Meets automotive EMC requirements without additional shielding or ferrites in typical layouts. |
| Start-up into prebiased loads | Enables safe hot-plug operation where output rail is already biased - critical for hot-swap systems. |
| Independent UVLO and OVP | Each channel monitors its own input and output; prevents false triggering and improves fault isolation. |
Applications
| FPGA Core & I/O Power | HDD/SSD Controller Supply |
|---|---|
Use Scenario: Powering Xilinx Artix-7 FPGA VCCINT (1.2 V) and VCCO (2.5 V) rails from a shared 5 V bus. IC Role / Device Role / Timing Role: Dual synchronous buck regulator providing tightly regulated, sequenced core and I/O voltages with independent power good signaling. Use Value: Eliminates need for two discrete converters; 180° phase shift cuts input ripple by 50%, reducing bulk capacitor size by 30%. | Use Scenario: Generating 1.2 V core and 3.3 V I/O supplies for SATA SSD controller ICs in portable storage devices. IC Role / Device Role / Timing Role: High-efficiency dual DC/DC converter delivering 2 A per rail from 5 V USB input with minimal board area. Use Value: 93% peak efficiency at light loads extends battery life; 2.2 MHz operation enables use of 1.5 µH inductors < 2 mm height. |
| USB-Powered Embedded Systems | CPU/ASIC Core & Auxiliary Rails |
Use Scenario: Powering ARM Cortex-A53 SoC (1.1 V core, 1.8 V DDR) and peripheral logic (3.3 V) from USB 5 V source in industrial gateways. IC Role / Device Role / Timing Role: Dual buck regulator with independent enable and power good for controlled power-up sequence across subsystems. Use Value: Precision enable thresholds (1.04 V) allow reliable sequencing using simple resistor dividers off 5 V rail. | Use Scenario: Supplying 1.2 V core and 2.5 V I/O rails for custom ASIC in set-top box mainboard, sharing 5 V input with HDMI PHY and audio codec. IC Role / Device Role / Timing Role: Monolithic dual buck converter with separate VIND1/VIND2 pins enabling localized input decoupling per domain. Use Value: Independent power grounds (PGND1/PGND2) prevent noise coupling between digital core and analog I/O sections. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar dual-buck DC/DC converter applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TPS54290RTWR | Fixed 500 kHz frequency; lower max output current (1.5 A/channel); no integrated bottom FET - requires external sync rectifier. | Suitable for cost-sensitive industrial controls where size is less constrained and efficiency >90% is acceptable at lower load. | Select when board space is not critical and external MOSFETs are acceptable for thermal management flexibility. |
| MP2491DS-LF-Z | 2.2 MHz frequency; 2 A/channel; but only one enable and one PG pin - no independent channel control. | Applicable in simpler dual-rail systems like IoT sensor hubs where simultaneous enable and identical sequencing suffices. | Choose when independent sequencing is unnecessary and BOM count reduction outweighs loss of per-channel fault visibility. |
Compared with TPS54290RTWR and MP2491DS-LF-Z, the LM26420XMHX/NOPB uniquely delivers independent enable/PG per channel, 180° phase shift, and full integration (dual FETs) in a thermally optimized HTSSOP package - making it optimal for FPGA, CPU, and high-density embedded power applications requiring reliability and layout simplicity.
Availability
LM26420XMHX/NOPB is available at Aetrix Electronics and suitable for FPGA power delivery, HDD/SSD controller supplies, and USB-powered embedded systems requiring stable component supply and long-term production continuity.
Supply support for LM26420XMHX/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 ICs, with decades of expertise in high-efficiency DC/DC conversion.
The LM26420 product line was designed specifically for space-constrained, high-performance dual-rail applications in computing, storage, and portable electronics - emphasizing integration, EMI robustness, and ease of use.
FAQ
What is the switching frequency of the LM26420XMHX/NOPB and how does it impact design?
The LM26420XMHX/NOPB operates at a fixed 2.2 MHz switching frequency. This high frequency allows designers to use smaller inductors (typically 1–2.2 µH) and ceramic output capacitors, significantly reducing solution footprint and enabling compact PCB layouts. It also shifts switching noise above sensitive AM radio bands, easing EMI filtering requirements in consumer and portable applications.
Does the LM26420XMHX/NOPB support start-up into a prebiased output?
Yes, the LM26420XMHX/NOPB supports start-up into prebiased output loads. Its control architecture prevents reverse current flow during startup by disabling the bottom FET until the feedback voltage rises above the soft-start ramp level. This feature is essential for hot-swap and modular power systems where downstream rails may already be energized when the LM26420XMHX/NOPB is enabled.
How are the power good (PG) signals implemented on the LM26420XMHX/NOPB?
The LM26420XMHX/NOPB provides two independent open-drain power good outputs - PG1 and PG2 - each monitoring its respective buck channel's feedback voltage. Each PG asserts low when the output falls outside ±7.5% of the programmed voltage. An external pull-up resistor (10–100 kΩ) is required to generate a logic-high signal for sequencing or fault indication, enabling flexible system-level power management.
What thermal considerations apply to the LM26420XMHX/NOPB in the HTSSOP package?
The LM26420XMHX/NOPB in HTSSOP (PWP) package has a junction-to-ambient thermal resistance (RθJA) of 38.5°C/W under standard JEDEC conditions. Effective thermal design requires soldering the exposed DAP pad to a large internal or external copper plane, using ≥4 thermal vias to inner ground layers, and minimizing trace length between PGND pins and the DAP. Derating is recommended above 85°C ambient for continuous 2 A operation.
Can the LM26420XMHX/NOPB be used with different input voltages for each buck channel?
Yes, the LM26420XMHX/NOPB supports independent input supplies via dedicated VIND1 and VIND2 pins. This allows Buck 1 and Buck 2 to be powered from separate sources - for example, VIND1 from a 5 V USB rail and VIND2 from a 3.3 V always-on supply - enabling flexible power domain isolation, fault containment, and optimized efficiency per channel based on input voltage headroom.
LM26420XMHX/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:
- 2
- Voltage - Input (Min):
- 3V
- Voltage - Input (Max):
- 5.5V
- Voltage - Output (Min/Fixed):
- 0.8V
- Voltage - Output (Max):
- 4.5V
- Current - Output:
- 2A
- Frequency - Switching:
- 2.2MHz
- Synchronous Rectifier:
- Yes
- Operating Temperature:
- -40°C ~ 125°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 20-HTSSOP
LM26420XMHX/NOPB FAQ
1.How can I place an order for LM26420XMHX/NOPB through Aetrix?
Please submit a Request for Quotation (RFQ) for LM26420XMHX/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 LM26420XMHX/NOPB reliable?
The price and inventory of LM26420XMHX/NOPB are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM26420XMHX/NOPB is usually 5 days.
3.What payment methods are accepted for LM26420XMHX/NOPB?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM26420XMHX/NOPB transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM26420XMHX/NOPB?
LM26420XMHX/NOPB orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM26420XMHX/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 LM26420XMHX/NOPB?
For technical support, including LM26420XMHX/NOPB datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM26420XMHX/NOPB requirements.
6.How does Aetrix verify that LM26420XMHX/NOPB is sourced from the original manufacturer or authorized distributors?
All LM26420XMHX/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 LM26420XMHX/NOPB meets industry standards.
7.What is the process for return or replacement of LM26420XMHX/NOPB?
All LM26420XMHX/NOPB units undergo pre-shipment inspection (PSI). If there is an issue with LM26420XMHX/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 LM26420XMHX/NOPB part is unused and in its original packaging.
Return procedure for LM26420XMHX/NOPB:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LM26420XMHX/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…
