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Texas Instruments LM26420YSQX/NOPB
- Part No.:
- LM26420YSQX/NOPB
- Manufacturer:
- Texas Instruments
- Package:
- 16-WQFN Exposed Pad
- Datasheet:
-
LM26420YSQX/NOPB.pdf
- Description:
- IC REG BUCK ADJ 2A DL 16WQFN
- Quantity:
- Payment:
- Shipping:
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Product details
Overview
LM26420YSQX/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 output, operating from 3 V to 5.5 V input with 0.55 MHz switching frequency, internal 0.8 V reference (±1.5%), and independent enable/power-good signals - used for core/I/O voltage regulation in FPGAs and USB-powered devices.
For engineers reviewing the LM26420YSQX/NOPB datasheet, LM26420YSQX/NOPB pinout, LM26420YSQX/NOPB application, or LM26420YSQX/NOPB equivalent, key selection criteria include verified 0.55 MHz operation (Y variant), confirmed 75 mΩ PMOS / 50 mΩ NMOS switch RDS(on), thermal shutdown at 165°C, ±40 mV power-good hysteresis, and HTSSOP-20 package compatibility with prebiased start-up support.
Technical Context
The LM26420YSQX/NOPB implements current-mode PWM control with internal compensation, supporting 180° out-of-phase operation between channels to reduce input ripple. Its BICMOS process integrates 75-mΩ PMOS top switches and 50-mΩ NMOS bottom switches, enabling ≥93% peak efficiency across 3–5.5 V input and 0.8–4.5 V output ranges.
It features independent precision enable thresholds (1.04 V typical, 150 mV hysteresis) and open-drain power-good outputs with ±40 mV hysteresis, plus cycle-by-cycle current limiting (3.3 A typical) and overvoltage protection triggered at ~15% above VFB.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Input Voltage Range | 3 V to 5.5 V - supports single-cell Li-ion, USB 5 V, and 3.3 V/5 V system rails without external LDO pre-regulation. |
| Switching Frequency | 0.55 MHz - enables compact 1–2.2 µH inductors and low-ESR ceramic capacitors; avoids AM radio band interference. |
| Output Current (per channel) | 2 A continuous - sufficient for FPGA core logic, CPU I/O domains, and ASIC subsystems without external current boosting. |
| Feedback Reference | 0.8 V ±1.5% - sets output accuracy via resistor divider; enables 1.2 V and 2.5 V outputs with ≤3.5% total tolerance using 1% resistors. |
| Top-Switch RDS(on) | 75 mΩ (typical) - limits conduction loss at 2 A to <300 mW per channel under full load at 5 V input. |
| Thermal Shutdown | 165°C junction - protects against sustained overload or poor PCB thermal design; auto-recovery at ~150°C. |
| Power-Good Hysteresis | ±40 mV - ensures stable sequencing during line/load transients without chatter on PG1/PG2 outputs. |
Pinout & Package
LM26420YSQX/NOPB is packaged in a thermally enhanced 20-pin HTSSOP (PWP) with 6.50 mm × 4.40 mm body size and 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 regulators and error amplifiers; requires RC filter (1–10 Ω + 0.22–1 µF) to suppress VIN noise. |
| EN1 / EN2 | Independent enable inputs | Logic-high (>1.04 V) activates respective buck channel; 150 mV hysteresis prevents false triggering during slow-rising supplies. |
| VIND1 / VIND2 | Power input for Buck 1/2 | Separate high-current paths minimize crosstalk; each accepts 3–5.5 V with UVLO (2.628 V rising, 2.3 V falling). |
| SW1 / SW2 | Switch node outputs | Drive external inductors; require low-inductance layout to minimize EMI and voltage spikes during 0.55 MHz switching. |
| FB1 / FB2 | Feedback inputs | Connect to resistor dividers setting VOUT; 0.4–100 nA bias current enables high-impedance networks for low quiescent loss. |
| PG1 / PG2 | Open-drain Power Good | Assert low when respective output is within ±4% of target; require external pull-up (10–100 kΩ) for sequencing or fault indication. |
| PGND1 / PGND2 | Power ground returns | Separate ground pins per channel reduce shared-impedance coupling and improve load transient response. |
| AGND | Signal ground reference | Reference point for FB, EN, and internal circuits; must be tied to PGND near DAP with minimal trace length. |
| DAP | Die attach pad | Primary thermal path to PCB; must be soldered to solid copper pour connected to system ground for RθJA = 38.5°C/W. |
Key Features
| Feature | Design Value |
|---|---|
| 180° out-of-phase switching | Reduces input capacitor RMS current by ~30%, allowing smaller bulk capacitance and lower EMI emissions. |
| Start-up into prebiased outputs | Enables safe hot-plug operation without reverse current flow or output overshoot when VOUT is already biased. |
| Internal soft-start (600 µs) | Controls output ramp rate to limit inrush current; supports ratiometric startup of both channels when EN1/EN2 are tied. |
| CISPR25 Class 5 compliance | Validated conducted emissions performance meets automotive EMC requirements without added filtering components. |
| Current-mode PWM control | Provides inherent cycle-by-cycle current limiting, fast transient response (<10 µs), and stable operation across wide VIN/VOUT ranges. |
Applications
| FPGA Core & I/O Power | HDD/SSD Controller Supply |
|---|---|
Use Scenario: Powering Xilinx Artix-7 FPGA banks requiring 1.2 V core and 2.5 V I/O simultaneously from a 5 V bus. IC Role / Device Role / Timing Role: Dual-buck regulator providing tightly regulated, sequenced, and monitored voltages with independent PG signaling for configuration safety. Use Value: Eliminates need for two discrete converters; 0.55 MHz operation allows use of 1.5 µH inductors and 22 µF ceramic output caps per rail. | Use Scenario: Generating 1.2 V and 2.5 V for SATA controller ICs and NAND flash interface logic in portable storage enclosures. IC Role / Device Role / Timing Role: High-efficiency dual DC/DC converter delivering stable low-noise supplies with thermal protection during burst-write operations. Use Value: Achieves >91% efficiency at 1.5 A per rail, reducing thermal load in sealed enclosures; PG outputs enable firmware-controlled power sequencing. |
| USB-Powered Embedded Systems | ASIC Core & Auxiliary Rail |
Use Scenario: Powering ARM Cortex-M7 MCU, DDR3L memory, and sensor interface from a 5 V USB Type-C port. IC Role / Device Role / Timing Role: Primary power management IC supplying core (1.2 V) and I/O (2.5 V) rails with independent enable control for low-power sleep modes. Use Value: Enables deep-sleep current as low as 0.05 µA (shutdown); EN1/EN2 allow selective channel disable to cut system standby power. | Use Scenario: Delivering 1.2 V core and 2.5 V auxiliary voltage to custom SoC in industrial gateway with strict thermal constraints. IC Role / Device Role / Timing Role: Dual synchronous buck converter with integrated MOSFETs and thermal shutdown, supporting high ambient temperature operation. Use Value: DAP-connected thermal pad maintains TJ < 125°C at full load in 60°C ambient; 165°C thermal shutdown prevents permanent damage. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar dual-buck regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LM26422YSQX/NOPB | Same pinout, identical specs, but includes spread-spectrum clocking for reduced EMI peaks. | Better suited for noise-sensitive RF co-location; no change to BOM or layout required. | Select when CISPR25 Class 5 margin is insufficient or board-level EMI filtering is cost-constrained. |
| TPS54290PWPR | 2.2 MHz fixed frequency, 3.5 A per channel, 4.5–20 V input range; larger HTSSOP-28 package. | Requires higher input voltage; supports higher current and wider VIN, but needs redesign of input filter and layout. | Choose only if input exceeds 5.5 V or load current exceeds 2 A per rail; not drop-in compatible. |
Compared with LM26422YSQX/NOPB, the LM26420YSQX/NOPB lacks spread-spectrum modulation but offers identical thermal, electrical, and mechanical behavior - making it ideal for cost-sensitive, non-RF applications. Versus TPS54290PWPR, it trades input voltage range and current headroom for tighter integration and lower quiescent current in 5 V systems.
Availability
LM26420YSQX/NOPB is available at Aetrix Electronics and suitable for FPGA power delivery, USB-powered embedded systems, and HDD/SSD controller supply requiring stable component supply, long-term production continuity, and TI-qualified automotive-grade reliability.
Supply support for LM26420YSQX/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 designing analog ICs, embedded processors, and power management solutions for industrial, automotive, and consumer applications.
The LM26420 belongs to TI's high-efficiency dual buck converter product line, engineered specifically for space-constrained, multi-rail power systems in portable and embedded electronics where thermal density and EMI compliance are critical.
FAQ
What is the switching frequency of the LM26420YSQX/NOPB?
The LM26420YSQX/NOPB operates at a fixed 0.55 MHz switching frequency, as designated by the "Y" suffix in its part number. This frequency enables compact magnetics and low-profile ceramic capacitors while avoiding AM-band interference. It is factory-trimmed and does not require external frequency-setting components.
Does the LM26420YSQX/NOPB support start-up into a prebiased output?
Yes, the LM26420YSQX/NOPB supports controlled start-up into prebiased outputs. Its current-mode architecture and internal control logic prevent reverse current flow and output overshoot during hot-plug conditions, ensuring safe operation when VOUT is already present before enable.
What is the purpose of the VINC pin on the LM26420YSQX/NOPB?
The VINC pin on the LM26420YSQX/NOPB supplies regulated bias to internal control circuitry, including the error amplifier and PWM comparator. It must be filtered with an RC network (e.g., 4.7 Ω + 0.47 µF) referenced to AGND to reject high-frequency noise from the main input rail and ensure stable regulation.
How does the power-good function work on the LM26420YSQX/NOPB?
The LM26420YSQX/NOPB provides two open-drain power-good outputs (PG1 and PG2), each asserting low when its respective output voltage falls outside a ±4% window around the programmed value. Each requires an external pull-up resistor (10–100 kΩ) and exhibits ±40 mV hysteresis to prevent chatter during marginal conditions.
What thermal metrics apply to the LM26420YSQX/NOPB in HTSSOP-20 package?
For the LM26420YSQX/NOPB in HTSSOP-20 (PWP) package, the key thermal metrics are RθJA = 38.5°C/W (junction-to-ambient, JEDEC standard), RθJC(bot) = 3.5°C/W (junction-to-case bottom), and RθJB = 19.9°C/W (junction-to-board). These values assume proper DAP soldering to a 2-layer 1 oz Cu PCB with 1 in² thermal pad.
LM26420YSQX/NOPB Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- -
- Package/Case:
- 16-WQFN Exposed Pad
- 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:
- 550kHz
- Synchronous Rectifier:
- Yes
- Operating Temperature:
- -40°C ~ 125°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 16-WQFN (4x4)
LM26420YSQX/NOPB FAQ
1.How can I place an order for LM26420YSQX/NOPB through Aetrix?
Please submit a Request for Quotation (RFQ) for LM26420YSQX/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 LM26420YSQX/NOPB reliable?
The price and inventory of LM26420YSQX/NOPB are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM26420YSQX/NOPB is usually 5 days.
3.What payment methods are accepted for LM26420YSQX/NOPB?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM26420YSQX/NOPB transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM26420YSQX/NOPB?
LM26420YSQX/NOPB orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM26420YSQX/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 LM26420YSQX/NOPB?
For technical support, including LM26420YSQX/NOPB datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM26420YSQX/NOPB requirements.
6.How does Aetrix verify that LM26420YSQX/NOPB is sourced from the original manufacturer or authorized distributors?
All LM26420YSQX/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 LM26420YSQX/NOPB meets industry standards.
7.What is the process for return or replacement of LM26420YSQX/NOPB?
All LM26420YSQX/NOPB units undergo pre-shipment inspection (PSI). If there is an issue with LM26420YSQX/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 LM26420YSQX/NOPB part is unused and in its original packaging.
Return procedure for LM26420YSQX/NOPB:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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