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Texas Instruments LM2621MMX/NOPB
- Part No.:
- LM2621MMX/NOPB
- Manufacturer:
- Texas Instruments
- Package:
- 8-TSSOP, 8-MSOP (0.118", 3.00mm Width)
- Datasheet:
-
LM2621MMX/NOPB.pdf
- Description:
- IC REG BST SEPIC ADJ 8VSSOP
- Quantity:
- Payment:
- Shipping:
Inventory:3,424
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Product details
Overview
LM2621MMX/NOPB from Texas Instruments is a high-efficiency, low-input-voltage step-up DC-DC converter IC with an integrated 0.17-Ω N-channel MOSFET switch. It operates from 1.2 V to 14 V input and delivers adjustable regulated output from 1.24 V to 14 V at up to 1 A load current, achieving up to 90% efficiency in compact battery-powered systems such as PDAs and GPS devices.
For engineers reviewing the LM2621MMX/NOPB datasheet, LM2621MMX/NOPB pinout, LM2621MMX/NOPB application, or LM2621MMX/NOPB equivalent, key selection considerations include its gated-oscillator topology for ultra-low quiescent current (80 µA), programmable switching frequency up to 2 MHz, shutdown current below 2.5 µA, and VSSOP-8 package with 1.09-mm height for space-constrained designs.
Technical Context
The LM2621MMX/NOPB implements a constant-duty-cycle gated oscillator control scheme with 70% fixed on-time and 30 mV hysteresis at the FB pin, enabling high efficiency across wide load ranges without external compensation. Its internal power switch and bootstrapped gate drive (via BOOT and VDD pins) support operation down to 0.65 V after startup.
Startup occurs from as low as 1.1 V input, with internal circuitry initially forcing continuous 70% duty-cycle switching until output reaches 2.5 V, then transitioning to regulated gated-oscillator mode. Thermal protection disables the MOSFET above ~160°C junction temperature, re-enabling at ~135°C.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Input Voltage Range | 1.2 V to 14 V - supports single-cell Li-ion, two/three alkaline/NiMH, and wide industrial supply rails |
| Output Voltage Range | 1.24 V to 14 V - set via external resistive divider; FB pin reference is 1.24 V ±2.2% |
| Switching Frequency | 300 kHz to 2 MHz - externally resistor-programmable; enables use of sub-3 mm surface-mount inductors |
| Peak Switch Current Limit | 2.85 A typical - cycle-by-cycle protection prevents damage during overload or short-circuit conditions |
| Quiescent Current | 80 µA typical - enables long battery standby in portable electronics without compromising regulation |
| Shutdown Current | <2.5 µA - extends battery life in off-state; EN pin active-low with 0.15×VDD threshold |
| Efficiency | 87% at 3.6 VIN/5 VOUT/500 mA - achieved using integrated 0.17-Ω MOSFET and optimized gate drive |
Pinout & Package
VSSOP-8 (DGK) package: 3.00 mm × 3.00 mm body, 1.09 mm maximum height, 0.65 mm pin pitch, lead-free and RoHS-compliant.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| PGND (Pin 1) | Power Ground | Low-impedance return path for high-current switch node; must be connected to power ground plane near SW pin |
| EN (Pin 2) | Active-Low Enable | Logic input; device enabled when voltage >0.7×VDD, disabled when <0.15×VDD; pulls internal circuitry into ultra-low-power state |
| FREQ (Pin 3) | Frequency Adjust | Analog input; sets oscillator frequency via resistor to VDD (Pin 6); 300 kHz–2 MHz range |
| FB (Pin 4) | Voltage Feedback | High-impedance input monitoring output via resistive divider; 1.24 V reference triggers hysteresis-based gating |
| SGND (Pin 5) | Signal Ground | Reference for FB, EN, FREQ; isolated from PGND to prevent noise coupling into feedback path |
| VDD (Pin 6) | Internal Power Supply | Bias supply for control circuitry; can be bootstrapped from output (2.5–5 V) or supplied externally |
| BOOT (Pin 7) | Bootstrap Supply | Provides gate drive voltage for internal N-MOSFET; requires external capacitor between BOOT and SW |
| SW (Pin 8) | Switch Drain | Drain terminal of internal MOSFET; connects to inductor and output diode; carries high-frequency pulsed current |
Key Features
| Feature | Design Value |
|---|---|
| Gated Oscillator Topology | Delivers 87% efficiency at light loads by disabling switching entirely when output is within hysteresis window - eliminates PWM control losses |
| Low-Voltage Startup | Starts regulation from 1.1 V input - critical for single-cell alkaline or NiMH applications where voltage sags under load |
| Integrated Power Switch | 0.17-Ω N-channel MOSFET eliminates external FET and reduces BOM count, PCB area, and layout sensitivity |
| Thermal Protection | Automatic shutdown at ~160°C junction temperature with hysteresis - prevents permanent damage during sustained overload |
| Ultra-Thin Packaging | VSSOP-8 footprint (3 mm × 3 mm) and 1.09 mm height enable integration into slim handheld devices like palmtop computers and memory cards |
Applications
| Handheld GPS Receivers | Flash Memory Programming |
|---|---|
Use Scenario: Portable GPS units powered by two AA batteries (1.8–3.2 V) require stable 3.3 V rail for RF front-end and baseband processor. IC Role / Device Role / Timing Role: Step-up regulator generating clean 3.3 V output from decaying battery input; maintains regulation down to 0.65 V post-startup. Use Value: Enables full GPS functionality over entire battery discharge curve without brownouts; 80 µA quiescent current extends standby time. | Use Scenario: Embedded microcontroller programming flash memory requiring 12 V pulse for write/erase cycles from 3.3 V system rail. IC Role / Device Role / Timing Role: Boost converter generating programmable 12 V output; FB divider sets exact voltage needed for memory cell stress testing. Use Value: Eliminates need for separate charge-pump IC; 14 V max output headroom ensures reliable programming across process/voltage corners. |
| TFT-LCD Bias Supplies | PCMCIA Card Power Management |
Use Scenario: Small-format TFT displays in medical handhelds needing +5 V and –5 V bias rails from single 3.3 V source. IC Role / Device Role / Timing Role: Primary boost stage generating +5 V; drives external inverting charge pump for negative rail generation. Use Value: High 2 MHz switching frequency allows use of 4.7 µH shielded inductor - reduces solution size by >40% vs legacy 500 kHz designs. | Use Scenario: PCMCIA Type II card with integrated Wi-Fi module requiring 5 V from host's 3.3 V bus during hot-plug insertion. IC Role / Device Role / Timing Role: Standalone boost converter providing isolated 5 V rail; EN pin synchronized to card-detect signal for automatic power sequencing. Use Value: <2.5 µA shutdown current prevents parasitic drain on host system when card is ejected; VSSOP-8 fits tight card-edge layout constraints. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar step-up DC-DC converter applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TPS61022DRVR | Higher 2.2-A peak current limit; fixed 1.2-MHz frequency; no FREQ pin adjustment | Requires smaller inductor due to higher frequency; lacks programmable frequency for EMI tuning | Select when higher output current or simpler layout is prioritized over frequency flexibility |
| MAX17062ETA+ | Integrated Schottky diode; 1.8-MHz fixed frequency; 2.5-V minimum start-up voltage | Reduces external component count but cannot start from 1.1 V; less suitable for deep-discharge battery apps | Select when board space is extremely limited and input never drops below 2.5 V |
Compared with TPS61022DRVR and MAX17062ETA+, the LM2621MMX/NOPB uniquely balances ultra-low start-up voltage (1.1 V), programmable frequency (300 kHz–2 MHz), and minimal external components - making it optimal for cost-sensitive, battery-deep-discharge applications where layout flexibility matters.
Availability
LM2621MMX/NOPB is available at Aetrix Electronics and suitable for handheld instrumentation, GPS receivers, and flash memory programming systems requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.
Supply support for LM2621MMX/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 delivering analog and embedded processing solutions, with decades of expertise in power management IC design and manufacturing.
The LM2621 product line targets ultra-compact, battery-powered portable electronics - engineered specifically for low-input-voltage boost conversion with minimal external components and industry-leading quiescent current performance.
FAQ
What is the minimum input voltage required for the LM2621MMX/NOPB to start switching?
The LM2621MMX/NOPB starts switching from an input voltage as low as 1.1 V. During startup, it forces continuous 70% duty-cycle operation until the output reaches 2.5 V, after which normal gated-oscillator regulation begins. This capability makes LM2621MMX/NOPB suitable for single-cell alkaline or NiMH battery applications where voltage sags significantly under load.
How does the LM2621MMX/NOPB achieve high efficiency at light loads?
The LM2621MMX/NOPB uses a gated oscillator control scheme with 30 mV hysteresis at the FB pin. When output voltage stays within this window, the IC stops switching entirely - reducing quiescent current to just 80 µA. This eliminates switching losses present in PWM converters, delivering up to 87% efficiency even at 200 mA load with 2.5 V input.
Can the LM2621MMX/NOPB operate without an external bootstrap capacitor?
No - the LM2621MMX/NOPB requires an external capacitor between BOOT (Pin 7) and SW (Pin 8) to generate the gate drive voltage for its internal N-channel MOSFET. Omitting this capacitor prevents proper switch turn-on and causes regulation failure. Typical value is 0.1 µF ceramic placed adjacent to the IC.
What is the function of the SGND and PGND pins on the LM2621MMX/NOPB?
SGND (Pin 5) serves as the reference ground for sensitive analog inputs (FB, EN, FREQ), while PGND (Pin 1) provides the high-current return path for the power switch (SW). Separating these grounds minimizes noise coupling from switching transients into the feedback loop - a critical layout requirement to maintain regulation stability in the LM2621MMX/NOPB.
Is the LM2621MMX/NOPB pin-compatible with other Texas Instruments boost converters?
No - the LM2621MMX/NOPB has a unique VSSOP-8 pinout optimized for its gated oscillator architecture and bootstrap gate drive. Pins such as FREQ (3), BOOT (7), and SW (8) serve functions not found in standard PWM boost ICs like the TPS610xx series. Direct replacement requires schematic and layout revision; always verify pin mapping against the official LM2621MMX/NOPB datasheet before substitution.
LM2621MMX/NOPB Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- -
- Package/Case:
- 8-TSSOP, 8-MSOP (0.118", 3.00mm Width)
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Function:
- Step-Up, Step-Up/Step-Down
- Output Configuration:
- Positive
- Topology:
- Boost, SEPIC
- Output Type:
- Adjustable
- Number of Outputs:
- 1
- Voltage - Input (Min):
- 1.2V
- Voltage - Input (Max):
- 14V
- Voltage - Output (Min/Fixed):
- 1.24V
- Voltage - Output (Max):
- 14V
- Current - Output:
- 2.85A (Switch)
- Frequency - Switching:
- 300kHz ~ 2MHz
- Synchronous Rectifier:
- No
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-VSSOP
LM2621MMX/NOPB FAQ
1.How can I place an order for LM2621MMX/NOPB through Aetrix?
Please submit a Request for Quotation (RFQ) for LM2621MMX/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 LM2621MMX/NOPB reliable?
The price and inventory of LM2621MMX/NOPB are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LM2621MMX/NOPB is usually 5 days.
3.What payment methods are accepted for LM2621MMX/NOPB?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LM2621MMX/NOPB transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LM2621MMX/NOPB?
LM2621MMX/NOPB orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LM2621MMX/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 LM2621MMX/NOPB?
For technical support, including LM2621MMX/NOPB datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LM2621MMX/NOPB requirements.
6.How does Aetrix verify that LM2621MMX/NOPB is sourced from the original manufacturer or authorized distributors?
All LM2621MMX/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 LM2621MMX/NOPB meets industry standards.
7.What is the process for return or replacement of LM2621MMX/NOPB?
All LM2621MMX/NOPB units undergo pre-shipment inspection (PSI). If there is an issue with LM2621MMX/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 LM2621MMX/NOPB part is unused and in its original packaging.
Return procedure for LM2621MMX/NOPB:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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