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Analog Devices Inc. LTC3646HMSE-1#PBF
- Part No.:
- LTC3646HMSE-1#PBF
- Manufacturer:
- Analog Devices Inc.
- Package:
- 16-TFSOP (0.118", 3.00mm Width) Exposed Pad
- Datasheet:
-
LTC3646HMSE-1#PBF.pdf
- Description:
- IC REG BUCK ADJ 1A 16MSOP
- Quantity:
- Payment:
- Shipping:
Inventory:200
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Product details
Overview
LTC3646HMSE-1#PBF from Analog Devices (formerly Linear Technology) is a 40V input, 1A synchronous step-down DC/DC converter in thermally enhanced 16-lead MSOP package, featuring ±1% reference accuracy, 0.6V to 15V output voltage range, and selectable Burst Mode® or forced continuous operation. It delivers high efficiency up to 95% across wide load range and supports automotive and industrial point-of-load applications with robust overvoltage, short-circuit, and thermal protection.
For engineers reviewing the LTC3646HMSE-1#PBF datasheet, LTC3646HMSE-1#PBF pinout, LTC3646HMSE-1#PBF application, or LTC3646HMSE-1#PBF equivalent, key selection considerations include its 4.0V–40V input range, 0.6V output minimum, –40°C to 150°C operating junction temperature, 200kHz–3MHz programmable switching frequency, and integrated 200mΩ/120mΩ MOSFETs enabling compact, high-reliability power designs.
Technical Context
The LTC3646HMSE-1#PBF implements a current-mode, controlled-on-time architecture with valley-current sensing and internal error amplifier transconductance of 300µS. Its on-time calculation dynamically scales with VON/VIN ratio, enabling stable regulation across large step-down ratios without output overvoltage risk.
It integrates dual power MOSFETs (200mΩ high-side, 120mΩ low-side), a 5.0V INTVCC regulator (±2% load regulation), and PGOOD with 7.5% overvoltage/–7.5% undervoltage thresholds and 15–30µs filter time. The device supports external clock synchronization and internal soft-start (250–500µs).
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Input Voltage Range | 4.0V to 40V - supports 12V/24V/36V automotive and industrial rails with 43.5V OVLO protection. |
| Output Voltage Range | 0.6V to 15V - enables core logic, FPGA I/O, and analog rail generation with 0.6V reference and ±1% accuracy. |
| Max Output Current | 1A - guaranteed across full temperature range with valley current limit of 0.9A–1.5A and negative limit of –0.3A. |
| Switching Frequency | 200kHz to 3.0MHz - set via RT resistor or synchronized externally; default 2.25MHz when RT = INTVCC. |
| Quiescent Current | 140µA typical in Burst Mode at no load - enables >90% efficiency at 1mA load for always-on systems. |
| Operating Temperature | –40°C to 150°C junction - H-grade qualification ensures reliability in under-hood and industrial environments. |
| Package | 16-Lead Plastic MSOP with exposed PGND pad - θJA = 38°C/W; requires soldered thermal pad for rated performance. |
Pinout & Package
Package: 16-Lead Plastic MSOP (MSE), 4mm × 3mm body, exposed thermal pad (Pin 17) connected to PGND. Requires PCB soldering of exposed pad for thermal and electrical integrity.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| SGND (Pin 1) | Analog Ground Reference | Low-noise return path for feedback and compensation; must be isolated from noisy PGND until single-point connection. |
| VFB (Pin 2) | Feedback Input | Connects to resistor divider; compares against 0.6V reference to regulate output; input bias current ±20nA. |
| ITH (Pin 3) | Error Amplifier Output | Loop compensation node; sets valley current threshold; connect RC network for stability or tie to INTVCC for internal compensation. |
| RT (Pin 4) | Oscillator Programming | Resistor-to-ground sets frequency (200kHz–3MHz); floating prohibited; 450kΩ → 200kHz, 30kΩ → 3MHz. |
| VON (Pin 5) | On-Time Scaling Input | Connected to VOUT to enable constant-frequency operation across wide VIN/VOUT ratios; 600kΩ input impedance. |
| PGOOD (Pin 6) | Power Good Status | Open-drain output pulled low if VFB deviates >7.5% from 0.6V; includes 15–30µs glitch filter. |
| MODE/SYNC (Pin 7) | Mode Control / Clock Input | Tie to INTVCC for Burst Mode, ground for forced continuous; accepts external clock 0.2–3.0MHz for synchronization. |
| PVIN (Pins 9,10) | Main Power Input | High-voltage supply for top MOSFET; decouple with ≥10µF low-ESR capacitor to PGND. |
| SW (Pin 11) | Switch Node | Connects to inductor and boost capacitor; carries high di/dt; requires tight layout and Kelvin routing. |
| BOOST (Pin 12) | Bootstrap Supply | Generates gate drive voltage for top MOSFET; swing = INTVCC to PVIN + INTVCC; requires ceramic cap to SW. |
| INTVCC (Pin 13) | Internal 5.0V Regulator | Supplies control circuitry; decouple with ≥4.7µF low-ESR cap to PGND; disabled when RUN = low. |
| EXTVCC (Pin 14) | External Bias Input | Optional 4.5–6.0V supply for lower quiescent current; tie to SGND if unused. |
| RUN (Pin 15) | Enable Input | Active-high enable; threshold 1.17–1.26V rising; hysteresis 110mV; leakage ±1µA at 1.3V. |
| SVIN (Pin 16) | Control Circuit Supply | Must match PVIN for accurate on-time calculation; decouple with >1µF low-ESR cap to SGND. |
| PGND (Exposed Pad) | Power Ground | Primary thermal and current return path; must be soldered to large PCB copper area for θJA = 38°C/W. |
Key Features
| Feature | Design Value |
|---|---|
| Patented Controlled On-Time Architecture | Enables stable constant-frequency operation across 40:1 input-to-output ratios without output overvoltage risk. |
| Integrated Dual MOSFETs | 200mΩ high-side and 120mΩ low-side switches eliminate external FETs and reduce BOM count and layout complexity. |
| Selectably Optimized Efficiency Modes | Burst Mode achieves 140µA IQ at no load; forced continuous mode eliminates switching ripple for noise-sensitive analog circuits. |
| Robust Protection Suite | Includes SVIN/PVIN overvoltage lockout (43.5V), short-circuit current limiting (1.2A typ), thermal shutdown, and PGOOD monitoring. |
| Flexible Frequency Control | RT-programmable (200kHz–3MHz), INTVCC-default (2.25MHz), or external clock synchronization for EMI reduction and system timing alignment. |
Applications
| Automotive Infotainment Power | Industrial PLC I/O Module |
|---|---|
Use Scenario: Powering 1.2V/1.8V FPGA core and 3.3V I/O rails in head-unit systems exposed to 45V load-dump transients. IC Role / Device Role / Timing Role: Primary synchronous buck regulator delivering regulated low-voltage rails from 12V/24V battery with transient immunity. Use Value: 40V max input rating and 43.5V OVLO protect against ISO 7637-2 pulses; 150°C junction rating ensures operation near engine bay heat sources. |
Use Scenario: Generating 5V and 3.3V supplies for digital isolators, ADCs, and microcontrollers in DIN-rail mounted controllers. IC Role / Device Role / Timing Role: Point-of-load DC/DC converter providing isolated field-side power with precise voltage tracking and low ripple. Use Value: ±1% reference accuracy and 0.6V feedback enable tight regulation; forced continuous mode eliminates switching noise in measurement circuits. |
| Medical Portable Diagnostic Device | Telecom Remote Radio Unit |
Use Scenario: Battery-powered ultrasound front-end requiring ultra-low IQ during standby and fast transient response during imaging bursts. IC Role / Device Role / Timing Role: Main system power converter managing Li-ion (3.0–4.2V) and 24V adapter inputs to generate multiple low-noise rails. Use Value: 140µA Burst Mode IQ extends battery life; 250–500µs soft-start prevents inrush into sensitive analog signal chains. |
Use Scenario: Powering GaN PA bias and FPGA logic in outdoor 5G RRUs with wide ambient temperature swings and limited cooling. IC Role / Device Role / Timing Role: High-efficiency intermediate bus converter stepping 48V down to 12V/5V for downstream POL stages. Use Value: 95% peak efficiency reduces thermal load; 150°C H-grade rating maintains reliability without active cooling in sealed enclosures. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar synchronous step-down converter applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LT8610EMSE#PBF | 42V input, 3.5A output, 2.5µA IQ in Silent Switcher mode; fixed 2.2MHz frequency; no VON pin or adjustable min on-time. | Better EMI performance and higher current, but lacks wide output range (0.6V–24V) and programmable frequency of LTC3646HMSE-1#PBF. | Choose LT8610EMSE#PBF for noise-critical RF subsystems where EMI compliance is paramount and 3.5A output suffices. |
| TPS54240DGQR | 40V input, 2.5A output, 115µA IQ; external compensation only; no PGOOD or SYNC; 100kHz–2.5MHz frequency range. | Lower cost and higher current, but lacks integrated PGOOD, Burst Mode optimization, and thermal grade (only –40°C to 125°C). | Choose TPS54240DGQR for cost-sensitive industrial controls where 125°C max junction temperature is acceptable and PGOOD is not required. |
Compared with LT8610EMSE#PBF and TPS54240DGQR, the LTC3646HMSE-1#PBF uniquely combines 0.6V–15V output flexibility, –40°C to 150°C H-grade operation, and VON-based on-time scaling for stable wide-ratio conversion-making it optimal for automotive and high-reliability embedded systems demanding both precision and ruggedness.
Availability
LTC3646HMSE-1#PBF is available at Aetrix Electronics and suitable for automotive infotainment, industrial PLC I/O modules, and medical portable diagnostic devices requiring stable component supply with extended temperature support and long-term lifecycle assurance.
Supply support for LTC3646HMSE-1#PBF 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
Analog Devices, Inc. (acquired Linear Technology in 2017) is a global leader in high-performance analog, mixed-signal, and power management semiconductors, serving precision instrumentation, industrial automation, and automotive markets.
The LTC3646HMSE-1#PBF belongs to Linear's high-voltage monolithic buck regulator product line, engineered specifically for robust, wide-input industrial and automotive power conversion where reliability across extreme temperatures and transients is critical.
FAQ
What is the maximum input voltage rating for the LTC3646HMSE-1#PBF?
The LTC3646HMSE-1#PBF has an absolute maximum PVIN/SVIN rating of 45V, with overvoltage lockout (OVLO) triggered at 43.5V (typical) and 2.0V hysteresis. Its operational input range is specified from 4.0V to 40V, making it suitable for 24V and 36V industrial rails and automotive systems subject to load-dump transients. Exceeding 45V risks permanent damage per Absolute Maximum Ratings.
Does the LTC3646HMSE-1#PBF support output voltages below 1.0V?
Yes, the LTC3646HMSE-1#PBF supports output voltages as low as 0.6V due to its fixed 0.6V internal reference and ±1% accuracy over temperature. When configured with appropriate feedback resistors (e.g., R1 = 0Ω, R2 = 10kΩ for 0.6V), it reliably regulates sub-1V rails required by modern FPGA cores and ASICs. The VON pin connection to VOUT ensures stable on-time control even at these low outputs.
How does the MODE/SYNC pin function in the LTC3646HMSE-1#PBF?
The MODE/SYNC pin on the LTC3646HMSE-1#PBF serves dual roles: when tied to INTVCC, it enables high-efficiency Burst Mode® operation for light loads; when grounded, it forces continuous conduction mode to minimize output ripple. When driven with an external 0.2–3.0MHz clock, it synchronizes switching while maintaining forced continuous operation-enabling EMI reduction and system-level timing coordination.
What thermal performance can be expected from the LTC3646HMSE-1#PBF in MSOP package?
The LTC3646HMSE-1#PBF in 16-lead MSOP (MSE) package has a specified θJA of 38°C/W when the exposed PGND pad is properly soldered to a minimum 1-inch² copper area on the PCB. With 1A load and 12V input, typical power dissipation is ~350mW; this yields ~13°C rise above ambient, supporting reliable operation up to 150°C junction temperature in well-designed layouts.
Is external compensation required for stable operation of the LTC3646HMSE-1#PBF?
No, external compensation is optional. The LTC3646HMSE-1#PBF supports internal compensation by connecting the ITH pin directly to INTVCC, simplifying design for standard applications. External compensation (via RC network on ITH) is recommended only for non-standard output capacitors, wide input/output ranges, or stringent transient response requirements-providing full loop tuning flexibility without mandatory complexity.
LTC3646HMSE-1#PBF Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc.
- Series:
- -
- Package/Case:
- 16-TFSOP (0.118", 3.00mm Width) Exposed Pad
- Packaging:
- Tube
- Product Status:
- Active
- Function:
- Step-Down
- Output Configuration:
- Positive
- Topology:
- Buck
- Output Type:
- Adjustable
- Number of Outputs:
- 1
- Voltage - Input (Min):
- 4V
- Voltage - Input (Max):
- 40V
- Voltage - Output (Min/Fixed):
- 0.6V
- Voltage - Output (Max):
- 15V
- Current - Output:
- 1A
- Frequency - Switching:
- 200kHz ~ 3MHz
- Synchronous Rectifier:
- Yes
- Operating Temperature:
- -40°C ~ 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 16-MSOP-EP
LTC3646HMSE-1#PBF FAQ
1.How can I place an order for LTC3646HMSE-1#PBF through Aetrix?
Please submit a Request for Quotation (RFQ) for LTC3646HMSE-1#PBF 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 LTC3646HMSE-1#PBF reliable?
The price and inventory of LTC3646HMSE-1#PBF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LTC3646HMSE-1#PBF is usually 5 days.
3.What payment methods are accepted for LTC3646HMSE-1#PBF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LTC3646HMSE-1#PBF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LTC3646HMSE-1#PBF?
LTC3646HMSE-1#PBF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LTC3646HMSE-1#PBF 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 LTC3646HMSE-1#PBF?
For technical support, including LTC3646HMSE-1#PBF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LTC3646HMSE-1#PBF requirements.
6.How does Aetrix verify that LTC3646HMSE-1#PBF is sourced from the original manufacturer or authorized distributors?
All LTC3646HMSE-1#PBF 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 LTC3646HMSE-1#PBF meets industry standards.
7.What is the process for return or replacement of LTC3646HMSE-1#PBF?
All LTC3646HMSE-1#PBF units undergo pre-shipment inspection (PSI). If there is an issue with LTC3646HMSE-1#PBF, 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 LTC3646HMSE-1#PBF part is unused and in its original packaging.
Return procedure for LTC3646HMSE-1#PBF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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