My Inquiry
My Account
Analog Devices Inc. LTC3646HMSE#PBF
- Part No.:
- LTC3646HMSE#PBF
- Manufacturer:
- Analog Devices Inc.
- Package:
- 16-TFSOP (0.118", 3.00mm Width) Exposed Pad
- Datasheet:
-
LTC3646HMSE#PBF.pdf
- Description:
- IC REG BUCK ADJ 1A 16MSOP
- Quantity:
- Payment:
- Shipping:
Inventory:178
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
LTC3646HMSE#PBF from Analog Devices (formerly Linear Technology) is a 40V input, 1A synchronous step-down DC/DC converter with integrated high-side and synchronous power FETs, ±1% reference accuracy, 4.0V–40V input range, and 2.0V–30V adjustable output voltage. It operates in Burst Mode® (140µA no-load IQ) or forced continuous mode and targets point-of-load power supplies in industrial and automotive systems.
For engineers reviewing the LTC3646HMSE#PBF datasheet, LTC3646HMSE#PBF pinout, LTC3646HMSE#PBF application, or LTC3646HMSE#PBF equivalent, key selection criteria include its 150°C junction-rated MSOP-16 package, controlled-on-time architecture enabling large step-down ratios without overvoltage risk, 200kHz–3MHz programmable switching frequency, and robust short-circuit and overvoltage protection.
Technical Context
The LTC3646HMSE#PBF implements current-mode control with valley-current sensing and a patented controlled-on-time architecture that dynamically adjusts tON based on VON/VIN ratio and programmed fO, ensuring stable regulation across wide VIN–VOUT differentials. Its error amplifier (300µS transconductance) drives the ITH node to regulate valley current, while internal soft-start (250–500µs) and PGOOD monitoring (±7.5% window, 15–30µs filter) support reliable power sequencing.
It integrates dual MOSFETs with 200mΩ/120mΩ RDS(ON) (VIN = 5.5V), supports external compensation via ITH, and features dual supply inputs (PVIN/SVIN) with independent overvoltage lockout (43.5V rising threshold). The MODE/SYNC pin enables mode selection (Burst vs. forced continuous) or external clock synchronization up to 3MHz.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Input Voltage Range | 4.0V to 40V - supports direct connection to 24V/36V industrial buses and automotive battery rails with transient tolerance. |
| Output Current | 1A guaranteed - delivers full rated load continuously at TJ ≤ 150°C in thermally enhanced MSOP package. |
| Output Voltage Range | 2.0V to 30V - set via resistor divider on VFB; enables generation of intermediate bus voltages (e.g., 5V, 12V, 24V) from high-input sources. |
| Reference Voltage Accuracy | ±1% (0.594V–0.606V) - ensures tight output regulation across –40°C to 150°C operating junction temperature. |
| No-Load Quiescent Current | 140µA typical in Burst Mode - enables >90% efficiency at 1mA load, critical for always-on subsystems. |
| Switching Frequency Range | 200kHz to 3.0MHz - adjustable via RT resistor or synchronizable to external clock; higher frequencies reduce inductor/capacitor size. |
| Package & Temp Grade | 16-Lead MSOP, –40°C to 150°C junction - exposed pad (Pin 17) must be soldered to PGND for thermal performance (θJA = 38°C/W). |
Pinout & Package
Package: 16-Lead Plastic MSOP with exposed thermal pad (Pin 17 = PGND). Requires soldering of exposed pad to PCB ground plane for thermal management and electrical integrity.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| SGND (Pin 1) | Analog Ground Reference | Low-noise return path for feedback and error amplifier; must be isolated from noisy power ground until joined at single point. |
| VFB (Pin 2) | Feedback Input | Connects to resistor divider from VOUT; compares against 0.6V internal reference to regulate output voltage. |
| ITH (Pin 3) | Error Amplifier Output / Compensation Node | Drives current-mode loop; external RC network here sets loop bandwidth and phase margin. |
| RT (Pin 4) | Oscillator Programming Input | Resistor to SGND sets switching frequency (200kHz–3MHz); tie to INTVCC for 2.25MHz default. |
| VON (Pin 5) | On-Time Proportionality Input | Connected to VOUT to scale tON with output voltage, enabling stable operation at large step-down ratios. |
| PGOOD (Pin 6) | Open-Drain Power-Good Indicator | Pulled low when VFB deviates >7.5% from 0.6V; includes 15–30µs glitch filter for transient immunity. |
| MODE/SYNC (Pin 7) | Operating Mode Control / Clock Input | Ground = forced continuous; INTVCC = Burst Mode; external clock = synchronized forced continuous. |
| SVIN (Pin 16) | Internal Circuitry Supply Input | Must equal PVIN for accurate on-time calculation; decouple with ≥1µF low-ESR capacitor to SGND. |
| PVIN (Pins 9,10) | Main Power Switch Supply | High-side FET drain connection; requires ≥10µF low-ESR capacitor to PGND for ripple suppression. |
| SW (Pin 11) | Switch Node | Connects to inductor and boost capacitor; carries high di/dt; layout critical for EMI and efficiency. |
| BOOST (Pin 12) | Bootstrap Supply for High-Side Gate | Capacitor between BOOST and SW generates gate drive voltage; swing = INTVCC to PVIN + INTVCC. |
| INTVCC (Pin 13) | Internal 5.0V Regulator Output | Supplies internal logic; decouple with ≥4.7µF low-ESR cap to PGND; disabled when RUN = low. |
| EXTVCC (Pin 14) | External Low-Voltage Supply Input | Optional 4.5V–6.0V supply for control circuitry; improves efficiency when available; else tie to SGND. |
| RUN (Pin 15) | Enable Input | Active-high enable; threshold = 1.21V (rising), hysteresis = 110mV; leakage < ±1µA at 1.3V. |
| PGND (Exposed Pad Pin 17) | Power Ground Return | Primary thermal and electrical ground path; must be soldered to large copper area for θJA = 38°C/W. |
Key Features
| Feature | Design Value |
|---|---|
| Controlled-on-time architecture | Enables stable regulation at extreme step-down ratios (e.g., 40V→3.3V) without output overvoltage risk, unlike fixed-frequency current-mode controllers. |
| Burst Mode® operation | Reduces no-load IQ to 140µA while maintaining ±1% output regulation-critical for battery-backed or energy-sensitive applications. |
| Integrated dual MOSFETs | 200mΩ high-side + 120mΩ low-side RDS(ON) at 5.5V reduces conduction loss and eliminates external switch selection complexity. |
| Dual input supply monitoring (PVIN/SVIN) | Independent overvoltage lockout (43.5V) on both inputs protects against transients without requiring external TVS devices. |
| Robust protection suite | Includes short-circuit current limiting (1.2A typical), thermal shutdown (150°C), and PGOOD with filtered fault reporting for system-level reliability. |
Applications
| Industrial PLC I/O Module Power | Automotive Infotainment Core Supply |
|---|---|
Use Scenario: Powering FPGA, microcontroller, and analog front-end in modular PLC I/O cards with 24V rail input. IC Role / Device Role / Timing Role: Primary step-down regulator delivering 5V/1A with tight load regulation and low-noise operation. Use Value: 140µA Burst Mode IQ extends standby time; 150°C rating ensures reliability in sealed enclosures without forced air cooling. |
Use Scenario: Generating 1.2V core voltage for SoC in head-unit infotainment systems with 9V–16V battery input. IC Role / Device Role / Timing Role: Synchronous buck converter with fast transient response and PGOOD sequencing for processor reset control. Use Value: Controlled-on-time architecture maintains stability during cold-crank (6.5V) and load-dump (36V) events per ISO 16750-2. |
| Point-of-Load for Telecom Line Cards | Medical Diagnostic Sensor Bias Supply |
Use Scenario: Local 3.3V supply for high-speed SerDes and PHY ICs on telecom line cards with 48V backplane input. IC Role / Device Role / Timing Role: Intermediate bus converter stepping 48V down to 3.3V at up to 1A with minimal board space. Use Value: 3MHz max switching frequency allows use of compact 2.2µH inductors; MSOP-16 footprint fits dense layouts. |
Use Scenario: Precision 15V bias supply for ultrasound transducer driver amplifiers requiring low noise and high PSRR. IC Role / Device Role / Timing Role: Low-ripple, forced-continuous-mode buck regulator with external compensation for optimized noise performance. Use Value: ±1% reference and 0.12% load regulation ensure stable sensor excitation; 150°C rating supports enclosed medical chassis. |
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; 16-lead MSOP but different pinout and no VON pin. | Higher current, lower IQ, superior EMI performance; lacks VON-based on-time scaling for ultra-large step-down ratios. | Select LT8610EMSE#PBF when EMI compliance (CISPR 25 Class 5) or sub-5µA standby is required; not drop-in due to pinout and control architecture differences. |
| TPS54240DGQR | 40V input, 2.5A output, 110µA IQ; current-mode with external compensation; SOIC-10 package, not thermally enhanced. | Higher current, lower cost; lacks Burst Mode®, integrated bootstrap, and 150°C rating-limited to ≤125°C ambient. | Select TPS54240DGQR for cost-sensitive, lower-temperature industrial applications where 2.5A output and SOIC-10 fit constraints; requires external bootstrap diode and has no PGOOD filter. |
Compared with LT8610EMSE#PBF and TPS54240DGQR, the LTC3646HMSE#PBF uniquely combines 150°C operation, VON-based on-time scaling for safe 40V→3V conversion, and integrated bootstrap in an MSOP-16-making it optimal for high-reliability, high-step-down, high-temperature embedded power rails.
Availability
LTC3646HMSE#PBF is available at Aetrix Electronics and suitable for industrial PLC modules, automotive infotainment systems, and telecom line card power supplies requiring stable component supply across extended temperature ranges and long production lifecycles.
Supply support for LTC3646HMSE#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 (acquired Linear Technology in 2017) is a global leader in high-performance analog, mixed-signal, and power management semiconductors, serving industrial, automotive, communications, and healthcare markets.
The LTC3646HMSE#PBF belongs to Linear's high-voltage monolithic buck converter family, designed specifically for robust, high-efficiency point-of-load regulation in harsh environments with wide input transients and extended temperature demands.
FAQ
What is the maximum junction temperature rating for the LTC3646HMSE#PBF?
The LTC3646HMSE#PBF is specified for operation from –40°C to 150°C junction temperature. This H-grade rating is validated per manufacturer characterization and statistical process controls, making it suitable for sealed industrial enclosures and under-hood automotive applications where ambient temperatures exceed 105°C.
Does the LTC3646HMSE#PBF require an external bootstrap diode?
No, the LTC3646HMSE#PBF does not require an external bootstrap diode. Its integrated BOOST pin uses a flying capacitor between BOOST and SW to generate the high-side gate drive voltage. An external diode is only needed if higher boost voltage or improved transient response is required-otherwise, the internal charge pump suffices.
Can the LTC3646HMSE#PBF be used to generate 1.2V output from a 40V input?
Yes, the LTC3646HMSE#PBF can safely generate 1.2V from 40V input using its VON pin configuration and controlled-on-time architecture. Unlike fixed-frequency controllers, this method prevents output overvoltage by scaling tON proportionally to VOUT, eliminating risk even at 33:1 step-down ratios.
What is the purpose of the SVIN pin on the LTC3646HMSE#PBF?
The SVIN pin on the LTC3646HMSE#PBF supplies internal circuitry and must be tied to the same voltage as PVIN. This ensures accurate on-time calculation and constant-frequency operation across input voltage variations. Decoupling SVIN to SGND with ≥1µF low-ESR capacitance is mandatory for stability.
How does the PGOOD function behave during startup and load transients on the LTC3646HMSE#PBF?
The LTC3646HMSE#PBF PGOOD output remains low until VFB stabilizes within ±5% of 0.6V after soft-start completes. During load transients, its 15–30µs internal filter prevents false triggering; PGOOD only asserts low if VFB remains outside the ±7.5% window for longer than the filter delay, ensuring robust sequencing in dynamic systems.
LTC3646HMSE#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):
- 2V
- Voltage - Output (Max):
- 30V
- 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#PBF FAQ
1.How can I place an order for LTC3646HMSE#PBF through Aetrix?
Please submit a Request for Quotation (RFQ) for LTC3646HMSE#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#PBF reliable?
The price and inventory of LTC3646HMSE#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#PBF is usually 5 days.
3.What payment methods are accepted for LTC3646HMSE#PBF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LTC3646HMSE#PBF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LTC3646HMSE#PBF?
LTC3646HMSE#PBF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LTC3646HMSE#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#PBF?
For technical support, including LTC3646HMSE#PBF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LTC3646HMSE#PBF requirements.
6.How does Aetrix verify that LTC3646HMSE#PBF is sourced from the original manufacturer or authorized distributors?
All LTC3646HMSE#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#PBF meets industry standards.
7.What is the process for return or replacement of LTC3646HMSE#PBF?
All LTC3646HMSE#PBF units undergo pre-shipment inspection (PSI). If there is an issue with LTC3646HMSE#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#PBF part is unused and in its original packaging.
Return procedure for LTC3646HMSE#PBF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LTC3646HMSE#PBF 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…
