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Analog Devices Inc. LTC3646IDE-1#TRPBF
- Part No.:
- LTC3646IDE-1#TRPBF
- Manufacturer:
- Analog Devices Inc.
- Package:
- 14-WFDFN Exposed Pad
- Datasheet:
-
LTC3646IDE-1#TRPBF.pdf
- Description:
- IC REG BUCK ADJ 1A 14DFN
- Quantity:
- Payment:
- Shipping:
Inventory:2,638
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Product details
Overview
LTC3646IDE-1#TRPBF 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, 0.6V to 15V output voltage range, and selectable Burst Mode® or forced continuous operation - used in automotive intermediate bus supplies and industrial point-of-load regulation.
For engineers reviewing the LTC3646IDE-1#TRPBF datasheet, LTC3646IDE-1#TRPBF pinout, LTC3646IDE-1#TRPBF application, or LTC3646IDE-1#TRPBF equivalent, this page delivers verified technical context, package mapping, real-world load-step behavior, thermal performance at 125°C junction, and validated alternative options for high-voltage buck conversion.
Technical Context
The LTC3646IDE-1#TRPBF implements a current-mode, controlled-on-time architecture with valley-current sensing and internal 0.6V reference. Its on-time calculation depends on VON/VIN ratio and programmed frequency, enabling stable large step-down ratios without output overvoltage risk.
It supports dual supply inputs (PVIN/SVIN), features integrated soft-start (250–500µs), PGOOD with 7.5% over/under threshold and 15–30µs filter, and offers external frequency programming (200kHz–3MHz) or synchronization via MODE/SYNC pin - all while maintaining 140µA no-load quiescent current in Burst Mode.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Input Voltage Range | 4.0V to 40V - supports wide-range industrial and automotive battery inputs including cold-crank and load-dump conditions. |
| Output Voltage Range | 0.6V to 15V - enables direct core-voltage regulation for low-VDD processors and FPGAs. |
| Max Output Current | 1A guaranteed - sufficient for powering SoCs, sensors, and interface ICs in space-constrained systems. |
| Reference Accuracy | ±1% over –40°C to 125°C - ensures tight output regulation across full operating temperature range. |
| Quiescent Current | 140µA typical in Burst Mode - extends battery life in always-on subsystems without sacrificing startup time. |
| Switching Frequency | 200kHz to 3.0MHz - allows trade-off between inductor size (high-freq) and efficiency (low-freq). |
| Package | 14-lead 3mm × 4mm DFN - thermally enhanced exposed-pad package rated for 125°C junction operation. |
Pinout & Package
Package: 14-lead (3mm × 4mm) plastic DFN with exposed PGND pad (Pin 15), rated for –40°C to 125°C operating junction temperature and θJA = 43°C/W.
| 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 traces. |
| VFB (Pin 2) | Feedback input | Connects to resistor divider; compares output voltage against internal 0.6V reference for regulation. |
| ITH (Pin 3) | Error amplifier output | Compensation node - sets valley current limit and loop stability; connect to INTVCC for internal compensation. |
| RT (Pin 4) | Oscillator programming | Resistor-to-ground sets switching frequency (200kHz–3MHz); tie to INTVCC for 2.25MHz default. |
| VON (Pin 5) | On-time control input | Connected to VOUT to scale on-time proportionally - critical for constant-frequency operation across wide VIN/VOUT ratios. |
| 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 selection / sync input | Ground = forced continuous; INTVCC = Burst Mode; external clock = synchronized forced continuous. |
| PVIN (Pin 8) | Main power switch supply | High-side FET source connection; requires ≥10µF low-ESR ceramic decoupling to PGND. |
| SW (Pin 9) | Switch node | Connects to inductor and boost capacitor; carries high di/dt switching waveform. |
| BOOST (Pin 10) | Bootstrap supply | Generates gate drive voltage for high-side FET via SW–BOOST capacitor; swing = INTVCC to PVIN + INTVCC. |
| INTVCC (Pin 11) | Internal 5.0V regulator | Supplies control circuitry; decouple with ≥4.7µF low-ESR capacitor to PGND; disabled when RUN = low. |
| EXTVCC (Pin 12) | External bias input | Optional 4.5–6.0V supply for improved efficiency; tie to SGND if unused. |
| RUN (Pin 13) | Enable control | Active-high enable; threshold = 1.21V rising; hysteresis = 110mV; leakage < ±1µA at 1.3V. |
| SVIN (Pin 14) | Control circuit supply | Must match PVIN voltage to ensure accurate on-time calculation and stable frequency. |
| PGND (Pin 15) | Power ground | Exposed thermal pad - must be soldered to PCB ground plane for thermal and electrical performance. |
Key Features
| Feature | Design Value |
|---|---|
| Patented controlled-on-time architecture | Enables stable 40V-to-0.6V conversion without output overvoltage risk, even under light loads or fast transients. |
| 140µA no-load quiescent current | Extends runtime in battery-backed systems while maintaining fast wake-up response from Burst Mode sleep state. |
| Integrated short-circuit protection | Withstands sustained output shorts by limiting valley current to ~1.2A and reducing switching frequency automatically. |
| 0.6V ±1% reference over temperature | Ensures consistent output accuracy across –40°C to 125°C without external trimming or calibration. |
| Thermally enhanced DFN package | Exposes PGND pad for low-thermal-resistance PCB mounting - supports 1A continuous load at 125°C junction. |
Applications
| Automotive Infotainment Power | Industrial PLC I/O Module |
|---|---|
Use Scenario: Regulating 12V vehicle battery down to 1.2V for FPGA core logic in head-unit systems. IC Role / Device Role / Timing Role: Primary synchronous buck regulator delivering 1A at 1.2V with tight transient response and low EMI. Use Value: Achieves >90% efficiency at 500mA load while maintaining 140µA quiescent current during standby - meeting OEM low-power requirements. |
Use Scenario: Generating 3.3V from 24V industrial rail for microcontroller and sensor interfaces in programmable logic controllers. IC Role / Device Role / Timing Role: High-voltage input buck converter with SVIN/PVIN overvoltage lockout (43.5V) for surge immunity. Use Value: Survives 40V transients and maintains regulation during brownouts due to 4.0V UVLO and robust valley-current limiting. |
| Medical Point-of-Care Display | Test Equipment Auxiliary Supply |
Use Scenario: Powering LCD backlight driver ICs requiring stable 5V from variable 8–36V portable battery pack. IC Role / Device Role / Timing Role: Wide-input buck regulator with PGOOD monitoring and soft-start for system sequencing. Use Value: Internal 250–500µs soft-start prevents inrush current; PGOOD confirms regulation before enabling downstream loads. |
Use Scenario: Providing isolated 12V auxiliary supply for analog front-end circuits in benchtop multimeters. IC Role / Device Role / Timing Role: Precision buck converter with ±1% reference and external compensation for low-noise output. Use Value: External loop compensation (via ITH) enables optimization for ultra-low output ripple (<10mVpp) at 1A load. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar synchronous buck regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LT8610ACDE#TRPBF | 42V input, 3.5A output, 2.5µA quiescent current, requires external compensation. | Higher current capability but larger 16-lead DFN package; optimized for ultra-low IQ rather than wide VOUT range. | Select when >1A load or sub-µA standby is required; not drop-in due to different pinout and compensation scheme. |
| TPS54340DDAR | 40V input, 3.5A output, 145µA IQ, fixed 0.8V reference, no VON pin or controlled-on-time architecture. | Lacks VON-based on-time scaling - less stable at extreme step-down ratios; uses voltage-mode control instead of current mode. | Choose for cost-sensitive 3.3V/5V fixed-output designs where 0.6V reference and wide VOUT range are unnecessary. |
Compared with LT8610ACDE#TRPBF and TPS54340DDAR, the LTC3646IDE-1#TRPBF uniquely combines 0.6V–15V programmable output, controlled-on-time stability across 40V:0.6V ratios, and 140µA Burst Mode IQ in a compact 14-lead DFN - making it optimal for precision, wide-range, thermally constrained buck applications.
Availability
LTC3646IDE-1#TRPBF is available at Aetrix Electronics and suitable for automotive infotainment, industrial PLC I/O modules, medical point-of-care displays, and test equipment auxiliary supplies requiring stable component supply across extended temperature ranges.
Supply support for LTC3646IDE-1#TRPBF 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 and maintains its high-performance power management portfolio with rigorous qualification and long-term product support.
The LTC3646IDE-1#TRPBF belongs to Linear's monolithic synchronous buck regulator family designed for high-input-voltage, wide-output-range, and thermally demanding applications in automotive, industrial, and medical systems.
FAQ
What is the maximum input voltage rating for the LTC3646IDE-1#TRPBF?
The LTC3646IDE-1#TRPBF has an absolute maximum PVIN/SVIN rating of 45V, with overvoltage lockout triggered at 43.5V (rising) and 41.5V (falling). It operates continuously from 4.0V to 40V, making it suitable for 24V and 36V industrial rails and automotive battery systems with transient suppression.
Does the LTC3646IDE-1#TRPBF support output voltages below 1.0V?
Yes - the LTC3646IDE-1#TRPBF supports output voltages from 0.6V to 15V. Its internal 0.6V reference and precise feedback amplifier enable stable regulation at sub-1V levels, such as 0.8V or 0.9V for modern processor cores, provided appropriate resistor divider accuracy and layout practices are followed.
How does the VON pin function in the LTC3646IDE-1#TRPBF?
The VON pin in the LTC3646IDE-1#TRPBF feeds the output voltage into the on-time controller to maintain constant switching frequency across varying input and output conditions. When connected directly to VOUT, it scales the on-time proportionally (tON ∝ VON/VIN × fO), preventing frequency collapse during large step-down conversions.
Can the LTC3646IDE-1#TRPBF be synchronized to an external clock?
Yes - the MODE/SYNC pin of the LTC3646IDE-1#TRPBF accepts an external clock signal (0.2–3.0MHz) to synchronize switching frequency. When driven externally, the device operates in forced continuous mode and adjusts its on-time to match the applied clock, eliminating beat frequencies in multi-rail systems.
What thermal derating applies to the LTC3646IDE-1#TRPBF at 125°C junction temperature?
The LTC3646IDE-1#TRPBF is specified for continuous operation up to 125°C junction temperature. At this limit, its 1A output current rating remains valid when mounted on a 4-layer PCB with the exposed PGND pad fully soldered to ≥2 in² copper area - no additional current derating is required per the datasheet specifications.
LTC3646IDE-1#TRPBF Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc.
- Series:
- -
- Package/Case:
- 14-WFDFN Exposed Pad
- Packaging:
- Tape & Reel (TR)
- 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:
- 14-DFN (4x3)
LTC3646IDE-1#TRPBF FAQ
1.How can I place an order for LTC3646IDE-1#TRPBF through Aetrix?
Please submit a Request for Quotation (RFQ) for LTC3646IDE-1#TRPBF 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 LTC3646IDE-1#TRPBF reliable?
The price and inventory of LTC3646IDE-1#TRPBF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LTC3646IDE-1#TRPBF is usually 5 days.
3.What payment methods are accepted for LTC3646IDE-1#TRPBF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LTC3646IDE-1#TRPBF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LTC3646IDE-1#TRPBF?
LTC3646IDE-1#TRPBF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LTC3646IDE-1#TRPBF 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 LTC3646IDE-1#TRPBF?
For technical support, including LTC3646IDE-1#TRPBF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LTC3646IDE-1#TRPBF requirements.
6.How does Aetrix verify that LTC3646IDE-1#TRPBF is sourced from the original manufacturer or authorized distributors?
All LTC3646IDE-1#TRPBF 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 LTC3646IDE-1#TRPBF meets industry standards.
7.What is the process for return or replacement of LTC3646IDE-1#TRPBF?
All LTC3646IDE-1#TRPBF units undergo pre-shipment inspection (PSI). If there is an issue with LTC3646IDE-1#TRPBF, 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 LTC3646IDE-1#TRPBF part is unused and in its original packaging.
Return procedure for LTC3646IDE-1#TRPBF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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