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Analog Devices Inc. LTC3631EDD-3.3#TRPBF
- Part No.:
- LTC3631EDD-3.3#TRPBF
- Manufacturer:
- Analog Devices Inc.
- Package:
- 8-WFDFN Exposed Pad
- Datasheet:
-
LTC3631EDD-3.3#TRPBF.pdf
- Description:
- IC REG BUCK 3.3V 100MA 8DFN
- Quantity:
- Payment:
- Shipping:
Inventory:5,863
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Product details
Overview
LTC3631EDD-3.3#TRPBF from Analog Devices (formerly Linear Technology) is a high-voltage, synchronous step-down DC/DC converter with integrated high-side and low-side MOSFETs, delivering up to 100mA output at fixed 3.3V, operating from 4.5V to 45V input, featuring 12µA quiescent current in Burst Mode® and internal overvoltage lockout up to 60V. It targets industrial control supplies and battery-operated devices requiring robust, low-power regulation.
For engineers reviewing the LTC3631EDD-3.3#TRPBF datasheet, LTC3631EDD-3.3#TRPBF pinout, LTC3631EDD-3.3#TRPBF application, or LTC3631EDD-3.3#TRPBF equivalent, key selection criteria include its 3.3V fixed output, 8-pin 3mm × 3mm DFN package with exposed thermal pad, programmable peak current limit (50–225mA), precise RUN pin threshold (1.21V rising), and no-compensation design for rapid implementation.
Technical Context
The LTC3631EDD-3.3#TRPBF employs a hysteretic Burst Mode® control architecture with an internal 0.800V ±1% feedback reference and 5mV comparator hysteresis, enabling ultra-low quiescent current operation while maintaining regulation across load currents from 100µA to 100mA. Its dual-MOSFET synchronous rectification eliminates external diode losses.
Input protection includes undervoltage lockout (UVLO) at 3.75V (falling) and overvoltage lockout (OVLO) at 47V (rising), with sustained 60V surge tolerance. The device integrates soft-start via internal 0.75ms ramp or external SS pin capacitor, and supports adjustable hysteresis via HYST pin for controlled enable/disable sequencing.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Input Voltage Range | 4.5V to 45V - supports wide-range industrial and automotive power rails without pre-regulation |
| Output Voltage | Fixed 3.3V ±1.2% - eliminates external resistor divider, reduces BOM count and layout sensitivity |
| Max Output Current | 100mA - sufficient for microcontrollers, sensors, and interface ICs in space-constrained systems |
| Quiescent Current | 12µA typical in Burst Mode® - enables multi-year battery life in always-on remote sensors |
| Peak Current Limit | Programmable 50mA to 225mA via ISET resistor - allows optimization of inductor size and efficiency at light loads |
| Overvoltage Protection | 60V surge tolerance with 47V OVLO threshold - protects against load dump transients in 24V/36V systems |
| Package | 8-lead 3mm × 3mm DFN with exposed GND pad - provides low thermal resistance (θJC = 3°C/W) for high ambient operation |
Pinout & Package
Package: 8-lead (3mm × 3mm) plastic DFN with exposed thermal pad (Pin 9), rated for –40°C to 125°C junction temperature. Exposed pad must be soldered to PCB ground plane for thermal and electrical integrity.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| SW (Pin 1) | Switch node | Connection point for external inductor; carries high dv/dt switching waveform - requires tight layout and minimal trace length |
| VIN (Pin 2) | Main input supply | Accepts 4.5V–45V input; bypass capacitor required between VIN and GND for stability and EMI suppression |
| ISET (Pin 3) | Peak current programming | Sources 1µA; resistor to GND sets peak inductor current from 50mA (shorted) to 225mA (open) |
| SS (Pin 4) | Soft-start control | Sources 5µA; external capacitor sets output voltage ramp time - prevents input droop during startup |
| RUN (Pin 5) | Enable control | Active-high logic: ≥1.21V enables operation; ≤1.10V disables - precise threshold enables reliable brown-out detection |
| VOUT/VFB (Pin 6) | Output feedback | Internally connected to 3.3V output; no external divider needed - simplifies layout and improves noise immunity |
| HYST (Pin 7) | Run hysteresis output | Open-drain logic output pulled low when RUN < 1.2V - used to add external hysteresis to RUN pin via resistor divider |
| GND (Pins 8 & 9) | Ground reference | Pins 8 and 9 (exposed pad) are internally connected - pad must be soldered to PCB ground plane for thermal performance and EMI reduction |
Key Features
| Feature | Design Value |
|---|---|
| No compensation required | Internal hysteretic control loop eliminates external compensation network - reduces component count and design iteration time |
| Low dropout operation | 100% duty cycle capability - maintains regulation down to VIN ≈ VOUT, critical for battery end-of-life operation |
| Internal soft-start | 0.75ms default ramp - prevents inrush current and output overshoot during power-up without external components |
| Precise RUN threshold | 1.21V rising / 1.10V falling with 110mV hysteresis - enables clean, glitch-free enable/disable sequencing in multi-rail systems |
| Burst Mode® efficiency | ≥85% efficiency at 1mA load (VIN=12V, VOUT=3.3V) - extends battery life in intermittent-duty applications like wireless sensor nodes |
Applications
| 4–20mA Current Loop Transmitter | Industrial Sensor Node Power |
|---|---|
Use Scenario: Powering analog transmitter circuitry (e.g., HART modem, DAC, op-amps) from a 24V loop supply with strict current budget. IC Role / Device Role / Timing Role: Primary 3.3V regulator supplying precision analog and digital subsystems; operates in Burst Mode® during idle periods to minimize loop current draw. Use Value: 12µA quiescent current ensures total transmitter current remains within 4mA lower limit; 45V max input accommodates loop transients and wiring drops. | Use Scenario: Providing stable 3.3V rail to low-power MCU, MEMS accelerometer, and BLE radio in battery-powered condition monitoring node. IC Role / Device Role / Timing Role: Main system regulator enabling deep-sleep modes; programmable peak current allows use of small 4.7µH inductor to reduce board area. Use Value: 100mA output headroom supports radio transmit bursts; 60V surge tolerance protects against ESD and inductive kickback in factory environments. |
| Automotive Body Control Module | Portable Test Instrument |
Use Scenario: Regulating 3.3V for microcontroller and CAN transceiver in under-hood modules exposed to 12V/24V battery variations and load dump events. IC Role / Device Role / Timing Role: High-reliability DC/DC converter with integrated OVLO and UVLO - replaces discrete protection + LDO solution. Use Value: 45V operating range and 60V surge rating meet ISO 7637-2 Pulse 5a requirements; DFN package withstands thermal cycling in engine bay. | Use Scenario: Powering handheld multimeter or oscilloscope front-end ASIC from 9V alkaline or Li-ion battery pack. IC Role / Device Role / Timing Role: Efficient step-down regulator supporting both active measurement and sleep states; low dropout enables full battery utilization. Use Value: 100% duty cycle operation extends usable battery voltage down to 3.3V; 3mm × 3mm DFN minimizes footprint in compact handheld enclosure. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar step-down converter applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LMR36015RNXR | 3.3V fixed output, 1.5A rating, 4V–60V input, 26µA IQ, 16-pin WQFN | Higher current capacity and wider input range; larger package and higher quiescent current | Select when >100mA load or >45V input is required; not drop-in due to pinout and footprint mismatch |
| TPS560200DBVR | 3.3V fixed output, 600mA rating, 4.5V–17V input, 24µA IQ, SOT-23-6 | Narrower input range, higher IQ, smaller package; lacks OVLO and programmable current limit | Choose for cost-sensitive, low-current applications with stable 12V input; requires external OVLO circuit for automotive use |
Compared with LMR36015RNXR and TPS560200DBVR, the LTC3631EDD-3.3#TRPBF delivers optimal balance of ultra-low IQ (12µA), 45V input capability, and integrated 60V surge protection in a thermally efficient 3mm × 3mm DFN - making it uniquely suited for battery-backed and industrial 24V systems where standby power and transient robustness are critical.
Availability
LTC3631EDD-3.3#TRPBF is available at Aetrix Electronics and suitable for industrial control supplies, 4–20mA current loops, and portable instrumentation requiring stable component supply, long-term lifecycle support, and guaranteed traceable sourcing.
Supply support for LTC3631EDD-3.3#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, Inc. (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 LTC3631 product line was designed specifically for high-input-voltage, low-quiescent-current DC/DC conversion in harsh environments - emphasizing robustness, simplicity, and extended battery life in distributed power and sensor applications.
FAQ
What is the maximum input voltage the LTC3631EDD-3.3#TRPBF can withstand without damage?
The LTC3631EDD-3.3#TRPBF has an absolute maximum VIN rating of 60V and includes internal overvoltage lockout (OVLO) that disables switching above 47V (rising). This allows the device to survive automotive load dump transients and industrial power surges while maintaining safe operation within its 4.5V–45V functional input range. Continuous operation above 45V is not recommended.
Does the LTC3631EDD-3.3#TRPBF require external compensation components?
No, the LTC3631EDD-3.3#TRPBF uses a proprietary hysteretic Burst Mode® control architecture that requires no external compensation components. Its internal feedback loop is inherently stable across all operating conditions and output capacitor types, eliminating the need for RC networks or complex loop tuning - significantly reducing design time and BOM count.
How is the output voltage set on the LTC3631EDD-3.3#TRPBF?
The LTC3631EDD-3.3#TRPBF features a factory-trimmed fixed 3.3V output. Pin 6 (VOUT/VFB) is internally connected to the regulated output, so no external resistor divider is required. This configuration ensures ±1.2% output accuracy over temperature and line, simplifies PCB layout, and improves noise rejection compared to adjustable versions.
Can the LTC3631EDD-3.3#TRPBF operate with 100% duty cycle?
Yes, the LTC3631EDD-3.3#TRPBF supports 100% duty cycle operation, allowing it to maintain regulation when VIN approaches VOUT (e.g., 3.6V input to 3.3V output). This capability is essential for maximizing battery runtime in portable equipment, as it enables usable energy extraction down to the lowest possible cell voltage before shutdown.
What thermal performance can be expected from the LTC3631EDD-3.3#TRPBF in its DFN package?
The LTC3631EDD-3.3#TRPBF in the 3mm × 3mm DFN package achieves θJC = 3°C/W (junction-to-case) when the exposed thermal pad (Pin 9) is properly soldered to a minimum 100mm² copper pour on the PCB. With adequate board-level copper, it sustains 100mA continuous output at 85°C ambient - verified by thermal characterization in Linear Technology's datasheet Figure 1.
LTC3631EDD-3.3#TRPBF Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc.
- Series:
- -
- Package/Case:
- 8-WFDFN Exposed Pad
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Function:
- Step-Down
- Output Configuration:
- Positive or Negative
- Topology:
- Buck
- Output Type:
- Fixed
- Number of Outputs:
- 1
- Voltage - Input (Min):
- 4.5V
- Voltage - Input (Max):
- 45V
- Voltage - Output (Min/Fixed):
- 3.3V
- Voltage - Output (Max):
- -
- Current - Output:
- 100mA
- Frequency - Switching:
- -
- Synchronous Rectifier:
- Yes
- Operating Temperature:
- -40°C ~ 125°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-DFN (3x3)
LTC3631EDD-3.3#TRPBF FAQ
1.How can I place an order for LTC3631EDD-3.3#TRPBF through Aetrix?
Please submit a Request for Quotation (RFQ) for LTC3631EDD-3.3#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 LTC3631EDD-3.3#TRPBF reliable?
The price and inventory of LTC3631EDD-3.3#TRPBF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LTC3631EDD-3.3#TRPBF is usually 5 days.
3.What payment methods are accepted for LTC3631EDD-3.3#TRPBF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LTC3631EDD-3.3#TRPBF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LTC3631EDD-3.3#TRPBF?
LTC3631EDD-3.3#TRPBF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LTC3631EDD-3.3#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 LTC3631EDD-3.3#TRPBF?
For technical support, including LTC3631EDD-3.3#TRPBF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LTC3631EDD-3.3#TRPBF requirements.
6.How does Aetrix verify that LTC3631EDD-3.3#TRPBF is sourced from the original manufacturer or authorized distributors?
All LTC3631EDD-3.3#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 LTC3631EDD-3.3#TRPBF meets industry standards.
7.What is the process for return or replacement of LTC3631EDD-3.3#TRPBF?
All LTC3631EDD-3.3#TRPBF units undergo pre-shipment inspection (PSI). If there is an issue with LTC3631EDD-3.3#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 LTC3631EDD-3.3#TRPBF part is unused and in its original packaging.
Return procedure for LTC3631EDD-3.3#TRPBF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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