My Inquiry
My Account
Analog Devices Inc. LT3686AEDD#TRPBF
- Part No.:
- LT3686AEDD#TRPBF
- Manufacturer:
- Analog Devices Inc.
- Package:
- 10-WFDFN Exposed Pad
- Datasheet:
-
LT3686AEDD#TRPBF.pdf
- Description:
- IC REG BUCK ADJ 1.2A 10DFN
- Quantity:
- Payment:
- Shipping:
Inventory:1,848
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
LT3686AEDD#TRPBF from Analog Devices (formerly Linear Technology) is a 3.6V–37V input, 1.2A synchronous step-down DC/DC converter in a thermally enhanced 10-lead 3mm × 3mm DFN package. It delivers regulated 3.3V output at up to 1.2A with adjustable switching frequency (300kHz–2.5MHz), internal compensation, and integrated boost diode - optimized for automotive battery and industrial 24V supply regulation.
For engineers reviewing the LT3686AEDD#TRPBF datasheet, LT3686AEDD#TRPBF pinout, LT3686AEDD#TRPBF application, or LT3686AEDD#TRPBF equivalent, key selection criteria include its 100ns minimum on-time enabling 16VIN→3.3VOUT conversion at 2MHz, BD-pin active load for fixed-frequency light-load operation, and overvoltage lockout protecting against 60V transients.
Technical Context
The LT3686AEDD#TRPBF uses current-mode PWM control with cycle-by-cycle current limiting, thermal shutdown, and DA-pin valley-current sensing for short-circuit robustness. Its internal bipolar NPN switch features BOOST-pin-driven gate drive and 680mV typical VCE(SAT) at 1.2A, enabling high efficiency across wide input ranges.
It supports external synchronization (SYNC/MODE pin), programmable UVLO via EN/UVLO resistor divider, and tracking soft-start via SS pin with internal 2µA current source. The BD pin enables an internal active load when SYNC/MODE > 0.8V, eliminating pulse-skipping and maintaining constant 2MHz switching above audio/AM bands.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Input Voltage Range | 3.6V to 37V continuous; withstands 60V non-repetitive transients - supports direct connection to automotive batteries and 24V industrial rails. |
| Output Current | 1.2A maximum continuous - sufficient for powering microcontrollers, sensors, and interface ICs in compact systems. |
| Switching Frequency | Adjustable 300kHz–2.5MHz via RT resistor; 2MHz operation enables use of 6.8µH inductors and ultra-small ceramic capacitors. |
| Feedback Reference | 0.790V–0.815V (±1.9% over temp) - enables precise output voltage setting with standard resistor dividers. |
| Quiescent Current | <1µA in shutdown (VEN/UVLO < 0.4V); 1.1–1.4mA in standby - critical for always-on automotive modules. |
| Minimum On-Time | 100ns typical - allows 16VIN→3.3VOUT conversion at 2MHz without duty-cycle limitation. |
| Package | 10-lead 3mm × 3mm DFN with exposed pad - JA = 43°C/W; requires PCB thermal pad for 125°C junction operation. |
Pinout & Package
LT3686AEDD#TRPBF is housed in a 10-lead plastic DFN (3mm × 3mm) with exposed thermal pad (Pin 11) that must be soldered to PCB ground for thermal performance. Pin numbering follows top-view orientation with Pin 1 at bottom-left corner.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1,2 VIN | Power input | Dual-input configuration supplies internal regulator and power switch; requires local 2.2µF X7R ceramic bypass. |
| 2,3 BD | Active load control | Regulated current sink (≤40mA) activated when SYNC/MODE > 0.8V to maintain fixed-frequency operation at light loads. |
| 3,4 FB | Feedback reference | Regulated to 0.8V ±1.9%; sets output voltage via R1/R2 divider (e.g., R2 = 10kΩ, R1 = 31.6kΩ for 3.3V). |
| 4,5 SS | Soft-start/tracking | Internal 2µA current source ramps external capacitor; controls both FB reference and oscillator frequency during startup. |
| 5,6 RT | Frequency programming | Resistor-to-ground sets switching frequency (e.g., 15.4kΩ → 2.1MHz); supports sync input when driven externally. |
| 6,7 EN/UVLO | Enable/undervoltage lockout | 1.28V threshold enables UVLO function; pull <0.4V for full shutdown (<1µA IQ). |
| 7,8 SYNC/MODE | Sync input / mode select | Accepts external clock (≥200ns pulse width); also enables BD active load when >0.8V. |
| 8,9 BOOST | Switch driver supply | Boost capacitor voltage drives internal NPN switch; requires external 10nF ceramic between BOOST and SW. |
| 9,10 DA | Catch diode anode sense | Monitors catch diode current; triggers frequency foldback if valley current exceeds 1.7A - protects during short-circuit events. |
| 10,11 SW | Switch node | Connects to inductor, catch diode cathode, and BOOST capacitor; carries high di/dt switching current. |
Key Features
| Feature | Design Value |
|---|---|
| Integrated boost diode | Eliminates external Schottky diode (e.g., MBRM140), reducing BOM count and board area in space-constrained designs. |
| Constant frequency at light loads | BD-pin active load maintains full 2MHz switching down to zero load - ensures predictable EMI profile and low output ripple above AM band. |
| Overvoltage lockout (OVLO) | 37V–39V threshold protects against load-dump transients in automotive 12V/24V systems without external clamping. |
| Internal compensation | Reduces external component count by eliminating need for loop compensation network - simplifies layout and validation. |
| Thermally enhanced DFN | Exposed pad + 43°C/W junction-to-ambient enables 1.2A operation at 125°C ambient without heatsink or airflow. |
Applications
| Automotive Infotainment Power | Industrial Sensor Node Supply |
|---|---|
Use Scenario: Powering display controllers and audio codecs in head units with 12V/24V battery input and strict EMI requirements. IC Role / Device Role / Timing Role: Primary 3.3V step-down regulator delivering 1.2A with fixed 2MHz switching to avoid AM radio interference. Use Value: BD-pin active load eliminates pulse-skipping noise; OVLO withstands 35V load-dump transients per ISO 7637-2. |
Use Scenario: Regulating power for wireless sensor transceivers (e.g., LoRa, NB-IoT) in factory-floor condition monitoring nodes. IC Role / Device Role / Timing Role: High-efficiency 3.6V–37V input buck converter supporting wide-range 24V industrial supplies and brownout resilience. Use Value: 100ns min-on-time enables 2MHz operation with small 6.8µH inductor; <1µA shutdown current extends battery life in sleep modes. |
| Medical Portable Diagnostic Device | Ruggedized Edge Computing Module |
Use Scenario: Providing clean, low-noise 3.3V rail for ADCs and FPGA configuration in handheld ultrasound or glucose meters. IC Role / Device Role / Timing Role: Synchronous buck regulator with internal compensation and precision 0.8V feedback reference for stable analog performance. Use Value: Internal boost diode and integrated compensation reduce component count; 0.790V–0.815V VFB tolerance ensures ±1.9% output accuracy over temperature. |
Use Scenario: Powering ARM-based edge AI processors in outdoor telecom cabinets with 48V PoE-derived input and thermal constraints. IC Role / Device Role / Timing Role: Robust 37V-rated buck converter operating at 125°C junction temperature with thermal shutdown and current limiting. Use Value: Exposed-pad DFN package achieves 43°C/W θJA; DA-pin valley-current sensing prevents inductor saturation during processor burst loads. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar step-down regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LTC3630EMSE#PBF | Lower 3.1V–40V input range; 1.5A output; no BD pin or active load; MSOP-12 only | Lacks fixed-frequency light-load operation; better suited for higher-current, non-automotive applications | Select when >1.2A output or simpler light-load behavior is acceptable; not drop-in due to different pinout and missing BD functionality |
| MP2451DT-LF-Z | 3.3V–36V input; 0.6A output; 2MHz fixed frequency; no synchronization or BD pin; smaller SOIC-8 package | Half the output current; no active load or sync capability; lower thermal performance (θJA ≈ 100°C/W) | Choose for cost-sensitive, lower-power applications where BD and sync features are unnecessary; requires layout change |
Compared with LTC3630EMSE#PBF and MP2451DT-LF-Z, the LT3686AEDD#TRPBF uniquely combines 1.2A output, BD-pin active load for AM-band-clean operation, and 300kHz–2.5MHz adjustability - making it optimal for automotive and industrial systems requiring EMI control, transient robustness, and thermal efficiency in minimal footprint.
Availability
LT3686AEDD#TRPBF is available at Aetrix Electronics and suitable for automotive infotainment, industrial sensor nodes, and medical portable diagnostics requiring stable component supply, long-term lifecycle support, and AEC-Q200-aligned reliability.
Supply support for LT3686AEDD#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 continues its legacy of high-performance power management ICs with rigorous automotive and industrial qualification.
The LT3686AEDD#TRPBF belongs to Linear's high-voltage monolithic buck regulator family, designed specifically for harsh-environment applications including automotive battery regulation, industrial 24V systems, and equipment requiring robust transient protection and EMI-controlled switching.
FAQ
What is the maximum input voltage rating for LT3686AEDD#TRPBF in continuous operation?
The LT3686AEDD#TRPBF has a continuous input voltage rating of 37V, with overvoltage lockout activating at 37V–39V. It can withstand non-repetitive 60V transients for up to one second, making it suitable for automotive load-dump conditions per ISO 7637-2. This rating is validated across the full –40°C to 125°C junction temperature range.
How does the BD pin function in LT3686AEDD#TRPBF, and what design impact does it have?
The BD pin in LT3686AEDD#TRPBF enables an internal active load when SYNC/MODE > 0.8V, drawing up to 40mA to maintain constant switching frequency at light loads. This eliminates pulse-skipping noise and keeps output ripple predictable above the AM band (1.6–3MHz), which is essential for automotive audio and RF-sensitive applications.
Can LT3686AEDD#TRPBF operate at 2MHz with a 3.3V output, and what inductor value is recommended?
Yes, LT3686AEDD#TRPBF supports 2MHz operation with 3.3V output using a 6.8µH inductor (e.g., Sumida CDRH4D28 or Würth WE-TPC). This is enabled by its 100ns minimum on-time, allowing stable 16VIN→3.3VOUT conversion at full frequency without duty-cycle limitation.
What is the purpose of the DA pin in LT3686AEDD#TRPBF, and how does it improve fault protection?
The DA pin in LT3686AEDD#TRPBF senses catch diode anode current and triggers frequency foldback when valley current exceeds 1.7A. This prevents inductor saturation and limits peak current during output short-circuits, especially at high input voltages - enhancing robustness beyond standard cycle-by-cycle current limit.
Is LT3686AEDD#TRPBF pin-compatible with LT3686EDD#TRPBF, and what are the key functional differences?
No, LT3686AEDD#TRPBF is not pin-compatible with LT3686EDD#TRPBF. The LT3686A adds BD-pin active load control and external synchronization capability via the SYNC/MODE pin - features absent in the base LT3686. These enhancements require distinct pin functionality and cannot be retrofitted without schematic and layout changes.
LT3686AEDD#TRPBF Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc.
- Series:
- -
- Package/Case:
- 10-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):
- 3.6V
- Voltage - Input (Max):
- 37V
- Voltage - Output (Min/Fixed):
- 0.8V
- Voltage - Output (Max):
- 37V
- Current - Output:
- 1.2A
- Frequency - Switching:
- 300kHz ~ 2.5MHz
- Synchronous Rectifier:
- No
- Operating Temperature:
- -40°C ~ 125°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 10-DFN (3x3)
LT3686AEDD#TRPBF FAQ
1.How can I place an order for LT3686AEDD#TRPBF through Aetrix?
Please submit a Request for Quotation (RFQ) for LT3686AEDD#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 LT3686AEDD#TRPBF reliable?
The price and inventory of LT3686AEDD#TRPBF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LT3686AEDD#TRPBF is usually 5 days.
3.What payment methods are accepted for LT3686AEDD#TRPBF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LT3686AEDD#TRPBF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LT3686AEDD#TRPBF?
LT3686AEDD#TRPBF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LT3686AEDD#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 LT3686AEDD#TRPBF?
For technical support, including LT3686AEDD#TRPBF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LT3686AEDD#TRPBF requirements.
6.How does Aetrix verify that LT3686AEDD#TRPBF is sourced from the original manufacturer or authorized distributors?
All LT3686AEDD#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 LT3686AEDD#TRPBF meets industry standards.
7.What is the process for return or replacement of LT3686AEDD#TRPBF?
All LT3686AEDD#TRPBF units undergo pre-shipment inspection (PSI). If there is an issue with LT3686AEDD#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 LT3686AEDD#TRPBF part is unused and in its original packaging.
Return procedure for LT3686AEDD#TRPBF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LT3686AEDD#TRPBF 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…
