My Inquiry
My Account
Analog Devices Inc. LT3663IDCB-3.3
- Part No.:
- LT3663IDCB-3.3
- Manufacturer:
- Analog Devices Inc.
- Package:
- 8-WFDFN Exposed Pad
- Datasheet:
-
LT3663IDCB-3.3.pdf
- Description:
- IC REG BUCK 3.3V 1.2A 8DFN
- Quantity:
- Payment:
- Shipping:
Inventory:3,230
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
LT3663IDCB-3.3 from Analog Devices (formerly Linear Technology) is a fixed 3.3V, 1.2A step-down switching regulator with programmable output current limit (0.4–1.2A), integrated boost diode, and internal compensation. It operates from 7.5V to 36V input (60V transient tolerant) and delivers regulated power in automotive battery regulation, industrial supplies, and wall transformer applications.
For engineers reviewing the LT3663IDCB-3.3 datasheet, LT3663IDCB-3.3 pinout, LT3663IDCB-3.3 application, or LT3663IDCB-3.3 equivalent, key selection criteria include its 1.5MHz fixed-frequency current-mode control, 275mV switch VCE(SAT) at 1A, thermal shutdown, and –40°C to 125°C operating junction temperature range.
Technical Context
The LT3663IDCB-3.3 implements constant-frequency peak current-mode control with internal slope compensation and an internally compensated error amplifier (G1) that regulates the FB pin to 0.8V. Its servo-based output current limit circuit compares ISENSE voltage against a reference set by RILIM, enabling precise average current limiting independent of load transients.
It integrates a bipolar NPN power switch driven via an internal boost stage (BOOST pin ≥2.3V above SW), eliminating external bootstrap components. Input protection includes undervoltage lockout (7.5V rising threshold) and overvoltage lockout (39V typical), allowing safe operation up to 60V nonrepetitive transients while maintaining shutdown state.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | Fixed 3.3V ±2% (3.234V–3.366V), eliminates external feedback divider |
| Max Output Current | 1.2A continuous, limited by internal current-sense amplifier and ILIM resistor programming |
| Input Voltage Range | 7.5V to 36V operating; withstands 60V nonrepetitive transients without damage |
| Switching Frequency | 1.5MHz typical, enables compact LC filter design with ≤4.7µH inductors |
| Switch VCE(SAT) | 275mV at 1A, reduces conduction loss and improves efficiency at high load currents |
| Junction Temp Range | –40°C to +125°C, qualified for automotive and industrial ambient environments |
| Thermal Resistance θJA | 64°C/W (DCB package), requires exposed pad soldered to PCB ground plane for thermal performance |
Pinout & Package
LT3663IDCB-3.3 is housed in an 8-lead (2mm × 3mm) plastic DFN package with exposed GND pad (Pin 9), optimized for low thermal resistance (θJA = 64°C/W). The exposed pad must be soldered to a PCB ground plane with thermal vias for reliable operation at full load.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| VIN | Power input supply | Accepts 7.5–36V; bypassed with ≥1µF ceramic capacitor; handles 60V transients in shutdown |
| RUN | Enable/shutdown control | Logic-high ≥2.5V enables regulation; logic-low ≤0.3V disables switching and reduces quiescent current to 0.01µA |
| FB | Feedback reference node | Internally regulated to 0.8V; unused in fixed-output LT3663IDCB-3.3 (no external divider required) |
| ILIM | Current limit programming | Resistor-to-GND sets output current limit (e.g., 28.7kΩ → 1.2A); enables system-level power dissipation control |
| BOOST | Internal switch gate drive boost | Connected to internal boost diode anode; requires ≥0.1µF capacitor to SW for NPN saturation |
| SW | Switch node | Drives external inductor and catch diode; high dv/dt node requiring short PCB trace and local ground loop |
| ISENSE | Current sense input | Positive terminal of internal current-sense resistor; also anode of internal boost diode |
| VOUT | Regulated output return | Negative terminal of internal current-sense resistor; connects to output capacitor negative terminal |
| GND (exposed pad) | Power and signal ground | Pins 1–8 reference this node; exposed pad (Pin 9) must be soldered to PCB ground for thermal and electrical integrity |
Key Features
| Feature | Design Value |
|---|---|
| Integrated boost diode | Eliminates external bootstrap diode, reducing BOM count and layout complexity in 3.3V+ outputs |
| Programmable current limit | 0.4A–1.2A via single ILIM resistor, enabling precise system-level power budgeting and component derating |
| Fixed-frequency current mode | 1.5MHz operation ensures predictable EMI profile and stable loop response without external compensation |
| Transient-tolerant input | Withstands 60V nonrepetitive transients while disabled, simplifying front-end protection in automotive and industrial 24V systems |
| Thermally enhanced DFN | 2mm × 3mm footprint with exposed GND pad supports 1.2A continuous output at +85°C ambient with proper PCB copper |
Applications
| Automotive Battery Regulation | Industrial 24V Supply Regulation |
|---|---|
Use Scenario: Regulating unfiltered 12V/24V vehicle battery rail (with load dump transients up to 60V) to power infotainment microcontrollers and CAN transceivers. IC Role / Device Role / Timing Role: Primary DC/DC step-down regulator providing stable 3.3V at up to 1.2A; monitors input overvoltage and shuts down safely during transients. Use Value: Eliminates need for external TVS or crowbar circuits due to 60V transient tolerance and internal OVP, reducing system cost and board area. | Use Scenario: Converting ruggedized 24V factory floor power to 3.3V for PLC I/O modules, sensor interfaces, and fieldbus controllers operating in –40°C to +85°C environments. IC Role / Device Role / Timing Role: Fixed-output buck converter with programmable current limit protecting downstream logic from overload faults. Use Value: Tight current limiting (±10%) prevents thermal runaway in sealed enclosures, enabling smaller heatsinks and longer MTBF. |
| Wall Adapter Power Conversion | Distributed Point-of-Load Regulation |
Use Scenario: Replacing linear regulators in universal-input AC/DC wall adapters (12V/24V nominal) powering USB peripherals, IoT gateways, and smart home hubs. IC Role / Device Role / Timing Role: High-efficiency (≥90% at 1A) switching regulator replacing inefficient LDOs, reducing heat generation and adapter size. Use Value: 1.5MHz switching allows use of tiny 4.7µH inductors and 22µF ceramic output capacitors, enabling ultra-compact adapter designs. | Use Scenario: Providing localized 3.3V power to FPGA I/O banks or high-speed ADCs on dense digital boards where remote 5V/12V rails are already present. IC Role / Device Role / Timing Role: Compact point-of-load regulator minimizing IR drop and noise coupling via short VIN–VOUT paths. Use Value: DFN package with exposed pad enables direct mounting under FPGA/ADC, improving thermal path and reducing thermal resistance by >30% vs. MSOP. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar step-down regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LT3663EDCB-3.3 | Same electrical specs and pinout; rated for 0°C to 125°C (vs. –40°C to 125°C for LT3663IDCB-3.3) | Not suitable for extended cold-start automotive or outdoor industrial use below 0°C | Select LT3663IDCB-3.3 when guaranteed operation at –40°C is required; otherwise LT3663EDCB-3.3 offers cost advantage |
| LT3663IMS8E-3.3 | Identical functionality in 8-lead MSOP package; θJA = 35°C/W (vs. 64°C/W), better thermal performance but larger footprint (3mm × 3mm) | Better suited for low-airflow, high-ambient-temperature environments where DFN thermal limits are exceeded | Choose LT3663IMS8E-3.3 when thermal headroom is constrained and PCB space permits larger package |
Compared with LT3663EDCB-3.3, the LT3663IDCB-3.3 guarantees full specification compliance down to –40°C, making it essential for cold-climate deployments; versus LT3663IMS8E-3.3, it trades thermal performance for 30% smaller footprint and lower profile-ideal for space-constrained consumer and portable designs.
Availability
LT3663IDCB-3.3 is available at Aetrix Electronics and suitable for automotive battery regulation, industrial 24V supply regulation, and wall transformer regulation requiring stable component supply across extended temperature ranges and long production lifecycles.
Supply support for LT3663IDCB-3.3 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 full product support, documentation, and manufacturing continuity for the LT3663 family.
The LT3663 product line was designed for high-reliability, wide-input-voltage step-down regulation in harsh environments-specifically targeting automotive, industrial, and telecom power systems where transient immunity and precise current limiting are critical.
FAQ
What is the guaranteed operating temperature range for LT3663IDCB-3.3?
The LT3663IDCB-3.3 is specified for operation from –40°C to +125°C junction temperature. This I-grade rating ensures full electrical performance compliance across automotive cold-cranking and industrial high-ambient scenarios, unlike the E-grade LT3663EDCB-3.3 which only guarantees 0°C minimum.
Does LT3663IDCB-3.3 require external compensation components?
No. The LT3663IDCB-3.3 features fully internal compensation, including pole-zero network on the VC node. No external capacitors or resistors are needed for loop stability-only input/output capacitors, inductor, catch diode, and optional ILIM resistor are required for basic operation.
Can LT3663IDCB-3.3 be used with input voltages above 36V?
Yes-LT3663IDCB-3.3 safely withstands nonrepetitive 60V transients on VIN while in shutdown mode. However, normal regulation is only guaranteed from 7.5V to 36V. Sustained operation above 36V will disable switching and discharge the output; external clamping is required for continuous >36V operation.
What is the purpose of the ILIM pin on LT3663IDCB-3.3?
The ILIM pin on LT3663IDCB-3.3 programs the output current limit from 0.4A to 1.2A using a single resistor to GND. This feature enables precise control of system power dissipation, protects external inductors and diodes during overload, and allows tighter thermal design margins without oversized passive components.
Is the BOOST capacitor mandatory for LT3663IDCB-3.3 operation?
Yes. A minimum 0.1µF ceramic capacitor between BOOST and SW is mandatory to generate sufficient gate drive voltage for the internal NPN switch. Without it, the switch cannot saturate, causing excessive conduction loss, thermal stress, and potential failure-even at light loads.
LT3663IDCB-3.3 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc.
- Series:
- -
- Package/Case:
- 8-WFDFN Exposed Pad
- Packaging:
- Tube
- Product Status:
- Obsolete
- Function:
- Step-Down
- Output Configuration:
- Positive
- Topology:
- Buck
- Output Type:
- Fixed
- Number of Outputs:
- 1
- Voltage - Input (Min):
- 7.5V
- Voltage - Input (Max):
- 36V
- Voltage - Output (Min/Fixed):
- 3.3V
- Voltage - Output (Max):
- -
- Current - Output:
- 1.2A
- Frequency - Switching:
- 1MHz
- Synchronous Rectifier:
- No
- Operating Temperature:
- -40°C ~ 125°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-DFN (2x3)
LT3663IDCB-3.3 FAQ
1.How can I place an order for LT3663IDCB-3.3 through Aetrix?
Please submit a Request for Quotation (RFQ) for LT3663IDCB-3.3 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 LT3663IDCB-3.3 reliable?
The price and inventory of LT3663IDCB-3.3 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LT3663IDCB-3.3 is usually 5 days.
3.What payment methods are accepted for LT3663IDCB-3.3?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LT3663IDCB-3.3 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LT3663IDCB-3.3?
LT3663IDCB-3.3 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LT3663IDCB-3.3 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 LT3663IDCB-3.3?
For technical support, including LT3663IDCB-3.3 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LT3663IDCB-3.3 requirements.
6.How does Aetrix verify that LT3663IDCB-3.3 is sourced from the original manufacturer or authorized distributors?
All LT3663IDCB-3.3 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 LT3663IDCB-3.3 meets industry standards.
7.What is the process for return or replacement of LT3663IDCB-3.3?
All LT3663IDCB-3.3 units undergo pre-shipment inspection (PSI). If there is an issue with LT3663IDCB-3.3, 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 LT3663IDCB-3.3 part is unused and in its original packaging.
Return procedure for LT3663IDCB-3.3:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LT3663IDCB-3.3 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…
