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Analog Devices Inc. LT1506IR-3.3SYNC#TRPBF
- Part No.:
- LT1506IR-3.3SYNC#TRPBF
- Manufacturer:
- Analog Devices Inc.
- Package:
- TO-263-8, D2PAK (7 Leads + Tab), TO-263CA
- Datasheet:
-
LT1506IR-3.3SYNC#TRPBF.pdf
- Description:
- IC REG BUCK 3.3V 4.5A DDPAK-7
- Quantity:
- Payment:
- Shipping:
Inventory:1,451
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Product details
Overview
LT1506IR-3.3SYNC#TRPBF from Analog Devices (formerly Linear Technology) is a 4.5A, 500kHz fixed-output synchronous buck switching regulator in SO-8 package with integrated 0.07Ω NPN power switch, 3.3V output, and SYNC pin for external clock synchronization up to 1MHz. It operates from 4V to 15V input, delivers up to 4A continuous load current at 3.3V, and features cycle-by-cycle current limiting and thermal shutdown - used in portable computers and battery-powered systems requiring compact, efficient DC/DC conversion.
For engineers reviewing the LT1506IR-3.3SYNC#TRPBF datasheet, LT1506IR-3.3SYNC#TRPBF pinout, LT1506IR-3.3SYNC#TRPBF application, or LT1506IR-3.3SYNC#TRPBF equivalent, key selection considerations include its fixed 3.3V SENSE-pin interface, 500kHz nominal switching frequency (synchronizable to 1MHz), 4.5A switch current limit, 4V minimum input voltage, and SO-8 fused-ground package with GND-connected tab for thermal management.
Technical Context
The LT1506IR-3.3SYNC#TRPBF implements constant-frequency current-mode control using an internal 500kHz oscillator and peak-current sensing via the SENSE pin. Its bipolar NPN switch is driven by a BOOST pin that supplies >VIN voltage to saturate the transistor, achieving low 0.07Ω on-resistance and high efficiency (>89% at 5V→3.3V/4A).
Synchronization replaces the SHDN function: the SYNC pin accepts logic-level signals (10–90% duty cycle) to lock the oscillator between 580kHz and 1MHz. The device includes dual-threshold shutdown (0.4V full micropower, 2.38V UVLO), slope compensation for stability at >50% duty cycle, and foldback protection reducing frequency and current limit under short-circuit conditions.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | Fixed 3.3V ±1.5% (SENSE pin tied directly to output; no external divider required) |
| Switch Current Limit | 4.5A typical (guaranteed ≥4.5A up to 50% duty cycle; derates nonlinearly above) |
| Switch On Resistance | 0.07Ω typical (enables high efficiency with minimal conduction loss at full load) |
| Switching Frequency | 500kHz nominal (adjustable 580kHz–1MHz via SYNC pin; line regulation ≤0.15%/V) |
| Input Voltage Range | 4.0V to 15V (minimum 4.0V guaranteed; supports single-cell Li-ion and 5V rail inputs) |
| Shutdown Current | ≤50µA (at VSHDN = 0V; drops to few µA after lockout at 2.38V threshold) |
| Thermal Shutdown | Active at TJ ≥125°C (with hysteresis; SO-8 package θJA = 80°C/W with fused GND) |
Pinout & Package
LT1506IR-3.3SYNC#TRPBF is housed in an 8-lead plastic SO package with fused GND pin connected to internal tab for enhanced thermal dissipation. The GND pin must be soldered to a large copper area to maintain junction temperature within limits during 4A operation.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| VIN | Power switch collector & IC supply input | Connects to input source (4–15V); carries high dI/dt; requires local bypass capacitor and catch diode placement |
| BOOST | Switch drive voltage boost node | Must be held ≥VIN + 2.3V (min) via external capacitor/diode to saturate NPN switch and achieve 0.07Ω RON |
| GND | Reference ground & thermal path | Fused pin tied to internal tab; must connect to large PCB copper area for θJA = 80°C/W; critical for load regulation and EMI control |
| VSW | Switch emitter node | Drives inductor; swings from ~0V to VIN during operation; clamped negative to –0.8V by external catch diode |
| SYNC | External clock synchronization input | Replaces SHDN pin; logic-compatible (1.5–2.2V threshold); enables 580kHz–1MHz frequency locking without layout changes |
| VC | Error amplifier output / current comparator input | Used for loop compensation; also serves as current clamp point (0.9V switch threshold, 2.1V upper clamp) |
| SENSE | Fixed-output voltage feedback | Direct connection to 3.3V output; replaces FB pin; sets regulation point at 3.3V ±1.5% (3.25–3.35V) |
| NC | No-connect (pin 1) | Unused terminal; left unconnected per datasheet; not internally bonded |
Key Features
| Feature | Design Value |
|---|---|
| Integrated 4.5A NPN power switch | Eliminates external MOSFET; reduces BOM count and layout area while maintaining 0.07Ω conduction loss |
| BOOST-driven saturation architecture | Enables bipolar switch efficiency >89% at 5V→3.3V/4A - matching FET-based regulators without die size penalty |
| Current-mode control with slope compensation | Ensures stable operation across 0–93% duty cycle range; prevents subharmonic oscillation without external components |
| Programmable synchronization (580kHz–1MHz) | Allows noise-sensitive systems to avoid EMI bands or align multiple converters without changing component values |
| Short-circuit foldback protection | Reduces switching frequency and peak current when SENSE voltage drops below 1V, limiting power dissipation in IC and external components |
Applications
| Portable Computers | Battery-Powered Systems |
|---|---|
Use Scenario: Core voltage regulation for low-power microcontrollers and I/O peripherals in clamshell notebooks and 2-in-1 devices. IC Role / Device Role / Timing Role: Primary 3.3V buck converter supplying SoC subsystems; operates from single-cell Li-ion (3.0–4.2V) or 5V USB-C PD rail. Use Value: Enables 4A output with <4.5V minimum input - supporting deep discharge operation while maintaining regulation through battery sag. | Use Scenario: Power management in handheld test equipment, portable medical monitors, and ruggedized field instruments. IC Role / Device Role / Timing Role: Main system regulator delivering 3.3V to mixed-signal ADCs, RF front-ends, and display controllers from primary battery or backup cell. Use Value: 20µA shutdown current extends battery life during sleep; SYNC pin allows coordinated power sequencing with other rails. |
| Battery Charger | Distributed Power |
Use Scenario: Auxiliary 3.3V rail generation in multi-bay smart chargers for Li-ion/LiPo packs. IC Role / Device Role / Timing Role: Powers charger controller MCU, status LEDs, and communication interfaces (I²C/UART) independently of main charging path. Use Value: Fixed 3.3V SENSE interface eliminates resistor network errors; thermal shutdown protects against enclosure overheating during simultaneous charging cycles. | Use Scenario: Point-of-load (POL) conversion in industrial PLC backplanes and telecom line cards with distributed 5V/12V intermediate buses. IC Role / Device Role / Timing Role: Local 3.3V regulator for FPGA configuration, memory buffers, and sensor interfaces; synchronized to system clock to reduce beat frequencies. Use Value: SO-8 fused-GND package provides robust thermal performance on dense boards; 500kHz base frequency minimizes filter component size vs. lower-frequency alternatives. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar buck regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LTC3605EDE-3.3#TRPBF | 4A monolithic synchronous buck; 3MHz switching; integrated MOSFETs; 2.5–5.5V input | Requires higher minimum input (2.5V); optimized for ultra-small footprint, not wide-input industrial use | Select for space-constrained designs needing >1MHz operation; not suitable for 4–15V input range or legacy SO-8 layouts |
| TPS54331DR | 3A adjustable-output buck; 570kHz; external MOSFET drivers; 3.5–28V input | Lower current rating; requires external high-side/low-side FETs; no integrated switch | Choose when input exceeds 15V or when design requires programmable output; lacks fixed 3.3V SENSE simplicity |
Compared with LTC3605EDE-3.3#TRPBF and TPS54331DR, the LT1506IR-3.3SYNC#TRPBF uniquely combines 4.5A integrated bipolar switch, 4V–15V input range, fixed 3.3V SENSE interface, and SO-8 thermal package - making it optimal for cost-sensitive, thermally demanding 3.3V POL applications where input voltage spans battery and adapter sources.
Availability
LT1506IR-3.3SYNC#TRPBF is available at Aetrix Electronics and suitable for portable computers, battery-powered systems, and distributed power applications requiring stable component supply, long-term industrial lifecycle support, and consistent parametric performance across temperature.
Supply support for LT1506IR-3.3SYNC#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) is a global leader in high-performance analog, mixed-signal, and power management semiconductors, serving precision instrumentation, industrial automation, and communications markets.
The LT1506 product line was designed for high-efficiency, wide-input-range DC/DC conversion in space- and thermal-constrained applications - emphasizing integrated bipolar switch architecture, synchronization capability, and robust protection for battery-fed and distributed power systems.
FAQ
What is the minimum input voltage required for stable operation of the LT1506IR-3.3SYNC#TRPBF?
The LT1506IR-3.3SYNC#TRPBF guarantees stable regulation down to 4.0V input (typical 4.3V), validated across temperature and load. This enables direct operation from partially discharged single-cell Li-ion batteries (≥3.6V) when paired with appropriate inductor sizing and BOOST capacitor voltage margin. Operation below 4.0V may cause undervoltage lockout activation at the 2.38V threshold on the VC pin.
How does the SYNC pin function differ from the SHDN pin in the LT1506IR-3.3SYNC#TRPBF?
In the LT1506IR-3.3SYNC#TRPBF, the SYNC pin replaces the SHDN pin found on non-SYNC variants. It accepts logic-level signals (1.5–2.2V threshold) to synchronize the internal oscillator from 580kHz to 1MHz - enabling EMI reduction and multi-rail coordination. Unlike SHDN, it provides no shutdown capability; full micropower mode requires grounding SYNC and disabling the oscillator externally if needed.
Can the LT1506IR-3.3SYNC#TRPBF be used with ceramic output capacitors?
Yes, the LT1506IR-3.3SYNC#TRPBF supports ceramic output capacitors, but ESR must be ≥0.05Ω to ensure loop stability. Low-ESR ceramics (<0.03Ω) may cause instability due to reduced phase margin in the current-mode control loop. Recommended solutions include adding a small series RC network (e.g., 0.1Ω + 10nF) or selecting tantalum capacitors (e.g., AVX TPS series, 0.1Ω max ESR) as specified in the datasheet for reliable 500kHz operation.
What thermal derating applies to the LT1506IR-3.3SYNC#TRPBF at 4A load current?
At 4A continuous load with 5V input and 3.3V output, the LT1506IR-3.3SYNC#TRPBF dissipates ~0.7W. With the SO-8 fused-GND package (θJA = 80°C/W) on a standard 1oz copper board, this yields ~56°C rise above ambient. To maintain TJ ≤125°C, ambient must stay ≤69°C. For higher ambient, increase copper area under the GND tab or add airflow - thermal shutdown activates at 125°C with hysteresis.
Is the LT1506IR-3.3SYNC#TRPBF pin-compatible with other LT1506 variants like LT1506IR-3.3#TRPBF?
No - the LT1506IR-3.3SYNC#TRPBF is not pin-compatible with LT1506IR-3.3#TRPBF. The SYNC variant replaces SHDN (pin 6) with SYNC functionality and reassigns pin functions accordingly. Pin 6 is SYNC (not SHDN), and pin 1 is NC (not FB). Layouts designed for -3.3#TRPBF require modification to accommodate the different pin mapping and absence of shutdown control.
LT1506IR-3.3SYNC#TRPBF Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc.
- Series:
- -
- Package/Case:
- TO-263-8, D2PAK (7 Leads + Tab), TO-263CA
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Function:
- Step-Down
- Output Configuration:
- Positive
- Topology:
- Buck
- Output Type:
- Fixed
- Number of Outputs:
- 1
- Voltage - Input (Min):
- 4V
- Voltage - Input (Max):
- 15V
- Voltage - Output (Min/Fixed):
- 3.3V
- Voltage - Output (Max):
- -
- Current - Output:
- 4.5A
- Frequency - Switching:
- 500kHz
- Synchronous Rectifier:
- No
- Operating Temperature:
- -40°C ~ 125°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- DDPAK-7
LT1506IR-3.3SYNC#TRPBF FAQ
1.How can I place an order for LT1506IR-3.3SYNC#TRPBF through Aetrix?
Please submit a Request for Quotation (RFQ) for LT1506IR-3.3SYNC#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 LT1506IR-3.3SYNC#TRPBF reliable?
The price and inventory of LT1506IR-3.3SYNC#TRPBF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LT1506IR-3.3SYNC#TRPBF is usually 5 days.
3.What payment methods are accepted for LT1506IR-3.3SYNC#TRPBF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LT1506IR-3.3SYNC#TRPBF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LT1506IR-3.3SYNC#TRPBF?
LT1506IR-3.3SYNC#TRPBF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LT1506IR-3.3SYNC#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 LT1506IR-3.3SYNC#TRPBF?
For technical support, including LT1506IR-3.3SYNC#TRPBF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LT1506IR-3.3SYNC#TRPBF requirements.
6.How does Aetrix verify that LT1506IR-3.3SYNC#TRPBF is sourced from the original manufacturer or authorized distributors?
All LT1506IR-3.3SYNC#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 LT1506IR-3.3SYNC#TRPBF meets industry standards.
7.What is the process for return or replacement of LT1506IR-3.3SYNC#TRPBF?
All LT1506IR-3.3SYNC#TRPBF units undergo pre-shipment inspection (PSI). If there is an issue with LT1506IR-3.3SYNC#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 LT1506IR-3.3SYNC#TRPBF part is unused and in its original packaging.
Return procedure for LT1506IR-3.3SYNC#TRPBF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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