My Inquiry
My Account
Analog Devices Inc. LT1506IS8#PBF
- Part No.:
- LT1506IS8#PBF
- Manufacturer:
- Analog Devices Inc.
- Package:
- 8-SOIC (0.154", 3.90mm Width)
- Datasheet:
-
LT1506IS8#PBF.pdf
- Description:
- IC REG BUCK ADJ 4.5A 8SO
- Quantity:
- Payment:
- Shipping:
Inventory:2,823
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
LT1506IS8#PBF from Analog Devices (formerly Linear Technology) is a 500kHz monolithic buck switching regulator with integrated 4.5A NPN power switch, optimized for 4V–15V input and fixed 3.3V output. It features cycle-by-cycle current limiting, thermal shutdown, 0.07Ω switch on-resistance, 20µA shutdown current, and operates in current-mode control for fast transient response. Used in portable computers and battery-powered systems requiring compact, efficient DC/DC conversion.
For engineers reviewing the LT1506IS8#PBF datasheet, LT1506IS8#PBF pinout, LT1506IS8#PBF application, or LT1506IS8#PBF equivalent, key selection considerations include its fixed 3.3V SENSE-pin configuration, fused-GND SO-8 package, 500kHz ±40kHz switching frequency, 4.5A peak switch current limit, and compatibility with low-profile surface-mount inductors down to 1.8µH.
Technical Context
The LT1506IS8#PBF implements constant-frequency current-mode control using an internal 500kHz oscillator, error amplifier (2000 µMho transconductance), and peak-current comparator referenced to the VC pin. Its bipolar NPN switch is driven via BOOST pin voltage boosting to ensure saturation and low conduction loss.
It integrates undervoltage lockout (2.38V SHDN threshold), dual-mode shutdown (micropower at 0.4V), and foldback protection: switching frequency reduces below 1V FB/SENSE voltage and current limit decreases below 1.7V - both active during short-circuit conditions to limit power dissipation in IC and external components.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | Fixed 3.3V ±1.5% (SENSE pin directly connected to output) |
| Switching Frequency | 500kHz typical (460–540kHz over temp); synchronizable up to 1MHz |
| Peak Switch Current Limit | 4.5A at ≤50% duty cycle; derates nonlinearly to ~3.7A at 80% DC |
| Switch On Resistance | 0.07Ω typical (measured at 4.5A), enabling high efficiency with low VCE(sat) |
| Shutdown Supply Current | 20µA typical (15–50µA), enabling ultra-low quiescent power in standby |
| Input Voltage Range | 4.0V to 15V minimum-to-maximum; supports single-cell Li-ion and 5V rail inputs |
| Thermal Protection | Internal thermal shutdown with automatic recovery after junction cooldown |
Pinout & Package
The LT1506IS8#PBF is housed in an 8-lead plastic SOIC (SO-8) package with fused GND pin attached to internal tab for enhanced thermal performance. θJA = 80°C/W with standard PCB layout.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| VIN | Power switch collector & internal bias supply | Connects to input source; requires low-inductance bypass capacitor and catch diode placement adjacent to minimize dI/dt spikes |
| BOOST | Switch driver boost voltage input | Must be held ≥2.3V above VIN to saturate NPN switch; drives external boost capacitor/diode network |
| GND | Reference ground & thermal tab connection | Fused GND pin tied to internal tab; must connect to large copper area for thermal management and low-noise reference |
| VSW | Power switch emitter | Swings from near VIN (on) to –0.8V (off); drives inductor; negative swing clamped by external catch diode |
| SYNC | Oscillator synchronization input | Replaces SHDN on -SYNC variants; logic-compatible (10–90% duty cycle); enables external clock locking from 580kHz to 1MHz |
| VC | Error amplifier output / current limit comparator input | Used for loop compensation; also serves as current clamp point; floats between ~1V (light load) and ~2V (full load) |
| SENSE | Fixed-output voltage sense input | Direct connection to 3.3V output (replaces FB pin); sets regulation point and enables foldback protection |
Key Features
| Feature | Design Value |
|---|---|
| Current-mode topology | Enables fast transient response and stable loop compensation without external slope compensation networks |
| Integrated BOOST drive circuitry | Reduces switch VCE(sat) to ~0.3V at 4.5A, improving efficiency vs. conventional bipolar regulators |
| Programmable foldback protection | Automatically reduces switching frequency and peak current limit when SENSE voltage drops below 1.7V or 1.0V |
| Fused-GND SO-8 package | Provides low thermal resistance path to PCB copper plane while maintaining standard SO-8 footprint compatibility |
| Full-cycle short-circuit protection | Combines cycle-by-cycle current limiting with thermal shutdown to survive sustained output shorts |
Applications
| Portable Computers | Battery-Powered Systems |
|---|---|
Use Scenario: Powering core logic and I/O rails in sub-notebook and tablet platforms with constrained board space and thermal envelope. IC Role / Device Role / Timing Role: Primary 5V-to-3.3V step-down regulator delivering up to 4A continuous output with tight load regulation. Use Value: Enables use of small 1.8µH inductors and solid tantalum output capacitors, reducing solution size by >30% vs. legacy 300kHz converters. | Use Scenario: Regulating power for handheld test equipment, medical monitors, and portable instrumentation operating from single Li-ion cells. IC Role / Device Role / Timing Role: Main system regulator converting 4.2V–15V input to stable 3.3V for microcontrollers and sensors. Use Value: 20µA shutdown current extends battery life in sleep mode; wide 4V min input ensures operation down to nearly depleted cell voltage. |
| Battery Charger | Distributed Power |
Use Scenario: Providing isolated auxiliary 3.3V bias for charger controller ICs and status LEDs in multi-cell Li-ion charging modules. IC Role / Device Role / Timing Role: Secondary regulator powered from intermediate bus (e.g., 12V), delivering clean 3.3V with low EMI. Use Value: BOOST-driven saturated switch minimizes heat generation in sealed enclosures; fused-GND improves thermal reliability under continuous load. | Use Scenario: Local point-of-load regulation in industrial PLC backplanes and telecom line cards where multiple 3.3V domains require independent regulation. IC Role / Device Role / Timing Role: Compact, self-contained buck converter eliminating need for external MOSFET drivers or discrete controllers. Use Value: Synchronization capability allows multiple LT1506IS8#PBF units to operate at common frequency, simplifying EMI filtering across distributed rails. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar buck regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LTC3605EDE#PBF | 4A synchronous buck, 3MHz switching, integrated MOSFETs, no BOOST pin required | Higher efficiency at light loads; smaller inductor size; requires different compensation and layout | Preferred for new designs needing higher frequency, lower EMI, and synchronous rectification - but not pin-compatible |
| TPS54331DR | 3A non-synchronous buck, 570kHz, adjustable output, external BOOT capacitor | Lower current rating; requires external feedback divider; lacks foldback protection and fused-GND thermal design | Suitable for cost-sensitive, lower-current applications where thermal performance is less critical |
Compared with LTC3605EDE#PBF and TPS54331DR, the LT1506IS8#PBF delivers higher peak current (4.5A), superior thermal robustness via fused-GND SO-8, and unique foldback protection - making it optimal for ruggedized 3.3V systems where reliability under fault conditions is prioritized over ultra-small size or light-load efficiency.
Availability
LT1506IS8#PBF is available at Aetrix Electronics and suitable for portable computers, battery-powered systems, and distributed power applications requiring stable component supply, long-term lifecycle support, and guaranteed traceable sourcing.
Supply support for LT1506IS8#PBF 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 technical and manufacturing continuity for legacy Linear power products.
The LT1506 product line was designed specifically for high-current, low-input-voltage buck conversion in space-constrained portable and battery-operated equipment - emphasizing thermal resilience, fault tolerance, and minimal external component count.
FAQ
What is the function of the SENSE pin on the LT1506IS8#PBF?
The SENSE pin on the LT1506IS8#PBF replaces the FB pin found on adjustable versions and connects directly to the 3.3V output to provide fixed-voltage regulation. It also enables foldback protection: when SENSE voltage drops below 1.7V, the LT1506IS8#PBF reduces peak switch current limit, and below 1.0V, it lowers switching frequency to manage power dissipation during overload or short-circuit events.
Can the LT1506IS8#PBF synchronize to an external clock?
No - the LT1506IS8#PBF does not include a SYNC pin. It is the fixed-output, shutdown-capable variant (S8 package with SHDN pin). Synchronization is only available on -SYNC variants like LT1506IS8#PBF-SYNC (which replaces SHDN with SYNC). For LT1506IS8#PBF, the SHDN pin provides micropower disable functionality but cannot accept external timing signals.
What is the minimum input voltage required for the LT1506IS8#PBF to regulate 3.3V?
The LT1506IS8#PBF guarantees operation down to 4.0V input (typical 4.3V) while maintaining 3.3V regulation under full load. This minimum is defined by internal bias regulation stability - actual usable minimum depends on output current and inductor value. At 4A load with 1.8µH inductor, regulation holds down to ~4.2V across temperature per typical performance curves.
How does the BOOST pin improve efficiency in the LT1506IS8#PBF?
The BOOST pin on the LT1506IS8#PBF supplies a voltage ≥2.3V above VIN to the internal NPN switch driver, forcing deep saturation and reducing VCE(sat) to ~0.3V at 4.5A. This cuts conduction loss significantly versus standard bipolar designs (which exhibit ~1.5V drop), raising efficiency from ~75% to >89% at full load - a key advantage enabled by the external BOOST capacitor/diode network.
Is the LT1506IS8#PBF RoHS compliant and lead-free?
Yes - the "#PBF" suffix in LT1506IS8#PBF explicitly denotes lead-free (Pb-free) and RoHS-compliant packaging. The device uses matte tin lead finish, meets JEDEC J-STD-020 moisture sensitivity level 3, and is qualified for reflow soldering per IPC/JEDEC J-STD-020 standards.
LT1506IS8#PBF Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc.
- Series:
- -
- Package/Case:
- 8-SOIC (0.154", 3.90mm Width)
- Packaging:
- Tube
- 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):
- 15V
- Voltage - Output (Min/Fixed):
- 2.42V
- Voltage - Output (Max):
- 13.95V
- 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:
- 8-SO
LT1506IS8#PBF FAQ
1.How can I place an order for LT1506IS8#PBF through Aetrix?
Please submit a Request for Quotation (RFQ) for LT1506IS8#PBF 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 LT1506IS8#PBF reliable?
The price and inventory of LT1506IS8#PBF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LT1506IS8#PBF is usually 5 days.
3.What payment methods are accepted for LT1506IS8#PBF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LT1506IS8#PBF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LT1506IS8#PBF?
LT1506IS8#PBF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LT1506IS8#PBF 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 LT1506IS8#PBF?
For technical support, including LT1506IS8#PBF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LT1506IS8#PBF requirements.
6.How does Aetrix verify that LT1506IS8#PBF is sourced from the original manufacturer or authorized distributors?
All LT1506IS8#PBF 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 LT1506IS8#PBF meets industry standards.
7.What is the process for return or replacement of LT1506IS8#PBF?
All LT1506IS8#PBF units undergo pre-shipment inspection (PSI). If there is an issue with LT1506IS8#PBF, 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 LT1506IS8#PBF part is unused and in its original packaging.
Return procedure for LT1506IS8#PBF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LT1506IS8#PBF 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…
