My Inquiry
My Account
Analog Devices Inc. LT1507IN8-3.3#PBF
- Part No.:
- LT1507IN8-3.3#PBF
- Manufacturer:
- Analog Devices Inc.
- Package:
- 8-DIP (0.300", 7.62mm)
- Datasheet:
-
LT1507IN8-3.3#PBF.pdf
- Description:
- IC REG BUCK 3.3V 1.5A 8PDIP
- Quantity:
- Payment:
- Shipping:
Inventory:4,831
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
LT1507IN8-3.3#PBF from Analog Devices (formerly Linear Technology) is a fixed 3.3V, 500kHz monolithic buck switching regulator in an 8-pin PDIP package, featuring a 1.5A internal NPN power switch, 0.3Ω typical on-resistance, cycle-by-cycle current limiting, and thermal shutdown. It operates from 4V to 15V input and delivers up to 1.25A output with >85% efficiency at 5V→3.3V conversion in portable computing power rails.
For engineers reviewing the LT1507IN8-3.3#PBF datasheet, LT1507IN8-3.3#PBF pinout, LT1507IN8-3.3#PBF application, or LT1507IN8-3.3#PBF equivalent, key selection criteria include its fixed 3.3V output, -40°C to 85°C industrial temperature grade, 20µA shutdown current, BOOST pin–enabled saturated switch architecture, and compatibility with standard surface-mount inductors as small as 2µH.
Technical Context
The LT1507IN8-3.3#PBF implements current-mode control with a 500kHz fixed-frequency oscillator and dual feedback loops: one for voltage regulation via the SENSE pin (internally biased to 3.3V), and another for cycle-by-cycle peak current sensing. Its bipolar NPN switch uses BOOST pin–driven saturation to achieve low conduction loss (0.3Ω typical), enabling high efficiency without requiring external MOSFET drivers.
It integrates undervoltage lockout (2.38V threshold on SHDN), foldback current limiting below 1.5V SENSE voltage, and frequency reduction below 1V SENSE voltage-features critical for short-circuit protection in battery-powered systems. The VC pin serves as both error amplifier output and current limit reference, supporting external compensation and loop override.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | Fixed 3.3V ±1.5% (3.25V–3.35V), internally trimmed-no external resistor divider required. |
| Switching Frequency | 500kHz ±8% (460–540kHz), constant-frequency operation enables predictable EMI filtering and small external LC components. |
| Max Output Current | 1.25A continuous at VIN = 5V, limited by thermal design and inductor saturation-not the 1.5A switch rating alone. |
| Input Voltage Range | 4V to 15V-supports single-cell Li-ion (4.2V max) and multi-cell alkaline/NiMH inputs without pre-regulation. |
| Shutdown Current | 20µA typical (15–50µA), enabling ultra-low-power sleep modes in portable devices. |
| Switch On-Resistance | 0.3Ω typical (0.4Ω max), achieved via BOOST pin–assisted saturation-reduces conduction loss vs. conventional bipolar designs. |
| Thermal Shutdown | Active at TJ ≥ 125°C with hysteresis-prevents permanent damage during sustained overload or poor PCB heatsinking. |
Pinout & Package
LT1507IN8-3.3#PBF is housed in an 8-lead plastic DIP (N8) package with through-hole mounting, rated for industrial temperature range (–40°C to +85°C). Pin spacing is 0.300", body width 0.355", and lead finish is matte tin over nickel.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1 - BOOST | Boost capacitor drive node | Provides elevated gate drive to saturate internal NPN switch; requires external diode + capacitor (e.g., 1N914 + 3.3nF) to achieve 0.3Ω RON. |
| 2 - VIN | Main power input | Accepts 4V–15V DC; supplies bias and switch current; must be bypassed with low-ESR capacitor near pin. |
| 3 - VSW | Switch collector node | Drives external catch diode (e.g., 1N5818); swings from VIN to ~–0.7V (clamped by diode); not internally clamped. |
| 4 - SHDN | Enable/disable control | Logic-compatible input: >2.38V = normal operation; <0.4V = micropower shutdown (20µA IQ). |
| 5 - SYNC | External clock synchronization | Accepts 580kHz–1MHz logic-level signal; allows EMI reduction via frequency dithering or system-wide clock alignment. |
| 6 - GND | Analog/digital ground reference | Single ground plane connection point; must tie all grounds (VIN, BOOST, SENSE, VC) here to minimize noise coupling. |
| 7 - SENSE | Output voltage sense input | Internally connected to 3.3V output; monitors regulation accuracy and triggers foldback protection if voltage drops below 1.5V. |
| 8 - VC | Error amplifier output / current limit reference | DC voltage (1V–2V) sets peak switch current; used for compensation (type II/III), current clamp, or external override. |
Key Features
| Feature | Design Value |
|---|---|
| Saturated NPN switch architecture | Enables 0.3Ω RON and >85% efficiency at 1.25A, eliminating need for external MOSFET drivers or complex gate drive circuits. |
| Integrated cycle-by-cycle current limiting | Prevents switch destruction during output shorts or startup surges without external current-sense resistors or protection ICs. |
| Two-threshold shutdown pin | Combines precise UVLO (2.38V) and deep shutdown (0.4V) in one pin-simplifies power sequencing and battery monitoring. |
| Frequency foldback under fault | Reduces switching frequency 5:1 when SENSE < 1V, lowering power dissipation in IC, diode, and inductor during sustained short-circuit conditions. |
| Industrial temperature grade | Rated for –40°C to +85°C ambient operation-suitable for automotive cabin electronics, industrial controllers, and outdoor IoT nodes. |
Applications
| Portable Computing Power | Battery-Powered Instrumentation |
|---|---|
Use Scenario: Regulating 5V USB or Li-ion battery (4.2V) down to clean 3.3V for microcontroller cores, FPGAs, and ADCs in handheld test equipment. IC Role / Device Role / Timing Role: Primary DC-DC step-down converter delivering stable 3.3V rail with fast transient response and low quiescent current. Use Value: Enables >10-hour runtime on 2000mAh battery due to 20µA shutdown current and >85% efficiency across 0.1–1.25A load range. | Use Scenario: Powering precision analog front-ends (op-amps, references, sensors) in field-deployed environmental monitors. IC Role / Device Role / Timing Role: Low-noise, thermally robust 3.3V supply with built-in short-circuit foldback to survive sensor cable faults. Use Value: Eliminates need for external current-limiting circuitry while maintaining regulation accuracy within ±1.5% over –40°C to +85°C. |
| Distributed Power Architecture | Battery Charger Auxiliary Rail |
Use Scenario: Generating local 3.3V bias for isolated communication interfaces (RS-485, CAN transceivers) in multi-board industrial PLC backplanes. IC Role / Device Role / Timing Role: Point-of-load regulator with SYNC pin support for synchronized switching across multiple rails to reduce conducted EMI. Use Value: Allows EMI filter size reduction by 30% via 500kHz fixed frequency and external synchronization capability. | Use Scenario: Providing regulated 3.3V for charger management MCU, LED indicators, and status reporting circuitry in wall-mounted Li-ion chargers. IC Role / Device Role / Timing Role: Secondary supply derived from main charging bus (5–12V), operating continuously during charge cycles. Use Value: Withstands input transients up to 16V and maintains regulation during AC line dropout thanks to 4V minimum input voltage. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar buck regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LTC3621EDD-3.3#TRMPBF | 4MHz synchronous buck, 1.2A, integrated MOSFETs, 2.5µA quiescent current-higher efficiency but requires different layout and no BOOST pin. | Best for space-constrained, high-efficiency apps where PCB area is premium; not drop-in due to different pinout and control scheme. | Select LTC3621EDD-3.3#TRMPBF only when upgrading to synchronous topology and accepting redesign effort for 3× smaller inductor. |
| TPS54331DR | 3.5MHz adjustable buck, 3A, integrated FETs, 4.5–28V input-wider VIN range but fixed 3.3V version requires external resistors. | Suitable for higher-input-voltage systems (e.g., 12V automotive) needing 3.3V at >1.25A; lacks thermal shutdown hysteresis and foldback behavior of LT1507IN8-3.3#PBF. | Choose TPS54331DR when input exceeds 15V or output current demand exceeds 1.25A, accepting trade-offs in fault protection sophistication. |
Compared with LTC3621EDD-3.3#TRMPBF and TPS54331DR, the LT1507IN8-3.3#PBF offers superior short-circuit survivability via foldback current limiting and frequency reduction, simpler external component count (no bootstrap capacitor), and proven reliability in legacy industrial designs-but at lower switching frequency and higher quiescent current than modern alternatives.
Availability
LT1507IN8-3.3#PBF is available at Aetrix Electronics and suitable for portable computing power, battery-powered instrumentation, distributed power architecture, and battery charger auxiliary rail applications requiring stable component supply, long-term lifecycle support, and industrial-grade temperature performance.
Supply support for LT1507IN8-3.3#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, Inc. (ADI) is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, formed through the acquisition of Linear Technology in 2017.
The LT1507 product line was developed by Linear Technology specifically for compact, efficient, and robust non-synchronous buck conversion in cost-sensitive industrial and portable applications-emphasizing simplicity, thermal resilience, and intrinsic fault protection without external components.
FAQ
What is the maximum continuous output current of the LT1507IN8-3.3#PBF?
The LT1507IN8-3.3#PBF delivers up to 1.25A continuous output current under typical conditions (VIN = 5V, TA = 25°C, proper PCB thermal relief). This is less than its 1.5A switch rating due to thermal limits and inductor saturation constraints. At higher ambient temperatures or with inadequate copper area, derating is required-e.g., 0.9A at 85°C ambient per the thermal resistance θJA = 120°C/W specification.
Does the LT1507IN8-3.3#PBF require an external feedback resistor divider?
No, the LT1507IN8-3.3#PBF does not require an external feedback resistor divider. It is the fixed-output variant with internal resistor network trimmed to 3.3V, and pin 7 is labeled SENSE-not FB-to indicate direct connection to the output. External resistors are only needed for adjustable versions like LT1507IN8.
How does the BOOST pin function in the LT1507IN8-3.3#PBF?
The BOOST pin (pin 1) in the LT1507IN8-3.3#PBF provides an elevated drive voltage to the base of the internal NPN power switch, enabling saturation and reducing on-resistance to 0.3Ω typical. It requires an external charge pump: a Schottky diode (e.g., 1N914) and capacitor (e.g., 3.3nF) connected between BOOST and VSW. Without this, efficiency drops significantly due to higher VCE(sat).
Can the LT1507IN8-3.3#PBF be synchronized to an external clock?
Yes, the LT1507IN8-3.3#PBF supports external synchronization via its SYNC pin (pin 5). It accepts logic-level signals from 580kHz to 1MHz with 10–90% duty cycle, allowing EMI reduction through frequency alignment or spread-spectrum techniques. No level-shifting is required-the pin is TTL/CMOS compatible.
What protection features are built into the LT1507IN8-3.3#PBF?
The LT1507IN8-3.3#PBF includes full cycle-by-cycle current limiting, thermal shutdown (125°C junction), undervoltage lockout (2.38V on SHDN), foldback current limiting below 1.5V SENSE voltage, and frequency foldback below 1V SENSE voltage. These operate autonomously without external components, providing robust fault tolerance in unattended or harsh-environment deployments.
LT1507IN8-3.3#PBF Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc.
- Series:
- -
- Package/Case:
- 8-DIP (0.300", 7.62mm)
- Packaging:
- Tube
- 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):
- 16V
- Voltage - Output (Min/Fixed):
- 3.3V
- Voltage - Output (Max):
- -
- Current - Output:
- 1.5A
- Frequency - Switching:
- 500kHz
- Synchronous Rectifier:
- No
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- 8-PDIP
LT1507IN8-3.3#PBF FAQ
1.How can I place an order for LT1507IN8-3.3#PBF through Aetrix?
Please submit a Request for Quotation (RFQ) for LT1507IN8-3.3#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 LT1507IN8-3.3#PBF reliable?
The price and inventory of LT1507IN8-3.3#PBF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LT1507IN8-3.3#PBF is usually 5 days.
3.What payment methods are accepted for LT1507IN8-3.3#PBF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LT1507IN8-3.3#PBF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LT1507IN8-3.3#PBF?
LT1507IN8-3.3#PBF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LT1507IN8-3.3#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 LT1507IN8-3.3#PBF?
For technical support, including LT1507IN8-3.3#PBF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LT1507IN8-3.3#PBF requirements.
6.How does Aetrix verify that LT1507IN8-3.3#PBF is sourced from the original manufacturer or authorized distributors?
All LT1507IN8-3.3#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 LT1507IN8-3.3#PBF meets industry standards.
7.What is the process for return or replacement of LT1507IN8-3.3#PBF?
All LT1507IN8-3.3#PBF units undergo pre-shipment inspection (PSI). If there is an issue with LT1507IN8-3.3#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 LT1507IN8-3.3#PBF part is unused and in its original packaging.
Return procedure for LT1507IN8-3.3#PBF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LT1507IN8-3.3#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…
