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Analog Devices Inc. LT1269CSW#PBF
- Part No.:
- LT1269CSW#PBF
- Manufacturer:
- Analog Devices Inc.
- Package:
- 20-SOIC (0.295", 7.50mm Width)
- Datasheet:
-
LT1269CSW#PBF.pdf
- Description:
- IC REG BUCK BOOST ADJ 4A 20SO
- Quantity:
- Payment:
- Shipping:
Inventory:3,232
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Product details
Overview
LT1269CSW#PBF from Analog Devices (formerly Linear Technology) is a monolithic 100kHz, 4A high-efficiency switching regulator IC in a 20-lead wide SOIC package. It integrates a high-current power switch, oscillator, current-mode control, and thermal/overcurrent protection. Designed for buck, boost, flyback, and inverting topologies, it delivers up to ~15W output power (e.g., 5V/3A) with ~90% efficiency at mid-load in boost mode.
For engineers reviewing the LT1269CSW#PBF datasheet, LT1269CSW#PBF pinout, LT1269CSW#PBF application, or LT1269CSW#PBF equivalent, key selection criteria include its 100kHz switching frequency, 4A internal switch current limit, 3.5V–30V input range, 1.244V feedback reference, and flyback-capable floating output configuration - all critical for PC power supplies, battery up-converters, and multi-rail embedded systems.
Technical Context
The LT1269CSW#PBF employs current-mode PWM control with adaptive anti-saturation gate drive, enabling stable operation across wide load ranges without efficiency loss. Its error amplifier features 4400 µmho transconductance and 800 V/V voltage gain, supporting precise regulation under dynamic line/load conditions.
It supports external synchronization (per LT1072 datasheet), shutdown mode with 100µA quiescent current, and flyback-regulated mode with fully floating outputs. The device includes built-in overcurrent protection, thermal shutdown, and 60V switch breakdown voltage - enabling robust operation in noisy industrial environments.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Switching Frequency | 100kHz typical - enables compact magnetics and low EMI in space-constrained designs. |
| Internal Switch Current Limit | 4A typical at 50% duty cycle - supports ≥3A continuous output in buck mode with proper heatsinking. |
| Input Voltage Range | 3.5V to 30V - accommodates 5V, 12V, and 24V rails, including automotive and industrial inputs. |
| Feedback Reference Voltage | 1.244V ±20mV - sets output voltage via resistor divider; enables accurate 3.3V, 5V, or 12V regulation. |
| Quiescent Supply Current | 7mA typical - minimizes no-load power loss in always-on systems. |
| Shutdown Current | 100µA typical - enables ultra-low-power standby in battery-powered applications. |
| Switch "On" Resistance | 0.33Ω typical - reduces conduction loss and improves efficiency at high load currents. |
| Max Output Switch Voltage | 60V - allows safe operation in boost/flyback configurations with reflected voltages ≤60V. |
Pinout & Package
LT1269CSW#PBF is housed in a 20-lead plastic wide SOIC (SW) package (0.300" body width), optimized for thermal performance on PCBs with ground plane copper. Pin 1 is marked by notch or cavity per JEDEC MS-013.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| VIN | Power Input | Connects to unregulated DC input (3.5V–30V); requires local 1µF ceramic bypass capacitor. |
| VSW | Switch Output | Drives external inductor/diode; connects to drain of internal N-channel MOSFET switch. |
| GND | Power Ground | Common return for input capacitor, output rectifier, and control circuitry; multiple pins (pins 4,5,6,7,14,15,16) reduce ground impedance. |
| FB | Feedback Input | Senses output voltage via resistor divider; regulates output to 1.244V reference at this pin. |
| VC | Control Voltage | Output of error amplifier; used for loop compensation and external current limiting. |
| NC | No Connect | Pins 3, 11, 12, 13, 17, 18, 19 are internally unused; must remain unconnected. |
Key Features
| Feature | Design Value |
|---|---|
| Integrated 4A Power Switch | Eliminates external MOSFET and driver, reducing BOM count and layout complexity in buck/boost converters. |
| Flyback-Regulated Mode Support | Enables fully floating secondary outputs without optocoupler or auxiliary winding - ideal for isolated dual-rail supplies. |
| Current-Mode Control Architecture | Provides inherent cycle-by-cycle current limiting and excellent transient response to load steps. |
| Adaptive Anti-Saturation Drive | Maintains high efficiency across 0.1A–3A load range by dynamically optimizing gate drive timing. |
| External Synchronization Capability | Allows phase alignment with system clock or other regulators to suppress beat frequencies and simplify EMI filtering. |
| Self-Protected Operation | Includes thermal shutdown, overcurrent foldback, and 60V switch rating - enables "bust-proof" operation like linear regulators. |
Applications
| PC Power Supply with Multiple Outputs | Battery Up-Converter |
|---|---|
Use Scenario: Generating +5V, +12V, and –12V rails from a single 12V ATX-compatible source in desktop or embedded computing platforms. IC Role / Device Role / Timing Role: Primary controller in flyback topology, regulating isolated secondary windings via direct feedback sensing. Use Value: Achieves >85% efficiency at full load while eliminating optocouplers and TL431 references - reducing cost and component count. | Use Scenario: Boosting 3.7V Li-ion battery voltage to 5V/3A USB power delivery in portable test equipment or handheld instruments. IC Role / Device Role / Timing Role: High-current boost converter controller with integrated 4A switch and 100kHz fixed-frequency operation. Use Value: Delivers stable 5V output down to 3.5V battery input, with <0.3V dropout during pulse loads due to low RDS(on) and fast current-mode control. |
| Negative-to-Positive Converter | High Efficiency Buck Converter |
Use Scenario: Converting –12V rail to +5V/1.5A for analog front-end circuitry in industrial data acquisition modules. IC Role / Device Role / Timing Role: Inverting buck-boost controller operating in flyback-regulated mode with floating feedback path. Use Value: Provides galvanically isolated +5V output without transformer center-tap or additional isolation components - simplifying transformer design. | Use Scenario: Stepping down 24V industrial bus to 5V/3A for microcontroller and sensor subsystems in factory automation controllers. IC Role / Device Role / Timing Role: Synchronous-capable buck regulator controller driving external high-side MOSFET (with external low-side diode or FET). Use Value: Supports >90% peak efficiency at 1.5A with minimal external parts - only one inductor, two capacitors, and one diode required. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar switching regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LT1374CN8#PBF | 500kHz switching frequency, 4.5A switch, SO-8 package, VIN ≤ 25V. | Better suited for high-density, low-inductance designs; not flyback-capable. | Select when board space is constrained and flyback isolation is unnecessary. |
| LT1271CT#PBF | 60kHz frequency, TO-220-5 package, identical pinout but lower frequency and higher thermal resistance (θJA = 50°C/W). | Preferred for high-reliability through-hole assembly and higher ambient temperature environments. | Select when mechanical robustness and manual reworkability outweigh surface-mount density requirements. |
Compared with LT1269CSW#PBF, LT1374CN8#PBF offers higher frequency and smaller magnetics but lacks flyback support and has lower max input voltage; LT1271CT#PBF provides identical topology flexibility in a thermally superior through-hole package but requires larger PCB area and delivers lower power density.
Availability
LT1269CSW#PBF is available at Aetrix Electronics and suitable for PC power supplies, battery-powered instrumentation, industrial embedded controllers, and isolated DC-DC converters requiring stable component supply and long-term manufacturability.
Supply support for LT1269CSW#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. (acquired Linear Technology in 2017) is a global leader in high-performance analog, mixed-signal, and power management semiconductors.
The LT1269 belongs to Linear's legacy high-power monolithic switching regulator family, designed specifically for robust, low-component-count DC-DC conversion in industrial, computing, and test equipment where reliability and topology flexibility are critical.
FAQ
What is the maximum recommended output power for LT1269CSW#PBF in boost configuration?
The LT1269CSW#PBF supports up to ~15W output power in boost mode (e.g., 5V/3A) with proper thermal management and external components. At 100kHz switching frequency and 4A internal switch limit, peak efficiency (~90%) occurs between 0.4A–1.5A load; sustained 3A output requires careful PCB copper area and airflow per θJA = 30°C/W spec for SW package.
Does LT1269CSW#PBF support flyback topology with isolated outputs?
Yes, LT1269CSW#PBF supports flyback-regulated mode with fully floating outputs. Its FB pin accepts feedback from an isolated secondary winding via resistive divider, and the device maintains regulation without optocoupler or auxiliary winding - confirmed in LT1271/LT1269 datasheet Figure TA02 and electrical specifications for flyback reference voltage (16.3V typical).
What is the minimum input voltage required for LT1269CSW#PBF to start switching?
The LT1269CSW#PBF has a minimum input voltage of 3.5V for guaranteed operation, with absolute minimum specified at 3.0V (per Note 3 in Electrical Characteristics table). Below 3.5V, startup may fail or regulation accuracy degrades; the internal bandgap reference and oscillator require sufficient headroom to bias correctly.
Can LT1269CSW#PBF be synchronized to an external clock signal?
Yes, LT1269CSW#PBF supports external synchronization as stated in the datasheet feature list ("Can Be Externally Synchronized (See LT1072 Data Sheet)"). The VC pin accepts external clock injection to override internal oscillator frequency - enabling EMI reduction and multi-regulator phase alignment in complex power systems.
What is the thermal resistance (θJA) of LT1269CSW#PBF in its SW package?
The LT1269CSW#PBF in 20-lead wide SOIC (SW) package has θJA = 30°C/W when soldered to 0.5 square inch of 1oz copper ground plane, per package drawing LTC DWG #05-08-1620. This value assumes optimal PCB layout; actual θJA increases significantly with reduced copper area or no thermal vias.
LT1269CSW#PBF Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc.
- Series:
- -
- Package/Case:
- 20-SOIC (0.295", 7.50mm Width)
- Packaging:
- Tube
- Product Status:
- Active
- Function:
- Step-Up, Step-Down, Step-Up/Step-Down
- Output Configuration:
- Positive or Negative
- Topology:
- Buck, Boost, Buck-Boost, Flyback
- Output Type:
- Adjustable
- Number of Outputs:
- 1
- Voltage - Input (Min):
- 3.5V
- Voltage - Input (Max):
- 30V
- Voltage - Output (Min/Fixed):
- 1.244V
- Voltage - Output (Max):
- 60V (Switch)
- Current - Output:
- 4A (Switch)
- Frequency - Switching:
- 100kHz
- Synchronous Rectifier:
- No
- Operating Temperature:
- 0°C ~ 100°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 20-SO
LT1269CSW#PBF FAQ
1.How can I place an order for LT1269CSW#PBF through Aetrix?
Please submit a Request for Quotation (RFQ) for LT1269CSW#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 LT1269CSW#PBF reliable?
The price and inventory of LT1269CSW#PBF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LT1269CSW#PBF is usually 5 days.
3.What payment methods are accepted for LT1269CSW#PBF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LT1269CSW#PBF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LT1269CSW#PBF?
LT1269CSW#PBF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LT1269CSW#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 LT1269CSW#PBF?
For technical support, including LT1269CSW#PBF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LT1269CSW#PBF requirements.
6.How does Aetrix verify that LT1269CSW#PBF is sourced from the original manufacturer or authorized distributors?
All LT1269CSW#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 LT1269CSW#PBF meets industry standards.
7.What is the process for return or replacement of LT1269CSW#PBF?
All LT1269CSW#PBF units undergo pre-shipment inspection (PSI). If there is an issue with LT1269CSW#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 LT1269CSW#PBF part is unused and in its original packaging.
Return procedure for LT1269CSW#PBF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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