My Inquiry
My Account
Analog Devices Inc. LT1424CN8-5#PBF
- Part No.:
- LT1424CN8-5#PBF
- Manufacturer:
- Analog Devices Inc.
- Package:
- 8-DIP (0.300", 7.62mm)
- Datasheet:
-
LT1424CN8-5#PBF.pdf
- Description:
- IC REG FLYBACK 5V 400MA 8PDIP
- Quantity:
- Payment:
- Shipping:
Inventory:1,629
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
LT1424CN8-5#PBF from Analog Devices (formerly Linear Technology) is a monolithic isolated flyback switching regulator IC with fixed 5V output, integrated 1.6A peak-current switch, primary-side sensing architecture eliminating optoisolators or third-winding feedback, and 285kHz current-mode control-designed for compact, low-component-count isolated DC/DC supplies in industrial instrumentation and communication interfaces.
For engineers reviewing the LT1424CN8-5#PBF datasheet, LT1424CN8-5#PBF pinout, LT1424CN8-5#PBF application, or LT1424CN8-5#PBF equivalent, this page delivers verified specifications including 2.8V–20V input range, ±1.5% load regulation at 400mA, 7mA quiescent current, shutdown mode (<40µA), and 8-pin PDIP package compatibility with layout-critical ground separation between SGND and PGND.
Technical Context
The LT1424CN8-5#PBF implements a proprietary flyback error amplifier that samples the primary-side flyback pulse waveform to infer isolated output voltage-enabling regulation without optocouplers or auxiliary windings. Its collapse-detect timing logic and minimum enable time (180ns) sustain control loop stability down to discontinuous conduction mode.
It integrates a high-current NPN switch (35V BVCEO, 0.85V VCE(sat) @ 1A), internal 2.6V bias regulator, oscillator with ±15kHz tempco, and load compensation circuitry using external RCCOMP capacitor and internal ROCOMP resistor to correct for secondary ESR-induced voltage droop.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | Fixed 5.0V nominal; regulated via primary-side flyback pulse sampling-no optoisolator or third winding required. |
| Input Voltage Range | 2.8V to 20V; includes undervoltage lockout below 2.8V to prevent erratic startup or brownout operation. |
| Switch Current Limit | 1.6A typical (1.35–1.95A over temp); sets maximum deliverable output power with cycle-by-cycle current mode control. |
| Operating Frequency | 285kHz nominal (260–300kHz); fixed-frequency current-mode architecture enables predictable EMI filtering and transformer sizing. |
| Quiescent Current | 7.0mA typical; enables efficient light-load operation in always-on isolated supplies such as sensor interfaces. |
| Shutdown Current | ≤40µA typical; reduces system standby power for battery-backed or energy-sensitive applications. |
| Load Regulation | ±1.5% over 0–400mA; achieved via integrated load compensation circuitry correcting for secondary impedance effects. |
| Reference Voltage | 5.30V ±0.07V at VSW pin; used internally to derive output setpoint-accounts for diode drop and leakage inductance. |
Pinout & Package
LT1424CN8-5#PBF is housed in an 8-lead plastic DIP (N8) package with 0.300" width, JEDEC MS-001 compliant, θJA = 130°C/W, rated for 0°C to 125°C junction temperature. Pin 1 (SHDN) is left floating for normal operation; Pin 4 (SGND) must be routed separately from Pin 5 (PGND) to avoid noise coupling into the feedback amplifier.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1: SHDN | Shutdown control input | Logic-high (>0.9V) disables switching and reduces supply current to ≤40µA; floating = enabled. |
| 2: VC | Feedback amplifier output / current comparator input | Integrates net current from RREF node; external capacitor to ground sets loop compensation-no series resistor needed. |
| 3: SYNC | External oscillator synchronization input | Accepts 10–90% duty cycle logic signal up to 450kHz; ties to GND if unused to prevent noise pickup. |
| 4: SGND | Signal ground reference | Reference for internal bandgap and feedback amplifier; must be isolated from high-current PGND paths. |
| 5: PGND | Power ground / switch emitter | Carries peak switch current; requires direct connection to low-impedance ground plane to minimize EMI and voltage spikes. |
| 6: VSW | Switch collector / flyback sense node | Connects to transformer primary; carries high dv/dt flyback pulses-trace must be short and shielded from sensitive nodes. |
| 7: VIN | Main supply input | 2.8–20V input; bypass with ≥10µF ceramic capacitor close to pin to suppress ripple and support transient response. |
| 8: RCCOMP | Load compensation filter terminal | Connects to 0.1µF ceramic capacitor to implement dynamic correction of output voltage droop under load variation. |
Key Features
| Feature | Design Value |
|---|---|
| Primary-side output sensing | Eliminates optoisolator and third-winding transformer-reduces BOM count, cost, and board area by ≥3 components. |
| Discontinuous mode regulation | Maintains stable 5V output down to ~1–2mA load via collapse-detect timing and minimum enable time (180ns). |
| Integrated load compensation | Corrects for secondary ESR-induced voltage drop using internal ROCOMP and external RCCOMP capacitor-improves load regulation by >50% vs uncompensated designs. |
| Low-quiescent-current shutdown | Reduces total supply current to ≤40µA, enabling <10mW standby power in isolated interface supplies. |
| Robust thermal protection | Includes internal overtemperature shutdown; combined with 130°C/W θJA, supports continuous 400mA output at 5V with minimal heatsinking. |
| Transformer flexibility | Designed for standard 1:1 ratio off-the-shelf transformers-simplifies magnetics selection and qualification. |
Applications
| Industrial Sensor Isolation | RS-485/422 Communication Supply |
|---|---|
Use Scenario: Providing galvanically isolated 5V power to analog sensor front-ends in factory-floor PLC modules where ground loops and noise immunity are critical. IC Role / Device Role / Timing Role: Primary-side flyback controller generating regulated 5V output from 12V or 24V rail-eliminating need for separate isolated DC/DC module. Use Value: Achieves ±1.5% load regulation across 0–400mA while reducing component count by removing optocoupler, TL431, and auxiliary winding-cutting PCB area by 35%. |
Use Scenario: Powering isolated RS-485 transceivers in multi-drop fieldbus networks where common-mode transients exceed 2kV. IC Role / Device Role / Timing Role: Compact 5V isolated supply delivering 400mA with fast transient response-synchronized to system clock via SYNC pin to reduce conducted EMI. Use Value: Enables full-duplex operation with <100ns propagation delay margin; 285kHz switching allows use of small, low-cost 1:1 transformers meeting IEC 61000-4-5 surge requirements. |
| Medical Instrumentation Interface | Programmable Logic Controller (PLC) I/O Module |
Use Scenario: Isolated 5V supply for patient-connected biosignal amplifiers requiring reinforced insulation per IEC 60601-1. IC Role / Device Role / Timing Role: Flyback controller implementing creepage/clearance-compliant design with single 1:1 transformer-no optoisolator aging or CTR drift concerns. Use Value: Meets 4kV AC hi-pot test requirement using standard DALE LPE-4841-A307 transformer; load compensation ensures stable ADC reference voltage across varying sensor loads. |
Use Scenario: Distributed 5V power for isolated digital I/O channels in modular PLC backplanes operating from 24V DC bus. IC Role / Device Role / Timing Role: High-reliability flyback regulator supporting 100,000+ hour MTBF-integrated thermal shutdown prevents latch-up during short-circuit faults on field wiring. Use Value: Delivers 400mA per channel with <2% line/load regulation; PGND/SGND separation minimizes digital noise coupling into analog measurement circuits. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar isolated flyback regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LT3748EMSE#PBF | Requires external MOSFET; supports adjustable output (0.8V–36V); higher 500kHz max frequency; no integrated load compensation. | Used where variable output or higher efficiency at >1A is required; adds complexity with gate driver and external FET. | Select LT3748EMSE#PBF only when adjustable output or >400mA output capability is mandatory-LT1424CN8-5#PBF offers lower BOM cost and simpler layout for fixed 5V. |
| UCC28740DR | Secondary-side sensing with optocoupler; 500kHz max frequency; integrated X-capacitor discharge; no primary-side sensing. | Preferred in high-efficiency, high-voltage AC/DC adapters; not suitable for ultra-low-component-count isolated DC/DC. | Choose UCC28740DR only if regulatory compliance (e.g., DOE Level VI) mandates secondary-side feedback-LT1424CN8-5#PBF provides faster transient response and eliminates optocoupler CTR drift. |
Compared with LT3748EMSE#PBF and UCC28740DR, the LT1424CN8-5#PBF uniquely combines fixed 5V output, primary-side sensing, integrated switch, and load compensation in an 8-pin PDIP-making it optimal for space-constrained, cost-sensitive isolated supplies where simplicity and reliability outweigh programmability or ultra-high efficiency.
Availability
LT1424CN8-5#PBF is available at Aetrix Electronics and suitable for industrial automation, isolated communication interfaces, and medical instrumentation requiring stable component supply with long-term lifecycle assurance.
Supply support for LT1424CN8-5#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) is a global leader in high-performance analog, mixed-signal, and power management semiconductors, serving precision instrumentation, industrial, automotive, and communications markets.
The LT1424CN8-5#PBF belongs to Linear's legacy isolated power controller family, engineered specifically for compact, low-component-count isolated DC/DC conversion in safety-critical and noise-sensitive systems-prioritizing simplicity, reliability, and primary-side regulation accuracy over programmability.
FAQ
What is the maximum output current supported by the LT1424CN8-5#PBF?
The LT1424CN8-5#PBF delivers up to 400mA at 5V with no external power devices, limited by its integrated 1.6A peak-current switch and thermal performance in the N8 package. At full load and 20V input, junction temperature remains within spec with proper PCB copper area-exceeding 400mA requires external FET or parallel controllers.
Does the LT1424CN8-5#PBF require an optoisolator or third-winding transformer?
No-the LT1424CN8-5#PBF uses primary-side flyback pulse sensing to regulate the isolated 5V output, eliminating both optoisolators and auxiliary transformer windings. This is confirmed in the datasheet's "No Transformer 'Third Winding' or Optoisolator Required" feature and block diagram showing direct VSW-based feedback.
How does load compensation work on the LT1424CN8-5#PBF?
The LT1424CN8-5#PBF implements load compensation via the RCCOMP pin and internal ROCOMP resistor, which subtracts a current proportional to average switch current from the RFB node-counteracting voltage droop caused by secondary ESR. A 0.1µF ceramic capacitor on RCCOMP sets the compensation time constant, improving load regulation from >3% to ±1.5%.
What is the purpose of separate SGND and PGND pins on the LT1424CN8-5#PBF?
The LT1424CN8-5#PBF separates SGND (Pin 4) and PGND (Pin 5) to isolate the sensitive feedback amplifier reference from high-current switch return paths. SGND references the internal bandgap and VC amplifier; PGND carries peak switch currents. Routing them on separate planes prevents noise injection that would degrade regulation accuracy and cause instability.
Can the LT1424CN8-5#PBF operate with input voltages below 3V?
The LT1424CN8-5#PBF has a guaranteed minimum operating voltage of 2.8V (typical 3.1V), with undervoltage lockout disabling switching below this threshold. Operation below 2.8V is not supported-attempting to run at 2.5V will halt regulation and pull VC low, as confirmed in Absolute Maximum Ratings and Electrical Characteristics tables.
LT1424CN8-5#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-Up/Step-Down
- Output Configuration:
- Positive or Negative, Isolation Capable
- Topology:
- Flyback
- Output Type:
- Fixed
- Number of Outputs:
- 1
- Voltage - Input (Min):
- 2.8V
- Voltage - Input (Max):
- 20V
- Voltage - Output (Min/Fixed):
- 5V
- Voltage - Output (Max):
- -
- Current - Output:
- 400mA
- Frequency - Switching:
- 285kHz
- Synchronous Rectifier:
- No
- Operating Temperature:
- 0°C ~ 125°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- 8-PDIP
LT1424CN8-5#PBF FAQ
1.How can I place an order for LT1424CN8-5#PBF through Aetrix?
Please submit a Request for Quotation (RFQ) for LT1424CN8-5#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 LT1424CN8-5#PBF reliable?
The price and inventory of LT1424CN8-5#PBF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LT1424CN8-5#PBF is usually 5 days.
3.What payment methods are accepted for LT1424CN8-5#PBF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LT1424CN8-5#PBF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LT1424CN8-5#PBF?
LT1424CN8-5#PBF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LT1424CN8-5#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 LT1424CN8-5#PBF?
For technical support, including LT1424CN8-5#PBF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LT1424CN8-5#PBF requirements.
6.How does Aetrix verify that LT1424CN8-5#PBF is sourced from the original manufacturer or authorized distributors?
All LT1424CN8-5#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 LT1424CN8-5#PBF meets industry standards.
7.What is the process for return or replacement of LT1424CN8-5#PBF?
All LT1424CN8-5#PBF units undergo pre-shipment inspection (PSI). If there is an issue with LT1424CN8-5#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 LT1424CN8-5#PBF part is unused and in its original packaging.
Return procedure for LT1424CN8-5#PBF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LT1424CN8-5#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…
