My Inquiry
My Account
Analog Devices Inc. LT1424IN8-9#PBF
- Part No.:
- LT1424IN8-9#PBF
- Manufacturer:
- Analog Devices Inc.
- Package:
- 8-DIP (0.300", 7.62mm)
- Datasheet:
-
LT1424IN8-9#PBF.pdf
- Description:
- IC REG FLYBACK 9V 200MA 8PDIP
- Quantity:
- Payment:
- Shipping:
Inventory:4,332
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
LT1424IN8-9#PBF from Analog Devices (formerly Linear Technology) is a monolithic isolated flyback switching regulator IC designed for PCMCIA Type II-compliant –9V isolated LAN supplies. It integrates a 1.6A peak-current switch, primary-side output voltage sensing, load compensation, and 285kHz fixed-frequency current-mode control - delivering up to 200mA at –9V without optoisolators or third-winding feedback. Its 8-pin PDIP package meets 2.41mm height constraints for compact portable designs.
For engineers reviewing the LT1424IN8-9#PBF datasheet, LT1424IN8-9#PBF pinout, LT1424IN8-9#PBF application, or LT1424IN8-9#PBF equivalent, key selection considerations include its primary-side regulation architecture, –9V fixed output, shutdown current of 40µA max, load compensation capability via RCCOMP pin, and compatibility with PCMCIA Type II mechanical envelope requirements.
Technical Context
The LT1424IN8-9#PBF implements a proprietary flyback error amplifier that samples the primary-side flyback pulse waveform to infer isolated secondary output voltage - eliminating need for optoisolators or auxiliary windings. Its collapse-detect timing logic enables stable regulation down to discontinuous conduction mode.
It features integrated load compensation via external RCCOMP capacitor and internal current-sense amplifier, dynamically adjusting target output voltage to counteract secondary-side ESR-induced droop. The VC pin serves as both feedback amplifier output and current comparator input, enabling direct current-mode control with 1.9V clamp limiting peak switch current.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Output Voltage | Fixed –9V nominal; derived from primary-side flyback pulse sampling - no secondary feedback components required. |
| Switching Frequency | 285kHz typical; fixed oscillator frequency ensures predictable EMI profile and simplifies filter design. |
| Peak Switch Current | 1.6A typical; supports ≥200mA output at –9V with standard transformer and diode selection. |
| Input Voltage Range | 2.8V to 20V; includes undervoltage lockout below 2.8V to prevent erratic startup or brownout operation. |
| Shutdown Current | 40µA maximum; enables ultra-low-power standby in battery-powered PCMCIA applications. |
| Reference Voltage | 9.15V typical at VSW pin; accounts for diode drop and leakage effects - maps to –9V output in intended circuit. |
| Thermal Resistance | θJA = 130°C/W (PDIP); requires minimal heatsinking for 200mA operation at full ambient range. |
Pinout & Package
LT1424IN8-9#PBF is housed in an 8-lead narrow-body PDIP (N8) package with 0.300-inch width and 2.41mm max height - compliant with PCMCIA Type II mechanical specifications.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| SHDN (Pin 1) | Shutdown control input | Logic-low active; pulls supply current to ≤40µA when driven below 0.9V - enables system-level power gating. |
| VC (Pin 2) | Feedback amplifier output / current comparator input | Integrates loop compensation via external capacitor to ground; clamped at 1.9V to limit peak switch current. |
| SYNC (Pin 3) | External oscillator synchronization input | Accepts 10–90% duty-cycle logic signal up to 450kHz; allows EMI spreading or multi-regulator phase alignment. |
| SGND (Pin 4) | Signal ground reference | Low-noise ground for internal bandgap and feedback amplifier - must be isolated from high-current PGND paths. |
| RCCOMP (Pin 8) | Load compensation network connection | Receives current proportional to average switch current; cancels output impedance droop under varying load. |
| VIN (Pin 7) | Main supply input | Accepts 2.8–20V; requires ≥10µF local ceramic bypass to suppress switching noise and ensure stable UVLO behavior. |
| VSW (Pin 6) | Switch collector node | High dv/dt node connected to transformer primary; demands shortest possible PCB trace to minimize EMI and voltage spikes. |
| PGND (Pin 5) | Power ground return | Emitter of integrated NPN switch; carries high pulsed currents - must connect directly to solid ground plane. |
Key Features
| Feature | Design Value |
|---|---|
| Primary-side output sensing | Eliminates optoisolator and third-winding - reduces BOM count, cost, and board area while improving long-term reliability. |
| Discontinuous mode regulation | Maintains ±3% output regulation down to ~2–3mA load via collapse-detect timing - critical for low-power LAN interface standby states. |
| Load compensation | Adjusts target output voltage in real time using RCCOMP pin current - corrects for diode drop and secondary ESR across full load range. |
| PCMCIA Type II height compliance | 2.41mm max component height achieved with N8 PDIP package - enables integration into space-constrained laptop peripheral slots. |
| Integrated 1.6A switch | Monolithic NPN transistor eliminates need for external high-current switch - simplifies layout and improves thermal coupling. |
Applications
| PCMCIA Type II Isolated LAN Supply | Ethernet Isolated 5V to –9V Converter |
|---|---|
Use Scenario: Powering isolated Ethernet PHY interfaces in laptop PCMCIA cards where strict 2.41mm height limit applies. IC Role / Device Role / Timing Role: Primary-side flyback controller providing regulated –9V rail with no secondary feedback components. Use Value: Enables fully isolated, optocoupler-free LAN supply meeting PCMCIA mechanical spec - reducing part count by ≥3 and eliminating aging-related drift. | Use Scenario: Generating isolated –9V bias for RS-485 transceivers or analog front-ends in industrial gateways powered from 5V USB or logic rails. IC Role / Device Role / Timing Role: Fixed-frequency current-mode flyback controller with load compensation for stable negative output under dynamic load steps. Use Value: Delivers ±2% load regulation from 0–200mA using single external capacitor (RCCOMP), avoiding complex compensation networks. |
| Isolated CAN Bus Bias Supply | Medical Sensor Isolation Interface |
Use Scenario: Providing galvanically isolated –9V supply for CAN transceiver bias in automotive diagnostic tools with limited PCB real estate. IC Role / Device Role / Timing Role: Compact flyback regulator with shutdown control for low-quiescent power during bus idle periods. Use Value: Achieves <40µA shutdown current and 285kHz switching - minimizing conducted EMI in sensitive CAN communication bands. | Use Scenario: Powering isolated analog signal conditioning circuits in patient-connected medical sensors requiring reinforced isolation and low leakage. IC Role / Device Role / Timing Role: Transformer-coupled flyback controller delivering creepage/clearance-compliant –9V rail without secondary-side components. Use Value: Removes optoisolator failure mode and enables >10-year lifetime specification - critical for Class II medical device certification. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar isolated flyback regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LT1424CS8-9 | Same silicon die, SO-8 package (θJA = 110°C/W); 1.5mm height - exceeds PCMCIA Type II limit. | Preferred for non-height-constrained industrial boards where thermal performance is prioritized over mechanical fit. | Select when PCB space allows SO-8 and thermal margin is tighter than 130°C/W. |
| LT1425CSW#PBF | 16-pin general-purpose flyback controller; external RREF, RFB, RCOMP - programmable for ±5V, ±12V, or custom outputs. | Used for prototyping or multi-voltage designs where fixed –9V output is insufficient. | Choose when flexibility across output voltages or transformer ratios is required - not a drop-in replacement. |
Compared with LT1424CS8-9, the LT1424IN8-9#PBF trades thermal efficiency for mechanical compliance; compared with LT1425CSW#PBF, it sacrifices configurability for optimized size, cost, and ease-of-use in dedicated –9V applications.
Availability
LT1424IN8-9#PBF is available at Aetrix Electronics and suitable for PCMCIA peripherals, isolated industrial interfaces, medical sensor modules, and embedded LAN applications requiring stable component supply with guaranteed long-term manufacturability.
Supply support for LT1424IN8-9#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 product support, documentation, and manufacturing continuity for legacy Linear parts including the LT1424 series.
The LT1424 family was designed specifically for compact, isolated flyback power supplies in portable and space-constrained systems - emphasizing mechanical compliance, primary-side regulation, and minimal external component count.
FAQ
What is the primary function of the LT1424IN8-9#PBF in a power supply design?
The LT1424IN8-9#PBF functions as a monolithic isolated flyback switching regulator IC that generates a fixed –9V output without requiring optoisolators or auxiliary transformer windings. It achieves this by sampling the primary-side flyback pulse waveform to infer secondary output voltage - making the LT1424IN8-9#PBF ideal for compact, reliable, and low-component-count isolated DC/DC conversion.
Does the LT1424IN8-9#PBF require external feedback components on the secondary side?
No, the LT1424IN8-9#PBF does not require any external feedback components on the secondary side. Its proprietary flyback error amplifier derives output voltage information directly from the primary-side VSW node during the flyback period - eliminating optoisolators, TL431 references, and secondary-side resistive dividers. This architecture is intrinsic to the LT1424IN8-9#PBF design and validated in its PCMCIA Type II reference circuit.
How does the LT1424IN8-9#PBF maintain regulation at very light loads?
The LT1424IN8-9#PBF maintains regulation down to ~2–3mA using collapse-detect timing logic that extends feedback amplifier enable time into discontinuous conduction mode. Unlike conventional controllers, its minimum flyback enable time (tEN) and enable delay (tED) are precisely calibrated to extract valid voltage data even when secondary current approaches zero - a core capability confirmed in the LT1424IN8-9#PBF's electrical characteristics table and typical performance curves.
What is the role of the RCCOMP pin on the LT1424IN8-9#PBF?
The RCCOMP pin on the LT1424IN8-9#PBF connects to an external capacitor that implements load compensation - subtracting a current proportional to average switch current from the feedback node to counteract output voltage droop caused by secondary-side ESR. This function is documented in the LT1424IN8-9#PBF datasheet's "Load Compensation Theory" section and directly improves load regulation from no-load to full 200mA.
Can the LT1424IN8-9#PBF be synchronized to an external clock?
Yes, the LT1424IN8-9#PBF supports external synchronization via its SYNC pin (Pin 3), which accepts logic-level signals from 330kHz to 450kHz with 10–90% duty cycle. When synchronized, the internal 285kHz oscillator locks to the external source - enabling EMI reduction through frequency dithering or phase alignment in multi-rail systems. This capability is specified in the LT1424IN8-9#PBF's Electrical Characteristics table under "Synchronization Range."
LT1424IN8-9#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):
- 9V
- Voltage - Output (Max):
- -
- Current - Output:
- 200mA
- Frequency - Switching:
- 285kHz
- Synchronous Rectifier:
- No
- Operating Temperature:
- -40°C ~ 125°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- 8-PDIP
LT1424IN8-9#PBF FAQ
1.How can I place an order for LT1424IN8-9#PBF through Aetrix?
Please submit a Request for Quotation (RFQ) for LT1424IN8-9#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 LT1424IN8-9#PBF reliable?
The price and inventory of LT1424IN8-9#PBF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LT1424IN8-9#PBF is usually 5 days.
3.What payment methods are accepted for LT1424IN8-9#PBF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LT1424IN8-9#PBF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LT1424IN8-9#PBF?
LT1424IN8-9#PBF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LT1424IN8-9#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 LT1424IN8-9#PBF?
For technical support, including LT1424IN8-9#PBF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LT1424IN8-9#PBF requirements.
6.How does Aetrix verify that LT1424IN8-9#PBF is sourced from the original manufacturer or authorized distributors?
All LT1424IN8-9#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 LT1424IN8-9#PBF meets industry standards.
7.What is the process for return or replacement of LT1424IN8-9#PBF?
All LT1424IN8-9#PBF units undergo pre-shipment inspection (PSI). If there is an issue with LT1424IN8-9#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 LT1424IN8-9#PBF part is unused and in its original packaging.
Return procedure for LT1424IN8-9#PBF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LT1424IN8-9#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…
