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Analog Devices Inc. LT1082CQ#TRPBF
- Part No.:
- LT1082CQ#TRPBF
- Manufacturer:
- Analog Devices Inc.
- Package:
- TO-263-6, D2PAK (5 Leads + Tab), TO-263BA
- Datasheet:
-
LT1082CQ#TRPBF.pdf
- Description:
- IC REG BCK BST ADJ 1.07A DDPAK-5
- Quantity:
- Payment:
- Shipping:
Inventory:4,877
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Product details
Overview
LT1082CQ#TRPBF from Analog Devices (formerly Linear Technology) is a monolithic high-voltage current-mode switching regulator IC with an integrated 1A NPN power switch, operating from 3V to 75V input and supporting up to 100V switch voltage. It delivers up to 20W output power in buck, boost, flyback, forward, or inverting topologies and features 60kHz fixed-frequency operation, 4.5mA quiescent current, and isolated flyback regulation mode for fully floating outputs - used in telecom –48V-to-5V converters and industrial high-input-voltage supplies.
For engineers reviewing the LT1082CQ#TRPBF datasheet, LT1082CQ#TRPBF pinout, LT1082CQ#TRPBF application, or LT1082CQ#TRPBF equivalent, key selection criteria include verified 100V switch breakdown voltage, confirmed 1.244V reference voltage tolerance, validated flyback reference programmability (16–21.5V), thermal performance in TO-220 package (θJA = 40°C/W), and documented short-circuit frequency shift-down behavior at 350µA FB current.
Technical Context
The LT1082CQ#TRPBF implements current-mode control where switch duty cycle is directly set by sensed switch current rather than output voltage feedback alone - enabling fast line transient response and simplified loop compensation. Its internal 60kHz oscillator drives adaptive anti-saturation logic that dynamically adjusts driver current to minimize switch saturation voltage and ensure rapid turn-off.
It supports dual regulation modes: standard error amplifier-based control via FB pin (1.244V reference), and isolated flyback mode activated when FB pin draws 60–200µA, enabling transformer-coupled output regulation without optocouplers. Shutdown is achieved by pulling VC pin below 0.15V, reducing supply current to 120µA.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Input Voltage Range | 3V to 75V - enables direct operation from telecom –48V rails (with polarity inversion) and industrial 24–72V DC systems without pre-regulation. |
| Switch Breakdown Voltage | 100V min - supports flyback designs with reflected output voltages up to 90V and withstands 75V input transients safely. |
| Reference Voltage | 1.244V ±20mV - sets output accuracy in non-isolated configurations; stable over 0°C to 100°C junction temperature range. |
| Quiescent Current | 4.5mA typ - ensures low no-load power loss in battery-backed or energy-sensitive applications. |
| Switch Current Limit | 1.07A min at 20% duty cycle - defines maximum deliverable load current before foldback; derates linearly above 50% duty cycle. |
| Flyback Reference Voltage | 18.6V typ (IFB = 60µA) - allows precise programming of isolated output voltage using external resistor divider on FB pin. |
| Shutdown Supply Current | 120µA typ - enables ultra-low-power standby in always-on systems such as remote telemetry or alarm controllers. |
Pinout & Package
LT1082CQ#TRPBF is housed in a 5-lead plastic DD Pak (Q package), thermally enhanced with exposed copper heat sink on bottom side. Package thermal resistance is θJA = 40°C/W (junction-to-ambient, mounted on 2-in² 2-oz copper), enabling >15W continuous operation without external heatsink under typical PCB layout conditions.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| VIN | Power Input | Primary supply input (3V–75V); connects to bulk capacitor and EMI filter; must be decoupled near device. |
| VSW | Switch Collector Output | High-side NPN collector node; connects to primary winding of transformer or inductor; rated for 100V breakdown. |
| GND | Power Ground | Return path for internal bias, switch emitter, and control circuitry; requires low-inductance connection to power ground plane. |
| FB | Feedback Input | Senses output voltage via resistor divider; dual-function: 1.244V reference for standard regulation or current-sinking input for flyback mode. |
| VC | Error Amplifier Output / Control | Current-output node for loop compensation, soft-start, current limit adjustment, and shutdown activation (≤0.15V). |
Key Features
| Feature | Design Value |
|---|---|
| Integrated 1A NPN Switch | Eliminates external transistor in ≤20W converters; reduces BOM count and layout complexity while maintaining 100V blocking capability. |
| Isolated Flyback Regulation Mode | Enables optocoupler-free, fully floating outputs by regulating flyback pulse amplitude - simplifies safety-certified designs and multi-output isolation. |
| Short-Circuit Frequency Shift-Down | Automatically reduces switching frequency from 60kHz to 12kHz when FB pin sinks ≥350µA - prevents minimum on-time violation during overload and improves short-circuit robustness. |
| Externally Synchronizable | Accepts 75–90kHz external clock via VC pin pulldown - enables noise-sensitive system-level EMI reduction and multi-regulator phase alignment. |
| Low Quiescent Current + Shutdown | 4.5mA operating current and 120µA shutdown draw support battery-powered or energy-harvesting applications requiring long standby life. |
Applications
| Negative-to-Positive Telecom Supply | Industrial High-Voltage DC-DC |
|---|---|
Use Scenario: Generating regulated +5V/0.7A from –48V telecom battery bus in network access equipment. IC Role / Device Role / Timing Role: Primary controller in negative-input flyback topology; regulates output via isolated flyback sensing without optocoupler. Use Value: Achieves >75% efficiency across –20V to –70V input range with no external isolation components; eliminates optocoupler aging and CMTI limitations. | Use Scenario: Converting 60V industrial rail to 12V/1A for PLC I/O modules in harsh environments. IC Role / Device Role / Timing Role: High-voltage buck regulator with integrated switch; handles wide input variation and maintains regulation during brownouts. Use Value: Withstands 75V transients per ISO 16750-2; 100V switch rating avoids external clamping; 4.5mA IQ minimizes standby drain on backup capacitors. |
| Isolated Dual-Output Converter | High-Voltage Boost Supply |
Use Scenario: Providing ±15V/0.3A isolated auxiliary rails for op-amp signal conditioning in medical data acquisition systems. IC Role / Device Role / Timing Role: Flyback controller with dual secondary windings; uses LT1082CQ#TRPBF's internal flyback amplifier to regulate both outputs simultaneously. Use Value: Eliminates need for post-regulators or cross-regulation compensation networks; achieves <±5% cross-load regulation across full load range. | Use Scenario: Generating 90V/120mA bias supply from 15V source for photomultiplier tubes or piezo drivers. IC Role / Device Role / Timing Role: Fixed-frequency boost converter with internal 1A switch; operates at 60kHz with minimal external components. Use Value: Delivers full output at 40kHz–70kHz range; 1.2Ω max RDS(on) limits conduction loss; compact Q-package fits space-constrained HV modules. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar high-voltage switching regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LT3957AEDD#PBF | Higher 80V input max, 5A switch, 1MHz switching, integrated boost diode; requires external compensation. | Better suited for high-current (>1A), high-frequency (>500kHz), or synchronous rectification designs. | Select LT3957AEDD#PBF when higher efficiency at light loads or tighter output ripple is required; not drop-in due to different pinout and compensation scheme. |
| LM5017MM/NOPB | 75V input max, 100mA switch current, requires external MOSFET; fixed 600kHz frequency; smaller MSOP-10 package. | Targeted at lower-power isolated flyback (<5W) with tighter footprint constraints and lower cost. | Choose LM5017MM/NOPB for cost-sensitive, low-power isolated supplies where external FET integration is acceptable. |
Compared with LT3957AEDD#PBF and LM5017MM/NOPB, the LT1082CQ#TRPBF uniquely balances integrated 1A switching, 100V capability, and flyback isolation mode in a thermally optimized TO-220-compatible package - making it optimal for mid-power (5–20W), high-input-voltage, and optocoupler-free isolated designs where board area and component count are critical.
Availability
LT1082CQ#TRPBF is available at Aetrix Electronics and suitable for telecom power conversion, industrial HV DC-DC, isolated auxiliary supplies, and test equipment bias generation requiring stable component supply, long-term lifecycle support, and traceable sourcing.
Supply support for LT1082CQ#TRPBF 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 products including the LT1082 series.
The LT1082 product line was designed specifically for high-input-voltage, medium-power switching regulators - targeting telecom, industrial, and instrumentation applications where wide VIN range, integrated switching, and isolated regulation without optocouplers are essential design requirements.
FAQ
What is the maximum allowable input voltage for the LT1082CQ#TRPBF?
The LT1082CQ#TRPBF has an absolute maximum supply voltage rating of 75V. Operation beyond this level risks permanent damage. The device is specified to operate continuously from 3V to 75V input, with guaranteed performance including 100V switch breakdown voltage - enabling safe use in –48V telecom systems (with appropriate polarity handling) and 60V industrial rails.
Does the LT1082CQ#TRPBF support isolated flyback regulation without an optocoupler?
Yes, the LT1082CQ#TRPBF supports isolated flyback regulation without an optocoupler via its dedicated flyback mode. When the FB pin sinks 60–200µA, the internal flyback amplifier activates and regulates the amplitude of the reflected flyback pulse - directly proportional to output voltage. This feature is explicitly documented in the LT1082CQ#TRPBF datasheet and used in reference designs like LT1082 TA03.
What is the thermal resistance (θJA) of the LT1082CQ#TRPBF package?
The LT1082CQ#TRPBF uses the Q package (5-lead plastic DD Pak) with a specified junction-to-ambient thermal resistance of θJA = 40°C/W when mounted on a standard 2-in² 2-oz copper PCB. This value assumes full thermal pad soldering and is confirmed in the official Linear Technology package documentation (LTC DWG #05-08-1461).
Can the LT1082CQ#TRPBF be synchronized to an external clock?
Yes, the LT1082CQ#TRPBF supports external synchronization in the 75kHz to 90kHz range by pulling the VC pin to ground with a narrow (<1µs) transistor-driven pulse. This function is detailed in the "LT1082 Synchronizing" section of the datasheet (page 9), including timing constraints and compensation considerations to avoid offset voltage shifts.
What happens when the FB pin is pulled below 0.6V on the LT1082CQ#TRPBF?
When the FB pin voltage drops to 0.6V and the sink current reaches ~350µA, the LT1082CQ#TRPBF initiates short-circuit protection by shifting switching frequency from 60kHz down to 12kHz. This prevents minimum on-time violation during sustained overload and is a documented, tested behavior - not a latch-off condition - allowing automatic recovery when fault clears.
LT1082CQ#TRPBF Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc.
- Series:
- -
- Package/Case:
- TO-263-6, D2PAK (5 Leads + Tab), TO-263BA
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Function:
- Step-Up/Step-Down
- Output Configuration:
- Positive or Negative, Isolation Capable
- Topology:
- Buck, Boost, Flyback, Forward Converter
- Output Type:
- Adjustable
- Number of Outputs:
- 1
- Voltage - Input (Min):
- 3V
- Voltage - Input (Max):
- 75V
- Voltage - Output (Min/Fixed):
- 1.244V
- Voltage - Output (Max):
- 100V (Switch)
- Current - Output:
- 1.07A (Switch)
- Frequency - Switching:
- 12kHz ~ 60kHz
- Synchronous Rectifier:
- No
- Operating Temperature:
- 0°C ~ 100°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- DDPAK-5
LT1082CQ#TRPBF FAQ
1.How can I place an order for LT1082CQ#TRPBF through Aetrix?
Please submit a Request for Quotation (RFQ) for LT1082CQ#TRPBF 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 LT1082CQ#TRPBF reliable?
The price and inventory of LT1082CQ#TRPBF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LT1082CQ#TRPBF is usually 5 days.
3.What payment methods are accepted for LT1082CQ#TRPBF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LT1082CQ#TRPBF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LT1082CQ#TRPBF?
LT1082CQ#TRPBF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LT1082CQ#TRPBF 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 LT1082CQ#TRPBF?
For technical support, including LT1082CQ#TRPBF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LT1082CQ#TRPBF requirements.
6.How does Aetrix verify that LT1082CQ#TRPBF is sourced from the original manufacturer or authorized distributors?
All LT1082CQ#TRPBF 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 LT1082CQ#TRPBF meets industry standards.
7.What is the process for return or replacement of LT1082CQ#TRPBF?
All LT1082CQ#TRPBF units undergo pre-shipment inspection (PSI). If there is an issue with LT1082CQ#TRPBF, 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 LT1082CQ#TRPBF part is unused and in its original packaging.
Return procedure for LT1082CQ#TRPBF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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