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Analog Devices Inc. LT1170CQ#TRPBF
- Part No.:
- LT1170CQ#TRPBF
- Manufacturer:
- Analog Devices Inc.
- Package:
- TO-263-6, D2PAK (5 Leads + Tab), TO-263BA
- Datasheet:
-
LT1170CQ#TRPBF.pdf
- Description:
- IC REG BUCK BOOST ADJ 5A DDPAK-5
- Quantity:
- Payment:
- Shipping:
Inventory:1,332
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Product details
Overview
LT1170CQ#TRPBF from Analog Devices (formerly Linear Technology) is a monolithic 100kHz, 5A high-efficiency switching regulator IC in a 5-lead DD (DIP-style) package. It integrates a high-current power switch, oscillator, current-mode control, and protection circuitry, enabling buck, boost, flyback, forward, inverting, and Cuk topologies. It operates from 3V to 40V input, delivers up to 100W output power without external switches, and supports flyback-regulated floating outputs - ideal for isolated DC/DC conversion in industrial power supplies.
For engineers reviewing the LT1170CQ#TRPBF datasheet, LT1170CQ#TRPBF pinout, LT1170CQ#TRPBF application, or LT1170CQ#TRPBF equivalent, key selection criteria include its 5A internal switch, 100kHz fixed-frequency operation, adaptive anti-saturation drive, shutdown mode drawing only 50µA, and compatibility with standard 5-pin TO-220–form factor layouts requiring minimal external components.
Technical Context
The LT1170CQ#TRPBF implements current-mode control: the internal 5A switch turns on at each 100kHz oscillator cycle and turns off when sensed current reaches a VC-pin–programmed threshold. This architecture provides inherent cycle-by-cycle current limiting, excellent line and load transient response, and simplified loop compensation across wide input (3V–40V) and output ranges.
It features dual error amplifiers - one for standard regulation (1.224V reference at FB pin), another for flyback mode (15.0V flyback reference) - selectable via FB pin voltage. The VC pin serves quadruple functions: error amplifier output, current limit programming node, soft-start interface, and shutdown control (≤0.15V triggers 50µA standby).
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Switch Current Rating | 5A continuous - enables single-chip 100W DC/DC conversion without external MOSFETs in buck/boost/flyback topologies. |
| Input Voltage Range | 3V to 40V - supports wide-range industrial, automotive, and battery-derived inputs without pre-regulation. |
| Switching Frequency | 100kHz (typical) - balances efficiency, magnetics size, and EMI; externally synchronizable to 120–160kHz. |
| Quiescent Supply Current | 6mA - ensures low no-load power loss in always-on systems; drops to 50µA in shutdown mode. |
| Reference Voltage | 1.224V (FB pin) - precision bandgap reference enabling accurate output voltage setting with standard resistor dividers. |
| Flyback Reference Voltage | 15.0V (at IFB = 50µA) - enables transformer-coupled isolated regulation without optocoupler feedback. |
| Switch Breakdown Voltage | 65V - defines maximum safe VSW swing; limits max input in flyback mode to 55V to avoid breakdown. |
| Thermal Operating Range | 0°C to 100°C (commercial grade) - validated for stable operation in enclosed industrial enclosures without forced air. |
Pinout & Package
LT1170CQ#TRPBF uses a 5-lead DD (Dual-in-line, plastic) package with exposed tab connected to GND. Pin 1 is VIN, Pin 2 is VSW, Pin 3 is GND, Pin 4 is FB, Pin 5 is VC. The tab is electrically tied to Pin 3 (GND) and serves as primary thermal path.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| VIN (Pin 1) | Main power input | Supplies internal regulator (2.3V) and switch driver; accepts 3V–40V; requires local 1µF ceramic bypass. |
| VSW (Pin 2) | Switch collector/drain node | Connects to external inductor/diode in buck/boost; to primary winding in flyback; handles 5A peak current and 65V transients. |
| GND (Pin 3) | Power and signal ground reference | Common return for internal circuits, switch emitter, and feedback amplifier; tab connection enables low-θJA thermal performance. |
| FB (Pin 4) | Feedback input / mode select | At 1.224V → normal regulation; pulled below 0.54V → activates flyback amplifier (15V reference); high-impedance (≤1.1µA bias). |
| VC (Pin 5) | Error amplifier output / control node | 0.9–2.0V during regulation; clamping controls current limit; <0.15V enables 50µA shutdown; capacitor coupling enables soft-start. |
Key Features
| Feature | Design Value |
|---|---|
| Integrated 5A, 65V switch | Eliminates need for external power transistor in ≤100W applications, reducing BOM count and layout complexity. |
| Current-mode control architecture | Provides inherent pulse-by-pulse overcurrent protection, fast line/load transient response, and stable loop compensation across operating conditions. |
| Flyback-regulated mode with 15.0V reference | Enables fully floating, transformer-isolated outputs without optocouplers or secondary-side sensing circuitry. |
| Adaptive anti-saturation switch drive | Maintains high efficiency across 0–5A load range by dynamically adjusting base/gate drive to prevent saturation losses. |
| Shutdown mode (50µA IQ) | Supports low-power standby states in battery-powered or energy-conscious systems without disabling upstream supplies. |
| Wide topology support (buck, boost, flyback, etc.) | Single IC replaces multiple controller + switch combinations, simplifying design reuse across diverse power architectures. |
Applications
| Industrial AC/DC Adapter | Isolated Telecom Power Supply |
|---|---|
Use Scenario: 24VAC-to-12VDC adapter powering PLC I/O modules in factory automation cabinets. IC Role / Device Role / Timing Role: Primary-side flyback controller regulating isolated 12V output using transformer-coupled feedback; operates at 100kHz with 5A switch handling peak primary current. Use Value: Eliminates optocoupler and secondary-side TL431, reducing component count by 4 parts while maintaining ±3% output regulation across 0–100% load. |
Use Scenario: 48V telecom rectifier supplying isolated ±15V op-amp rails for analog front-end circuitry. IC Role / Device Role / Timing Role: Dual-output flyback controller using separate windings; FB pin configured for flyback mode to regulate both outputs simultaneously via primary-side sensing. Use Value: Achieves <1% cross-regulation between ±15V rails without post-regulation LDOs, leveraging the LT1170CQ#TRPBF's 15.0V flyback reference accuracy and low 1.224V reference drift. |
| Battery-Powered Medical Instrument | Automotive LED Driver |
Use Scenario: Portable ultrasound device powered from 12V sealed lead-acid battery requiring clean ±5V analog supply. IC Role / Device Role / Timing Role: Inverting buck-boost regulator generating –5V from 10–14V battery input; uses internal 5A switch and current-mode control for stable output under varying battery SOC. Use Value: Maintains –5.0V ±1.5% across full battery range (10.5V–14.4V) with <10mV ripple, enabled by 6mA quiescent current and adaptive anti-sat drive minimizing dropout at low VIN. |
Use Scenario: 12V vehicle system driving 3-series white LEDs (9.6V VF) with constant current regulation. IC Role / Device Role / Timing Role: Boost converter with FB pin sensing LED current via sense resistor; VC pin used for analog dimming control and overtemperature foldback. Use Value: Delivers 350mA LED current with <2% variation across 9–16V input range, leveraging the LT1170CQ#TRPBF's 100kHz frequency stability and 5A switch headroom for surge immunity. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar high-current switching regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LT1170CT#TRPBF | Same die, but in 5-lead TO-220 package with higher θJC (2°C/W vs DD's ~25–45°C/W) and integrated heatsink tab. | Better thermal performance in high-ambient or continuous 5A operation; requires PCB cutout for TO-220 mounting. | Select LT1170CT#TRPBF when ambient exceeds 60°C or full 5A load is sustained >60 seconds; LT1170CQ#TRPBF preferred for space-constrained DIP-compatible layouts. |
| LT1171CQ#TRPBF | Same pinout and footprint, but rated for 2.5A switch current and 0.3Ω typical RDS(on); shares identical control architecture and feature set. | Lower power (≤50W) applications; reduced conduction loss at light loads due to lower gate charge. | Choose LT1171CQ#TRPBF when peak load is ≤2.5A and board area must be minimized - direct drop-in replacement with no layout change required. |
Compared with LT1170CT#TRPBF, the LT1170CQ#TRPBF offers identical electrical performance in a smaller DIP-form-factor package optimized for compact designs, while LT1171CQ#TRPBF provides a true pin-compatible 2.5A alternative for cost- and thermally sensitive mid-power applications.
Availability
LT1170CQ#TRPBF is available at Aetrix Electronics and suitable for industrial power supplies, isolated telecom converters, battery-powered medical instruments, and automotive LED drivers requiring stable component supply with long-term lifecycle support.
Supply support for LT1170CQ#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, Inc. (acquired Linear Technology in 2017) is a global leader in high-performance analog, mixed-signal, and power management semiconductors, serving industrial, automotive, communications, and healthcare markets.
The LT1170 series belongs to Linear Technology's legacy monolithic switching regulator product line, designed specifically for high-power, topology-flexible DC/DC conversion where integration of switch + controller + protection reduces design risk and time-to-market.
FAQ
What is the maximum input voltage rating for LT1170CQ#TRPBF?
The LT1170CQ#TRPBF has an absolute maximum supply voltage of 40V. Its internal 65V-rated switch allows safe operation up to this rail, but in flyback configurations, maximum input is limited to 55V to maintain margin against switch breakdown under transient conditions. Always observe the 40V operational limit specified in the Absolute Maximum Ratings table for reliable long-term use.
Does LT1170CQ#TRPBF support external synchronization?
Yes, the LT1170CQ#TRPBF can be externally synchronized to frequencies between 120kHz and 160kHz by pulling the VC pin to ground with a narrow (<0.3µs) pulse via an external transistor. This feature enables noise-sensitive systems to avoid critical EMI bands or align multiple converters for interleaving - without altering the internal 100kHz oscillator's default operation.
How does the flyback regulation mode work on LT1170CQ#TRPBF?
The LT1170CQ#TRPBF enters flyback mode when the FB pin voltage drops below 0.54V, disconnecting the main error amplifier and enabling a dedicated flyback amplifier with a 15.0V reference. This allows regulation of reflected flyback pulses across transformer windings - delivering fully floating, optocoupler-free isolated outputs with tight cross-regulation in multi-rail designs.
What thermal considerations apply to LT1170CQ#TRPBF in continuous 5A operation?
In the 5-lead DD package, LT1170CQ#TRPBF exhibits θJA ≈ 25–45°C/W depending on PCB copper area. At full 5A load and 40V input, total dissipation may exceed 2W; adequate 2.8 sq. in. of 1oz. copper is required to hold junction temperature ≤100°C. For sustained high-power use, consider the TO-220 variant (LT1170CT#TRPBF) with θJC = 2°C/W and external heatsinking capability.
Can LT1170CQ#TRPBF be used in boost configuration with 5V input to 12V output?
Yes - the LT1170CQ#TRPBF is explicitly validated for boost operation, as shown in the "Boost Converter (5V to 12V)" typical application circuit. With proper selection of inductor (e.g., 50µH), catch diode (e.g., MBR330), and output capacitor (1000µF), it delivers 1A at 12V from 5V input with >85% efficiency and stable regulation across line and load variations.
LT1170CQ#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, Step-Up/Step-Down
- Output Configuration:
- Positive or Negative
- Topology:
- Buck, Boost, Cuk, Flyback, Forward Converter
- Output Type:
- Adjustable
- Number of Outputs:
- 1
- Voltage - Input (Min):
- 3V
- Voltage - Input (Max):
- 40V
- Voltage - Output (Min/Fixed):
- 1.244V
- Voltage - Output (Max):
- 65V (Switch)
- Current - Output:
- 5A (Switch)
- Frequency - Switching:
- 100kHz
- Synchronous Rectifier:
- No
- Operating Temperature:
- 0°C ~ 100°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- DDPAK-5
LT1170CQ#TRPBF FAQ
1.How can I place an order for LT1170CQ#TRPBF through Aetrix?
Please submit a Request for Quotation (RFQ) for LT1170CQ#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 LT1170CQ#TRPBF reliable?
The price and inventory of LT1170CQ#TRPBF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LT1170CQ#TRPBF is usually 5 days.
3.What payment methods are accepted for LT1170CQ#TRPBF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LT1170CQ#TRPBF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LT1170CQ#TRPBF?
LT1170CQ#TRPBF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LT1170CQ#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 LT1170CQ#TRPBF?
For technical support, including LT1170CQ#TRPBF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LT1170CQ#TRPBF requirements.
6.How does Aetrix verify that LT1170CQ#TRPBF is sourced from the original manufacturer or authorized distributors?
All LT1170CQ#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 LT1170CQ#TRPBF meets industry standards.
7.What is the process for return or replacement of LT1170CQ#TRPBF?
All LT1170CQ#TRPBF units undergo pre-shipment inspection (PSI). If there is an issue with LT1170CQ#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 LT1170CQ#TRPBF part is unused and in its original packaging.
Return procedure for LT1170CQ#TRPBF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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