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Analog Devices Inc. LTC3803HS6-5#TRMPBF
- Part No.:
- LTC3803HS6-5#TRMPBF
- Manufacturer:
- Analog Devices Inc.
- Category:
- DC DC Switching Controllers
- Package:
- SOT-23-6 Thin, TSOT-23-6
- Datasheet:
-
LTC3803HS6-5#TRMPBF.pdf
- Description:
- IC REG CTRLR FLYBACK TSOT23-6
- Quantity:
- Payment:
- Shipping:
Inventory:500
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Product details
Overview
LTC3803HS6-5#TRMPBF from Analog Devices (formerly Linear Technology) is a constant-frequency current-mode flyback DC/DC controller in a 6-lead ThinSOT™ package, optimized for driving N-channel MOSFETs in high-input-voltage isolated power supplies. It operates from 5V to 50V input, delivers ±1.5% output voltage accuracy, maintains 200kHz switching across light-to-full load, and features internal shunt regulation enabling direct high-VIN biasing. It is used in automotive auxiliary supplies and telecom housekeeping converters.
For engineers reviewing the LTC3803HS6-5#TRMPBF datasheet, LTC3803HS6-5#TRMPBF pinout, LTC3803HS6-5#TRMPBF application, or LTC3803HS6-5#TRMPBF equivalent, key selection criteria include its –40°C to 150°C operating junction temperature, ground-referenced current sensing, programmable slope compensation, and 240μA quiescent current - all critical for rugged, low-noise isolated converter design.
Technical Context
The LTC3803HS6-5#TRMPBF implements fixed-frequency (200kHz) current-mode control with an internal oscillator, RS latch, and current comparator that sets peak switch current via the ITH/RUN pin voltage. Its error amplifier drives the ITH/RUN node to regulate VFB at 0.788–0.812V, closing the feedback loop through external resistive divider and slope-compensated current sensing on the SENSE pin.
It integrates undervoltage lockout (VTURNON = 4.8V, VTURNOFF = 4.0V), internal soft-start (0.7ms), and a 8.1V VCC shunt regulator capable of sinking up to 25mA. The NGATE driver delivers 1A peak current with 40ns rise/fall times into 3000pF, supporting fast-switching N-MOSFETs in flyback, SEPIC, and boost topologies.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Oscillator Frequency | 200kHz typical; enables predictable EMI filtering and stable operation down to light loads without frequency foldback. |
| Output Voltage Accuracy | ±1.5% over temperature; ensures tight regulation for sensitive downstream circuitry without post-regulation. |
| Quiescent Current | 240μA typical; minimizes no-load power loss in always-on auxiliary supplies. |
| Junction Temperature Range | –40°C to 150°C; supports under-hood automotive and industrial environments without derating. |
| VCC Shunt Regulation | Clamps at 8.1V with 25mA sink capability; allows simple resistor-fed bias from VIN up to 50V without external LDO. |
| Peak Current Sense Threshold | 100mV typical; sets precise overcurrent limit with minimal power loss in RSENSE. |
| Gate Drive Rise/Fall Time | 40ns into 3000pF; enables efficient switching of low-Qg MOSFETs while limiting dv/dt-induced noise. |
Pinout & Package
Package: 6-lead Low Profile (1mm) TSOT-23 (ThinSOT™), JEDEC MO-193 compliant, 3.85mm × 2.90mm footprint.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| ITH/RUN (1) | Error amplifier output & shutdown control | Sets current comparator threshold; pulled to ~0.7V at startup; <0.28V forces shutdown. |
| GND (2) | Analog and power ground reference | Common return for feedback, sense, and gate drive; must be low-impedance to avoid noise coupling. |
| VFB (3) | Feedback input | Monitors output via resistive divider; regulated to 0.788–0.812V; 10nA input bias minimizes divider error. |
| SENSE (4) | Current sense & slope compensation injection | Detects MOSFET source current; injects 5μA linear ramp for duty-cycle-dependent slope compensation. |
| VCC (5) | Supply input with internal shunt regulator | Accepts 5–50V input; internally clamped to 8.1V; requires local 10μF ceramic bypass to GND. |
| NGATE (6) | N-channel MOSFET gate driver | 0V to VCC swing; 1A peak drive; 40ns edges; directly drives logic-level or standard N-MOSFETs. |
Key Features
| Feature | Design Value |
|---|---|
| Constant-frequency current-mode control | 200kHz operation maintained across full load range, simplifying EMI filter design and improving transient response vs. variable-frequency alternatives. |
| Ground-referenced current sensing | Enables high-side primary-side sensing without level-shifting; supports input voltages far exceeding IC absolute maximum ratings. |
| Programmable slope compensation | 5μA ramp injected at SENSE pin allows external resistor (e.g., 5.9kΩ) to stabilize control loop above 50% duty cycle and prevent subharmonic oscillation. |
| Internal soft-start | 0.7ms controlled ITH/RUN ramp limits inrush current and prevents output overshoot during power-up. |
| High-temperature grade (H-grade) | Specified from –40°C to 150°C junction temperature; qualified for under-hood automotive and harsh industrial applications. |
Applications
| Automotive Auxiliary Power Supply | Telecom Housekeeping Converter |
|---|---|
|
Use Scenario: Generating isolated 5V/3.3V bias rails for microcontrollers and interface ICs in 12V/24V/48V vehicle systems. IC Role / Device Role / Timing Role: Flyback controller regulating secondary-side output using primary-side sensing; provides galvanic isolation and wide input tolerance. Use Value: –40°C to 150°C rating ensures reliability in engine bay environments; 240μA IQ enables low-power standby modes. |
Use Scenario: Providing isolated 12V/5V auxiliary power for control circuitry in telecom line cards with 36–75V input range. IC Role / Device Role / Timing Role: Constant-frequency flyback controller driving external N-MOSFET; uses transformer-coupled feedback for tight regulation without optocoupler. Use Value: 200kHz fixed frequency simplifies compliance with EN55022 Class B conducted EMI limits; ±1.5% accuracy eliminates need for post-regulation. |
| Power over Ethernet (PoE) Interface | Industrial Isolated Sensor Supply |
|
Use Scenario: Deriving isolated 3.3V/5V from PoE midspan or endpoint PSE outputs (up to 57V) for PD-side PHY and MCU. IC Role / Device Role / Timing Role: Primary-side regulated flyback controller with ground-referenced sensing; avoids optocoupler aging and drift. Use Value: VCC shunt regulator allows direct bias from PoE input; 4.8V UVLO prevents erratic startup during PoE classification phase. |
Use Scenario: Generating isolated 15V/–15V dual rails for precision analog front-ends in factory automation sensors. IC Role / Device Role / Timing Role: SEPIC or flyback controller supporting wide VIN (6–50V) and maintaining regulation during brownouts. Use Value: Adjustable slope compensation ensures stability across varying load and input conditions; low IQ extends battery backup runtime. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar flyback controller applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LTC3805ES6-5#TRMPBF | Adjustable frequency (100–600kHz); higher 350μA IQ; same 6-lead SOT-23 package. | Better EMI flexibility via frequency tuning; less suitable for ultra-low-power standby due to higher IQ. | Select when frequency optimization or multi-rail synchronization is required; not drop-in due to different UVLO and soft-start timing. |
| LTC3873HS6-5#TRMPBF | No external current sense resistor needed (No RSENSE™); 100kHz fixed frequency; 150μA IQ. | Reduces BOM count and PCB area; lower switching frequency increases magnetics size but lowers switching loss. | Choose for cost-sensitive, space-constrained designs where peak current sensing accuracy is secondary to simplicity. |
Compared with LTC3803HS6-5#TRMPBF, LTC3805ES6-5#TRMPBF offers frequency agility at higher quiescent cost, while LTC3873HS6-5#TRMPBF eliminates RSENSE but trades off switching speed and peak-current precision for integration - making LTC3803HS6-5#TRMPBF optimal for rugged, high-efficiency, fixed-frequency flyback designs requiring accurate current limiting.
Availability
LTC3803HS6-5#TRMPBF is available at Aetrix Electronics and suitable for automotive auxiliary power supplies, telecom housekeeping converters, and industrial isolated sensor supplies requiring stable component supply across extended temperature ranges.
Supply support for LTC3803HS6-5#TRMPBF 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. (including legacy Linear Technology products) is a global semiconductor leader specializing in high-performance analog, mixed-signal, and power management ICs for precision and power-critical applications.
The LTC3803 family is designed as compact, high-voltage flyback controllers for isolated DC/DC conversion in space- and thermal-constrained environments - targeting automotive, telecom, and industrial systems needing reliable, low-IQ, wide-input operation.
FAQ
What is the operating temperature range of the LTC3803HS6-5#TRMPBF?
The LTC3803HS6-5#TRMPBF is specified for a junction temperature range of –40°C to 150°C, making it suitable for under-hood automotive and high-ambient industrial applications. This H-grade qualification exceeds the E- and I-grade versions (–40°C to 125°C) and is verified per manufacturer test data across the full range.
How does the LTC3803HS6-5#TRMPBF achieve input voltage independence beyond its absolute maximum ratings?
The LTC3803HS6-5#TRMPBF achieves input voltage independence via ground-referenced current sensing and isolated feedback architecture. Its SENSE and VFB pins operate at ground potential, while external components (MOSFET, transformer, diodes) handle high voltage - allowing VIN and VOUT to be limited only by those external parts, not the LTC3803HS6-5#TRMPBF's 25V absolute max rating.
Can the LTC3803HS6-5#TRMPBF be powered directly from a high input voltage like 48V?
Yes - the LTC3803HS6-5#TRMPBF includes an internal VCC shunt regulator that clamps at 8.1V and can sink up to 25mA. When biased through a series resistor from 48V, it self-regulates VCC without external regulators, provided power dissipation in the resistor remains within safe limits and CVCC (≥10μF ceramic) is placed adjacent to the VCC pin.
What is the purpose of the SENSE pin on the LTC3803HS6-5#TRMPBF?
The SENSE pin on the LTC3803HS6-5#TRMPBF serves two functions: (1) it monitors voltage across an external current sense resistor to implement peak-current-mode control, and (2) it injects a 5μA linear ramp current used for programmable slope compensation - critical for loop stability in flyback converters operating above 50% duty cycle.
Does the LTC3803HS6-5#TRMPBF require an external optocoupler for feedback?
No - the LTC3803HS6-5#TRMPBF supports primary-side regulation using reflected voltage sensing across the transformer auxiliary winding, eliminating the need for an optocoupler or third winding. Its VFB pin regulates based on a scaled version of the output, enabling simpler, more reliable, and longer-lifetime isolated power supplies.
LTC3803HS6-5#TRMPBF Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc.
- Series:
- -
- Package/Case:
- SOT-23-6 Thin, TSOT-23-6
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Output Type:
- Transistor Driver
- Function:
- Step-Up/Step-Down
- Output Configuration:
- Positive, Isolation Capable
- Topology:
- Flyback
- Number of Outputs:
- 1
- Output Phases:
- 1
- Voltage - Supply (Vcc/Vdd):
- 4V ~ 8.1V
- Frequency - Switching:
- 200kHz
- Duty Cycle (Max):
- 80%
- Synchronous Rectifier:
- No
- Clock Sync:
- No
- Serial Interfaces:
- -
- Control Features:
- Current Limit, Enable
- Operating Temperature:
- -40°C ~ 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- TSOT-23-6
LTC3803HS6-5#TRMPBF FAQ
1.How can I place an order for LTC3803HS6-5#TRMPBF through Aetrix?
Please submit a Request for Quotation (RFQ) for LTC3803HS6-5#TRMPBF 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 LTC3803HS6-5#TRMPBF reliable?
The price and inventory of LTC3803HS6-5#TRMPBF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LTC3803HS6-5#TRMPBF is usually 5 days.
3.What payment methods are accepted for LTC3803HS6-5#TRMPBF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LTC3803HS6-5#TRMPBF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LTC3803HS6-5#TRMPBF?
LTC3803HS6-5#TRMPBF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LTC3803HS6-5#TRMPBF 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 LTC3803HS6-5#TRMPBF?
For technical support, including LTC3803HS6-5#TRMPBF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LTC3803HS6-5#TRMPBF requirements.
6.How does Aetrix verify that LTC3803HS6-5#TRMPBF is sourced from the original manufacturer or authorized distributors?
All LTC3803HS6-5#TRMPBF 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 LTC3803HS6-5#TRMPBF meets industry standards.
7.What is the process for return or replacement of LTC3803HS6-5#TRMPBF?
All LTC3803HS6-5#TRMPBF units undergo pre-shipment inspection (PSI). If there is an issue with LTC3803HS6-5#TRMPBF, 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 LTC3803HS6-5#TRMPBF part is unused and in its original packaging.
Return procedure for LTC3803HS6-5#TRMPBF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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