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Analog Devices Inc. LTC3803ES6#TRMPBF
- Part No.:
- LTC3803ES6#TRMPBF
- Manufacturer:
- Analog Devices Inc.
- Category:
- DC DC Switching Controllers
- Package:
- SOT-23-6 Thin, TSOT-23-6
- Datasheet:
-
LTC3803ES6#TRMPBF.pdf
- Description:
- IC REG CTRLR FLYBACK TSOT23-6
- Quantity:
- Payment:
- Shipping:
Inventory:2,208
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Product details
Overview
LTC3803ES6#TRMPBF from Analog Devices (formerly Linear Technology) is a constant-frequency current-mode flyback DC/DC controller optimized for driving external N-channel MOSFETs in high-input-voltage telecom and industrial power supplies. It delivers ±1.5% output voltage accuracy, 200kHz fixed switching frequency, 240μA quiescent current, and operates with VIN and VOUT limited only by external components - enabling 36V–72V input telecom housekeeping supplies delivering 5V/2A.
For engineers reviewing the LTC3803ES6#TRMPBF datasheet, LTC3803ES6#TRMPBF pinout, LTC3803ES6#TRMPBF application, or LTC3803ES6#TRMPBF equivalent, this page provides verified functional identity, validated SOT-23-6 pin mapping, confirmed slope compensation programmability, real-world flyback design constraints, and two rigorously validated alternative controllers for telecom auxiliary power designs.
Technical Context
The LTC3803ES6#TRMPBF implements a current-mode control architecture with a 200kHz free-running oscillator, internal soft-start (1.4ms), and programmable slope compensation via external resistor on the SENSE pin. Its error amplifier drives the ITH/RUN pin to set peak current comparator threshold, directly linking feedback deviation to duty cycle modulation.
It features ground-referenced current sensing, micropower hysteretic start-up, and an internal shunt regulator clamping VCC to ~9.5V - allowing direct high-VIN biasing through a single resistor. Undervoltage lockout has wide hysteresis (VTURNON = 8.7V, VTURNOFF = 5.7V), supporting reliable bootstrap operation from transformer bias windings.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Switching Frequency | 200kHz fixed - enables compact magnetics and predictable EMI profile without frequency jitter. |
| Output Voltage Accuracy | ±1.5% - ensures stable regulation across temperature and line/load variations in telecom housekeeping rails. |
| Quiescent Current | 240μA - minimizes no-load power loss in always-on auxiliary supplies. |
| VCC Shunt Clamp | 9.5V typical - permits direct high-VIN powering via series resistor without external LDO. |
| UVLO Thresholds | VTURNON = 8.7V, VTURNOFF = 5.7V - supports reliable start-up from bias winding with >3V hysteresis. |
| Peak Sense Voltage | 100mV typical - sets precise current limit with low-loss external sense resistor (e.g., 68mΩ for 1.5A peak). |
| Soft-Start Time | 1.4ms - prevents inrush current stress on transformer, MOSFET, and output capacitors. |
Pinout & Package
Package: 6-lead TSOT-23 (ThinSOT™), 1mm height, RoHS-compliant, rated for –40°C to +125°C junction temperature.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| ITH/RUN (Pin 1) | Error amplifier output & shutdown control | Sets current comparator threshold (0.7V–1.9V range); pulled low (<0.28V) forces shutdown. |
| GND (Pin 2) | Power and signal reference | Ground return for all internal circuits and external sense resistor; must be low-impedance. |
| VFB (Pin 3) | Feedback input | Compares output divider voltage to 800mV internal reference; 10nA input current enables high-R dividers. |
| SENSE (Pin 4) | Current sense & slope ramp injection | Monitors external RSENSE voltage; sources 5μA linear ramp for slope compensation when RSL present. |
| VCC (Pin 5) | Supply input with internal shunt regulator | Accepts 5.7–9.5V; internal clamp regulates to ~9.5V up to 25mA - enables resistor-fed high-VIN biasing. |
| NGATE (Pin 6) | N-MOSFET gate driver output | Drives external N-channel MOSFET gate from 0V to VCC; 40ns rise/fall time into 3000pF load. |
Key Features
| Feature | Design Value |
|---|---|
| Constant-frequency current mode control | Enables predictable EMI filtering and stable loop response across 0–100% load without minimum load requirement. |
| Programmable slope compensation | 5μA ramp injected at SENSE pin allows external RSL to stabilize duty cycles >50% and prevent subharmonic oscillation. |
| Internal soft-start | 1.4ms controlled ITH/RUN voltage ramp prevents transformer saturation and output overshoot during power-up. |
| Ground-referenced current sensing | Allows primary-side sensing with low-side RSENSE, simplifying layout and eliminating need for isolated sense amplifiers. |
| Micropower hysteretic start-up | 0.3μA ITH/RUN pull-up and wide UVLO hysteresis enable reliable self-starting from transformer bias winding. |
Applications
| Telecom Housekeeping Supply | Automotive Auxiliary Power |
|---|---|
Use Scenario: Generating isolated 5V/2A rail from 36–72V telecom battery backup system for management MCU, EEPROM, and interface logic. IC Role / Device Role / Timing Role: Flyback controller regulating output via optocoupler feedback; 200kHz switching defines transformer size and EMI filter requirements. Use Value: ±1.5% accuracy maintains MCU brown-out immunity; 240μA quiescent current extends battery runtime during standby. |
Use Scenario: Deriving 12V auxiliary supply from 42V automotive main bus for infotainment display backlight and CAN transceiver bias. IC Role / Device Role / Timing Role: Primary-side flyback controller with transformer-coupled VCC bias; UVLO hysteresis accommodates cold-crank voltage dips. Use Value: Ground-referenced sensing eliminates high-side current monitor IC; internal shunt regulator avoids external LDO in space-constrained modules. |
| Power over Ethernet (PoE) PD | Industrial PLC Auxiliary Rail |
Use Scenario: Providing regulated 3.3V/1A output from PoE Class 4 (57V) input for Ethernet PHY and microcontroller in powered device. IC Role / Device Role / Timing Role: Constant-frequency flyback controller interfacing with IEEE 802.3af/at PD interface; ITH/RUN used for active current limiting. Use Value: Adjustable slope compensation ensures stability with wide input range; no minimum load required simplifies design for variable PHY activity. |
Use Scenario: Generating isolated 24V/500mA auxiliary supply from 120VAC rectified bus for PLC I/O module logic and sensor excitation. IC Role / Device Role / Timing Role: High-VIN flyback controller with transformer bias winding powering VCC; SENSE pin used for primary current limiting and OCP. Use Value: VIN/VOUT limited only by external components enables use with 1000V-rated MOSFETs and reinforced insulation transformers. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar flyback controller applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| UCC28C43DR | Fixed 275kHz frequency; no internal VCC shunt regulator; requires external bias supply or auxiliary winding. | Better suited for higher-frequency, lower-power designs where smaller magnetics are prioritized over high-VIN simplicity. | Select UCC28C43DR when optimizing for size/cost in <15W applications and external bias is available. |
| MAX17595ATP+T | Wide 4.5V–60V input; integrated 1.2A gate driver; requires external slope compensation capacitor (not resistor). | Designed for high-current industrial flyback with tighter thermal constraints; lacks micropower start-up capability. | Select MAX17595ATP+T for >3A output designs requiring robust gate drive and extended input range down to 4.5V. |
Compared with LTC3803ES6#TRMPBF, UCC28C43DR offers higher frequency but demands external biasing, while MAX17595ATP+T provides stronger gate drive and wider VIN range but requires different slope compensation implementation and lacks ultra-low IQ start-up - making LTC3803ES6#TRMPBF uniquely suited for high-VIN, low-quiescent telecom housekeeping.
Availability
LTC3803ES6#TRMPBF is available at Aetrix Electronics and suitable for telecom power supplies, automotive auxiliary converters, and Power over Ethernet powered devices requiring stable component supply, long-term lifecycle support, and guaranteed RoHS-compliant packaging.
Supply support for LTC3803ES6#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 acquired Linear Technology in 2017 and maintains full product support, datasheet documentation, and application engineering for legacy Linear power ICs.
The LTC3803ES6#TRMPBF belongs to Linear's high-voltage flyback controller family, designed specifically for isolated auxiliary power in telecom infrastructure, industrial systems, and automotive electronics where input voltages exceed 36V.
FAQ
What is the operating temperature range for the LTC3803ES6#TRMPBF?
The LTC3803ES6#TRMPBF is specified for operation from –40°C to +125°C junction temperature. This grade (E-grade) is validated across the full range with guaranteed performance for VFB, UVLO thresholds, and oscillator frequency - making it suitable for enclosed telecom chassis and under-hood automotive auxiliary supplies where ambient temperatures exceed 85°C.
Can the LTC3803ES6#TRMPBF be powered directly from a 48V input?
Yes - the LTC3803ES6#TRMPBF can be powered directly from 48V using a series resistor into the VCC pin. Its internal shunt regulator clamps VCC to ~9.5V and sinks up to 25mA, allowing simple resistor-based biasing without external regulators. For example, a 1.5kΩ resistor limits current to ~22mA at 48V, staying within safe operating limits while maintaining regulation.
Does the LTC3803ES6#TRMPBF require an external slope compensation network?
The LTC3803ES6#TRMPBF includes programmable slope compensation: a 5μA linear ramp is injected from the SENSE pin into an external resistor (RSL). If slope compensation is needed (e.g., for duty cycles >50%), RSL is added between SENSE and RSENSE. If not required, RSL may be omitted or replaced with a short - no mandatory external components are needed for basic operation.
What is the purpose of the ITH/RUN pin on the LTC3803ES6#TRMPBF?
The ITH/RUN pin on the LTC3803ES6#TRMPBF serves dual functions: it is the error amplifier output that sets the current comparator threshold (0.7V–1.9V range), and it acts as the run/shutdown control input. Pulling ITH/RUN below 0.28V forces shutdown; releasing it above this threshold - while VCC exceeds 8.7V - initiates soft-start and normal operation.
How does the LTC3803ES6#TRMPBF achieve ±1.5% output voltage accuracy?
The LTC3803ES6#TRMPBF achieves ±1.5% output voltage accuracy via a precision 800mV internal reference and low-input-bias-current (10nA) VFB pin. When paired with a resistive divider having ≤1% tolerance resistors and proper PCB layout (minimizing trace resistance near VFB), the regulation error remains within specification across line, load, and temperature - critical for powering sensitive telecom management ICs.
LTC3803ES6#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):
- 5.7V ~ 8V
- Frequency - Switching:
- 200kHz
- Duty Cycle (Max):
- 80%
- Synchronous Rectifier:
- No
- Clock Sync:
- No
- Serial Interfaces:
- -
- Control Features:
- Current Limit, Enable
- Operating Temperature:
- -40°C ~ 125°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- TSOT-23-6
LTC3803ES6#TRMPBF FAQ
1.How can I place an order for LTC3803ES6#TRMPBF through Aetrix?
Please submit a Request for Quotation (RFQ) for LTC3803ES6#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 LTC3803ES6#TRMPBF reliable?
The price and inventory of LTC3803ES6#TRMPBF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LTC3803ES6#TRMPBF is usually 5 days.
3.What payment methods are accepted for LTC3803ES6#TRMPBF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LTC3803ES6#TRMPBF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LTC3803ES6#TRMPBF?
LTC3803ES6#TRMPBF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LTC3803ES6#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 LTC3803ES6#TRMPBF?
For technical support, including LTC3803ES6#TRMPBF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LTC3803ES6#TRMPBF requirements.
6.How does Aetrix verify that LTC3803ES6#TRMPBF is sourced from the original manufacturer or authorized distributors?
All LTC3803ES6#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 LTC3803ES6#TRMPBF meets industry standards.
7.What is the process for return or replacement of LTC3803ES6#TRMPBF?
All LTC3803ES6#TRMPBF units undergo pre-shipment inspection (PSI). If there is an issue with LTC3803ES6#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 LTC3803ES6#TRMPBF part is unused and in its original packaging.
Return procedure for LTC3803ES6#TRMPBF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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