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Analog Devices Inc. LTC3803MPS6-3#TRMPBF
- Part No.:
- LTC3803MPS6-3#TRMPBF
- Manufacturer:
- Analog Devices Inc.
- Category:
- DC DC Switching Controllers
- Package:
- SOT-23-6 Thin, TSOT-23-6
- Datasheet:
-
LTC3803MPS6-3#TRMPBF.pdf
- Description:
- IC REG CTRLR FLYBACK TSOT23-6
- Quantity:
- Payment:
- Shipping:
Inventory:500
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Product details
Overview
LTC3803MPS6-3#TRMPBF from Analog Devices (formerly Linear Technology) is a constant-frequency current-mode flyback DC/DC controller optimized for high-input-voltage N-channel MOSFET drive, delivering ±1.5% output voltage accuracy, 300kHz fixed switching frequency, 240μA quiescent current, and operation across –55°C to 150°C. It enables nonisolated telecom housekeeping supplies with input ranges up to 72V.
For engineers reviewing the LTC3803MPS6-3#TRMPBF datasheet, LTC3803MPS6-3#TRMPBF pinout, LTC3803MPS6-3#TRMPBF application, or LTC3803MPS6-3#TRMPBF equivalent, key selection criteria include its extended temperature grade (–55°C to 150°C), ground-referenced current sensing, programmable slope compensation, internal soft-start (1.4ms), and VCC shunt regulation supporting resistor-fed or bias-winding power schemes.
Technical Context
The LTC3803MPS6-3#TRMPBF implements a current-mode control architecture with a 300kHz free-running oscillator, peak-current sensing via the SENSE pin, and an error amplifier driving the ITH/RUN node to modulate duty cycle between 8% and 80%. Its internal 0.8V reference feeds the VFB comparator, enabling precise output regulation independent of external component tolerances.
It features dual shutdown mechanisms: undervoltage lockout (VTURNON = 7.5V, VTURNOFF = 4V, hysteresis = 3V) and ITH/RUN forced shutdown (VITHSHDN = 0.09V). The NGATE driver delivers 1A peak sink/source capability with 40ns rise/fall times into 3000pF, directly driving N-channel MOSFET gates without external buffers.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Oscillator Frequency | 300kHz nominal; ensures predictable EMI profile and simplifies filter design for telecom and automotive auxiliary supplies. |
| Output Voltage Accuracy | ±1.5% over full temperature range; guarantees stable 5V housekeeping rail without post-regulation in telecom systems. |
| Quiescent Current | 240μA typical; enables high-efficiency light-load operation in always-on auxiliary power domains. |
| Operating Temperature | –55°C to 150°C junction; qualified for harsh environments including under-hood automotive and industrial control cabinets. |
| VCC Shunt Regulation | Clamps at 9.5V (1mA load); permits direct resistor-fed startup from 36–72V inputs without external LDO or regulator. |
| Peak Current Sense Threshold | 85mV minimum (MP grade); sets precise overcurrent protection point for primary-side MOSFETs in flyback topologies. |
| Soft-Start Time | 1.4ms typical; prevents inrush current stress on transformer windings and output capacitors during cold start. |
Pinout & Package
Package: 6-lead TSOT-23 (ThinSOT™), 1mm height, RoHS-compliant, moisture sensitivity level 1.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| ITH/RUN (Pin 1) | Error amplifier output & shutdown control | Sets current comparator threshold (0.7–1.9V range); pulled low (<0.09V) forces shutdown; hosts RC compensation network. |
| GND (Pin 2) | Power and signal reference | Common return for VCC bypass, sense resistor, and feedback divider; must be low-impedance star point. |
| VFB (Pin 3) | Feedback input | Compares resistive-divider output against 0.8V internal reference; 10nA input bias enables high-value dividers for low standby loss. |
| SENSE (Pin 4) | Current sense & slope ramp injection | Monitors MOSFET source voltage; injects 5μA linear ramp (8–80% duty) for external slope compensation via RSL. |
| VCC (Pin 5) | Supply input with internal shunt regulator | Accepts 7.5–9.4V turn-on; clamped at ~9.5V; requires ≥1μF ceramic bypass adjacent to pin. |
| NGATE (Pin 6) | N-channel MOSFET gate driver | Push-pull output swinging 0V to VCC; 1A peak drive supports fast switching of >10nC gate charges. |
Key Features
| Feature | Design Value |
|---|---|
| Ground-referenced current sensing | Enables high-side primary switch configurations without level-shifting circuitry or isolated sense amplifiers. |
| Programmable slope compensation | 5μA internal ramp + external RSL allows stability tuning for wide duty-cycle or high-VIN:VOUT ratio flyback designs. |
| Micropower hysteretic start-up | 240μA operating ICC + 40μA start-up ICC enables reliable bootstrap from bias winding with minimal trickle-charge resistor loss. |
| Wide UVLO hysteresis (3V) | Supports self-powered operation from transformer bias winding without external supervisor ICs or complex sequencing. |
| No minimum load requirement | Constant-frequency operation down to zero load eliminates burst-mode noise and simplifies EMI compliance testing. |
Applications
| Telecom Housekeeping Supply | Automotive Auxiliary Power |
|---|---|
Use Scenario: Generating 5V/2A auxiliary rail from 36–72V telecom rectified bus for management controllers and PHYs. IC Role / Device Role / Timing Role: Primary-side flyback controller regulating output via optocoupler-free feedback; provides timing reference for synchronous rectification. Use Value: Eliminates need for isolated DC/DC module; achieves >85% efficiency at full load with single-stage conversion and no minimum load constraint. |
Use Scenario: Deriving 5V supply for infotainment microcontrollers from 12V/42V vehicle battery with cold-crank tolerance. IC Role / Device Role / Timing Role: Constant-frequency flyback controller managing gate drive timing and current limiting for N-MOSFET power switch. Use Value: –55°C to 150°C rating ensures operation during engine-off storage and under-hood hot-soak; 300kHz switching avoids AM band interference. |
| Power over Ethernet PD | Industrial Control Auxiliary Rail |
Use Scenario: Providing regulated 3.3V/5V bias for PoE-powered device logic and interface ICs from IEEE 802.3af/at PSE output. IC Role / Device Role / Timing Role: Nonisolated flyback controller implementing secondary-side regulation using VFB feedback; controls NGATE timing for efficient energy transfer. Use Value: Internal 0.8V reference and ±1.5% accuracy meet PoE Class 3–5 power budgeting requirements without trimming resistors. |
Use Scenario: Generating isolated 5V/3.3V rails for PLC I/O modules and sensor interfaces in factory automation cabinets. IC Role / Device Role / Timing Role: Flyback controller driving primary-side MOSFET; coordinates soft-start and UVLO to prevent brownout-induced resets during line transients. Use Value: 1.4ms soft-start and 3V UVLO hysteresis ensure clean power-up during 24VDC supply recovery after short interruptions. |
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; 1.5% reference accuracy; 2.5mA start-up current; no internal VCC shunt regulator. | Requires external VCC LDO or bias winding with tighter voltage control; less suitable for resistor-fed high-VIN startup. | Select UCC28C43DR only when external regulation is already present and lower start-up current is not required. |
| MAX5021ASA+ | 300kHz frequency; ±2% reference accuracy; 1.2mA start-up current; integrated 7.5V LDO for VCC. | LDO-based VCC supply limits max input to ~20V unless externally boosted; narrower temp range (–40°C to 125°C). | Choose MAX5021ASA+ for cost-sensitive 12V/24V industrial supplies where extended temperature is not mandatory. |
Compared with UCC28C43DR and MAX5021ASA+, the LTC3803MPS6-3#TRMPBF uniquely combines ultra-low quiescent current (240μA), internal VCC shunt regulation for direct high-VIN startup, and military-grade temperature range - making it optimal for unregulated telecom and automotive auxiliary rails where reliability and simplicity are critical.
Availability
LTC3803MPS6-3#TRMPBF is available at Aetrix Electronics and suitable for telecom housekeeping supplies, automotive auxiliary power, Power over Ethernet powered devices, and industrial control auxiliary rails requiring stable component supply across extreme temperature conditions.
Supply support for LTC3803MPS6-3#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 its legacy of high-performance analog and power management ICs with rigorous qualification standards.
The LTC3803 family was designed specifically for rugged, high-input-voltage flyback and boost converter applications in telecom, automotive, and industrial systems demanding extended temperature operation and minimal external components.
FAQ
What is the maximum input voltage supported by the LTC3803MPS6-3#TRMPBF?
The LTC3803MPS6-3#TRMPBF itself has no intrinsic VIN limit - its absolute maximum VCC rating is 8V, but it supports input voltages beyond that via ground-referenced current sensing and external MOSFET selection. In practice, designs using the LTC3803MPS6-3#TRMPBF routinely operate from 36V to 72V input buses, limited only by the external MOSFET's BVDSS and transformer insulation ratings.
Does the LTC3803MPS6-3#TRMPBF require an external current sense resistor?
Yes, the LTC3803MPS6-3#TRMPBF requires an external current sense resistor (RSENSE) connected between the MOSFET source and ground. This resistor converts switch current into a voltage sensed at the SENSE pin. Typical values range from tens of milliohms to several ohms depending on desired peak current; the LTC3803MPS6-3#TRMPBF's 85mV minimum sense threshold defines the lower bound for RSENSE selection.
Can the LTC3803MPS6-3#TRMPBF be powered directly from a high-voltage input rail?
Yes, the LTC3803MPS6-3#TRMPBF can be powered directly from a high-voltage input rail (e.g., 48V or 72V) using a series dropping resistor into the VCC pin. Its internal shunt regulator clamps VCC at ~9.5V and sinks up to 25mA, enabling simple, low-component-count startup without external regulators - a key advantage over controllers requiring dedicated bias supplies.
What is the purpose of the SENSE pin on the LTC3803MPS6-3#TRMPBF?
The SENSE pin on the LTC3803MPS6-3#TRMPBF serves two functions: (1) it monitors the voltage across the external current sense resistor to implement peak-current-mode control, and (2) it injects a 5μA linear ramp current (from 0 to 80% duty cycle) used for programmable slope compensation. When combined with an external resistor (RSL), this ramp generates a duty-cycle-proportional voltage that stabilizes the control loop against subharmonic oscillation.
How does the LTC3803MPS6-3#TRMPBF achieve its –55°C to 150°C operating range?
The LTC3803MPS6-3#TRMPBF achieves its –55°C to 150°C operating range through full characterization and testing across that junction temperature span (LTC3803MP-3 grade), including validation of all electrical parameters - such as ±1.5% reference accuracy, 300kHz oscillator stability, and 85mV current sense threshold - under extreme thermal stress. This qualifies it for deployment in unheated outdoor telecom enclosures and under-hood automotive locations.
LTC3803MPS6-3#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:
- 300kHz
- Duty Cycle (Max):
- 80%
- Synchronous Rectifier:
- No
- Clock Sync:
- No
- Serial Interfaces:
- -
- Control Features:
- Current Limit, Enable
- Operating Temperature:
- -55°C ~ 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- TSOT-23-6
LTC3803MPS6-3#TRMPBF FAQ
1.How can I place an order for LTC3803MPS6-3#TRMPBF through Aetrix?
Please submit a Request for Quotation (RFQ) for LTC3803MPS6-3#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 LTC3803MPS6-3#TRMPBF reliable?
The price and inventory of LTC3803MPS6-3#TRMPBF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LTC3803MPS6-3#TRMPBF is usually 5 days.
3.What payment methods are accepted for LTC3803MPS6-3#TRMPBF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LTC3803MPS6-3#TRMPBF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LTC3803MPS6-3#TRMPBF?
LTC3803MPS6-3#TRMPBF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LTC3803MPS6-3#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 LTC3803MPS6-3#TRMPBF?
For technical support, including LTC3803MPS6-3#TRMPBF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LTC3803MPS6-3#TRMPBF requirements.
6.How does Aetrix verify that LTC3803MPS6-3#TRMPBF is sourced from the original manufacturer or authorized distributors?
All LTC3803MPS6-3#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 LTC3803MPS6-3#TRMPBF meets industry standards.
7.What is the process for return or replacement of LTC3803MPS6-3#TRMPBF?
All LTC3803MPS6-3#TRMPBF units undergo pre-shipment inspection (PSI). If there is an issue with LTC3803MPS6-3#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 LTC3803MPS6-3#TRMPBF part is unused and in its original packaging.
Return procedure for LTC3803MPS6-3#TRMPBF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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