My Inquiry
My Account
Analog Devices Inc. LT3748MPMS#PBF
- Part No.:
- LT3748MPMS#PBF
- Manufacturer:
- Analog Devices Inc.
- Category:
- DC DC Switching Controllers
- Package:
- 16-TFSOP (0.118", 3.00mm Width), 12 Leads
- Datasheet:
-
LT3748MPMS#PBF.pdf
- Description:
- IC REG CTRLR FLYBACK 16MSOP
- Quantity:
- Payment:
- Shipping:
Inventory:264
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
LT3748MPMS#PBF from Analog Devices is a high-voltage isolated flyback controller IC designed for primary-side regulation in telecom, automotive, and industrial power supplies. It operates across 5V–100V input, delivers up to ~25W output (e.g., 12V/2A), uses boundary mode control, and eliminates opto-isolators or third windings by sensing output voltage directly from the primary-side flyback waveform.
For engineers reviewing the LT3748MPMS#PBF datasheet, LT3748MPMS#PBF pinout, LT3748MPMS#PBF application, or LT3748MPMS#PBF equivalent, key selection criteria include its –55°C to 150°C operating junction temperature, 1.9A average gate drive capability, programmable soft-start and UVLO, and MSOP-16 (12-lead) package with enhanced thermal performance for high-reliability isolated DC/DC conversion.
Technical Context
The LT3748MPMS#PBF implements boundary-mode (critical conduction mode) current-mode control to achieve tight load regulation without secondary-side feedback components. Its internal error amplifier samples the flyback pulse at zero-secondary-current crossing, enabling accurate output voltage derivation from RFB/RREF resistor ratio and transformer turns ratio.
It features an internally regulated 7V INTVCC supply driving a low-side N-channel MOSFET gate, with programmable SENSE current limit threshold (90–110mV), 250ns minimum on-time, and 24µs maximum discontinuous off-time. Temperature compensation via TC/RREF supports stable regulation over –55°C to 150°C.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Input Voltage Range | 5V to 100V - supports wide-input isolated supplies including telecom (36–72V) and automotive transients. |
| Operating Junction Temp | –55°C to 150°C - qualified for military, aerospace, and high-temperature automotive applications. |
| INTVCC Regulation | 7.0V ±0.2V - powers gate driver with <0.7V dropout at 10mA, enabling robust MOSFET switching under load. |
| GATE Drive Capability | 1.9A avg source/sink - drives high-Qg external MOSFETs for multi-watt power delivery with fast rise/fall times (16ns). |
| SENSE Threshold Range | 90–110mV (VC = 2.2V) - sets precise current limit for transformer magnetizing current control in boundary mode. |
| Soft-Start Current | 5µA - enables predictable startup timing via external capacitor; threshold at 0.65V. |
| EN/UVLO Threshold | 1.223V rising - provides programmable undervoltage lockout with 2.4µA hysteresis current for stable enable/disable behavior. |
Pinout & Package
LT3748MPMS#PBF is housed in a 16-lead plastic MSOP package with four leads removed (12-lead functional layout), optimized for high-voltage isolation and thermal dissipation (θJA = 90°C/W). The exposed pad is not electrically connected and must be thermally anchored to PCB ground plane per Analog Devices layout guidelines.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| VIN (1) | Main input supply reference | Bypassed locally; supplies start-up circuitry and serves as reference for RFB feedback network. |
| EN/UVLO (3) | Enable & input undervoltage detection | Resistor divider from VIN sets turn-on threshold; sinks 2.4µA for hysteresis during UVLO release. |
| INTVCC (5) | Internally regulated gate driver supply | 7V output; can be tied to VIN if ≤20V and no third winding used; requires local bypass capacitor. |
| GATE (6) | N-channel MOSFET gate driver output | Switches between INTVCC and GND; 1.9A avg drive supports high-power external switches. |
| SENSE (7) | Primary-side current sense input | Kelvin-connected to MOSFET source resistor; monitors peak current for boundary-mode timing and OCP. |
| GND (8,9) | Power and signal ground reference | Dual pins reduce ground impedance; connect to low-inductance PCB ground plane near SENSE and GATE paths. |
| SS (10) | Soft-start timing node | Sources 5µA to external capacitor; switching begins when voltage reaches ~0.65V. |
| VC (11) | Error amplifier compensation node | Connect series RC to ground for loop stability; 100pF parallel cap suppresses noise. |
| TC (12) | Temperature compensation current source | Sources 0.55V/RTC current into RREF to cancel diode VF drift over temperature. |
| RREF (14) | Reference resistor connection | Typically 6.04kΩ; sets gain for flyback-sampled output voltage; bias current <500nA ensures accuracy. |
| RFB (16) | Feedback resistor connection | Connected to MOSFET drain; converts flyback pulse amplitude to current proportional to VOUT. |
Key Features
| Feature | Design Value |
|---|---|
| Primary-side regulation | Eliminates opto-isolator and third winding - reduces BOM cost, improves reliability, and avoids aging/nonlinearity issues. |
| Boundary mode operation | Enables zero-current switching each cycle - improves load regulation, allows smaller magnetics, and avoids subharmonic oscillation. |
| Wide temperature grade | –55°C to 150°C junction range - supports MIL-STD, extended automotive, and harsh-environment industrial deployments. |
| Programmable UVLO & soft-start | Configurable via external resistors/capacitors - enables custom inrush control and brown-out recovery behavior. |
| Integrated temperature compensation | TC pin sources PTAT current into RREF - actively corrects for output diode forward-voltage drift across full temp range. |
Applications
| Telecom Isolated Power Supply | Automotive High-Voltage DC/DC |
|---|---|
|
Use Scenario: 36–72V telecom rectified input converted to isolated 12V/2A for line-card power. IC Role / Device Role / Timing Role: Primary-side flyback controller regulating output via RFB sampling of drain flyback pulse; boundary-mode timing ensures zero-current switching. Use Value: Achieves ±1% output regulation without opto-isolator, reducing component count and improving long-term stability in 24/7 infrastructure. |
Use Scenario: 12V battery system with load-dump transients (up to 100V) powering isolated 5V microcontroller domain. IC Role / Device Role / Timing Role: High-reliability flyback controller with –55°C to 150°C operation; senses isolated output directly from primary side during flyback event. Use Value: Enables AEC-Q100-compliant design with no secondary feedback components - simplifies ISO 26262 functional safety architecture. |
| Industrial Isolated Auxiliary Supply | Military Harsh-Environment Converter |
|
Use Scenario: 24–48V industrial bus powering isolated 15V analog sensor interface with EMI-sensitive signal chains. IC Role / Device Role / Timing Role: Boundary-mode controller minimizing conducted emissions; RFB/RREF programming enables precise 15V setpoint without trimming. Use Value: Delivers stable, low-noise auxiliary rail with <5% total output variation across line/load/temp - critical for precision ADC references. |
Use Scenario: 28V aircraft bus (with 100V transients) powering isolated 28V avionics subsystem requiring extended temperature operation. IC Role / Device Role / Timing Role: Radiation-tolerant-capable flyback controller with MP-grade temp range; TC/RREF compensation maintains regulation across –55°C to +150°C ambient. Use Value: Meets MIL-PRF-38534 Class H requirements for high-temperature reliability without derating - extends field life in sealed enclosures. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar isolated flyback controller applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LT3748HMS#PBF | Same functionality and pinout; rated for –40°C to 150°C (vs. LT3748MPMS#PBF's –55°C to 150°C). | Lacks extended low-temp qualification; unsuitable for cryogenic or space-grade deployments. | Select when full –55°C operation is unnecessary and cost optimization is prioritized. |
| UCC28911DR | TI flyback controller with integrated 700V MOSFET; no external switch required; fixed 70kHz frequency vs. boundary-mode variable frequency. | Lower power (<10W); no primary-side sensing - requires auxiliary winding; limited to commercial temp range (–40°C to 125°C). | Choose for compact, low-cost <10W designs where integrated FET simplifies layout and variable frequency is not needed. |
Compared with LT3748HMS#PBF, the LT3748MPMS#PBF adds guaranteed operation down to –55°C for extreme environments; versus UCC28911DR, it offers higher power scalability, true primary-side regulation, and wider temperature compliance - making it essential for >20W, high-reliability isolated supplies.
Availability
LT3748MPMS#PBF is available at Aetrix Electronics and suitable for telecom power systems, automotive high-voltage DC/DC converters, and industrial isolated auxiliary supplies requiring stable component supply across extended temperature and long product lifecycles.
Supply support for LT3748MPMS#PBF 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. is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, serving precision instrumentation, communications, and power management markets.
The LT3748MPMS#PBF belongs to Analog Devices' Power by Linear™ isolated controller family, engineered specifically for high-efficiency, high-reliability primary-side regulated flyback converters in demanding environments.
FAQ
What is the operating temperature range of the LT3748MPMS#PBF?
The LT3748MPMS#PBF is specified for a junction temperature range of –55°C to 150°C, making it suitable for military, aerospace, and extended-temperature automotive applications. This MP-grade qualification exceeds standard industrial and automotive grades, and is verified per MIL-STD-883 test methods for high-reliability deployment.
Does the LT3748MPMS#PBF require an opto-isolator or third winding for regulation?
No - the LT3748MPMS#PBF achieves precise isolated output regulation using primary-side flyback waveform sampling, eliminating the need for opto-isolators or auxiliary transformer windings. This reduces component count, improves long-term reliability, and avoids performance degradation due to opto aging or winding coupling variations.
How does the LT3748MPMS#PBF implement temperature compensation?
The LT3748MPMS#PBF uses its TC pin to source a proportional-to-absolute-temperature (PTAT) current into the RREF node. When paired with an external RTC resistor to ground, this current offsets the negative temperature coefficient of the output diode's forward voltage, maintaining stable output regulation across –55°C to 150°C.
What is the purpose of the RFB and RREF pins on the LT3748MPMS#PBF?
RFB connects to the MOSFET drain to convert the flyback pulse amplitude into a current; RREF provides a ground-referenced node for that current to develop a voltage. Their resistor ratio - combined with the internal 1.223V bandgap - determines the regulated output voltage, enabling accurate programming without secondary-side components.
Can the LT3748MPMS#PBF drive high-gate-charge MOSFETs effectively?
Yes - the LT3748MPMS#PBF delivers 1.9A average gate drive source/sink current with 16ns rise/fall times (CL = 3300pF), enabling robust switching of high-Qg external N-channel MOSFETs. This supports efficient power delivery up to ~25W while maintaining boundary-mode timing integrity under dynamic load conditions.
LT3748MPMS#PBF Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc.
- Series:
- -
- Package/Case:
- 16-TFSOP (0.118", 3.00mm Width), 12 Leads
- Packaging:
- Tube
- 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):
- 5V ~ 100V
- Frequency - Switching:
- -
- Duty Cycle (Max):
- -
- Synchronous Rectifier:
- No
- Clock Sync:
- No
- Serial Interfaces:
- -
- Control Features:
- Enable, Soft Start
- Operating Temperature:
- -55°C ~ 150°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 16-MSOP
LT3748MPMS#PBF FAQ
1.How can I place an order for LT3748MPMS#PBF through Aetrix?
Please submit a Request for Quotation (RFQ) for LT3748MPMS#PBF 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 LT3748MPMS#PBF reliable?
The price and inventory of LT3748MPMS#PBF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LT3748MPMS#PBF is usually 5 days.
3.What payment methods are accepted for LT3748MPMS#PBF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LT3748MPMS#PBF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LT3748MPMS#PBF?
LT3748MPMS#PBF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LT3748MPMS#PBF 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 LT3748MPMS#PBF?
For technical support, including LT3748MPMS#PBF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LT3748MPMS#PBF requirements.
6.How does Aetrix verify that LT3748MPMS#PBF is sourced from the original manufacturer or authorized distributors?
All LT3748MPMS#PBF 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 LT3748MPMS#PBF meets industry standards.
7.What is the process for return or replacement of LT3748MPMS#PBF?
All LT3748MPMS#PBF units undergo pre-shipment inspection (PSI). If there is an issue with LT3748MPMS#PBF, 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 LT3748MPMS#PBF part is unused and in its original packaging.
Return procedure for LT3748MPMS#PBF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LT3748MPMS#PBF Tags
-
UCC28C45DR
Texas Instruments
-
UCC28C40DR
Texas Instruments
-
UCC28C43DR
Texas Instruments
-
ZXSC410E6TA
Diodes Incorporated
-
LM3524DMX/NOPB
Texas Instruments
-
LM3489MMX/NOPB
Texas Instruments
-
MIC2102YML-TR
Microchip Technology
-
LM5148RGYR
Texas Instruments
-
TL598CDR
Texas Instruments
-
LM5155DSSR
Texas Instruments
-
LM25085MYX/NOPB
Texas Instruments
-
UCC2813DTR-0
Texas Instruments
Tech Hub
A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.
The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…
The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…
A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…
A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …
An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…
Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…
An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…
Operational amplifier guide covering op amp basics, feedback, ideal vs real op amps, common configurations, buffer circuits, offset, bias current, gain-bandwidth, slew rate, rail-to-rail limits and sel…
Jumper cables guide covering safe connection order, red and black clamp placement, final ground connection, cable gauge, length, clamp quality, copper vs CCA cables, jump starter comparison and battery…
