My Inquiry
My Account
Analog Devices Inc. LT3755EMSE-2#TRPBF
- Part No.:
- LT3755EMSE-2#TRPBF
- Manufacturer:
- Analog Devices Inc.
- Category:
- LED Drivers
- Package:
- 16-TFSOP (0.118", 3.00mm Width) Exposed Pad
- Datasheet:
-
LT3755EMSE-2#TRPBF.pdf
- Description:
- IC LED DRIVER CTRLR PWM 16MSOP
- Quantity:
- Payment:
- Shipping:
Inventory:1,874
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
LT3755EMSE-2#TRPBF from Analog Devices is a constant-current, current-mode DC/DC LED controller optimized for automotive headlamp and high-power LED drivers. It supports boost, buck, buck-boost, SEPIC, and flyback topologies; delivers up to 75V output with 4.5V–40V input; features 100kHz–1MHz adjustable switching frequency; provides 3000:1 PWM dimming; and includes high-side current sensing with 100mV threshold for precise LED current regulation in 50W white LED headlamp applications.
For engineers reviewing the LT3755EMSE-2#TRPBF datasheet, LT3755EMSE-2#TRPBF pinout, LT3755EMSE-2#TRPBF application, or LT3755EMSE-2#TRPBF equivalent, key selection considerations include its AEC-Q100 qualification, open LED protection via OPENLED pin, programmable undervoltage lockout with hysteresis, improved open LED status reporting (LT3755-2 variant), and compatibility with external N-channel MOSFETs in thermally demanding LED driver designs.
Technical Context
The LT3755EMSE-2#TRPBF implements fixed-frequency current-mode control with internal 7.15V INTVCC regulator powering the gate driver and logic. Its high-side current sense architecture (ISP/ISN inputs) enables flexible topology selection and avoids ground loop interference in LED string current measurement.
It integrates dual-loop regulation: LED current is controlled via ISP–ISN differential voltage referenced to CTRL pin (100mV full-scale), while FB pin enables constant-voltage operation or open-LED fault detection at 1.25V nominal regulation. The LT3755-2 variant adds enhanced OPENLED latching behavior during overvoltage events.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Input Voltage Range | 4.5V to 40V - supports wide automotive battery range including cold-crank and load-dump conditions. |
| Output Voltage Capability | Up to 75V - enables driving long series-connected high-brightness LED strings. |
| Switching Frequency Range | 100kHz to 1MHz - adjustable via RT resistor to balance efficiency, EMI, and magnetic component size. |
| Current Sense Threshold | 100mV (typical) at ISP–ISN - enables accurate, low-loss high-side LED current sensing with minimal power dissipation. |
| PWM Dimming Ratio | 3000:1 - supports high-fidelity True Color PWM™ dimming without color shift in automotive lighting. |
| Operating Junction Temp | –40°C to 125°C - qualified per AEC-Q100 Grade E for under-hood automotive environments. |
| Package | 16-Lead MSOP with exposed pad - provides thermal enhancement for continuous high-power LED driver operation. |
Pinout & Package
LT3755EMSE-2#TRPBF is housed in a thermally enhanced 16-lead plastic MSOP package (3mm × 4.9mm) with exposed pad (Pin 17) soldered to PCB ground for optimal thermal performance (θJA = 43°C/W).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| PWMOUT (Pin 1) | Buffered PWM output | Drives NMOS disconnect switch; toggles low during FB overvoltage (>VFB + 60mV) to protect LEDs. |
| FB (Pin 2) | Voltage feedback input | Regulates to 1.25V nominal; enables CV mode and open-LED detection (pulls OPENLED when FB < VFB – 50mV). |
| ISN (Pin 3) | Negative current sense input | High-side current sense return; supports short-circuit detection when ISN < 3V (threshold = 150mV). |
| ISP (Pin 4) | Positive current sense input | High-side current sense input; bias current varies with CTRL voltage; used with ISN for 100mV threshold sensing. |
| VC (Pin 5) | Error amplifier output | Integrates error signal for loop stability; high-impedance during PWM low to retain state across dimming cycles. |
| CTRL (Pin 6) | Current threshold adjust | Sets LED current sense threshold: 100mV (VCTRL > 1.2V); linear scaling (0.1×VCTRL) below 1V for analog dimming. |
| VREF (Pin 7) | 2.0V reference output | Stable 2.0V source (±2%) for CTRL divider or temperature compensation networks; supplies ≤100µA. |
| PWM (Pin 8) | Digital dimming input | Active-high enable; disables switching and idles oscillator when low; internal pull-down. |
| OPENLED (Pin 9) | Open-LED fault indicator | Open-collector output asserted when FB drops below VFB – 50mV; latched on LT3755-2 after overvoltage recovery. |
| SS (Pin 10) | Soft-start control | 10µA internal pull-up to 2.5V rail; sets startup ramp time with external capacitor; reset by UVLO or thermal fault. |
| RT (Pin 11) | Frequency programming | Resistor-to-GND sets oscillator frequency (100kΩ → ~375kHz); no internal pull-up/down. |
| SHDN/UVLO (Pin 12) | Enable & undervoltage detect | 1.22V falling threshold with programmable hysteresis; sub-µA shutdown current when pulled ≤0.4V. |
| INTVCC (Pin 13) | Internal LDO output | 7.15V regulated supply (±150mV) for gate driver and logic; requires 4.7µF local ceramic bypass. |
| VIN (Pin 14) | Main input supply | 4.5V–40V input; powers INTVCC LDO and internal circuitry; requires local 0.22µF+ ceramic bypass. |
| SENSE (Pin 15) | Low-side current sense | Kelvin-connected to source of external N-MOSFET; monitors switch current for slope-compensated current-mode control. |
| GATE (Pin 16) | N-MOSFET gate driver | Drives external N-channel FET gate between INTVCC and GND; fast rise/fall (<35ns) into 3.3nF load. |
| Exposed Pad (Pin 17) | Thermal & electrical ground | Must be soldered to PCB ground plane; serves as primary thermal path and current sense return for SENSE. |
Key Features
| Feature | Design Value |
|---|---|
| High-side current sensing | Enables topology flexibility (boost/buck/buck-boost/SEPIC/flyback) without compromising LED string ground integrity. |
| AEC-Q100 Grade E qualification | Validated for automotive under-hood use (-40°C to +125°C junction), supporting functional safety requirements in headlamp systems. |
| Enhanced OPENLED latching (LT3755-2) | Reasserts OPENLED after FB recovers from overvoltage condition-improves fault diagnosis reliability in transient-rich automotive environments. |
| Programmable undervoltage lockout | Configurable hysteresis via external resistor divider enables robust start-up sequencing and brown-out immunity in 12V/24V systems. |
| 100mV current sense threshold | Minimizes power loss in sense resistor (e.g., 10mΩ yields 1A full-scale), improving thermal efficiency in high-current LED drivers. |
Applications
| Automotive LED Headlamps | Battery-Powered LED Lighting |
|---|---|
Use Scenario: Driving 50W white LED arrays in adaptive front-lighting systems (AFS) with dynamic beam shaping. IC Role / Device Role / Timing Role: Constant-current controller regulating LED string current via high-side ISP/ISN sensing; manages PWM dimming and open-LED fault signaling. Use Value: Enables AEC-Q100-compliant, thermally robust 50W headlamp design with 3000:1 dimming ratio and fail-safe open-LED detection. | Use Scenario: Portable high-lumen LED work lights powered from 12V sealed lead-acid or Li-ion battery packs. IC Role / Device Role / Timing Role: Buck-mode LED driver maintaining stable current across 10V–14.4V battery discharge curve; uses CTRL pin for analog dimming. Use Value: Delivers consistent light output and extended runtime with low quiescent current (<1µA shutdown) and wide VIN range. |
| Industrial High-Bay Lighting | UV-C LED Disinfection Systems |
Use Scenario: Multi-string 100–200W LED fixtures for warehouse and factory floor illumination. IC Role / Device Role / Timing Role: Boost-mode controller driving long LED strings from 24V DC distribution rails; leverages RT pin for EMI-optimized 400kHz switching. Use Value: Supports high-efficiency, thermally managed operation in enclosed luminaires using MSOP package with exposed pad. | Use Scenario: Precision current control of high-voltage UV-C LED arrays (e.g., 365nm, 275nm) requiring stable irradiance for surface disinfection. IC Role / Device Role / Timing Role: Constant-current source with tight 100mV sense threshold and open-LED protection to prevent catastrophic failure of expensive UV LEDs. Use Value: Ensures repeatable germicidal dose delivery and system reliability through accurate current regulation and fault monitoring. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar LED controller applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LTC3783 | Fixed 200kHz/600kHz dual-frequency option; no CTRL-based analog dimming; lower max output voltage (60V). | Targeted at simpler, cost-sensitive LED drivers where programmable frequency and analog dimming are not required. | Select LTC3783 only if fixed-frequency operation and absence of analog dimming are acceptable trade-offs for reduced BOM count. |
| LM3410XMY/NOPB | Integrated 1.5A MOSFET; lower max output (36V); no high-side sensing; limited to boost-only topology. | Suitable for low-power (<15W), single-string portable LED applications where integration outweighs flexibility. | Choose LM3410XMY/NOPB for space-constrained, low-complexity boost LED drivers-not for multi-topology or high-power automotive use. |
Compared with LTC3783 and LM3410XMY/NOPB, the LT3755EMSE-2#TRPBF offers superior topology flexibility, AEC-Q100 qualification, high-side sensing, and 3000:1 PWM dimming-making it uniquely suited for demanding automotive and industrial LED driver designs requiring reliability, precision, and configurability.
Availability
LT3755EMSE-2#TRPBF is available at Aetrix Electronics and suitable for automotive LED headlamps, industrial high-bay lighting, battery-powered portable lighting, and UV-C disinfection systems requiring stable component supply, AEC-Q100 compliance, and high-reliability current regulation.
Supply support for LT3755EMSE-2#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. is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, serving industrial, automotive, communications, and healthcare markets.
The LT3755 product line was designed specifically for high-efficiency, high-reliability LED current regulation in automotive and industrial lighting-emphasizing wide input range, topology flexibility, and integrated protection features like open-LED detection and overvoltage shutdown.
FAQ
What distinguishes LT3755EMSE-2#TRPBF from LT3755EMSE-1#TRPBF?
The LT3755EMSE-2#TRPBF includes an improved OPENLED status pin that reasserts the open-LED fault signal after recovery from an FB overvoltage event, whereas the LT3755EMSE-1#TRPBF lacks this latching behavior. Additionally, LT3755EMSE-2#TRPBF does not support frequency synchronization (SYNC), unlike LT3755EMSE-1#TRPBF which replaces OPENLED with SYNC functionality. Both share identical pinout, package, and core control architecture.
Can LT3755EMSE-2#TRPBF drive LEDs in buck configuration with input voltage higher than output voltage?
Yes, LT3755EMSE-2#TRPBF supports buck-mode operation when configured with appropriate external components, enabling efficient step-down LED current regulation-for example, driving a 24V LED string from a 40V input rail. Its high-side current sensing and current-mode control ensure stable regulation across varying input and output conditions.
What is the purpose of the CTRL pin on LT3755EMSE-2#TRPBF?
The CTRL pin on LT3755EMSE-2#TRPBF adjusts the LED current sense threshold: above 1.2V it fixes the threshold at 100mV for full-scale current; between 0V and 1V it scales linearly (0.1×VCTRL) to enable analog dimming. This allows precise, continuous brightness control independent of PWM duty cycle, enhancing thermal management in high-power LED applications.
How does LT3755EMSE-2#TRPBF handle open-LED fault detection?
LT3755EMSE-2#TRPBF detects open-LED faults by monitoring the FB pin: when FB falls below VFB – 50mV (≈1.20V), the OPENLED pin pulls low. Unlike earlier variants, LT3755EMSE-2#TRPBF reasserts OPENLED after FB recovers from overvoltage conditions, improving diagnostic reliability in noisy automotive environments where transient spikes may temporarily disable the fault signal.
Is LT3755EMSE-2#TRPBF compatible with standard MSOP-16 footprints and reflow profiles?
Yes, LT3755EMSE-2#TRPBF uses a standard 16-lead plastic MSOP package (3mm × 4.9mm) with exposed thermal pad, fully compatible with IPC-7351B MSOP-16 land patterns. It supports standard lead-free reflow profiles (J-STD-020), and the exposed pad must be soldered to a solid PCB ground plane to achieve specified θJA = 43°C/W and ensure reliable thermal performance in continuous 50W LED driver operation.
LT3755EMSE-2#TRPBF Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc.
- Series:
- -
- Package/Case:
- 16-TFSOP (0.118", 3.00mm Width) Exposed Pad
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Type:
- DC DC Controller
- Topology:
- Flyback, SEPIC, Step-Down (Buck), Step-Up (Boost)
- Internal Switch(s):
- No
- Number of Outputs:
- 1
- Voltage - Supply (Min):
- 4.5V
- Voltage - Supply (Max):
- 40V
- Voltage - Output:
- -
- Current - Output / Channel:
- -
- Frequency:
- 100kHz ~ 1MHz
- Dimming:
- Analog, PWM
- Applications:
- -
- Operating Temperature:
- 0°C ~ 125°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 16-MSOP-EP
LT3755EMSE-2#TRPBF FAQ
1.How can I place an order for LT3755EMSE-2#TRPBF through Aetrix?
Please submit a Request for Quotation (RFQ) for LT3755EMSE-2#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 LT3755EMSE-2#TRPBF reliable?
The price and inventory of LT3755EMSE-2#TRPBF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LT3755EMSE-2#TRPBF is usually 5 days.
3.What payment methods are accepted for LT3755EMSE-2#TRPBF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LT3755EMSE-2#TRPBF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LT3755EMSE-2#TRPBF?
LT3755EMSE-2#TRPBF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LT3755EMSE-2#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 LT3755EMSE-2#TRPBF?
For technical support, including LT3755EMSE-2#TRPBF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LT3755EMSE-2#TRPBF requirements.
6.How does Aetrix verify that LT3755EMSE-2#TRPBF is sourced from the original manufacturer or authorized distributors?
All LT3755EMSE-2#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 LT3755EMSE-2#TRPBF meets industry standards.
7.What is the process for return or replacement of LT3755EMSE-2#TRPBF?
All LT3755EMSE-2#TRPBF units undergo pre-shipment inspection (PSI). If there is an issue with LT3755EMSE-2#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 LT3755EMSE-2#TRPBF part is unused and in its original packaging.
Return procedure for LT3755EMSE-2#TRPBF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LT3755EMSE-2#TRPBF Tags
-
BCR402RE6327HTSA1
Infineon Technologies
-
BCR430UXTSA2
Infineon Technologies
-
BCR420UE6433HTMA1
Infineon Technologies
-
BCR420UE6327HTSA1
Infineon Technologies
-
BCR421UE6327HTSA1
Infineon Technologies
-
LYT1604D-TL
Power Integrations
-
HV9910CLG-G
Microchip Technology
-
CL2N8-G
Microchip Technology
-
BCR420UW6-7
Diodes Incorporated
-
BCR421UW6-7
Diodes Incorporated
-
BCR420UFD-7
Diodes Incorporated
-
BCR421UFD-7
Diodes Incorporated
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…
