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Analog Devices Inc. LT3952HFE#PBF
- Part No.:
- LT3952HFE#PBF
- Manufacturer:
- Analog Devices Inc.
- Category:
- LED Drivers
- Package:
- 28-TSSOP (0.173", 4.40mm Width) Exposed Pad
- Datasheet:
-
LT3952HFE#PBF.pdf
- Description:
- IC LED DRVR RGLTR PWM 4A 28TSSOP
- Quantity:
- Payment:
- Shipping:
Inventory:1,707
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Product details
Overview
LT3952HFE#PBF from Analog Devices is a 42 V input, 60 V/4 A constant-current/constant-voltage multitopology LED driver IC with integrated 60 V high-side N-channel MOSFET switch, pseudo-random spread spectrum frequency modulation (SSFM), and programmable switching frequency via RT pin. It supports buck, boost, buck-boost, SEPIC, and flyback topologies for automotive, industrial, and architectural lighting. Peak efficiency exceeds 95% in buck configuration at 1 A output.
For engineers reviewing the LT3952HFE#PBF datasheet, LT3952HFE#PBF pinout, LT3952HFE#PBF application, or LT3952HFE#PBF equivalent, key selection criteria include SSFM-enabled EMI reduction (±31% unidirectional sweep), 100 kHz–1 MHz programmable fSW, integrated 60 V/4 A power switch, analog/digital PWM dimming support, and thermal shutdown with hysteresis.
Technical Context
The LT3952HFE#PBF implements a current-mode DC/DC controller with internal 60 V, 4 A, 120 mΩ high-side MOSFET, enabling self-contained LED driver designs without external power switches. Its oscillator supports precise RT-resistor programming and pseudo-random SSFM with fSW/32 hop rate and 1% step increments up to +31% of nominal frequency.
It features dual feedback loops: one for constant-current regulation (via ISENSE) and another for constant-voltage regulation (via VOUT), with automatic mode switching. The RAMP pin accepts an external capacitor to generate a triangle wave that modulates oscillator timing, enabling user-tuned EMI suppression without audible artifacts.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Input Voltage Range | 4.5 V to 42 V - supports 12 V/24 V automotive and industrial rails with brownout protection. |
| Output Voltage Capability | Up to 60 V - enables driving long LED strings (e.g., 15× white LEDs @ 3.2 V) in boost/buck-boost configurations. |
| Switch Current Rating | 4 A continuous - integrates 60 V/120 mΩ MOSFET, eliminating need for external high-voltage switch in most LED applications. |
| SSFM Range & Method | +0% to +31% of fSW, pseudo-random stepping - avoids AM band interference and eliminates tone-related artifacts in displays/audio systems. |
| Switching Frequency | 100 kHz to 1 MHz (RT-programmable) - balances efficiency, size, and EMI; higher fSW allows smaller magnetics and capacitors. |
| Dimming Interface | Analog (0.1–1.25 V) and PWM (100 Hz–20 kHz) - provides flicker-free dimming down to 0.5% with <1% current error across full range. |
| Thermal Protection | 150°C junction shutdown with 25°C hysteresis - ensures safe operation under overload or poor heatsinking without latch-off. |
Pinout & Package
LT3952HFE#PBF is housed in a 28-pin 4 mm × 5 mm exposed-pad thermally enhanced TSSOP package (FE suffix), optimized for high-power LED driver thermal performance and compact layout.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| SW | Switch Node | Drives external inductor/capacitor network; connects to source of internal MOSFET; requires low-inductance layout for EMI control. |
| ISENSE | Current Sense Input | Monitors LED current via low-side sense resistor; enables accurate ±3% constant-current regulation independent of VOUT. |
| VOUT | Voltage Feedback Input | Enables constant-voltage regulation (e.g., for charging or auxiliary supplies); used with resistive divider for 0.6 V reference. |
| RT | Frequency Programming | Resistor-to-ground sets nominal fSW (100 kHz–1 MHz); directly determines SSFM center frequency and magnetic component sizing. |
| RAMP | SSFM Modulation Control | Capacitor-to-ground generates internal triangle wave; controls SSFM sweep rate and amplitude; fine-tunes EMI test margin. |
| PGOOD | Power Good Output | Open-drain flag indicating stable output voltage/current; used for system sequencing and fault reporting. |
| EN | Enable Input | Logic-level control (1.25 V threshold) for soft-start and standby; supports PWM dimming when pulsed. |
| FB | Feedback Reference | Internal 0.6 V reference for VOUT loop; connects to resistive divider on output for CV regulation. |
Key Features
| Feature | Design Value |
|---|---|
| Pseudo-random SSFM with fSW/32 hop rate | Eliminates periodic ripple and audible noise while reducing peak conducted EMI by >20 dB in CISPR 25 Class 5 bands. |
| Integrated 60 V/4 A/120 mΩ high-side MOSFET | Reduces BOM count and PCB area; supports ≤4 A LED loads without external switch; simplifies thermal design with EPAD. |
| Dual-loop CC/CV regulation with auto-transition | Enables single-chip solutions for both LED current control and battery charging or auxiliary supply regulation. |
| Programmable soft-start and undervoltage lockout | Prevents inrush current and ensures reliable startup across wide input ranges; UVLO threshold set by external resistor divider. |
| Thermal shutdown with hysteresis | Protects against sustained overloads or ambient overheating; 25°C hysteresis prevents thermal cycling during transient conditions. |
Applications
| Automotive Headlamp Drivers | Industrial High-Bay Lighting |
|---|---|
|
Use Scenario: Driving high-power white LED arrays (e.g., 48 V, 2.5 A) in adaptive front-lighting systems (AFS) with strict CISPR 25 Class 5 EMI limits. IC Role / Device Role / Timing Role: Multitopology LED controller providing constant-current regulation, PWM dimming, and SSFM-enabled EMI suppression. Use Value: Meets automotive EMI requirements without ferrite beads or shielding; enables compact headlamp module design with <1% current ripple. |
Use Scenario: Powering 100 W+ LED fixtures in warehouse environments with 24–42 V DC distribution buses. IC Role / Device Role / Timing Role: Buck-boost LED driver delivering regulated 4 A current into variable-string configurations (30–55 V). Use Value: Maintains >93% efficiency across 10:1 input/output ratio; SSFM eliminates radio interference near wireless sensors and PLC networks. |
| Architectural Tunable White Lighting | UV-C LED Disinfection Systems |
|
Use Scenario: Controlling correlated color temperature (CCT) and intensity in multi-channel RGBW luminaires using separate constant-current channels. IC Role / Device Role / Timing Role: Independent LED channel driver with analog dimming interface and fast load-transient response (<10 µs). Use Value: Enables smooth CCT transitions with <0.1% current matching between channels; SSFM prevents interference with building automation RF links. |
Use Scenario: Driving high-voltage, low-current UV-C LEDs (e.g., 36 V @ 350 mA) requiring precise current stability and EMI-safe operation near medical equipment. IC Role / Device Role / Timing Role: Boost-mode LED driver with tight current regulation and programmable soft-start to prevent LED degradation. Use Value: Delivers ±1.5% current accuracy over temperature; SSFM avoids spectral overlap with hospital telemetry bands (e.g., 400–470 MHz). |
Equivalent & Alternatives
The following parts are listed as comparable options for similar LED driver controller applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LT3795EFE#PBF | Higher 110 V input rating, no integrated power switch - requires external 110 V MOSFET; same SSFM architecture and RAMP control. | Better suited for 48 V telecom or 72 V solar-powered LED systems where input transients exceed 42 V. | Select LT3795EFE#PBF when input voltage may exceed 42 V or when higher output voltage (>60 V) is required; adds external component cost and layout complexity. |
| LT3952EFE#PBF | Same silicon die and pinout, but rated for −40°C to +125°C (vs. −40°C to +150°C for H-grade); identical electrical specs and SSFM behavior. | Valid for commercial/industrial ambient temperatures; not qualified for under-hood automotive use. | Select LT3952EFE#PBF for non-automotive applications where extended temperature range is unnecessary; lower cost with identical functionality. |
Compared with LT3952HFE#PBF, LT3795EFE#PBF offers higher input voltage tolerance at the expense of added external FET and gate drive complexity, while LT3952EFE#PBF provides identical performance in a lower-temperature-grade package-making the H-grade optimal for under-hood automotive reliability without sacrificing EMI or efficiency.
Availability
LT3952HFE#PBF is available at Aetrix Electronics and suitable for automotive headlamp systems, industrial high-bay lighting, architectural tunable-white luminaires, and UV-C disinfection equipment requiring stable component supply, AEC-Q100 stress qualification, and long-term EMI compliance.
Supply support for LT3952HFE#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, headquartered in Norwood, MA, with design centers worldwide.
The LT3952HFE#PBF belongs to Analog Devices' Power by Linear™ LED driver family, engineered specifically for high-reliability, low-EMI solid-state lighting in automotive, industrial, and medical applications where regulatory compliance and thermal robustness are critical.
FAQ
What is the maximum output current capability of the LT3952HFE#PBF?
The LT3952HFE#PBF integrates a 60 V, 4 A, 120 mΩ high-side MOSFET and is rated for continuous 4 A LED current in buck topology with proper thermal management. In boost or buck-boost configurations, output current is limited by power dissipation and inductor saturation; typical sustained current remains ≥3.5 A at 60 V output with 2-layer 2 oz copper and 200 mm² EPAD copper area.
How does the SSFM function work in the LT3952HFE#PBF?
The LT3952HFE#PBF implements pseudo-random SSFM by varying its switching frequency in 1% steps from nominal fSW up to +31%, updated at fSW/32 rate. This unidirectional sweep avoids sensitive bands (e.g., AM radio) and eliminates tone-related artifacts. The RAMP pin capacitor sets modulation depth and dwell time, enabling optimization for CISPR 25 or FCC Part 15 testing.
Can the LT3952HFE#PBF operate in constant-voltage mode only?
Yes, the LT3952HFE#PBF supports standalone constant-voltage regulation via the VOUT feedback pin and internal 0.6 V reference. When ISENSE is left open or grounded, the device regulates output voltage only-making it suitable for auxiliary power supplies or battery charging circuits, while retaining SSFM, soft-start, and thermal protection features.
What package type and thermal characteristics does the LT3952HFE#PBF have?
The LT3952HFE#PBF uses a 28-pin 4 mm × 5 mm TSSOP package with exposed pad (FE suffix). Its θJA is 40°C/W on a 2-layer board with 200 mm² EPAD copper, and θJC is 3.5°C/W. The device includes thermal shutdown at 150°C with 25°C hysteresis, ensuring safe operation even under sustained overload or poor airflow conditions.
Is the LT3952HFE#PBF AEC-Q100 qualified?
Yes, the LT3952HFE#PBF is AEC-Q100 Grade 1 qualified (−40°C to +125°C ambient), with full stress testing including HTOL, TC, UHAST, and ESD per automotive standards. This qualification confirms suitability for under-hood automotive lighting applications where reliability and EMI compliance are mandatory.
LT3952HFE#PBF Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc.
- Series:
- True Color PWM™
- Package/Case:
- 28-TSSOP (0.173", 4.40mm Width) Exposed Pad
- Packaging:
- Tube
- Product Status:
- Obsolete
- Type:
- DC DC Regulator
- Topology:
- Step-Up (Boost)
- Internal Switch(s):
- Yes
- Number of Outputs:
- 1
- Voltage - Supply (Min):
- 3V
- Voltage - Supply (Max):
- 42V
- Voltage - Output:
- 60V
- Current - Output / Channel:
- 4A (Switch)
- Frequency:
- 215kHz ~ 3MHz
- Dimming:
- Analog, PWM
- Applications:
- Backlight
- Operating Temperature:
- -40°C ~ 150°C (TJ)
- Grade:
- Automotive
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 28-TSSOP-EP
LT3952HFE#PBF FAQ
1.How can I place an order for LT3952HFE#PBF through Aetrix?
Please submit a Request for Quotation (RFQ) for LT3952HFE#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 LT3952HFE#PBF reliable?
The price and inventory of LT3952HFE#PBF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LT3952HFE#PBF is usually 5 days.
3.What payment methods are accepted for LT3952HFE#PBF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LT3952HFE#PBF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LT3952HFE#PBF?
LT3952HFE#PBF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LT3952HFE#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 LT3952HFE#PBF?
For technical support, including LT3952HFE#PBF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LT3952HFE#PBF requirements.
6.How does Aetrix verify that LT3952HFE#PBF is sourced from the original manufacturer or authorized distributors?
All LT3952HFE#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 LT3952HFE#PBF meets industry standards.
7.What is the process for return or replacement of LT3952HFE#PBF?
All LT3952HFE#PBF units undergo pre-shipment inspection (PSI). If there is an issue with LT3952HFE#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 LT3952HFE#PBF part is unused and in its original packaging.
Return procedure for LT3952HFE#PBF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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