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Analog Devices Inc. LT3932HUFD#PBF
- Part No.:
- LT3932HUFD#PBF
- Manufacturer:
- Analog Devices Inc.
- Category:
- LED Drivers
- Package:
- 28-WFQFN Exposed Pad
- Datasheet:
-
LT3932HUFD#PBF.pdf
- Description:
- IC LED DRIVER RGLTR PWM 2A 28QFN
- Quantity:
- Payment:
- Shipping:
Inventory:1,754
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Product details
Overview
LT3932HUFD#PBF from Analog Devices is a 36V, 2A synchronous step-down LED driver with Silent Switcher® architecture for low EMI, fixed-frequency peak-current control, and dual-mode dimming (analog voltage or PWM duty cycle at CTRL pin). It supports 200kHz–2MHz switching, open/short LED fault detection, and operates up to 150°C junction temperature in automotive lighting systems.
For engineers reviewing the LT3932HUFD#PBF datasheet, LT3932HUFD#PBF pinout, LT3932HUFD#PBF application, or LT3932HUFD#PBF equivalent, key selection criteria include ±1.5% LED current regulation accuracy, internal PWM dimming up to 128:1, AEC-Q100 qualification, spread-spectrum frequency modulation capability, and thermally enhanced 28-pin 4mm × 5mm QFN package with exposed GND pad.
Technical Context
The LT3932HUFD#PBF integrates a synchronous buck controller with dual power switches, peak-current mode control, and independent current/voltage regulation loops. Its current error amplifier (200 µA/V transconductance) compares ISP–ISN sense voltage against CTRL-programmed reference, while the voltage error amplifier (480 µA/V) overrides regulation when FB approaches 1.000 V to prevent LED overvoltage.
It features programmable switching via RT resistor or external SYNC clock, spread-spectrum modulation (100–125% frequency variation), and fault reporting via open-drain FAULT pin for open-circuit (>950 mV FB) and short-circuit (<200 mV FB) conditions. The H-grade variant guarantees operation from –40°C to +150°C junction temperature.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Input Voltage Range | 3.6 V to 36 V - supports wide automotive battery range including cold-crank and load-dump transients. |
| LED Current Accuracy | ±1.5% - ensures consistent luminance across temperature and line variations in safety-critical lighting. |
| Switching Frequency | 200 kHz to 2 MHz - enables compact magnetics and noise-sensitive placement near RF sections. |
| Dimming Ratio (PWM) | 5000:1 (LT3932) / 10000+:1 (LT3932-1) at 100 Hz - meets high-dynamic-range requirements in machine vision and adaptive headlights. |
| Junction Temperature Range | –40°C to +150°C - qualified per AEC-Q100 Grade H for under-hood automotive applications. |
| Package | 28-pin (4 mm × 5 mm) QFN with exposed thermal pad - provides θJA = 25°C/W on DC2286A evaluation board for reliable thermal management. |
| EMI Reduction | Silent Switcher® architecture + optional spread-spectrum modulation - reduces peak radiated emissions without shielding or layout compromises. |
Pinout & Package
LT3932HUFD#PBF uses a thermally enhanced 28-pin plastic QFN (4 mm × 5 mm) with exposed GND pad (Pin 29), rated for θJA = 25°C/W on DC2286A test board. All GND pins (1, 3, 14, 23, 29) must be soldered to PCB ground plane for thermal and EMI performance.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| VIN (Pins 1, 4, 5, 17, 18) | Input power supply input | Supplies analog circuitry and high-side switch; requires local ceramic bypassing to GND for stability and transient response. |
| ISP / ISN (Pins 6, 7) | Differential LED current sense inputs | Measure voltage across external sense resistor; common-mode range 0 V to 36 V enables high-side sensing in boost-buck configurations. |
| CTRL (Pin 15) | LED current programming interface | Accepts analog voltage (250–1250 mV) or digital pulse (100–1000 kHz, 12.5–62.5% duty) to set regulated LED current with 20:1 control range. |
| FB (Pin 4) | Output voltage limit feedback | Monitors LED string voltage via resistor divider; triggers overvoltage lockout at 1.050 V and fault reporting at open/short thresholds. |
| FAULT (Pin 8) | Open-drain fault indicator | Pulled low for open-circuit (FB > 950 mV + ISP–ISN < 10 mV) or short-circuit (FB < 200 mV); requires 100 kΩ pull-up to INTVCC. |
| PWM / RP / PWMTG (Pins 21, 9, 12) | Internal/external PWM dimming control | PWM pin accepts external signal or sets internal duty ratio; RP programs internal PWM frequency; PWMTG drives external high-side PMOS gate. |
| RT / SYNC/SPRD (Pins 10, 11) | Frequency programming & synchronization | RT sets base frequency (200 kHz–2 MHz); SYNC/SPRD accepts external clock or enables spread-spectrum when tied to INTVCC. |
Key Features
| Feature | Design Value |
|---|---|
| Silent Switcher® architecture | Minimizes PCB-level EMI emissions without ferrite beads or shielding, easing CISPR-25 Class 5 compliance in automotive designs. |
| Integrated PWM dimming generator | Eliminates need for external microcontroller or timer IC; supports 128:1 dimming ratio with RP-set frequency (7.4–128 kHz). |
| AEC-Q100 Grade H qualification | Validated for continuous operation at 150°C junction temperature, enabling placement near heat sources in headlamp modules. |
| Accurate LED current monitor (ISMON) | Provides buffered 10× scaled replica of ISP–ISN voltage (10 mV/mV), enabling real-time current diagnostics without additional amplification. |
| Programmable UVLO with hysteresis | EN/UVLO threshold (1.15 V typ.) and 20 mV hysteresis prevent erratic startup during battery brownouts in vehicle start-stop systems. |
Applications
| Automotive Adaptive Headlights | Industrial Machine Vision Lighting |
|---|---|
Use Scenario: High-intensity, dynamically steered LED arrays in ADAS-equipped vehicles requiring precise lumen output and rapid dimming response. IC Role / Device Role / Timing Role: Primary LED current regulator and PWM dimming controller with fault-safe shutdown for open/short LED strings. Use Value: ±1.5% current regulation ensures consistent beam pattern integrity; 5000:1 PWM dimming enables pixel-level brightness control for glare-free forward lighting. |
Use Scenario: Stroboscopic illumination synchronized to camera exposure in automated inspection systems for high-speed production lines. IC Role / Device Role / Timing Role: Synchronous buck LED driver with externally synchronized switching (via SYNC/SPRD) to eliminate frame-rate flicker. Use Value: 200 kHz–2 MHz programmable frequency allows exact alignment with camera shutter timing; spread-spectrum reduces EMI interference with image sensors. |
| Commercial Streetlight Drivers | Avionics Cabin Lighting |
Use Scenario: Outdoor LED luminaires operating across wide ambient temperatures and long service lifetimes with minimal maintenance. IC Role / Device Role / Timing Role: Robust current-regulated buck controller with thermal shutdown and overvoltage protection for unattended operation. Use Value: 150°C max junction rating extends lifetime in sealed enclosures; open/short LED fault reporting enables predictive maintenance via FAULT pin status. |
Use Scenario: Dimmable, low-EMI cabin lighting in commercial aircraft where conducted/radiated emissions must meet DO-160 Section 20 Level A limits. IC Role / Device Role / Timing Role: EMI-optimized LED driver with Silent Switcher® and spread-spectrum modulation for certified avionics subsystems. Use Value: Meets stringent aviation EMC requirements without added filtering; AEC-Q100 qualification provides proven reliability baseline for DO-160 qualification testing. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar LED driver applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LT3932IUFD#PBF | Same functionality and pinout; rated for –40°C to +125°C junction temperature (I-grade), not 150°C. | Limited to under-dash or interior automotive applications without extreme thermal exposure. | Select when full AEC-Q100 Grade H is unnecessary and cost optimization is prioritized over extended thermal margin. |
| LT3932HUFD-1#PBF | Identical package and thermal rating; supports 10000+:1 PWM dimming (vs. 5000:1) and higher dimming ratios via enhanced internal PWM logic. | Required for ultra-high dynamic range applications such as automotive matrix LED headlamps with individual pixel control. | Choose when >5000:1 dimming is mandatory; note that LT3932HUFD#PBF and LT3932HUFD-1#PBF are not functionally interchangeable due to dimming ratio specification. |
Compared with LT3932IUFD#PBF, the LT3932HUFD#PBF delivers guaranteed 150°C operation for under-hood use, while LT3932HUFD-1#PBF adds extended dimming capability-neither offers pin-to-pin replacement without verifying thermal and dimming requirements in final system validation.
Availability
LT3932HUFD#PBF is available at Aetrix Electronics and suitable for automotive lighting, industrial machine vision, and outdoor LED streetlight applications requiring stable component supply, AEC-Q100 qualification, and high-temperature reliability.
Supply support for LT3932HUFD#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 is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, serving automotive, industrial, communications, and healthcare markets.
The LT3932 product line delivers high-efficiency, low-EMI LED drivers for demanding applications including adaptive automotive lighting and precision industrial illumination, emphasizing robustness, accuracy, and regulatory compliance.
FAQ
What is the maximum junction temperature rating for the LT3932HUFD#PBF?
The LT3932HUFD#PBF is specified for continuous operation from –40°C to +150°C junction temperature and is AEC-Q100 Grade H qualified. This rating is validated through accelerated life testing and thermal characterization, making it suitable for under-hood automotive environments where ambient temperatures exceed 105°C. Derating applies above 125°C per Analog Devices' reliability guidelines.
Does the LT3932HUFD#PBF support spread-spectrum frequency modulation?
Yes, the LT3932HUFD#PBF supports spread-spectrum frequency modulation (SSFM) via the SYNC/SPRD pin. When this pin is tied to INTVCC, the switching frequency varies between 100% and 125% of the RT-set base frequency, reducing peak EMI emissions by spreading energy across a wider bandwidth. SSFM is fully compatible with Silent Switcher® architecture for best-in-class EMC performance.
How does the FAULT pin indicate open-circuit and short-circuit conditions on the LT3932HUFD#PBF?
The FAULT pin on the LT3932HUFD#PBF is an open-drain output pulled low under two distinct fault conditions: (1) open-circuit when FB voltage exceeds 950 mV *and* ISP–ISN voltage falls below 10 mV; (2) short-circuit when FB voltage drops below 200 mV. A 100 kΩ pull-up resistor to INTVCC is required for proper logic-level signaling and fault isolation in system-level diagnostics.
Can the LT3932HUFD#PBF operate without an external PWM signal?
Yes, the LT3932HUFD#PBF includes an integrated PWM dimming generator. With RP connected to GND and a DC voltage applied to the PWM pin (1.0–2.0 V), the device generates an internal PWM signal whose duty ratio scales linearly with input voltage. This eliminates dependency on external timing sources while delivering up to 128:1 dimming ratio-fully functional in the LT3932HUFD#PBF without external PWM hardware.
What is the purpose of the ISMON pin on the LT3932HUFD#PBF?
The ISMON pin on the LT3932HUFD#PBF provides a buffered, 10× scaled replica of the ISP–ISN sense voltage (e.g., 100 mV at ISMON corresponds to 10 mV across the sense resistor). This enables real-time monitoring of LED current without loading the precision sense node, supporting closed-loop diagnostics, current logging, or system-level fault analysis without additional op-amp circuitry.
LT3932HUFD#PBF Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc.
- Series:
- -
- Package/Case:
- 28-WFQFN Exposed Pad
- Packaging:
- Tube
- Product Status:
- Active
- Type:
- DC DC Regulator
- Topology:
- Step-Down (Buck)
- Internal Switch(s):
- Yes
- Number of Outputs:
- 1
- Voltage - Supply (Min):
- 3.6V
- Voltage - Supply (Max):
- 36V
- Voltage - Output:
- -
- Current - Output / Channel:
- 2A
- Frequency:
- 200kHz ~ 2MHz
- Dimming:
- Analog, PWM
- Applications:
- Lighting
- Operating Temperature:
- -40°C ~ 150°C (TJ)
- Grade:
- Automotive
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 28-QFN (4x5)
LT3932HUFD#PBF FAQ
1.How can I place an order for LT3932HUFD#PBF through Aetrix?
Please submit a Request for Quotation (RFQ) for LT3932HUFD#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 LT3932HUFD#PBF reliable?
The price and inventory of LT3932HUFD#PBF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LT3932HUFD#PBF is usually 5 days.
3.What payment methods are accepted for LT3932HUFD#PBF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LT3932HUFD#PBF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LT3932HUFD#PBF?
LT3932HUFD#PBF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LT3932HUFD#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 LT3932HUFD#PBF?
For technical support, including LT3932HUFD#PBF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LT3932HUFD#PBF requirements.
6.How does Aetrix verify that LT3932HUFD#PBF is sourced from the original manufacturer or authorized distributors?
All LT3932HUFD#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 LT3932HUFD#PBF meets industry standards.
7.What is the process for return or replacement of LT3932HUFD#PBF?
All LT3932HUFD#PBF units undergo pre-shipment inspection (PSI). If there is an issue with LT3932HUFD#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 LT3932HUFD#PBF part is unused and in its original packaging.
Return procedure for LT3932HUFD#PBF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LT3932HUFD#PBF Tags
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BCR402RE6327HTSA1
Infineon Technologies
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BCR430UXTSA2
Infineon Technologies
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BCR420UE6433HTMA1
Infineon Technologies
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BCR420UE6327HTSA1
Infineon Technologies
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BCR421UE6327HTSA1
Infineon Technologies
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LYT1604D-TL
Power Integrations
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HV9910CLG-G
Microchip Technology
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CL2N8-G
Microchip Technology
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BCR420UW6-7
Diodes Incorporated
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BCR421UW6-7
Diodes Incorporated
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BCR420UFD-7
Diodes Incorporated
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BCR421UFD-7
Diodes Incorporated
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