My Inquiry
My Account
Analog Devices Inc. LT3922IUFD#PBF
- Part No.:
- LT3922IUFD#PBF
- Manufacturer:
- Analog Devices Inc.
- Category:
- LED Drivers
- Package:
- 28-WFQFN Exposed Pad
- Datasheet:
-
LT3922IUFD#PBF.pdf
- Description:
- IC LED DRVR CTRLR PWM 2.3A 28QFN
- Quantity:
- Payment:
- Shipping:
Inventory:8,517
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
LT3922IUFD#PBF from Analog Devices is a monolithic, synchronous step-up DC/DC LED driver with ±2.5% LED current regulation, 2.8V–36V input range, and 2A internal switches. It supports analog or duty-cycle-based LED current control, 5000:1 PWM dimming at 100Hz, and operates in boost, buck, or buck-boost topologies for automotive lighting and machine vision systems.
For engineers reviewing the LT3922IUFD#PBF datasheet, LT3922IUFD#PBF pinout, LT3922IUFD#PBF application, or LT3922IUFD#PBF equivalent, key selection criteria include its 28-lead 4mm × 5mm QFN package, spread spectrum EMI reduction, open/short LED fault reporting, thermal shutdown, and dual-mode (analog/digital) dimming interface compatibility.
Technical Context
The LT3922IUFD#PBF implements fixed-frequency peak-current-mode control with programmable switching frequency (200kHz–2MHz via RT pin or external SYNC clock). Its dual error amplifiers independently regulate LED current (via ISP/ISN sense voltage) and output voltage (via FB pin), enabling robust string voltage limiting up to 34V while maintaining tight current accuracy across temperature.
It integrates a 2A/40V bottom switch and 2A/40V top switch with 140mΩ and 155mΩ on-resistances, respectively, and features an internal PWM generator (frequency set by RP pin) plus dedicated PWMTG gate driver for external high-side PMOS dimming control - all coordinated through a Silent Switcher® architecture to minimize conducted and radiated EMI.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Input Voltage Range | 2.8V to 36V - supports wide-input industrial and automotive battery rails without pre-regulation. |
| LED Current Regulation Accuracy | ±2.5% - ensures consistent brightness across temperature and line/load variations. |
| Switching Frequency Range | 200kHz to 2MHz - enables optimization of efficiency vs. size using small inductors and capacitors. |
| PWM Dimming Ratio | 5000:1 at 100Hz - delivers deep, flicker-free dimming for machine vision and display backlighting. |
| Internal Switch Rating | 2A, 40V - handles up to ~10W LED loads (e.g., 30V @ 333mA) with integrated power devices. |
| Package | 28-Lead (4mm × 5mm) QFN with exposed pad - provides low thermal resistance (θJA = 34°C/W) for high-power density designs. |
| Fault Protection | Open-circuit (FB > 1.14V + low sense voltage) and short-circuit (sense > 150mV) detection with open-drain FAULT pin - enables system-level safety monitoring. |
Pinout & Package
LT3922IUFD#PBF is housed in a thermally enhanced 28-lead plastic QFN (4mm × 5mm) with exposed GND pad (Pin 29), requiring soldering to PCB for thermal and electrical integrity.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| SW (Pins 1, 2, 24) | Switch Node | Internally connected to both power switches; must be tied together and routed with low-inductance layout for stable operation. |
| BST (Pin 3) | Bootstrap Supply | Drives top switch gate via 33nF BST–SW capacitor; internal diode charges capacitor during SW low phase. |
| ISP / ISN (Pins 10, 21) | Current Sense Inputs | Kelvin-connected to external sense resistor; differential voltage (0–100mV) sets regulated LED current with ±2.5% accuracy. |
| CTRL (Pin 8) | LED Current Programming | Accepts analog voltage (0.25–1.25V) or digital pulse (12.5–62.5% duty) to define target LED current; <200mV disables output. |
| PWM / RP (Pins 19, 18) | Dimming Control Interface | PWM pin accepts external signal or analog voltage (1–2V) to generate internal PWM; RP sets internal PWM frequency (7.3–129Hz). |
| FAULT (Pin 14) | Open/Short Fault Indicator | Open-drain output pulled low on LED open-circuit or short-circuit detection; requires external pull-up for system alert signaling. |
| RT (Pin 16) | Frequency Programming | Resistor-to-GND sets switching frequency (200kHz–2MHz); also accepts external SYNC clock or SSFM enable via SYNC/SPRD pin. |
Key Features
| Feature | Design Value |
|---|---|
| Silent Switcher® Architecture | Reduces EMI emissions via balanced switching node layout and integrated bypass paths - simplifies compliance with CISPR 25 Class 5. |
| Spread Spectrum Frequency Modulation | Modulates switching frequency ±25% around programmed center (e.g., 1.5–1.875MHz at 1.5MHz setting) to lower peak EMI. |
| Dual Regulation Loops | Independent current (ISP/ISN) and voltage (FB) regulation prevents LED overvoltage while maintaining precise current control. |
| Integrated PWM Driver (PWMTG) | Provides 10–11V gate drive (VOUT – VPWMTG) for external high-side PMOS - eliminates need for discrete level-shifting circuitry. |
| LED Current Monitor (ISMON) | Outputs 10mV per 1mV sense voltage (e.g., 100mV → 1V) - enables real-time current telemetry without additional op-amps. |
Applications
| Automotive Exterior Lighting | Machine Vision Illumination |
|---|---|
Use Scenario: High-brightness LED headlamps and DRLs requiring precise current control and robust fault handling in 12V/24V vehicle systems. IC Role / Device Role / Timing Role: Synchronous boost LED driver regulating current to multi-LED strings while monitoring open/short faults and suppressing EMI per automotive EMC standards. Use Value: ±2.5% current regulation ensures consistent lumen output across temperature; FAULT pin enables ASIL-B compatible diagnostics. | Use Scenario: Stroboscopic LED arrays used in industrial cameras for high-speed inspection, requiring microsecond-accurate PWM dimming and rapid transient response. IC Role / Device Role / Timing Role: Constant-current LED driver with 5000:1 PWM dimming at 100Hz and <200ns PWM propagation delay for synchronized illumination triggering. Use Value: Internal PWM generator (7–129Hz) and PWMTG driver eliminate external timing ICs; fast start-up (<5ms) supports burst-mode imaging. |
| Industrial Display Backlighting | UV-C LED Power Management |
Use Scenario: Wide-dynamic-range LCD backlights in medical or industrial HMIs where uniform brightness and flicker-free dimming are critical. IC Role / Device Role / Timing Role: Boost converter delivering stable current to series-connected white LEDs, supporting analog dimming via CTRL pin and PWM dimming via external signal. Use Value: 128:1 internal PWM dimming plus 5000:1 external PWM enables seamless brightness transitions without color shift. | Use Scenario: Driving high-voltage UV-C LED strings (e.g., 30V @ 333mA) in disinfection systems where overvoltage protection and thermal reliability are essential. IC Role / Device Role / Timing Role: Constant-current driver with 34V max VOUT capability, FB-based overvoltage lockout (1.266V threshold), and thermal shutdown (150°C junction limit). Use Value: ±2% output voltage regulation and FB OVLO prevent LED overvoltage failure; 28-lead QFN with exposed pad sustains continuous 10W operation. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar LED driver applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LTC3783EFE#PBF | Non-synchronous boost; no integrated top switch; requires external MOSFET; lacks spread spectrum and ISMON. | Lower integration; suited for cost-sensitive, lower-efficiency designs where EMI is less constrained. | Choose when board space and EMI performance are secondary to BOM cost and design simplicity. |
| MAX20050ATPA/VY+ | 36V, 2.5A synchronous boost; includes I²C interface and built-in diagnostics; no analog CTRL pin; different pinout and package (24-pin TQFN). | Targeted at automotive infotainment displays with digital control requirements; lacks analog dimming flexibility. | Choose when system-level digital control, ASIL compliance reporting, and higher current are prioritized over analog interface and pin compatibility. |
Compared with LTC3783EFE#PBF and MAX20050ATPA/VY+, the LT3922IUFD#PBF uniquely combines analog/digital dimming flexibility, Silent Switcher® EMI reduction, and integrated current monitor in a single 28-pin QFN - making it optimal for high-reliability, high-fidelity LED lighting where precision, diagnostics, and compactness are critical.
Availability
LT3922IUFD#PBF is available at Aetrix Electronics and suitable for automotive exterior lighting, machine vision illumination, and industrial display backlighting requiring stable component supply, long-term lifecycle support, and guaranteed -40°C to +125°C operation.
Supply support for LT3922IUFD#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 industrial, automotive, communications, and healthcare markets.
The LT3922 product line was designed specifically for high-efficiency, low-EMI LED driving in demanding environments - emphasizing precision current regulation, flexible dimming interfaces, and robust fault protection for automotive and industrial lighting.
FAQ
What is the operating temperature range for the LT3922IUFD#PBF?
The LT3922IUFD#PBF is rated for operation from –40°C to +125°C junction temperature. This grade ('I') is validated across the full range per Analog Devices' characterization and statistical process controls, making it suitable for under-hood automotive and industrial environments where thermal stability is critical. The device includes thermal shutdown protection that activates above 150°C.
Does the LT3922IUFD#PBF support both analog and PWM dimming simultaneously?
No - the LT3922IUFD#PBF supports either analog dimming (via CTRL pin voltage) or PWM dimming (via PWM pin signal or internal PWM generated from PWM pin voltage), but not simultaneous dual-mode control. When using internal PWM (RP pin grounded), the CTRL pin sets average current while the PWM pin sets duty cycle; external PWM overrides internal generation if RP is tied to GND.
How does the LT3922IUFD#PBF implement open-LED fault detection?
The LT3922IUFD#PBF detects open-LED conditions by monitoring two concurrent signals: FB voltage rising above 1.140V (indicating loss of load current) *and* ISP–ISN sense voltage falling below 10mV. When both thresholds are exceeded, the FAULT pin is pulled low. Hysteresis (50mV) prevents chatter, and fault response (hiccup vs. latch-off) is configured via the SS pin external resistor.
Can the LT3922IUFD#PBF operate in buck mode, and what are the requirements?
Yes - the LT3922IUFD#PBF supports buck operation when configured with appropriate external components and feedback network. In buck mode, VOUT is connected to the input rail (VIN), and the LED string is placed between VOUT and the ISP/ISN sense resistor. Operation requires disabling the boost path and ensuring the internal switches remain within SOA; refer to Analog Devices' Application Note AN158 for validated buck-mode schematics and layout guidance.
What is the purpose of the SS (Soft-Start) pin on the LT3922IUFD#PBF, and how is it configured?
The SS pin on the LT3922IUFD#PBF controls soft-start timing and fault recovery behavior. A 20µA internal current source charges an external capacitor to ramp FB voltage, limiting inrush current. For short-circuit fault response: no external resistor enables hiccup mode (repeated restart attempts); a 100kΩ resistor to INTVCC configures latch-off mode (requires EN/UVLO toggle to reset).
LT3922IUFD#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 Controller
- Topology:
- Step-Up (Boost)
- Internal Switch(s):
- No
- Number of Outputs:
- 1
- Voltage - Supply (Min):
- 2.8V
- Voltage - Supply (Max):
- 36V
- Voltage - Output:
- -
- Current - Output / Channel:
- 2.3A
- Frequency:
- 200kHz ~ 2MHz
- Dimming:
- Analog, PWM
- Applications:
- Lighting
- Operating Temperature:
- -40°C ~ 125°C (TJ)
- Grade:
- Automotive
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 28-QFN (4x5)
LT3922IUFD#PBF FAQ
1.How can I place an order for LT3922IUFD#PBF through Aetrix?
Please submit a Request for Quotation (RFQ) for LT3922IUFD#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 LT3922IUFD#PBF reliable?
The price and inventory of LT3922IUFD#PBF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LT3922IUFD#PBF is usually 5 days.
3.What payment methods are accepted for LT3922IUFD#PBF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LT3922IUFD#PBF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LT3922IUFD#PBF?
LT3922IUFD#PBF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LT3922IUFD#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 LT3922IUFD#PBF?
For technical support, including LT3922IUFD#PBF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LT3922IUFD#PBF requirements.
6.How does Aetrix verify that LT3922IUFD#PBF is sourced from the original manufacturer or authorized distributors?
All LT3922IUFD#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 LT3922IUFD#PBF meets industry standards.
7.What is the process for return or replacement of LT3922IUFD#PBF?
All LT3922IUFD#PBF units undergo pre-shipment inspection (PSI). If there is an issue with LT3922IUFD#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 LT3922IUFD#PBF part is unused and in its original packaging.
Return procedure for LT3922IUFD#PBF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LT3922IUFD#PBF 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…
