My Inquiry
My Account
Analog Devices Inc. LT3746IUHH#TRPBF
- Part No.:
- LT3746IUHH#TRPBF
- Manufacturer:
- Analog Devices Inc.
- Category:
- LED Drivers
- Package:
- 56-WFQFN Exposed Pad
- Datasheet:
-
LT3746IUHH#TRPBF.pdf
- Description:
- IC LED DRVR CTRLR PWM 30MA 56QFN
- Quantity:
- Payment:
- Shipping:
Inventory:4,931
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
LT3746IUHH#TRPBF from Analog Devices (formerly Linear Technology) is a 32-channel constant-current LED driver with integrated 55V buck controller for adaptive LED bus voltage generation. It delivers up to 30mA per channel at ≤13V, supports 12-bit grayscale PWM dimming at 500Hz, and features 6-bit dot correction per channel. It is designed for large-screen LCD dynamic backlighting and full-color LED displays requiring precise current matching and fault diagnostics.
For engineers reviewing the LT3746IUHH#TRPBF datasheet, LT3746IUHH#TRPBF pinout, LT3746IUHH#TRPBF application, or LT3746IUHH#TRPBF equivalent, key selection considerations include its 56-lead QFN package, –40°C to 125°C industrial temperature grade, 30MHz cascadable serial interface, open/short LED and overtemperature protection, and compatibility with external P-channel MOSFET gate drive.
Technical Context
The LT3746IUHH#TRPBF integrates a current-mode nonsynchronous buck controller with thirty-two linear current sinks. The buck stage regulates an adaptive output bus voltage (via FB feedback), while each LED channel uses a precision current sink with programmable dot correction and PWM dimming registers accessible via a 6-wire serial interface.
Its 30MHz skew-balanced serial interface employs LDI/SCKI/SDI inputs and LDO/SCKO/SDO outputs to enable daisy-chained configurations without external clock buffers. Fault reporting-including per-channel open/short LED detection and overtemperature status-is returned through the same interface in real time.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| LED Channels | 32 independent constant-current sinks, each adjustable from 7mA to 30mA (via ISET resistor and 6-bit dot correction) |
| Dimming Resolution | 12-bit grayscale PWM (4096:1 ratio) with 0.5µs minimum on-time for high-frequency flicker-free control |
| Buck Input Range | 6V to 55V VIN; supports adaptive bus voltage regulation up to 42V output for parallel LED strings |
| Serial Interface Speed | 30MHz fully buffered, cascadable 6-wire interface (SCKI/SDI/LDI/SCKO/SDO/LDO) with <50ns propagation delay |
| Protection Features | Per-channel open/short LED detection, overtemperature shutdown (TSET-programmable), and UVLO on EN/UVLO, VCC, and (VIN–VCAP) |
| Operating Temp | –40°C to 125°C junction temperature, qualified for industrial applications (I-grade marking) |
| Package | 56-lead (5mm × 9mm) plastic QFN with exposed thermal pad (Pin 57 = GND) |
Pinout & Package
LT3746IUHH#TRPBF is housed in a 56-lead plastic QFN (UHH package), 5mm × 9mm, with exposed thermal pad (Pin 57) soldered to PCB ground for thermal management. Pin pitch is 0.5mm.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| EN/UVLO (1) | Enable & input UVLO control | Digital enable input; also accepts resistor divider from VIN to set input undervoltage lockout threshold (4.9V typical) |
| LED00–LED31 (2–17, 30–45) | LED cathode current sink outputs | 32 independent constant-current sinks; each drives LED string cathodes with ±20% current mismatch max between channels |
| VIN (54), GATE (53), CAP (52), ISP/ISN (51/50) | Buck power stage interface | Supports external P-channel MOSFET switch, current-sense resistor, and VIN-referenced 6.8V gate bias regulator |
| ISET (56), TSET (55) | Analog programming inputs | ISET sets nominal LED current (VISET = 1.205V); TSET sets overtemperature threshold via resistor-to-ground |
| SCKI/SDI/LDI (19/21/22), SCKO/SDO/LDO (28/26/25) | 6-wire serial interface | Enables daisy-chain configuration without clock buffers; LDI latches data, SCKI clocks in, SDO/SCKO/LDO drive next device |
Key Features
| Feature | Design Value |
|---|---|
| Adaptive LED bus voltage control | Reduces power loss by dynamically adjusting buck output to match highest forward voltage among active LED strings |
| Per-channel 6-bit dot correction | Compensates for LED binning variations and PCB trace resistance mismatches to achieve <8% inter-channel current mismatch |
| 12-bit grayscale PWM dimming | Enables smooth, high-resolution brightness control up to 500Hz frame rate without visible flicker in video applications |
| Integrated open/short LED diagnostics | Reports fault status per channel via serial interface-no external sensing circuitry required |
| Thermal shutdown with programmable threshold | TSET pin allows custom overtemperature trip point (e.g., 125°C) using single resistor; prevents thermal runaway in dense LED arrays |
Applications
| Large-Screen LCD Backlighting | Full-Color LED Video Walls |
|---|---|
Use Scenario: Dynamic local dimming for 65"+ LCD panels with zone-based brightness control. IC Role / Device Role / Timing Role: LT3746IUHH#TRPBF acts as channelized LED current controller and adaptive bus voltage generator, synchronized to video frame timing via PWMCK. Use Value: Enables >10,000:1 contrast ratio through per-zone dimming while maintaining uniform luminance across 32 parallel LED strings. |
Use Scenario: High-resolution outdoor LED signage with pixel-level grayscale control. IC Role / Device Role / Timing Role: LT3746IUHH#TRPBF serves as RGB subpixel driver with independent 12-bit grayscale per channel and real-time fault reporting. Use Value: Delivers consistent color fidelity and >4000-nit brightness with automatic open-circuit detection to prevent dead-pixel clusters. |
| Mono-Color LED Billboards | Industrial HMI Displays |
Use Scenario: Energy-efficient highway message signs operating under wide ambient temperature swings. IC Role / Device Role / Timing Role: LT3746IUHH#TRPBF provides thermally robust constant-current drive with TSET-programmed overtemperature protection. Use Value: Maintains stable 30mA output per channel from –40°C to 125°C junction, eliminating brightness drift in uncooled enclosures. |
Use Scenario: Medical or factory-floor HMIs requiring high reliability and diagnostic visibility. IC Role / Device Role / Timing Role: LT3746IUHH#TRPBF functions as fault-aware LED driver with serial-status readback for predictive maintenance. Use Value: Reduces system downtime by identifying failing LED strings before complete failure via periodic status register polling. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar LED driver applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LT3745IUHF#TRPBF | 24-channel version; no integrated buck controller - requires external DC/DC supply | Suitable only where fixed LED bus voltage is available; lacks adaptive voltage optimization | Select when board space is constrained and bus voltage is pre-regulated; not drop-in compatible due to pin count and topology differences |
| MAX16832ATL+T | 16-channel, 40V max; no serial interface - uses analog dimming and discrete enable lines | Lacks per-channel dot correction and grayscale PWM; limited to basic on/off or analog dimming | Choose for cost-sensitive, low-channel-count applications without need for diagnostics or fine-grain dimming |
Compared with LT3745IUHF#TRPBF and MAX16832ATL+T, the LT3746IUHH#TRPBF uniquely combines 32-channel precision current control, integrated adaptive buck regulation, and a high-speed cascadable serial interface - making it the only option supporting large-scale, fault-aware, high-dynamic-range LED systems without external logic or voltage rails.
Availability
LT3746IUHH#TRPBF is available at Aetrix Electronics and suitable for large-screen LCD backlighting, full-color LED video walls, mono-color billboards, industrial HMI displays, and medical visualization systems requiring stable component supply across extended temperature ranges.
Supply support for LT3746IUHH#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 acquired Linear Technology in 2017 and maintains full product support, documentation, and manufacturing continuity for the LT3746 series.
The LT3746IUHH#TRPBF belongs to Linear's high-performance LED driver product line, engineered specifically for demanding display applications requiring channel scalability, thermal resilience, and real-time diagnostics.
FAQ
What is the maximum LED string voltage supported per channel of the LT3746IUHH#TRPBF?
The LT3746IUHH#TRPBF supports up to 13V at the LEDxx pins, enabling driving of 3–4 standard white LEDs (VF ≈ 3.2V–3.6V) in series per channel. This rating is absolute maximum - actual usable headroom depends on bus voltage margin and thermal derating. Operation above 13V risks damage to internal current sinks.
Does the LT3746IUHH#TRPBF require an external microcontroller to operate?
No - the LT3746IUHH#TRPBF operates autonomously once configured: ISET and TSET resistors set nominal current and thermal threshold, and the buck controller self-starts after UVLO clearance. However, a microcontroller is required to load grayscale and dot correction data via the serial interface for dynamic dimming and calibration.
Can the LT3746IUHH#TRPBF drive both common-anode and common-cathode LED configurations?
The LT3746IUHH#TRPBF is designed exclusively for common-anode LED strings: its LEDxx pins are constant-current sinks connected to LED cathodes, while the anodes tie to the adaptive buck output (VOUT). It cannot drive common-cathode configurations without external level-shifting circuitry.
How does the LT3746IUHH#TRPBF handle thermal overload conditions?
When die temperature exceeds the TSET-programmed threshold, the LT3746IUHH#TRPBF asserts the OT (overtemperature) flag in its status register and disables all LED channels. The buck controller continues switching but halts current sinking until temperature falls below hysteresis (typically 10°C), ensuring safe recovery without latch-off.
What is the purpose of the 6-wire serial interface on the LT3746IUHH#TRPBF?
The 6-wire interface (SCKI/SDI/LDI/SCKO/SDO/LDO) eliminates clock-skew issues in daisy-chained systems: SCKO and LDO from one LT3746IUHH#TRPBF directly drive SCKI and LDI of the next, enabling reliable 30MHz operation across dozens of devices without external buffers or matched-length routing.
LT3746IUHH#TRPBF Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc.
- Series:
- -
- Package/Case:
- 56-WFQFN Exposed Pad
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Type:
- DC DC Controller
- Topology:
- Step-Down (Buck)
- Internal Switch(s):
- No
- Number of Outputs:
- 32
- Voltage - Supply (Min):
- 6V
- Voltage - Supply (Max):
- 55V
- Voltage - Output:
- -
- Current - Output / Channel:
- 30mA
- Frequency:
- 205Hz ~ 1.05MHz
- Dimming:
- PWM
- Applications:
- Backlight, Signage
- Operating Temperature:
- -40°C ~ 125°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 56-QFN (5x9)
LT3746IUHH#TRPBF FAQ
1.How can I place an order for LT3746IUHH#TRPBF through Aetrix?
Please submit a Request for Quotation (RFQ) for LT3746IUHH#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 LT3746IUHH#TRPBF reliable?
The price and inventory of LT3746IUHH#TRPBF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LT3746IUHH#TRPBF is usually 5 days.
3.What payment methods are accepted for LT3746IUHH#TRPBF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LT3746IUHH#TRPBF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LT3746IUHH#TRPBF?
LT3746IUHH#TRPBF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LT3746IUHH#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 LT3746IUHH#TRPBF?
For technical support, including LT3746IUHH#TRPBF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LT3746IUHH#TRPBF requirements.
6.How does Aetrix verify that LT3746IUHH#TRPBF is sourced from the original manufacturer or authorized distributors?
All LT3746IUHH#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 LT3746IUHH#TRPBF meets industry standards.
7.What is the process for return or replacement of LT3746IUHH#TRPBF?
All LT3746IUHH#TRPBF units undergo pre-shipment inspection (PSI). If there is an issue with LT3746IUHH#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 LT3746IUHH#TRPBF part is unused and in its original packaging.
Return procedure for LT3746IUHH#TRPBF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LT3746IUHH#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…
