My Inquiry
My Account
Analog Devices Inc. LT3599IUH#TRPBF
- Part No.:
- LT3599IUH#TRPBF
- Manufacturer:
- Analog Devices Inc.
- Category:
- LED Drivers
- Package:
- 32-WFQFN Exposed Pad
- Datasheet:
-
LT3599IUH#TRPBF.pdf
- Description:
- IC LED DRV RGLTR PWM 120MA 32QFN
- Quantity:
- Payment:
- Shipping:
Inventory:3,811
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
LT3599IUH#TRPBF from Analog Devices (formerly Linear Technology) is a fixed-frequency 2A step-up DC/DC converter IC designed to drive four independent LED strings at up to 120mA per string with ±1.5% current matching, supporting output voltages up to 44V and input voltages from 3.1V to 30V - used in automotive and industrial TFT LCD backlighting systems.
For engineers reviewing the LT3599IUH#TRPBF datasheet, LT3599IUH#TRPBF pinout, LT3599IUH#TRPBF application, or LT3599IUH#TRPBF equivalent, this page delivers verified technical context, package-specific pin functions, real-world dimming performance (3000:1 True Color PWM), thermal derating capability, and validated alternative options for LED driver selection.
Technical Context
The LT3599IUH#TRPBF implements constant-frequency peak-current-mode control with an internal 2A NPN power switch and integrated PMOS disconnect switch (VO_SW) for shutdown and PWM dimming. It uses separate feedback paths for LED string voltage regulation and overvoltage protection via FB and VO_SW pins.
It supports dual dimming: analog dimming via CTRL pin (0–1V, up to 20:1 ratio) and true-color PWM dimming via PWM pin (0.033%–100% duty cycle, up to 3000:1 ratio), with open/short LED fault detection on each string and programmable thermal derating via TSET pin.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| LED String Count | 4 independent strings, each configurable up to 120mA with matched current regulation |
| Current Matching Accuracy | ±1.5% across all strings at 100mA - ensures uniform brightness in multi-string displays |
| Input Voltage Range | 3.1V to 30V - supports wide-range automotive and industrial supply rails without pre-regulation |
| Max Output Voltage | 44V - sufficient for driving 10+ white LEDs in series per string |
| Switching Frequency Range | 200kHz to 2.1MHz (resistor-programmable via RT pin) - enables EMI optimization and compact magnetics |
| Dimming Capability | True Color PWM up to 3000:1 ratio - preserves color fidelity during deep dimming in navigation displays |
| Junction Temp Range | –40°C to +125°C - qualified for under-hood and industrial ambient conditions |
| Package Thermal Resistance | θJA = 34°C/W (32-pin QFN, 5mm × 5mm) - requires exposed pad soldering for thermal reliability |
Pinout & Package
LT3599IUH#TRPBF is housed in a thermally enhanced 32-pin (5mm × 5mm) plastic QFN package with exposed ground pad (Pin 33), requiring PCB soldering to a continuous copper ground plane for thermal and electrical integrity.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| VIN | Input Supply | 3.1V–30V main power input; must be locally bypassed with ceramic capacitor |
| SW | Internal NPN Switch Collector | High-current switching node; minimal trace area required to reduce EMI |
| VOUT | Boost Output | Drives all LED strings; regulated up to 44V using feedback from LED string voltages |
| LED1–LED4 | LED String Cathode Outputs | Current-sink outputs; each regulates 30–120mA via ISET resistor; DISABLE4 allows disabling LED4 |
| ISET | LED Current Programming | Resistor-to-ground sets per-string current (e.g., 13.3kΩ → 99mA); supports 30–120mA range |
| PWM | PWM Dimming Control | 0.4V/1V logic thresholds; enables true-color dimming with 3000:1 ratio and fast transient recovery |
| CTRL | Analog Dimming Input | 0–1V input scales LED current linearly; <1V enables analog dimming up to 20:1 ratio |
| FB | Overvoltage Protection Feedback | 1.223V reference threshold; used with R1/R2 divider on VO_SW to set max VOUT when all strings open |
| VO_SW | PMOS Disconnect Switch Drain | Internally isolates FB divider from VOUT during PWM off-time to prevent false OPENLED flags |
| OPENLED / SHORTLED | Fault Flag Outputs | Open-collector alerts: OPENLED asserts if any LED string opens; SHORTLED asserts if LEDx shorts to VOUT |
| TSET | Thermal Derating Threshold | Programs junction temperature breakpoint (e.g., 595mV ≈ 75°C); above threshold, LED current reduces |
| RT | Frequency Programming | Resistor-to-ground sets switching frequency (200kHz–2.1MHz); also used for SYNC frequency offset |
| SHDN/UVLO | Enable & UVLO Input | 1.36V turn-on threshold; supports resistor-divider UVLO programming with 4µA hysteresis current |
| SS | Soft-Start Control | 11µA internal current charges external capacitor; controls VC ramp rate and limits inrush current |
| VC | Error Amplifier Output | Connects to external compensation network; directly controls peak switch current limit |
| VREF | 1.227V Bandgap Reference | Stable 1.227V source; supplies up to 100µA; used to bias CTRL, PWM, and DISABLE4 when unused |
Key Features
| Feature | Design Value |
|---|---|
| True Color PWM Dimming | 3000:1 dimming ratio with constant LED chromaticity - critical for automotive HUD and infotainment displays |
| Per-String Open/Short Detection | Dedicated OPENLED and SHORTLED flags with latch behavior during PWM low phase - enables robust fault logging |
| Programmable Thermal Derating | TSET pin accepts voltage divider with NTC thermistor to reduce LED current above user-defined junction temperature |
| Regulated Output with VIN > VOUT | Continues regulating LED current even when input exceeds output voltage - supports buck-boost hybrid topologies |
| Configurable LED String Count | DISABLE4 pin allows disabling LED4; remaining strings can be paralleled (e.g., LED1+LED2, LED3+LED4) for 2- or 3-string operation |
| External Frequency Synchronization | SYNC pin accepts external clock; RT resistor set 20% slower than SYNC frequency - eliminates beat frequencies in multi-rail systems |
Applications
| Automotive Navigation Displays | Industrial TFT LCD Backlighting |
|---|---|
|
Use Scenario: Driving high-brightness white LED arrays in 7–12 inch automotive TFT LCDs with wide ambient temperature range (–40°C to +105°C). IC Role / Device Role / Timing Role: Primary boost LED driver with per-string current regulation, fault monitoring, and synchronized dimming control. Use Value: ±1.5% current matching ensures uniform screen luminance; 3000:1 True Color PWM enables seamless day/night transition without color shift. |
Use Scenario: Powering ruggedized HMI displays in factory automation panels where EMI immunity and thermal stability are critical. IC Role / Device Role / Timing Role: Constant-current LED driver with programmable UVLO, thermal derating, and open-circuit protection for long-term reliability. Use Value: TSET-based thermal derating prevents LED degradation at elevated ambient temperatures; SHDN/UVLO hysteresis avoids supply brownout oscillation. |
| Desktop Monitor Backlight | Medical Imaging Display |
|
Use Scenario: Driving edge-lit LED backlights in 24–27 inch desktop monitors requiring flicker-free dimming and low acoustic noise. IC Role / Device Role / Timing Role: High-efficiency (90%) boost controller with adjustable switching frequency to avoid audible coil whine. Use Value: 200kHz–2.1MHz RT-programmable frequency allows tuning away from sensitive audio bands; soft-start minimizes inrush stress. |
Use Scenario: Backlighting diagnostic-grade grayscale medical displays demanding precise luminance stability and fault diagnostics. IC Role / Device Role / Timing Role: Fault-aware LED driver with latched OPENLED/SHORTLED flags and regulated current for DICOM-compliant calibration. Use Value: Independent per-string monitoring enables pixel-level backlight correction; VOUT regulation accuracy (±1.5%) supports consistent gamma curve rendering. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar LED driver applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LT3756IMSE#TRPBF | Higher 5A switch current; supports SEPIC/buck-boost topologies; no integrated OPENLED/SHORTLED flags | Better suited for high-power single-string or RGB LED systems; lacks per-string fault reporting | Select when driving >120mA per string or needing topology flexibility beyond boost-only operation |
| TPS61165DRVR | Lower 1.2A switch current; fixed 1.2MHz frequency; only 2-string support; no thermal derating or SYNC | Targeted at cost-sensitive consumer displays; limited to ≤40V output and no fault flag latching | Choose for compact 2-string designs where full diagnostic capability and thermal management are not required |
Compared with LT3599IUH#TRPBF, LT3756IMSE#TRPBF offers higher power headroom but sacrifices per-string diagnostics, while TPS61165DRVR provides simpler integration at the cost of scalability, thermal safety, and fault visibility - making LT3599IUH#TRPBF optimal for mission-critical multi-string backlighting with full system observability.
Availability
LT3599IUH#TRPBF is available at Aetrix Electronics and suitable for automotive navigation displays, industrial HMI backlighting, and medical imaging systems requiring stable component supply, long lifecycle support, and guaranteed parametric performance over –40°C to +125°C.
Supply support for LT3599IUH#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) is a global leader in high-performance analog, mixed-signal, and power management semiconductors, serving precision, industrial, automotive, and communications markets.
The LT3599IUH#TRPBF belongs to Linear's high-reliability LED driver product line, engineered specifically for multi-string TFT LCD backlighting with emphasis on current matching, fault resilience, and thermal-aware operation in harsh environments.
FAQ
What is the maximum LED string voltage supported by the LT3599IUH#TRPBF?
The LT3599IUH#TRPBF supports up to 44V output voltage, sufficient to drive 10–12 white LEDs (3.2–3.6V VF each) in series per string. This rating is confirmed in Absolute Maximum Ratings and Typical Application schematics, and applies across the full –40°C to +125°C operating junction temperature range.
Does the LT3599IUH#TRPBF support dimming below 1% duty cycle?
Yes - the LT3599IUH#TRPBF achieves true-color PWM dimming down to 0.033% duty cycle (3000:1 ratio) at 100Hz, as verified in Typical Performance Characteristics (Figure G11) and Applications Information. This enables ultra-deep dimming without color shift in automotive navigation displays.
How is LED current programmed on the LT3599IUH#TRPBF?
LED current is programmed via a resistor (RISET) between the ISET pin and GND. For example, 13.3kΩ yields ~99mA per string (per Table 4). The relationship is ILED ≈ 1330 / RISET (in kΩ), valid for CTRL > 1V. Analog dimming is also possible via 0–1V on the CTRL pin.
Can the LT3599IUH#TRPBF operate with input voltage higher than output voltage?
Yes - the LT3599IUH#TRPBF maintains accurate LED current regulation even when VIN exceeds VOUT, as explicitly stated in the Features list and Operation section. This behavior is enabled by its current-mode control architecture and independent LED string sensing.
What thermal management is required for the LT3599IUH#TRPBF in continuous operation?
The LT3599IUH#TRPBF requires soldering of its exposed pad (Pin 33) to a continuous PCB ground plane to achieve θJA = 34°C/W. Without proper thermal land design, junction temperature may exceed 125°C under full load (4×120mA @ 44V), triggering thermal derating or shutdown.
LT3599IUH#TRPBF Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc.
- Series:
- -
- Package/Case:
- 32-WFQFN Exposed Pad
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Type:
- DC DC Regulator
- Topology:
- Step-Up (Boost)
- Internal Switch(s):
- Yes
- Number of Outputs:
- 4
- Voltage - Supply (Min):
- 2.7V
- Voltage - Supply (Max):
- 30V
- Voltage - Output:
- 44V
- Current - Output / Channel:
- 120mA
- Frequency:
- 200kHz ~ 2.1MHz
- Dimming:
- Analog, PWM
- Applications:
- -
- Operating Temperature:
- -40°C ~ 125°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 32-QFN (5x5)
LT3599IUH#TRPBF FAQ
1.How can I place an order for LT3599IUH#TRPBF through Aetrix?
Please submit a Request for Quotation (RFQ) for LT3599IUH#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 LT3599IUH#TRPBF reliable?
The price and inventory of LT3599IUH#TRPBF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LT3599IUH#TRPBF is usually 5 days.
3.What payment methods are accepted for LT3599IUH#TRPBF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LT3599IUH#TRPBF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LT3599IUH#TRPBF?
LT3599IUH#TRPBF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LT3599IUH#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 LT3599IUH#TRPBF?
For technical support, including LT3599IUH#TRPBF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LT3599IUH#TRPBF requirements.
6.How does Aetrix verify that LT3599IUH#TRPBF is sourced from the original manufacturer or authorized distributors?
All LT3599IUH#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 LT3599IUH#TRPBF meets industry standards.
7.What is the process for return or replacement of LT3599IUH#TRPBF?
All LT3599IUH#TRPBF units undergo pre-shipment inspection (PSI). If there is an issue with LT3599IUH#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 LT3599IUH#TRPBF part is unused and in its original packaging.
Return procedure for LT3599IUH#TRPBF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LT3599IUH#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…
