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Analog Devices Inc. LT3599EFE#PBF
- Part No.:
- LT3599EFE#PBF
- Manufacturer:
- Analog Devices Inc.
- Category:
- LED Drivers
- Package:
- 28-TSSOP (0.173", 4.40mm Width) Exposed Pad
- Datasheet:
-
LT3599EFE#PBF.pdf
- Description:
- IC LED DRVR RGLTR PWM 28TSSOP
- Quantity:
- Payment:
- Shipping:
Inventory:131
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Product details
Overview
LT3599EFE#PBF 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 LT3599EFE#PBF datasheet, LT3599EFE#PBF pinout, LT3599EFE#PBF application, or LT3599EFE#PBF equivalent, this page delivers verified technical context, real-world dimming performance (3000:1 True Color PWM), thermal derating capability, open/short LED fault detection, and package-specific layout guidance for the 28-pin TSSOP variant.
Technical Context
The LT3599EFE#PBF 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 regulation (via LEDx pins) and overvoltage protection (via FB pin with 1.223V reference).
LED current is set by an external resistor on ISET (11k–44.2kΩ), while analog dimming is achieved via CTRL pin voltage (0–1V), and PWM dimming via dedicated PWM pin with 0.033% minimum duty cycle support. Thermal derating is programmable via TSET pin with VPTAT-based junction temperature sensing.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| LED String Count | 4 independent strings, each configurable for 30–120mA via ISET resistor |
| 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 supplies without pre-regulation |
| Max Output Voltage | 44V - sufficient for driving 10+ white LEDs in series per string |
| Switching Frequency Range | 200kHz to 2.1MHz (programmable via RT resistor) - enables EMI optimization and compact magnetics |
| PWM Dimming Ratio | Up to 3000:1 (True Color PWM™) - maintains consistent chromaticity across full brightness range |
| Junction Temp Range | –40°C to 125°C - qualified for automotive navigation and industrial display environments |
Pinout & Package
LT3599EFE#PBF is packaged in a thermally enhanced 28-pin plastic TSSOP (FE package) with exposed pad (Pin 29) soldered to PCB ground for thermal management. θJA = 28°C/W, θJC = 10°C/W.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| VIN | Input supply connection | Accepts 3.1V–30V; requires local ceramic bypass capacitor to GND |
| SW | Collector of internal 2A NPN switch | Connects to boost inductor; minimize trace area to reduce EMI |
| VOUT | Boost output node | Supplies power to all four LED strings; max 44V rating |
| LED1–LED4 | Current-sink outputs for LED strings | Each regulates 30–120mA; open-circuit detection threshold = 0.3V |
| ISET | LED current programming input | Resistor-to-GND sets nominal current: ILED ≈ 1330 / RISET (A) |
| CTRL | Analog dimming control | 0–1V input scales LED current linearly; >1V has no effect |
| PWM | Digital dimming enable/disable | High (>1V) enables switching; low (<0.4V) disables with VC state retention |
| SHDN/UVLO | Shutdown and UVLO programming | 1.36V threshold with 4µA hysteresis; supports resistor-divider UVLO setup |
| FB | Overvoltage protection feedback | 1.223V reference; used with R1/R2 divider to clamp VOUT when all strings open |
| VC | Error amplifier output | Connect external compensation network here; controls peak switch current |
| RT | Frequency programming | Resistor-to-GND sets fSW from 200kHz–2.1MHz; also enables SYNC mode |
| TSET | Thermal derating trigger | Internal VPTAT comparator reduces LED current above programmed junction temp |
| OPENLED / SHORTLED | Fault flag outputs | Open-collector alerts: OPENLED asserts if any LED string opens; SHORTLED if LEDx shorts to VOUT |
| DISABLE4 | LED4 disable control | Connect to VREF to disable LED4; allows 3-string operation with LED4 tied to LED3 |
Key Features
| Feature | Design Value |
|---|---|
| True Color PWM™ dimming | 3000:1 ratio with constant chromaticity - eliminates color shift during brightness adjustment |
| Programmable LED current derating | Via TSET pin and external resistor divider - protects LEDs from thermal overstress at high ambient temps |
| Integrated open/short LED protection | Dedicated OPENLED and SHORTLED flags with latched status - enables system-level fault diagnostics |
| Regulation with VIN > VOUT | Maintains LED current even when input exceeds output voltage - supports flexible power architecture |
| Synchronizable switching frequency | RT resistor configured 20% below external SYNC clock - eliminates beat frequencies in multi-rail systems |
| Programmable maximum output voltage | Via FB resistor divider (VOUT(MAX) = 1.223 × (1 + R2/R1)) - prevents overvoltage damage during open-string faults |
Applications
| Automotive Navigation Displays | Industrial TFT LCD Backlighting |
|---|---|
Use Scenario: Driving 4-string white LED backlight for 7–10 inch automotive infotainment displays operating across –40°C to 105°C ambient. IC Role / Device Role / Timing Role: Primary LED current regulator and boost controller with fault monitoring and thermal derating. Use Value: ±1.5% current matching ensures uniform screen luminance; 3000:1 PWM dimming enables seamless day/night transition without color shift. |
Use Scenario: Powering high-brightness TFT backlights in factory HMIs, medical monitors, and outdoor kiosks requiring stable light output under variable input voltage. IC Role / Device Role / Timing Role: Fixed-frequency boost LED driver with programmable UVLO, open/short detection, and robust thermal management. Use Value: 3.1V–30V input range accommodates 12V/24V industrial rails; programmable VOUT(MAX) prevents overvoltage during LED failure. |
| Notebook PC Display Backlight | Desktop Monitor Backlight Control |
Use Scenario: Compact 4-string LED driver for ultrabook displays where board space and thermal density are constrained. IC Role / Device Role / Timing Role: High-efficiency (90%) boost converter with integrated fault flags and soft-start for inrush control. Use Value: 28-pin TSSOP package enables dense layout; 11µA SS current allows precise start-up ramp rate and reduced inrush stress. |
Use Scenario: Driving dual-zone or full-array LED backlights in 24–27 inch desktop monitors with dynamic dimming requirements. IC Role / Device Role / Timing Role: Multi-string LED controller supporting analog + PWM hybrid dimming and thermal foldback. Use Value: CTRL + PWM dual-dimming interface enables smooth transitions; TSET-based derating extends LED lifetime at elevated enclosure temperatures. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar LED driver applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LT3599EUH#PBF | 32-pin 5mm × 5mm QFN package; θJA = 34°C/W vs 28°C/W for TSSOP; same electrical specs | Better thermal performance in high-power-density layouts; requires different PCB footprint and reflow profile | Select EUH for higher ambient temperature or higher continuous power designs where thermal resistance must be minimized. |
| LT3756IMSE#PBF | Single-channel, 100V-input capable boost/buck-boost LED controller; no integrated switch; requires external MOSFET | Supports wider input range (6–100V) and higher output voltages; lacks built-in 4-string matching and OPENLED/SHORTLED flags | Choose LT3756IMSE#PBF only when system requires >44V output, >30V input, or discrete FET control - not a drop-in replacement. |
Compared with LT3599EFE#PBF, the EUH variant offers superior thermal dissipation in space-constrained designs, while the LT3756IMSE#PBF trades integration for flexibility in high-voltage or custom topology applications - neither matches the exact 4-string matched-current functionality of the LT3599EFE#PBF.
Availability
LT3599EFE#PBF is available at Aetrix Electronics and suitable for automotive navigation displays, industrial HMI backlighting, and notebook PC display systems requiring stable component supply, long-term lifecycle support, and AEC-Q200-aligned reliability.
Supply support for LT3599EFE#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 acquired Linear Technology in 2017 and maintains its legacy precision analog and power management product lines with full datasheet, application note, and design tool support.
The LT3599 belongs to Linear's high-accuracy LED driver family, engineered specifically for TFT LCD backlighting in automotive, industrial, and computing displays where string matching, fault resilience, and thermal robustness are critical.
FAQ
What is the maximum LED string voltage supported by the LT3599EFE#PBF?
The LT3599EFE#PBF supports up to 44V output voltage, enabling it to drive 10–12 white LEDs (3.2–3.6V each) in series per string. This is confirmed in the Absolute Maximum Ratings table (VOUT, VO_SW ≤ 45V) and Typical Application section, where output voltage is specified as "up to 44V" under normal operation with full load.
Does the LT3599EFE#PBF support dimming when input voltage exceeds output voltage?
Yes, the LT3599EFE#PBF maintains accurate LED current regulation even when VIN > VOUT - a key feature explicitly stated in the Description and Applications Information sections. This allows operation in scenarios such as battery-powered systems where input voltage may temporarily exceed the LED string forward voltage during charge cycles.
How is LED current matching accuracy verified for the LT3599EFE#PBF?
The LT3599EFE#PBF guarantees ±1.5% LED current matching across all four strings at 100mA, as measured and specified in the Electrical Characteristics table under "LED String Current Matching". This value applies over the full operating temperature range (–40°C to 125°C) and is validated per Linear Technology's characterization methodology.
Can the LT3599EFE#PBF drive fewer than four LED strings?
Yes, the LT3599EFE#PBF supports 3-string operation via the DISABLE4 pin: tie DISABLE4 to VREF and connect LED4 to LED3. For 2-string operation, parallel LED1+LED2 and LED3+LED4. This configuration flexibility is documented in the Operation section and Pin Functions description for DISABLE4.
What protection features does the LT3599EFE#PBF provide against LED faults?
The LT3599EFE#PBF provides dedicated open-LED detection (OPENLED pin asserts if any LEDx voltage falls below 0.3V) and short-LED detection (SHORTLED pin asserts if VOUT–VLEDx exceeds 0.8–2.2V). Both flags are open-collector and latched during PWM low periods, enabling reliable system-level fault handling.
LT3599EFE#PBF Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc.
- Series:
- -
- Package/Case:
- 28-TSSOP (0.173", 4.40mm Width) Exposed Pad
- Packaging:
- Tube
- 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:
- 28-TSSOP-EP
LT3599EFE#PBF FAQ
1.How can I place an order for LT3599EFE#PBF through Aetrix?
Please submit a Request for Quotation (RFQ) for LT3599EFE#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 LT3599EFE#PBF reliable?
The price and inventory of LT3599EFE#PBF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LT3599EFE#PBF is usually 5 days.
3.What payment methods are accepted for LT3599EFE#PBF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LT3599EFE#PBF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LT3599EFE#PBF?
LT3599EFE#PBF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LT3599EFE#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 LT3599EFE#PBF?
For technical support, including LT3599EFE#PBF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LT3599EFE#PBF requirements.
6.How does Aetrix verify that LT3599EFE#PBF is sourced from the original manufacturer or authorized distributors?
All LT3599EFE#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 LT3599EFE#PBF meets industry standards.
7.What is the process for return or replacement of LT3599EFE#PBF?
All LT3599EFE#PBF units undergo pre-shipment inspection (PSI). If there is an issue with LT3599EFE#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 LT3599EFE#PBF part is unused and in its original packaging.
Return procedure for LT3599EFE#PBF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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