My Inquiry
My Account
Analog Devices Inc. LT3518EFE#PBF
- Part No.:
- LT3518EFE#PBF
- Manufacturer:
- Analog Devices Inc.
- Category:
- LED Drivers
- Package:
- 16-TSSOP (0.173", 4.40mm Width) Exposed Pad
- Datasheet:
-
LT3518EFE#PBF.pdf
- Description:
- IC LED DRV RGLTR PWM 16TSSOP
- Quantity:
- Payment:
- Shipping:
Inventory:801
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
LT3518EFE#PBF from Analog Devices is a constant-frequency current-mode DC/DC LED driver IC with an internal 2.3A, 45V power switch, supporting boost, buck, and buck-boost topologies. It delivers precise constant-current regulation via 100mV high-side current sensing, enables 3000:1 true-color PWM dimming, and operates across 3V–30V input voltage for display backlighting and automotive lighting systems.
For engineers reviewing the LT3518EFE#PBF datasheet, LT3518EFE#PBF pinout, LT3518EFE#PBF application, or LT3518EFE#PBF equivalent, key selection criteria include its 2.3A/45V integrated switch, 250kHz–2.5MHz adjustable switching frequency, open-LED protection, PMOS gate driver for LED disconnect, and dual constant-current/constant-voltage regulation capability.
Technical Context
The LT3518EFE#PBF implements a dual-loop control architecture: a voltage loop (FB pin, 1.01V threshold) and a current loop (ISP/ISN sense inputs, 100mV full-scale threshold), with the lower feedback demand dictating operating mode. Its internal transconductance error amplifier (550µS) drives the VC pin for loop compensation, while the RT pin sets oscillator frequency via external resistor (250kHz–2.5MHz).
It integrates a 7V-clamped top-gate driver (TG) for external PMOS LED disconnect, supports synchronization via SYNC pin with 20% slower RT-programmed frequency, and features soft-start (SS pin), shutdown (SHDN), and analog dimming (CTRL pin, 0–1V input scaling LED current linearly to 10:1 ratio).
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Switch Current Limit | 2.3A typical; defines maximum peak inductor current and LED drive capability in all topologies. |
| Input Voltage Range | 3V to 30V continuous; supports wide-range industrial and automotive supplies with 40V transient tolerance. |
| Current Sense Threshold | 100mV at ISP–ISN; enables accurate, low-loss LED current regulation with minimal power dissipation in sense resistor. |
| Switching Frequency Range | 250kHz to 2.5MHz; adjustable via RT resistor or external SYNC clock for optimization of efficiency vs. component size. |
| Dimming Capability | 3000:1 true-color PWM via PWM pin + 10:1 analog via CTRL pin; enables flicker-free, high-fidelity brightness control without color shift. |
| Operating Junction Temp | –40°C to 125°C; qualified for extended temperature industrial and automotive cabin applications. |
| Package Type | 16-pin TSSOP (FE package); surface-mount, thermally enhanced with exposed pad soldered to PCB ground plane. |
Pinout & Package
The LT3518EFE#PBF is housed in a 16-lead plastic TSSOP package (FE) with exposed pad (Pin 17) that must be soldered to PCB ground for thermal and electrical performance. Pin numbering follows standard JEDEC TSSOP top-view convention.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| VIN | Input supply rail | Accepts 3V–30V DC input; requires local 2.2µF ceramic bypass capacitor to minimize EMI and supply ripple. |
| SHDN | Enable/disable control | Logic-high ≥1.2V enables operation; logic-low ≤0.45V disables switch and reduces quiescent current to <1µA. |
| VREF | 2.0V reference output | Provides stable 2.0V ±2% reference (100µA sink/source); used to bias CTRL pin for full-scale 100mV current sense. |
| RT | Oscillator frequency set | Resistor-to-GND sets switching frequency (250kHz–2.5MHz); must not be left floating or capacitive-loaded. |
| SYNC | External clock input | Accepts TTL/CMOS clock; forces synchronized switching when active; RT must be set for 20% lower free-running frequency. |
| SS | Soft-start timing | Capacitor-to-GND controls ramp-up time of output current/voltage; prevents inrush and overshoot at startup. |
| PWM | Digital dimming input | Active-low signal disables main switch and asserts TG high; enables 3000:1 PWM dimming with fast transient recovery. |
| CTRL | Analog current setpoint | 0–1V input scales LED current linearly (ILED = VCTRL / (10 × RSENSE)); clamped at 100mV for VCTRL > 1V. |
| VC | Error amplifier output | gm amplifier output (550µS); connects to RC compensation network for loop stability in constant-current or -voltage modes. |
| FB | Voltage feedback input | Regulates output voltage to 1.01V threshold; provides overvoltage protection by disabling switch if FB exceeds 1.04V. |
| TG | Top-gate driver output | Inverted PWM output driving external PMOS; clamped to VISP – 7V for safe gate drive and LED string disconnect during PWM off. |
| ISP / ISN | High-side current sense | Differential inputs for 100mV sense resistor; rail-to-rail operation enables accurate current measurement across full LED string voltage range. |
| TGEN | PMOS driver enable | Logic-high ≥1.5V enables TG output; tied to GND to disable PMOS disconnect function. |
| SW | Power switch node | Drains 2.3A peak current into inductor/diode; requires minimized trace area and adjacent ground plane to reduce EMI. |
| GND | Ground reference | Exposed pad (Pin 17) is primary GND connection; must be soldered to large PCB ground plane for thermal management and noise immunity. |
Key Features
| Feature | Design Value |
|---|---|
| Integrated 2.3A/45V power switch | Eliminates external MOSFET and associated gate drive complexity in LED driver designs up to 30W. |
| 100mV high-side current sense | Reduces sense resistor power loss by >50% versus 200mV alternatives, improving thermal margin and efficiency. |
| 3000:1 true-color PWM dimming | Preserves LED chromaticity across full brightness range using synchronized PWM with stored VC state for zero-recovery delay. |
| Open LED protection | Automatically disables switching and asserts fault condition if ISP–ISN voltage exceeds 103mV, preventing overvoltage damage. |
| PMOS gate driver with 7V clamp | Enables robust LED string disconnect during PWM off-time, preventing output capacitor discharge and enabling faster dimming response. |
| Adjustable 250kHz–2.5MHz frequency | Allows trade-off between inductor size (higher fSW → smaller L) and conduction losses (lower fSW → higher efficiency). |
Applications
| Display Backlighting | Automotive Lighting |
|---|---|
Use Scenario: Driving white LED strings in LCD monitors, tablets, and industrial HMIs requiring uniform brightness and flicker-free dimming. IC Role / Device Role / Timing Role: Constant-current LED driver operating in boost topology to regulate 3–12 LED series strings from 5V–24V rails. Use Value: 3000:1 PWM dimming ensures no visible flicker at 120Hz, while 100mV current sense minimizes heat in compact enclosures. | Use Scenario: Headlamp DRL (Daytime Running Light), interior map lights, and dashboard illumination in passenger vehicles. IC Role / Device Role / Timing Role: Buck-mode LED driver powering 1–4 LED strings from 8V–16V battery supply with cold-crank tolerance down to 3V. Use Value: –40°C to 125°C operating range and open-LED protection ensure reliability under harsh automotive thermal and fault conditions. |
| Illumination Systems | Scanners & Medical Devices |
Use Scenario: Architectural and task lighting fixtures where precise dimming, long life, and thermal stability are critical. IC Role / Device Role / Timing Role: Buck-boost LED driver maintaining constant current across varying input (e.g., 9–32V PoE or battery) and LED forward voltage drift. Use Value: Dual-loop regulation adapts seamlessly between CC and CV modes, eliminating output instability during LED aging or temperature drift. | Use Scenario: High-speed barcode scanners and portable diagnostic equipment requiring strobed LED illumination with microsecond timing precision. IC Role / Device Role / Timing Role: Synchronized LED driver using SYNC pin to align PWM edges with image capture timing for motion artifact elimination. Use Value: 2.5MHz max switching frequency enables <3µs minimum PWM pulse width, supporting >3000:1 dimming at 100Hz+ frame rates. |
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 | Higher 4A switch current, 60V rating, and programmable current limit; lacks integrated PWM dimming control logic. | Better suited for high-power (>25W) LED arrays; requires external PWM generator and compensation design. | Select LTC3783EFE#PBF when >2.3A peak current or >45V input is required; accept added system complexity for scalability. |
| LM3409QMH/NOPB | 40V-rated 1.25A switch; fixed 500kHz frequency; no SYNC or analog CTRL dimming; only buck topology support. | Targeted at cost-sensitive automotive buck LED drivers; no boost/buck-boost flexibility or multi-ratio dimming. | Choose LM3409QMH/NOPB for simple, low-cost buck-only designs where 3000:1 dimming and topology flexibility are unnecessary. |
Compared with LTC3783EFE#PBF and LM3409QMH/NOPB, the LT3518EFE#PBF uniquely combines 2.3A/45V integration, three topology support, 3000:1 PWM + 10:1 analog dimming, and dual-loop regulation in a single 16-pin TSSOP-making it optimal for space-constrained, multi-function LED systems demanding both precision and versatility.
Availability
LT3518EFE#PBF is available at Aetrix Electronics and suitable for display backlighting, automotive lighting, and industrial illumination systems requiring stable component supply, extended temperature operation, and high-fidelity dimming performance.
Supply support for LT3518EFE#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 (now part of Analog Devices, Inc. following merger with Linear Technology) is a global leader in high-performance analog, mixed-signal, and power management semiconductors.
The LT3518EFE#PBF belongs to Linear Technology's LED driver product line, engineered specifically for high-efficiency, multi-topology constant-current LED regulation with advanced dimming and protection features for demanding visual applications.
FAQ
What is the maximum continuous input voltage rating for the LT3518EFE#PBF?
The LT3518EFE#PBF supports continuous operation up to 30V on the VIN pin. It tolerates nonrepetitive 40V transients for up to one second, as specified in Absolute Maximum Ratings. Exceeding 30V continuously risks exceeding thermal limits and reducing reliability, especially at high ambient temperatures or high duty cycles. Always verify worst-case power dissipation using the device's θJA = 40°C/W (TSSOP) in your layout.
How does the LT3518EFE#PBF achieve 3000:1 PWM dimming ratio?
The LT3518EFE#PBF achieves 3000:1 true-color PWM dimming by combining fast-switching capability (up to 2.5MHz), stored VC node state during PWM low periods, and synchronized edge alignment between PWM and SYNC signals. Minimum pulse width is ~3µs at 2MHz, and maximum period is typically 9ms, yielding 9ms ÷ 3µs = 3000:1. The internal PWM comparator and latch ensure precise on/off timing without color shift across the full range.
Can the LT3518EFE#PBF operate in buck, boost, and buck-boost configurations without external component changes?
Yes - the LT3518EFE#PBF supports all three topologies using the same IC, but external passive components (inductor, diode, sense resistor, feedback resistors) must be selected per topology and application requirements. For example, buck mode uses a single inductor and Schottky diode to ground; boost requires the diode to output; buck-boost needs additional capacitor and layout isolation. Reference schematics TA02a (buck), TA06a (boost), and TA04a (buck-boost) in the datasheet provide validated configurations for LT3518EFE#PBF.
What is the function of the TGEN pin on the LT3518EFE#PBF, and what happens if it is left unconnected?
The TGEN pin enables the internal top-gate driver (TG) output. When pulled ≥1.5V, it activates the inverted PWM signal on TG to drive an external PMOS for LED string disconnect. If left unconnected, the internal 40kΩ pull-down resistor pulls TGEN to GND, disabling the TG function. In that case, TG remains inactive, and LED current path remains closed during PWM off-time - potentially causing output capacitor discharge and slower dimming recovery.
Does the LT3518EFE#PBF require external compensation components, and where are they connected?
Yes - the LT3518EFE#PBF requires external compensation on the VC pin to stabilize the current and voltage control loops. A typical configuration uses a 10nF capacitor from VC to GND; a series resistor may be added to increase slew rate for improved transient response to VIN or CTRL changes. Compensation values depend on inductor, output capacitor, and operating point - refer to the Loop Compensation section and Figure 1 in the LT3518 datasheet for design guidance specific to LT3518EFE#PBF.
LT3518EFE#PBF Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc.
- Series:
- -
- Package/Case:
- 16-TSSOP (0.173", 4.40mm Width) Exposed Pad
- Packaging:
- Tube
- Product Status:
- Active
- Type:
- DC DC Regulator
- Topology:
- Step-Down (Buck), Step-Up (Boost)
- Internal Switch(s):
- Yes
- Number of Outputs:
- 1
- Voltage - Supply (Min):
- 3V
- Voltage - Supply (Max):
- 30V
- Voltage - Output:
- -
- Current - Output / Channel:
- 2.3A (Switch)
- Frequency:
- 250kHz ~ 2.5MHz
- Dimming:
- Analog, PWM
- Applications:
- Backlight
- Operating Temperature:
- -40°C ~ 125°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 16-TSSOP-EP
LT3518EFE#PBF FAQ
1.How can I place an order for LT3518EFE#PBF through Aetrix?
Please submit a Request for Quotation (RFQ) for LT3518EFE#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 LT3518EFE#PBF reliable?
The price and inventory of LT3518EFE#PBF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LT3518EFE#PBF is usually 5 days.
3.What payment methods are accepted for LT3518EFE#PBF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LT3518EFE#PBF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LT3518EFE#PBF?
LT3518EFE#PBF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LT3518EFE#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 LT3518EFE#PBF?
For technical support, including LT3518EFE#PBF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LT3518EFE#PBF requirements.
6.How does Aetrix verify that LT3518EFE#PBF is sourced from the original manufacturer or authorized distributors?
All LT3518EFE#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 LT3518EFE#PBF meets industry standards.
7.What is the process for return or replacement of LT3518EFE#PBF?
All LT3518EFE#PBF units undergo pre-shipment inspection (PSI). If there is an issue with LT3518EFE#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 LT3518EFE#PBF part is unused and in its original packaging.
Return procedure for LT3518EFE#PBF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LT3518EFE#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…
