My Inquiry
My Account
Analog Devices Inc. LT1618EDD#PBF
- Part No.:
- LT1618EDD#PBF
- Manufacturer:
- Analog Devices Inc.
- Package:
- 10-WFDFN Exposed Pad
- Datasheet:
-
LT1618EDD#PBF.pdf
- Description:
- IC REG BOOST ADJ 1.5A 10DFN
- Quantity:
- Payment:
- Shipping:
Inventory:448
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
LT1618EDD#PBF from Analog Devices (formerly Linear Technology) is a constant-current/constant-voltage 1.4MHz step-up DC/DC converter in a 10-pin 3mm × 3mm DFN package with exposed pad. It operates from 1.6V to 18V input, delivers up to 35V output, features 50mV current sense threshold, ±1% output voltage accuracy, and supports LED backlighting and USB-powered boost/SEPIC converters.
For engineers reviewing the LT1618EDD#PBF datasheet, LT1618EDD#PBF pinout, LT1618EDD#PBF application, or LT1618EDD#PBF equivalent, key selection criteria include its dual-loop control architecture, input current limiting capability, IADJ-adjustable current sense, thermal performance with θJA = 43°C/W, and compatibility with low-profile 10µH inductors and ceramic capacitors.
Technical Context
The LT1618EDD#PBF implements fixed-frequency current-mode control with two independent feedback loops: one for output voltage regulation via the FB pin (1.263V reference), and another for precise current regulation via ISP/ISN differential sensing (50mV nominal threshold). Its internal NPN switch exhibits 200mV VCE(SAT) at 1A and supports duty cycles up to 92%.
Operation transitions seamlessly between constant-current and constant-voltage modes based on which error amplifier input dominates. The IADJ pin enables dynamic reduction of the current sense threshold down to ~18mV using an external DC voltage or PWM-derived DC level, enabling brightness or charge current adjustment without resistor changes.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Switching Frequency | 1.4MHz typical - enables use of compact 3–10µH inductors and low-ESR ceramic capacitors |
| Input Voltage Range | 1.6V to 18V - supports single-cell Li-ion, multi-cell alkaline, and USB-powered systems |
| Output Voltage Max | 35V - sufficient for driving strings of white LEDs or powering 24V industrial interfaces |
| Current Sense Threshold | 50mV (adjustable via IADJ) - sets accurate current limit with minimal power loss in sense resistor |
| Reference Voltage (FB) | 1.263V ±1% - defines output voltage with high precision using standard resistor dividers |
| Switch VCE(SAT) | 200mV at 1A - reduces conduction loss and improves efficiency in high-current boost stages |
| Thermal Resistance θJA | 43°C/W - requires exposed pad soldered to PCB ground plane for reliable 1.5A continuous operation |
Pinout & Package
LT1618EDD#PBF uses a 10-pin (3mm × 3mm × 0.8mm) plastic DFN package with exposed thermal pad (Pin 11, GND). The exposed pad must be soldered to PCB ground for optimal thermal performance (θJA = 43°C/W, θJC = 3°C/W).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| FB (Pin 1) | Feedback Input | Connects to resistor divider to set regulated output voltage; 1.263V reference enables precise VOUT programming |
| ISN (Pin 2) | Current Sense (−) | Inverting input of current sense amplifier; used with ISP to monitor switch current via external sense resistor |
| ISP (Pin 3) | Current Sense (+) | Noninverting input of current sense amplifier; differential pair with ISN detects 50mV threshold across RSENSE |
| IADJ (Pin 4) | Current Sense Adjust | DC voltage input that linearly reduces current sense threshold (e.g., 1V → ~18mV); enables analog/PWM dimming or charge current scaling |
| GND (Pin 5) | Ground Reference | Analog and power ground reference; connects to PCB ground plane and exposed pad |
| SW (Pin 6) | Switch Collector | Internal NPN transistor collector node; connects to inductor and Schottky diode anode; high dV/dt node requiring short layout |
| VIN (Pin 8) | Input Supply | Primary power input (1.6–18V); requires local 1–4.7µF ceramic bypass capacitor placed adjacent to pin |
| SHDN (Pin 9) | Shutdown Control | Logic-level enable: >1V = active, <0.3V = shutdown; draws <1µA in shutdown mode |
| VC (Pin 10) | Error Amplifier Compensation | External RC network (e.g., 2kΩ + 10nF) sets loop stability; critical for transient response in CC/CV transition |
Key Features
| Feature | Design Value |
|---|---|
| Constant-current + constant-voltage dual-loop control | Enables single IC operation as LED driver, battery charger, or input-limited boost converter without external controllers |
| 1.4MHz fixed switching frequency | Permits use of miniature 3–10µH shielded inductors and avoids AM radio band interference |
| 50mV current sense threshold with IADJ adjustment | Reduces sense resistor power loss by >50% vs. conventional 100–200mV thresholds; supports fine-grained current tuning |
| ±1% output voltage accuracy over temperature | Ensures stable biasing for sensitive analog loads and eliminates need for post-regulation trimming |
| Exposed-pad DFN thermal design (θJA = 43°C/W) | Supports 1.5A continuous switch current in compact footprint without heatsink or forced air |
Applications
| LED Backlight Driver | USB-Powered Boost Converter |
|---|---|
Use Scenario: Driving 2–20 white LEDs from 1.6–5V sources including single Li-ion or USB ports. IC Role / Device Role / Timing Role: Constant-current source regulating LED string current while maintaining safe overvoltage protection via FB loop. Use Value: Enables PWM brightness control via IADJ pin without changing sense resistor; achieves >85% efficiency at 20–350mA LED currents. | Use Scenario: Generating 5V or 12V from 5V USB input for portable instrumentation or embedded peripherals. IC Role / Device Role / Timing Role: Input-current-limited boost converter preventing host port overload while delivering stable output under variable load. Use Value: Configurable 100mA/500mA input current limit via IADJ; maintains regulation during USB hot-plug events and short-circuit transients. |
| Battery Charger Controller | Input-Current-Limited SEPIC Converter |
Use Scenario: Charging single-cell Li-ion or NiMH batteries from low-voltage sources (e.g., solar, energy harvesting, or weak batteries). IC Role / Device Role / Timing Role: Constant-current/constant-voltage charger with programmable termination voltage and adjustable charge current. Use Value: Precise 50mV current sense enables ±5% charge current accuracy; FB-based voltage regulation ensures ±1% end-of-charge voltage. | Use Scenario: Providing isolated 5V/12V output from noisy or fluctuating 3–12V inputs (e.g., automotive or industrial rails). IC Role / Device Role / Timing Role: Input-current-regulated SEPIC controller delivering short-circuit protected output with DC isolation. Use Value: Input current limiting prevents inrush damage and provides robust short-circuit protection unattainable with standard boost topologies. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar step-up DC/DC converter applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LT3465EDE#PBF | Integrated Schottky diode; 1.2MHz switching; 2.7–16V input; 34V max output; no IADJ pin | Lacks adjustable current sense; optimized for fixed-current LED drivers rather than programmable CC/CV systems | Select when board space is constrained and integrated diode simplifies layout, but avoid if IADJ-based current scaling is required. |
| LTC3401EDD#PBF | Synchronous rectification; 3MHz switching; 0.5–5V input; 6V max output; 1A switch; no exposed pad | Lower voltage range and output; higher frequency enables smaller magnetics but unsuitable for >12V outputs or wide VIN apps | Prefer for ultra-low-input applications (e.g., coin cell) where efficiency >85% at sub-100mA is critical; not a functional replacement for LT1618EDD#PBF's 35V/18V capability. |
Compared with LT3465EDE#PBF and LTC3401EDD#PBF, the LT1618EDD#PBF uniquely combines wide 1.6–18V input, 35V output, dual-loop CC/CV control, and IADJ-adjustable current sensing-making it the only option among the three capable of USB-powered 12V boost with programmable input current limiting and thermal-efficient DFN packaging.
Availability
LT1618EDD#PBF is available at Aetrix Electronics and suitable for LED backlighting, USB-powered boost converters, and battery charging applications requiring stable component supply, long-term industrial availability, and RoHS-compliant packaging.
Supply support for LT1618EDD#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 full product support, documentation, and manufacturing continuity for legacy Linear parts including the LT1618 series.
The LT1618 belongs to Linear's high-efficiency, current-mode DC/DC converter product line, designed specifically for space-constrained, thermally demanding applications requiring precise constant-current regulation alongside voltage regulation-such as portable LED lighting and energy-efficient battery charging.
FAQ
What is the maximum output voltage supported by the LT1618EDD#PBF?
The LT1618EDD#PBF supports a maximum output voltage of 35V, as specified in the Absolute Maximum Ratings table. This rating allows the device to drive medium-length strings of white LEDs or power 24V logic interfaces directly from low-voltage sources like single-cell Li-ion batteries or USB ports. Operation above 35V risks permanent damage to the internal NPN switch and is strictly prohibited.
How does the IADJ pin affect current regulation in the LT1618EDD#PBF?
The IADJ pin on the LT1618EDD#PBF linearly reduces the current sense threshold from its nominal 50mV value. Applying a DC voltage VIADJ yields VISENSE = 1.263 − (0.8 × VIADJ)/25. For example, 1V on IADJ lowers the threshold to ~18mV, enabling reduced LED current or battery charge rate without changing the sense resistor. Voltages above 1.6V force the LT1618EDD#PBF into shutdown.
What thermal considerations apply to the LT1618EDD#PBF in its DFN package?
The LT1618EDD#PBF in the 10-pin DFN package has θJA = 43°C/W and θJC = 3°C/W, contingent upon soldering the exposed pad (Pin 11) directly to a solid PCB ground plane. Failure to connect the exposed pad results in severe thermal derating-junction temperature may exceed 125°C even at 800mA load. Thermal vias under the pad are strongly recommended for sustained >1A operation.
Can the LT1618EDD#PBF be used in SEPIC topology, and what modifications are needed?
Yes, the LT1618EDD#PBF supports SEPIC operation, as confirmed by Typical Application TA09 (USB to 5V SEPIC Converter). To implement SEPIC, replace the standard boost diode with a second inductor and capacitor, place the current sense resistor between VIN and the input inductor (not upstream of the input capacitor), and retain the same FB, IADJ, and compensation network. Input current limiting remains fully functional for short-circuit protection.
What is the recommended input capacitor for the LT1618EDD#PBF, and why?
The recommended input capacitor for the LT1618EDD#PBF is a 1–4.7µF X5R or X7R multilayer ceramic capacitor placed directly adjacent to the VIN and GND pins. Ceramic capacitors provide ultra-low ESR (<10mΩ), essential for minimizing input ripple and preventing instability caused by high-frequency switching current spikes. Tantalum or aluminum electrolytics are discouraged due to higher ESR and poorer high-frequency performance.
LT1618EDD#PBF Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc.
- Series:
- -
- Package/Case:
- 10-WFDFN Exposed Pad
- Packaging:
- Tube
- Product Status:
- Active
- Function:
- Step-Up
- Output Configuration:
- Positive
- Topology:
- Boost
- Output Type:
- Adjustable
- Number of Outputs:
- 1
- Voltage - Input (Min):
- 1.6V
- Voltage - Input (Max):
- 18V
- Voltage - Output (Min/Fixed):
- 1.263V
- Voltage - Output (Max):
- 36V (Switch)
- Current - Output:
- 1.5A (Switch)
- Frequency - Switching:
- 1.4MHz
- Synchronous Rectifier:
- No
- Operating Temperature:
- 0°C ~ 70°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 10-DFN (3x3)
LT1618EDD#PBF FAQ
1.How can I place an order for LT1618EDD#PBF through Aetrix?
Please submit a Request for Quotation (RFQ) for LT1618EDD#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 LT1618EDD#PBF reliable?
The price and inventory of LT1618EDD#PBF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LT1618EDD#PBF is usually 5 days.
3.What payment methods are accepted for LT1618EDD#PBF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LT1618EDD#PBF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LT1618EDD#PBF?
LT1618EDD#PBF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LT1618EDD#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 LT1618EDD#PBF?
For technical support, including LT1618EDD#PBF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LT1618EDD#PBF requirements.
6.How does Aetrix verify that LT1618EDD#PBF is sourced from the original manufacturer or authorized distributors?
All LT1618EDD#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 LT1618EDD#PBF meets industry standards.
7.What is the process for return or replacement of LT1618EDD#PBF?
All LT1618EDD#PBF units undergo pre-shipment inspection (PSI). If there is an issue with LT1618EDD#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 LT1618EDD#PBF part is unused and in its original packaging.
Return procedure for LT1618EDD#PBF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LT1618EDD#PBF Tags
-
TPS562201DDCR
Texas Instruments
-
MC34063ABD-TR
STMicroelectronics
-
TPS561201DDCR
Texas Instruments
-
MC33063ADR
Texas Instruments
-
MC34063ADR
Texas Instruments
-
TPS560200DBVR
Texas Instruments
-
AP3012KTR-G1
Diodes Incorporated
-
TLV61048DBVR
Texas Instruments
-
AZ34063UMTR-G1
Diodes Incorporated
-
TPS562200DDCR
Texas Instruments
-
AP62300TWU-7
Diodes Incorporated
-
MC34063EBD-TR
STMicroelectronics
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…
