My Inquiry
My Account
Analog Devices Inc. LT3503EDCB#TRMPBF
- Part No.:
- LT3503EDCB#TRMPBF
- Manufacturer:
- Analog Devices Inc.
- Package:
- 6-WFDFN Exposed Pad
- Datasheet:
-
LT3503EDCB#TRMPBF.pdf
- Description:
- IC REG BUCK ADJ 1A 6DFN
- Quantity:
- Payment:
- Shipping:
Inventory:724
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
LT3503EDCB#TRMPBF from Analog Devices (formerly Linear Technology) is a 1.45A, 2.2MHz current-mode step-down DC/DC converter with integrated bipolar NPN power switch, designed for compact, high-efficiency regulation from 3.6V to 20V inputs to fixed or adjustable outputs down to 780mV. It delivers 1A at 3.3V from ≥5.5V input and 1.2A at 3.3V from ≥8.5V input, targeting space-constrained industrial and battery-powered systems.
For engineers reviewing the LT3503EDCB#TRMPBF datasheet, LT3503EDCB#TRMPBF pinout, LT3503EDCB#TRMPBF application, or LT3503EDCB#TRMPBF equivalent, key selection factors include its 2.2MHz fixed-frequency operation enabling <3mm² solution size, thermally enhanced 2mm × 3mm 6-pin DFN package with exposed pad, cycle-by-cycle current limit, soft-start via SHDN pin, and <2µA shutdown current for low-power management.
Technical Context
The LT3503EDCB#TRMPBF employs constant-frequency current-mode PWM control with internal slope compensation and frequency foldback below 36kHz when FB voltage drops, improving overload robustness. Its bipolar NPN switch requires external BOOST capacitor/diode to achieve full saturation, with minimum boost voltage above SW pin specified at 2.3V.
Undervoltage lockout activates below ~3.4V VIN, and the error amplifier regulates FB pin to 780mV ±15mV across –40°C to 85°C. The VC node serves as both error amplifier output and current limit clamp, directly tied to SHDN for soft-start ramping and shutdown disconnect.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Input Voltage Range | 3.6V to 20V - supports wide-source regulation including 12V wall adapters and automotive batteries. |
| Switching Frequency | 2.2MHz (typ) - enables use of sub-3mm inductors and ceramic capacitors for ultra-compact layouts. |
| Output Voltage Range | Adjustable down to 780mV - allows precise low-voltage rail generation with external resistor divider. |
| Max Output Current | 1.2A continuous - sustained at 3.3V with ≥8.5V input; limited by thermal performance in 2mm × 3mm DFN. |
| Feedback Voltage | 780mV ±15mV - tight reference tolerance ensures accurate output regulation across temperature. |
| Shutdown Current | <2µA - enables true output disconnect and long battery life in portable equipment. |
| Switch VCE(SAT) | 400mV at 1A - low conduction loss improves efficiency at medium load currents. |
| Operating Temp Range | –40°C to +85°C - qualified for industrial and automotive ambient environments. |
Pinout & Package
LT3503EDCB#TRMPBF is housed in a thermally enhanced 6-pin DFN package (2mm × 3mm, 0.75mm height) with exposed GND pad (Pin 7) requiring PCB soldering for thermal and electrical integrity.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| FB (Pin 1) | Feedback input | Regulated to 780mV; sets output voltage via resistor divider; bias current ≤150nA minimizes divider error. |
| GND (Pin 2) | Power and signal ground | Reference for FB, SHDN, and internal regulators; must connect to local ground plane and exposed pad. |
| BOOST (Pin 3) | Bootstrap drive supply | Provides >VIN voltage to fully saturate internal NPN switch; requires external diode/capacitor network. |
| SW (Pin 4) | Switch node | Connects to inductor, catch diode, and BOOST capacitor; carries high di/dt switching current. |
| VIN (Pin 5) | Main power input | Supplies internal regulator and switch; must be bypassed with ≥1µF X7R/X5R ceramic capacitor near pin. |
| SHDN (Pin 6) | Shutdown and soft-start control | Logic-high (>2.3V) enables operation; grounded disables output; RC ramp enables controlled start-up. |
Key Features
| Feature | Design Value |
|---|---|
| Internally compensated current-mode control | Eliminates need for external compensation components; stable with ceramic output capacitors regardless of ESR. |
| Cycle-by-cycle current limiting | Protects against short-circuited outputs using real-time switch current sensing; limits peak current to 1.45A (typ). |
| Thermally enhanced DFN package | 2mm × 3mm footprint with exposed GND pad achieves θJA = 64°C/W, enabling 1.2A operation without forced air. |
| Soft-start via SHDN pin | External RC network on SHDN generates controlled voltage ramp, limiting inrush current during startup. |
| Frequency foldback under fault | Reduces switching frequency to ~36kHz when FB voltage falls, limiting average inductor current during overload. |
Applications
| Industrial Control Power Supply | Battery-Powered Portable Equipment |
|---|---|
Use Scenario: Regulating 12V or 24V field bus to 3.3V/5V for PLC I/O modules, sensors, and microcontrollers. IC Role / Device Role / Timing Role: Primary non-isolated buck converter delivering clean, regulated low-voltage rails with minimal board area. Use Value: 2.2MHz operation allows 2.2µH inductor and 10µF ceramic output capacitor, reducing total solution size to <100mm². |
Use Scenario: Powering handheld test instruments, medical monitors, or IoT edge nodes from single-cell Li-ion or multi-cell alkaline packs. IC Role / Device Role / Timing Role: Main system regulator providing 3.3V at up to 1.2A with ultra-low shutdown current for extended standby. Use Value: <2µA shutdown current preserves battery charge; wide 3.6V–20V input accommodates varying battery states and USB-C PD sources. |
| Wall Adapter Post-Regulation | Distributed Point-of-Load Regulation |
Use Scenario: Tightening ripple and improving transient response of unregulated 9V/12V wall adapters feeding sensitive analog or RF circuitry. IC Role / Device Role / Timing Role: Secondary buck stage after bulk AC/DC conversion, rejecting line noise and load-induced disturbances. Use Value: Fixed 2.2MHz frequency avoids audible noise; high PSRR at switching frequency suppresses adapter ripple. |
Use Scenario: Generating localized 3.3V or 5V rails on dense digital boards where centralized supplies cause IR drop or noise coupling. IC Role / Device Role / Timing Role: Compact point-of-load regulator placed adjacent to FPGA, MCU, or ADC to minimize trace inductance. Use Value: 2mm × 3mm DFN with exposed pad enables direct placement under IC; fast transient response maintains voltage within ±2% under 1A step loads. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar step-down regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LMR14010ADRCR | 1A, 40V-input, 2.1MHz synchronous buck; MOSFET-based, no external diode required. | Higher input voltage rating (40V vs. 20V); lower quiescent current (40µA vs. 2.6mA active); requires external compensation. | Preferred for >24V input systems or where synchronous rectification improves light-load efficiency. |
| TPS54202DRCT | 2A, 6V–17V input, 450kHz–2.5MHz adjustable frequency; integrated MOSFETs; 12µA shutdown current. | Lower max input (17V), higher current rating, but larger 3mm × 2mm SON package; requires external soft-start capacitor. | Chosen when 2A output capability or programmable frequency is needed, accepting larger footprint and reduced input range. |
Compared with LT3503EDCB#TRMPBF, LMR14010ADRCR offers wider input range and synchronous operation but lacks integrated soft-start control, while TPS54202DRCT provides higher current and adjustable frequency at the cost of reduced input headroom and less integrated power management features.
Availability
LT3503EDCB#TRMPBF is available at Aetrix Electronics and suitable for industrial control power supplies, battery-powered portable equipment, and distributed point-of-load regulation requiring stable component supply, consistent parametric performance, and long-term lifecycle support.
Supply support for LT3503EDCB#TRMPBF 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 of high-performance analog and power management ICs with rigorous characterization and reliability testing.
The LT3503 product line was designed for compact, high-frequency DC/DC conversion in space- and efficiency-critical applications, emphasizing integration, thermal performance, and ease of use in industrial and portable systems.
FAQ
What is the maximum output current capability of the LT3503EDCB#TRMPBF?
The LT3503EDCB#TRMPBF delivers up to 1.2A continuously at 3.3V output when input voltage is ≥8.5V, and 1A at 3.3V with ≥5.5V input. This is constrained by thermal limits in its 2mm × 3mm DFN package and internal 1.45A switch current limit. Derating is required above +60°C ambient, and inductor saturation current must exceed 2.2A for robust short-circuit survival. The LT3503EDCB#TRMPBF datasheet specifies typical performance curves for load current versus input voltage and inductor value.
Does the LT3503EDCB#TRMPBF require an external catch diode?
Yes, the LT3503EDCB#TRMPBF requires an external Schottky catch diode connected between SW and GND. Its internal bipolar NPN switch does not integrate a synchronous rectifier, so the diode conducts during switch-off periods to maintain inductor current continuity. A 1A–2A Schottky diode with reverse voltage rating ≥ maximum input voltage (e.g., ON Semiconductor MBRM140) is recommended. The LT3503EDCB#TRMPBF's BOOST circuit ensures efficient NPN saturation but does not eliminate the need for this external component.
How is soft-start implemented on the LT3503EDCB#TRMPBF?
Soft-start on the LT3503EDCB#TRMPBF is implemented by applying an external RC network to the SHDN pin: a resistor from VIN to SHDN and a capacitor from SHDN to GND generate a controlled voltage ramp. As SHDN rises from 0V to >2.3V, the internal VC node is clamped to this voltage, gradually increasing duty cycle and limiting inrush current. The LT3503EDCB#TRMPBF datasheet recommends selecting R to supply ≥20µA at 2.3V, with C sized to achieve desired ramp time. No separate soft-start pin is required-the SHDN pin serves dual function.
What package type and thermal considerations apply to the LT3503EDCB#TRMPBF?
The LT3503EDCB#TRMPBF uses a 6-pin 2mm × 3mm plastic DFN package with an exposed thermal pad (Pin 7) that must be soldered to a PCB ground plane. Thermal resistance is θJA = 64°C/W with proper layout-requiring multiple thermal vias under the pad and connection to a ≥1cm² internal or external copper pour. Without adequate thermal relief, junction temperature exceeds 125°C at full 1.2A load above +50°C ambient. The LT3503EDCB#TRMPBF's absolute maximum junction temperature is 125°C, and derating curves in the datasheet define safe operating area versus load and ambient.
Can the LT3503EDCB#TRMPBF operate with input voltages below 3.6V?
No, the LT3503EDCB#TRMPBF has an undervoltage lockout threshold of 3.0V to 3.6V (typical 3.4V); operation below 3.6V is not guaranteed. Below this threshold, the internal regulator disables switching and the part enters low-current state. While discontinuous conduction mode may allow marginal regulation near 3.3V input under light loads, the LT3503EDCB#TRMPBF datasheet explicitly specifies 3.6V as the minimum operating input voltage, and attempting sub-threshold operation risks instability, excessive dropout, or failure to start. For <3.6V inputs, alternative regulators such as the LTC3642 or TPS62130 should be evaluated.
LT3503EDCB#TRMPBF Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc.
- Series:
- -
- Package/Case:
- 6-WFDFN Exposed Pad
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Function:
- Step-Down
- Output Configuration:
- Positive
- Topology:
- Buck
- Output Type:
- Adjustable
- Number of Outputs:
- 1
- Voltage - Input (Min):
- 3.6V
- Voltage - Input (Max):
- 20V
- Voltage - Output (Min/Fixed):
- 0.78V
- Voltage - Output (Max):
- 16.2V
- Current - Output:
- 1A
- Frequency - Switching:
- 2.2MHz
- Synchronous Rectifier:
- No
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 6-DFN (2x3)
LT3503EDCB#TRMPBF FAQ
1.How can I place an order for LT3503EDCB#TRMPBF through Aetrix?
Please submit a Request for Quotation (RFQ) for LT3503EDCB#TRMPBF 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 LT3503EDCB#TRMPBF reliable?
The price and inventory of LT3503EDCB#TRMPBF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LT3503EDCB#TRMPBF is usually 5 days.
3.What payment methods are accepted for LT3503EDCB#TRMPBF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LT3503EDCB#TRMPBF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LT3503EDCB#TRMPBF?
LT3503EDCB#TRMPBF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LT3503EDCB#TRMPBF 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 LT3503EDCB#TRMPBF?
For technical support, including LT3503EDCB#TRMPBF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LT3503EDCB#TRMPBF requirements.
6.How does Aetrix verify that LT3503EDCB#TRMPBF is sourced from the original manufacturer or authorized distributors?
All LT3503EDCB#TRMPBF 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 LT3503EDCB#TRMPBF meets industry standards.
7.What is the process for return or replacement of LT3503EDCB#TRMPBF?
All LT3503EDCB#TRMPBF units undergo pre-shipment inspection (PSI). If there is an issue with LT3503EDCB#TRMPBF, 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 LT3503EDCB#TRMPBF part is unused and in its original packaging.
Return procedure for LT3503EDCB#TRMPBF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LT3503EDCB#TRMPBF 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…
