My Inquiry
My Account
Analog Devices Inc. LT3502IDC#TRMPBF
- Part No.:
- LT3502IDC#TRMPBF
- Manufacturer:
- Analog Devices Inc.
- Package:
- 8-WFDFN Exposed Pad
- Datasheet:
-
LT3502IDC#TRMPBF.pdf
- Description:
- IC REG BUCK ADJ 500MA 8DFN
- Quantity:
- Payment:
- Shipping:
Inventory:808
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
LT3502IDC#TRMPBF from Analog Devices (formerly Linear Technology) is a current-mode PWM step-down DC/DC converter with an integrated 500mA bipolar NPN power switch, operating at 1.1MHz switching frequency in a thermally enhanced 8-lead 2mm × 2mm DFN package. It supports 3V to 40V input voltage, delivers up to 500mA output current, and regulates to 0.8V feedback reference-enabling fixed 3.3V or 5V outputs for industrial power rails and automotive subsystems.
For engineers reviewing the LT3502IDC#TRMPBF datasheet, LT3502IDC#TRMPBF pinout, LT3502IDC#TRMPBF application, or LT3502IDC#TRMPBF equivalent, key selection criteria include its 1.1MHz constant-frequency operation, internal boost diode, cycle-by-cycle current limiting, soft-start via SHDN pin, and robust short-circuit protection with frequency foldback-critical for 24V industrial supplies and battery-powered equipment where EMI control and startup reliability are essential.
Technical Context
The LT3502IDC#TRMPBF uses current-mode control with slope compensation and an internal error amplifier that servos the VC node to maintain 0.8V at FB. Its oscillator drives an RS flip-flop to control the bipolar NPN switch, while DA pin monitoring enables valley-current-based frequency foldback during overload or short-circuit conditions.
Undervoltage lockout (~2.8V) prevents operation below 3V input; internal regulation powers control circuitry; and the BOOST pin-driven by an external capacitor and internal Schottky diode-provides gate drive voltage >VIN to fully saturate the switch. Maximum duty cycle is 90%, supporting high step-down ratios without pulse-skipping under normal conditions.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Input Voltage Range | 3V to 40V - supports direct connection to 24V industrial buses and automotive batteries without pre-regulation. |
| Switching Frequency | 1.1MHz - enables use of compact 6.8µH inductors and avoids AM-band interference. |
| Output Current | 500mA continuous - sufficient for powering microcontrollers, sensors, and interface ICs in space-constrained designs. |
| Feedback Reference | 0.8V ±13mV - allows precise output setting (e.g., 3.3V = 0.8V × (1 + R1/R2)) with minimal resistor tolerance impact. |
| Shutdown Current | <2µA - ensures ultra-low system standby power in battery-backed applications. |
| Current Limit Threshold | 0.75A to 1.1A (typ. 0.9A) - provides overcurrent protection while allowing peak transient delivery beyond nominal 500mA. |
| Thermal Package | 2mm × 2mm DFN with exposed GND pad (θJA = 102°C/W) - enables high-power density with PCB copper thermal relief. |
Pinout & Package
LT3502IDC#TRMPBF is housed in an 8-lead 2mm × 2mm plastic DFN package with exposed GND pad (Pin 9), which must be soldered to PCB for thermal and electrical performance. Pin numbering follows top-view orientation with Pin 1 at bottom-left corner.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| VIN (Pin 1) | Main power input | Supplies internal regulator and power switch; requires local 1µF ceramic bypass. |
| BD (Pin 2) | Boost diode anode connection | Connects to external boost capacitor; internal Schottky diode reduces component count. |
| FB (Pin 3) | Feedback sense node | Regulated to 0.8V; sets output via resistor divider (R1/R2); bias current ≤50nA minimizes error. |
| SHDN (Pin 4) | Shutdown & soft-start control | Logic-high ≥2V enables operation; RC ramp enables controlled start-up and frequency foldback. |
| GND (Pin 5) | Power and signal ground | Common return for switch, feedback, and control circuits; exposed pad must be soldered. |
| DA (Pin 6) | Valley current monitor | Detects catch diode current; triggers frequency foldback when valley current exceeds 650mA. |
| BOOST (Pin 7) | Switch driver supply | Must be ≥2.2V above SW pin; generated via external capacitor and internal diode. |
| SW (Pin 8) | Switch node | Connects to inductor, catch diode cathode, and boost capacitor; carries high dI/dt switching current. |
Key Features
| Feature | Design Value |
|---|---|
| Internal Boost Diode | Eliminates external Schottky diode in BOOST path, reducing BOM count and layout area in 2mm × 2mm footprint. |
| Cycle-by-Cycle Current Limit | Prevents switch damage during overload by terminating each switching cycle when peak current exceeds threshold. |
| Frequency Foldback | Reduces switching frequency under fault conditions (e.g., shorted output), limiting power dissipation and enabling safe sustained operation. |
| Internally Compensated | Requires no external compensation components-simplifies design and improves stability across load/line variations. |
| Soft-Start via SHDN Pin | RC-controlled voltage ramp on SHDN limits inrush current and prevents output overshoot during power-up. |
Applications
| Industrial Power Rail Regulation | Automotive Body Control Module |
|---|---|
Use Scenario: Regulating 24V vehicle battery to 3.3V for MCU, CAN transceiver, and sensor interfaces in door modules or lighting controllers. IC Role / Device Role / Timing Role: Primary step-down regulator providing clean, low-noise 3.3V rail with AM-band–free 1.1MHz switching. Use Value: Eliminates need for external boost diode and compensation network, reducing solution size by >30% vs. discrete controller + MOSFET solutions. |
Use Scenario: Powering infotainment display logic and touch controller from 12V battery with cold-crank immunity down to 3V input. IC Role / Device Role / Timing Role: Input-robust buck converter maintaining regulation during engine start (4.5V–16V transients) and shutdown leakage <2µA. Use Value: Undervoltage lockout and frequency foldback ensure reliable operation during battery dips and short-circuit events without latch-off. |
| Portable Medical Instrumentation | Smart Sensor Node Power |
Use Scenario: Generating 5V from dual AA/AAA battery pack (up to 3.2V) or USB port (5V) for analog front-end and BLE radio in handheld diagnostics. IC Role / Device Role / Timing Role: High-efficiency buck converter supporting wide VIN range and delivering 500mA peak for burst-mode wireless transmission. Use Value: 1.1MHz operation allows <10mm² total solution size including inductor and capacitors-critical for handheld enclosure constraints. |
Use Scenario: Powering LoRaWAN or NB-IoT sensor nodes from 3.6V LiSOCl₂ primary cell with multi-year battery life requirements. IC Role / Device Role / Timing Role: Low-quiescent, shutdown-capable regulator supplying 3.3V to microcontroller and RF IC during periodic wake-up cycles. Use Value: <2µA shutdown current extends shelf life; internal compensation and soft-start prevent brownout during wake-up current surges. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar step-down regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LT3502AIDC#TRMPBF | 2.2MHz switching frequency, 80% max duty cycle, tighter FB tolerance (±1.25% vs. ±1.6%). | Better suited for ultra-compact layouts requiring smallest possible inductors; less suitable for high step-down ratios (e.g., 24V→3.3V). | Select LT3502AIDC#TRMPBF when board space is constrained and input-to-output ratio is moderate (≤6:1). |
| LMR14050SQDDARQ1 | 40V, 500mA buck with integrated MOSFETs (not bipolar), 400kHz–2.5MHz adjustable frequency, lower IQ (40µA active). | Requires external compensation; lacks DA-pin foldback but offers spread-spectrum EMI reduction. | Choose LMR14050SQDDARQ1 for AEC-Q100 automotive qualification and flexible frequency tuning where bipolar switch limitations are unacceptable. |
Compared with LT3502AIDC#TRMPBF, the LT3502IDC#TRMPBF trades higher minimum on-time (60ns) and lower frequency for greater duty-cycle headroom in high-ratio applications; versus LMR14050SQDDARQ1, it offers simpler layout and inherent short-circuit robustness at the cost of fixed frequency and no AEC-Q100 rating.
Availability
LT3502IDC#TRMPBF is available at Aetrix Electronics and suitable for industrial power rail regulation, automotive body control modules, and portable medical instrumentation requiring stable component supply across extended temperature ranges (–40°C to 125°C).
Supply support for LT3502IDC#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 automotive-grade reliability testing.
The LT3502 series was designed specifically for rugged, wide-input industrial and automotive DC/DC conversion-emphasizing simplicity (internal compensation, boost diode), fault resilience (frequency foldback, current limit), and thermal efficiency in miniature DFN packages.
FAQ
What is the maximum input voltage supported by the LT3502IDC#TRMPBF?
The LT3502IDC#TRMPBF has an absolute maximum input voltage rating of 40V on the VIN pin. For reliable fixed-frequency operation, the practical maximum depends on output voltage and duty cycle limits-e.g., at 3.3V output, VIN(MAX) ≈ 30V for continuous conduction mode. Transient inputs up to 40V are tolerated, though output ripple increases above VIN(MAX) due to pulse-skipping behavior.
Does the LT3502IDC#TRMPBF require external compensation components?
No, the LT3502IDC#TRMPBF is internally compensated. Its control loop is optimized for stability with standard output capacitor types (ceramic, polymer) and typical inductor values (e.g., 6.8µH for 3.3V output). No external compensation network is needed-reducing design complexity and PCB area compared to controller-only solutions.
How does the DA pin function in the LT3502IDC#TRMPBF?
The DA pin on the LT3502IDC#TRMPBF monitors valley current through the external catch diode. When DA pin current exceeds ~650mA, the device initiates frequency foldback-reducing switching frequency to limit inductor valley current and sustain safe operation during short-circuit or overload conditions without latch-off.
Can the LT3502IDC#TRMPBF be used in automotive applications?
Yes-the LT3502IDC#TRMPBF is rated for –40°C to 125°C junction temperature and features undervoltage lockout (~2.8V), frequency foldback, and robust short-circuit protection. It is widely deployed in automotive body electronics (e.g., mirror controls, seat modules) where 12V/24V battery input and EMI-sensitive environments demand reliable, AM-band–free operation.
What is the purpose of the BOOST pin on the LT3502IDC#TRMPBF?
The BOOST pin on the LT3502IDC#TRMPBF supplies gate drive voltage to the internal bipolar NPN power switch. An external capacitor (typically 0.1µF) and the internal Schottky diode generate a BOOST voltage ~2.2V above the SW node, ensuring full saturation of the switch and minimizing conduction losses-even at high input voltages.
LT3502IDC#TRMPBF Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc.
- Series:
- -
- Package/Case:
- 8-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):
- 3V
- Voltage - Input (Max):
- 40V
- Voltage - Output (Min/Fixed):
- 0.8V
- Voltage - Output (Max):
- 36V
- Current - Output:
- 500mA
- Frequency - Switching:
- 1.1MHz
- Synchronous Rectifier:
- No
- Operating Temperature:
- -40°C ~ 125°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-DFN (2x2)
LT3502IDC#TRMPBF FAQ
1.How can I place an order for LT3502IDC#TRMPBF through Aetrix?
Please submit a Request for Quotation (RFQ) for LT3502IDC#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 LT3502IDC#TRMPBF reliable?
The price and inventory of LT3502IDC#TRMPBF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LT3502IDC#TRMPBF is usually 5 days.
3.What payment methods are accepted for LT3502IDC#TRMPBF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LT3502IDC#TRMPBF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LT3502IDC#TRMPBF?
LT3502IDC#TRMPBF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LT3502IDC#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 LT3502IDC#TRMPBF?
For technical support, including LT3502IDC#TRMPBF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LT3502IDC#TRMPBF requirements.
6.How does Aetrix verify that LT3502IDC#TRMPBF is sourced from the original manufacturer or authorized distributors?
All LT3502IDC#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 LT3502IDC#TRMPBF meets industry standards.
7.What is the process for return or replacement of LT3502IDC#TRMPBF?
All LT3502IDC#TRMPBF units undergo pre-shipment inspection (PSI). If there is an issue with LT3502IDC#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 LT3502IDC#TRMPBF part is unused and in its original packaging.
Return procedure for LT3502IDC#TRMPBF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LT3502IDC#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…
