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Analog Devices Inc. LTC3603IUF#TRPBF
- Part No.:
- LTC3603IUF#TRPBF
- Manufacturer:
- Analog Devices Inc.
- Package:
- 20-WFQFN Exposed Pad
- Datasheet:
-
LTC3603IUF#TRPBF.pdf
- Description:
- IC REG BUCK ADJ 2.5A 20QFN
- Quantity:
- Payment:
- Shipping:
Inventory:4,383
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Product details
Overview
LTC3603IUF#TRPBF from Analog Devices (formerly Linear Technology) is a monolithic synchronous step-down DC/DC converter delivering up to 2.5A output current, operating from 4.5V to 15V input, with adjustable 0.6V–14.5V output and 1MHz nominal switching frequency in a thermally enhanced 20-lead 4mm × 4mm QFN package. It serves as a high-efficiency point-of-load regulator in communications infrastructure and portable instrumentation.
For engineers reviewing the LTC3603IUF#TRPBF datasheet, LTC3603IUF#TRPBF pinout, LTC3603IUF#TRPBF application, or LTC3603IUF#TRPBF equivalent, key selection criteria include its 45mΩ/85mΩ internal MOSFET RDS(ON), OPTI-LOOP® compensation for transient optimization, programmable Burst Mode clamp, PGOOD monitoring, and thermal performance enabled by exposed SGND pad soldering.
Technical Context
The LTC3603IUF#TRPBF implements a constant-frequency current-mode control architecture with dual N-channel internal switches, where peak inductor current is regulated via ITH voltage feedback against a 0.6V reference. Its slope compensation recovery maintains stable maximum output current across duty cycles >30%.
It supports three operational modes-Burst Mode (75µA quiescent current), forced continuous conduction (reduced EMI), and external clock synchronization (300kHz–3MHz)-with mode selection and frequency setting handled through the SYNC/MODE and RT pins respectively.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Input Voltage Range | 4.5V to 15V - supports wide industrial and telecom supply rails without pre-regulation |
| Output Current | Up to 2.5A - sufficient for FPGA core, DSP, or ASIC point-of-load applications |
| Switch RDS(ON) | Top: 45mΩ, Bottom: 85mΩ - enables >95% efficiency at 12VIN/3.3VOUT and reduces thermal load |
| Quiescent Current | 75µA in Burst Mode - extends battery life in portable instruments during light-load standby |
| Feedback Reference | 0.6V ±1% - allows precise low-voltage regulation down to sub-1V for modern logic cores |
| Switching Frequency | Programmable 300kHz–3MHz - balances inductor size vs. efficiency; 1MHz typical with 105kΩ RT resistor |
| Power Good Output | Open-drain, ±10% window - provides reliable system-level power sequencing and fault detection |
| Thermal Performance | θJA = 37°C/W, θJC = 5°C/W - requires exposed SGND pad soldering to PCB for rated junction temperature operation |
Pinout & Package
Package: 20-lead (4mm × 4mm) plastic QFN with exposed SGND pad (Pin 21), rated for –40°C to 125°C operating junction temperature.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| PVIN (Pins 1, 2) | Power Input Supply | Primary input rail connection; must be decoupled to PGND with low-ESR capacitor |
| PGND (Pins 12–15) | Power Ground | High-current return path for internal switches; separate from SGND for noise isolation |
| SW (Pins 16–19) | Switch Node | Connection to external inductor; carries high di/dt; layout critical for EMI control |
| BOOST (Pin 20) | Bootstrap Supply | Provides gate drive voltage for top N-MOSFET; requires 0.1µF ceramic capacitor to SW |
| INTVCC (Pin 3) | Internal 5V LDO Output | Supplies internal circuitry; can power external bias components or SYNC/MODE pull-up |
| SYNC/MODE (Pin 4) | Mode Control & Sync Input | Selects Burst/continuous mode or accepts external 300kHz–3MHz clock; not floating |
| PGOOD (Pin 5) | Power Good Monitor | Open-drain flag indicating VOUT within ±10%; used for system enable sequencing |
| RT (Pin 6) | Frequency Set | Resistor-to-ground sets oscillator frequency; 105kΩ yields ~1MHz |
| ITH (Pin 7) | Error Amplifier Compensation | Compensation node for OPTI-LOOP®; connects to RC network for transient response tuning |
| VFB (Pin 8) | Feedback Input | Senses resistive divider output; regulates VOUT to 0.6V reference |
| SGND (Pin 9, Exposed Pad Pin 21) | Signal Ground | Analog ground reference for error amplifier and comparators; exposed pad must be soldered |
| RUN (Pin 10) | Enable Control | Active-high enable; 0.4V–1.1V threshold; tie to PVIN for always-on operation |
| TRACK/SS (Pin 11) | Tracking/Soft-Start | Enables voltage tracking of external rail or external soft-start via capacitor; 1.2µA internal current source |
Key Features
| Feature | Design Value |
|---|---|
| OPTI-LOOP® Compensation | Allows dynamic loop tuning across wide output capacitance and load ranges without external component changes |
| Adjustable Burst Mode Clamp | External voltage on SYNC/MODE pin sets minimum inductor peak current, enabling ripple optimization per application |
| 99% Maximum Duty Cycle | Supports ultra-low dropout operation near VIN = VOUT while maintaining BOOST capacitor recharge via periodic bottom-switch activation |
| Integrated Overtemperature Protection | Shuts down both switches at ~150°C junction temperature and auto-restarts below 115°C - prevents thermal runaway |
| Overvoltage & Undervoltage Monitoring | PGOOD asserts low if VOUT deviates >±10%; overvoltage condition actively clamps output via bottom switch conduction |
| Low RDS(ON) Synchronous Switches | Eliminates need for external Schottky diode, reducing BOM count and improving full-load efficiency by ~3–5% |
Applications
| Baseband Processor Power | FPGA Core Supply |
|---|---|
Use Scenario: Regulating 1.2V/2A for LTE/5G baseband processors requiring tight voltage tolerance and fast load transient response. IC Role / Device Role / Timing Role: Primary point-of-load regulator with PGOOD signaling to processor reset controller and TRACK/SS for coordinated I/O/core sequencing. Use Value: OPTI-LOOP® ensures <50mV undershoot during 1A/µs load steps; 75µA Burst Mode quiescent current extends idle battery life. | Use Scenario: Delivering 0.85V/2.5A to Xilinx Artix-7 FPGA core with strict ±3% regulation and low-noise operation. IC Role / Device Role / Timing Role: High-current synchronous buck converter with forced continuous mode to avoid switching harmonics in analog signal bands. Use Value: 45mΩ top switch and 0.6V reference enable ±1% accuracy at 0.85V; 1MHz operation allows compact 1.5µH inductor. |
| Portable Test Instrumentation | Optical Module Bias Supply |
Use Scenario: Powering mixed-signal ADC/DAC subsystems in handheld oscilloscopes with battery and USB input flexibility. IC Role / Device Role / Timing Role: Wide-input (4.5–15V) regulator supporting both Li-ion and wall adapter inputs, with RUN pin enabling sleep mode. Use Value: 4.5V minimum input allows operation down to single-cell Li-ion (3.4V after dropout); 125°C rating supports sealed enclosure thermal design. | Use Scenario: Generating stable 3.3V/1.5A bias for SFP+ transceivers in telecom line cards with strict EMI limits. IC Role / Device Role / Timing Role: Low-EMI synchronous buck with synchronized switching to avoid interference with 10Gbps data lanes. Use Value: External clock sync (via SYNC/MODE) aligns switching edges to system timing reference, suppressing conducted emissions in 1–10MHz band. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar synchronous step-down regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TPS54227PWPR | Lower max output current (2A), fixed 500kHz frequency, no Burst Mode clamp adjustment | Lacks programmable light-load efficiency tuning; less suitable for battery-powered portable instruments | Preferred for cost-sensitive, fixed-frequency designs where 2A output suffices and thermal margin is ample |
| MP2315DJ-LF-Z | Higher quiescent current (300µA), no PGOOD or TRACK/SS, smaller 8-pin SOIC package | No power sequencing support; limited to simpler systems without voltage tracking or system-level fault reporting | Appropriate for space-constrained, non-sequenced auxiliary rails where full feature set is unnecessary |
Compared with TPS54227PWPR and MP2315DJ-LF-Z, the LTC3603IUF#TRPBF offers superior light-load efficiency control, precision 0.6V reference, and comprehensive protection features - making it optimal for high-reliability, thermally demanding, or battery-sensitive point-of-load implementations.
Availability
LTC3603IUF#TRPBF is available at Aetrix Electronics and suitable for communications infrastructure, portable instrumentation, and FPGA power delivery requiring stable component supply, long-term lifecycle assurance, and traceable sourcing.
Supply support for LTC3603IUF#TRPBF 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 high-performance power management portfolio with rigorous characterization and automotive/industrial qualification.
The LTC3603IUF#TRPBF belongs to Linear's monolithic synchronous buck regulator product line, designed specifically for high-efficiency, low-noise point-of-load conversion in space- and thermal-constrained applications.
FAQ
What is the maximum junction temperature specification for the LTC3603IUF#TRPBF?
The LTC3603IUF#TRPBF has a maximum junction temperature (TJMAX) of 125°C and incorporates overtemperature protection that disables both internal switches at approximately 150°C. The device auto-restarts when junction temperature falls below 115°C. Thermal performance relies on proper soldering of the exposed SGND pad (Pin 21) to a thermal pad on the PCB.
Does the LTC3603IUF#TRPBF require an external Schottky diode?
No, the LTC3603IUF#TRPBF does not require an external Schottky diode because it integrates synchronous N-channel MOSFETs with 45mΩ (top) and 85mΩ (bottom) on-resistance. This eliminates reverse recovery losses and improves efficiency by 3–5% compared to asynchronous designs, especially at medium to high loads.
How is the switching frequency set on the LTC3603IUF#TRPBF?
The switching frequency of the LTC3603IUF#TRPBF is set using an external resistor (ROSC) connected between the RT pin (Pin 6) and ground. With ROSC = 105kΩ, the typical frequency is 1MHz. The usable range is 300kHz to 3MHz, calculated as ROSC ≈ (1.15 × 10¹¹ / fHz) – 10kΩ.
Can the LTC3603IUF#TRPBF operate with input voltage lower than the output voltage?
No, the LTC3603IUF#TRPBF is a step-down (buck) converter and cannot operate in boost or pass-through mode. Its minimum input voltage is 4.5V, and it requires VIN > VOUT to maintain regulation. However, it supports dropout operation up to 99% duty cycle when VIN approaches VOUT, using periodic bottom-switch activation to refresh the BOOST capacitor.
What is the function of the TRACK/SS pin on the LTC3603IUF#TRPBF?
The TRACK/SS pin (Pin 11) on the LTC3603IUF#TRPBF serves dual functions: (1) voltage tracking - applying a ramp voltage enables VOUT to follow an external supply (e.g., for core/I/O sequencing), and (2) external soft-start - connecting a capacitor to ground creates a controlled startup ramp. An internal 1.2µA current source enables precise timing; leaving the pin floating activates the default 1ms soft-start.
LTC3603IUF#TRPBF Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc.
- Series:
- -
- Package/Case:
- 20-WFQFN 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):
- 4.5V
- Voltage - Input (Max):
- 15V
- Voltage - Output (Min/Fixed):
- 0.6V
- Voltage - Output (Max):
- 14.5V
- Current - Output:
- 2.5A
- Frequency - Switching:
- 1MHz
- Synchronous Rectifier:
- Yes
- Operating Temperature:
- -40°C ~ 125°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 20-QFN (4x4)
LTC3603IUF#TRPBF FAQ
1.How can I place an order for LTC3603IUF#TRPBF through Aetrix?
Please submit a Request for Quotation (RFQ) for LTC3603IUF#TRPBF 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 LTC3603IUF#TRPBF reliable?
The price and inventory of LTC3603IUF#TRPBF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LTC3603IUF#TRPBF is usually 5 days.
3.What payment methods are accepted for LTC3603IUF#TRPBF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LTC3603IUF#TRPBF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LTC3603IUF#TRPBF?
LTC3603IUF#TRPBF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LTC3603IUF#TRPBF 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 LTC3603IUF#TRPBF?
For technical support, including LTC3603IUF#TRPBF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LTC3603IUF#TRPBF requirements.
6.How does Aetrix verify that LTC3603IUF#TRPBF is sourced from the original manufacturer or authorized distributors?
All LTC3603IUF#TRPBF 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 LTC3603IUF#TRPBF meets industry standards.
7.What is the process for return or replacement of LTC3603IUF#TRPBF?
All LTC3603IUF#TRPBF units undergo pre-shipment inspection (PSI). If there is an issue with LTC3603IUF#TRPBF, 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 LTC3603IUF#TRPBF part is unused and in its original packaging.
Return procedure for LTC3603IUF#TRPBF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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