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Analog Devices Inc. LTC3546EUFD#TRPBF
- Part No.:
- LTC3546EUFD#TRPBF
- Manufacturer:
- Analog Devices Inc.
- Package:
- 28-WFQFN Exposed Pad
- Datasheet:
-
LTC3546EUFD#TRPBF.pdf
- Description:
- IC REG BUCK ADJ 1A/2A DL 28QFN
- Quantity:
- Payment:
- Shipping:
Inventory:9,228
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Product details
Overview
LTC3546EUFD#TRPBF from Analog Devices (formerly Linear Technology) is a dual synchronous step-down DC/DC regulator IC with configurable 3A/1A or 2A/2A output capability, operating from 2.3V to 5.5V input and delivering adjustable outputs from 0.6V to 5V per channel. It integrates low-RDS(ON) internal MOSFETs (0.096Ω top/0.085Ω bottom for SW2A/B; 0.19Ω/0.18Ω for SW1), supports 2.25MHz fixed or 0.75–4MHz adjustable switching frequency, and features independent power-good signals, tracking/soft-start, and Burst Mode® operation for high light-load efficiency in point-of-load applications.
For engineers reviewing the LTC3546EUFD#TRPBF datasheet, LTC3546EUFD#TRPBF pinout, LTC3546EUFD#TRPBF application, or LTC3546EUFD#TRPBF equivalent, key selection criteria include dual-channel current-mode control architecture, SW1D-dependent configuration flexibility (3A/1A vs. 2A/2A), thermal performance of the 4mm × 5mm QFN package, and mode-selectable operation (Burst, pulse-skipping, forced continuous) for ripple-efficiency trade-offs in space-constrained embedded power systems.
Technical Context
The LTC3546EUFD#TRPBF implements a constant-frequency current-mode control architecture with shared oscillator and phase-selectable (0° or 180°) dual-channel operation. Each channel uses an error amplifier (2.5MHz GBW) comparing VFB to a 0.6V reference, modulating peak inductor current via ITH voltage (0–1.5V range) and supporting external compensation.
It enables three distinct low-load operating modes via the SYNC/MODE pin: Burst Mode® (high efficiency, ~30mVP-P ripple, IQ = 160µA), pulse-skipping (low ripple), and forced continuous (fixed frequency). The SW1D pin auto-detects connection to SW1 (enabling 2A/2A) or SW2A/B (enabling 3A/1A), with corresponding current limits (ILIM1+1D = 2.5–3.2A; ILIM2+1D = 3.75–4.8A) and RDS(ON) values validated per configuration.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VIN Range | 2.3V to 5.5V - Supports single-cell Li-ion, USB, and logic-supply rails without external LDO pre-regulation. |
| VOUT Range | 0.6V to 5V per channel - Enables core voltage scaling for processors, FPGAs, and memory interfaces. |
| Switching Frequency | 2.25MHz fixed or 0.75–4MHz adjustable - Allows compact magnetics (e.g., ≤1.22µH) and avoids AM radio band interference. |
| Peak Efficiency | Up to 96% - Achieved at mid-load with optimized inductor and capacitor selection; validated in 3A/1A and 2A/2A configurations. |
| RDS(ON) (SW2A/B) | 0.096Ω (top) / 0.085Ω (bottom) at VIN = 3.6V - Minimizes conduction loss in high-current 2A/3A channel, reducing thermal stress. |
| IQ (Burst Mode) | 160µA typical - Enables >100-hour battery life in always-on IoT sensors powered from coin cells or energy harvesters. |
| Shutdown Current | <1µA - Ensures negligible drain during system sleep states, critical for portable medical and wearables. |
Pinout & Package
The LTC3546EUFD#TRPBF is housed in a thermally enhanced 28-lead (4mm × 5mm) plastic QFN package with exposed pad (Pin 29 = GNDD), rated for –40°C to +85°C operation. Thermal resistance θJA = 34°C/W with standard PCB layout.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| SW1 | Channel 1 switch node | Connects to 1.22µH inductor; swings between VIN1 and PGND1; enables 1A primary output or 2A when SW1D is tied to it. |
| SW1D | Dependent switch node | Auto-detects external connection to SW1 (→ 2A/2A) or SW2A/B (→ 3A/1A); must never be tied to VIN or GND. |
| SW2A/SW2B | Channel 2 switch nodes | Must be externally shorted; connect to 0.56µH inductor; jointly deliver up to 3A when SW1D is attached. |
| VFB1/VFB2 | Feedback inputs | Monitor output voltage via resistive dividers; 0.6V nominal reference enables precise regulation across load/line/temp. |
| TRACK/SS1/SS2 | Tracking/soft-start inputs | Enable output voltage ramp control (internal 1.2ms soft-start or external tracking from another rail). |
| BMC1/BMC2 | Burst Mode clamp | Set Burst Mode threshold externally (0–0.6V) or tie to VCCA for internal default; tie to GND to disable Burst Mode. |
| PGOOD1/PGOOD2 | Power-good open-drain outputs | Assert low when respective VOUT deviates >–8% from target; used for sequencing and fault monitoring in multi-rail systems. |
| RUN1/RUN2 | Channel enable inputs | Active-high logic; both low → shutdown (<1µA IQ); independent control allows staggered startup or dynamic channel disabling. |
Key Features
| Feature | Design Value |
|---|---|
| Configurable dual-output topology | Supports either 3A/1A (SW1D→SW2A/B) or 2A/2A (SW1D→SW1) without changing BOM or layout-reduces design variants. |
| Three selectable light-load modes | Burst Mode® (160µA IQ, 30mVP-P ripple), pulse-skipping (low-noise), and forced continuous (EMI-controlled)-user-defined via SYNC/MODE pin voltage. |
| Integrated high-efficiency power switches | No external Schottky diodes required; RDS(ON) values optimized for 2.3–5.5V input ensure >90% efficiency at 1A–3A loads. |
| Independent tracking and soft-start | Each channel has dedicated TRACK/SS pin enabling independent or coordinated startup (e.g., VOUT1 tracks VOUT2 for FPGA core/I/O sequencing). |
| 100% duty-cycle low-dropout operation | Maintains regulation even as input approaches output voltage-critical for battery-powered systems nearing end-of-discharge. |
| Robust protection suite | Includes overcurrent limiting (programmable via BMC pins), undervoltage lockout (2.03V rising), and thermal shutdown-no external circuitry needed. |
Applications
| Netbooks / Ultra-Mobile PCs | Wireless Modems (LTE/5G) |
|---|---|
|
Use Scenario: Powering CPU core (1.2V @ 1A) and DDR3 memory I/O (2.5V @ 3A) from a single 3.6V Li-ion cell. IC Role / Device Role / Timing Role: Dual-channel buck regulator providing tightly regulated, sequenced, and tracked outputs with independent PGOOD signaling for system boot integrity. Use Value: Eliminates need for two discrete regulators; SW1D configuration enables 3A/1A split matching modem SoC rail requirements while minimizing board area. |
Use Scenario: Supplying RF transceiver (1.8V @ 2A) and baseband processor (1.2V @ 1A) in compact cellular modules with strict EMI limits. IC Role / Device Role / Timing Role: Synchronous dual buck with 180° phase shift (via PHASE pin) reducing input capacitance ripple and conducted EMI at 2.25MHz switching. Use Value: Phase interleaving cuts input RMS current by ~30%, allowing smaller 22µF ceramic input caps and easing compliance with EN 55022 Class B. |
| Point-of-Load DC/DC Conversion | PC Cards (ExpressCard/PCIe) |
|
Use Scenario: Generating 1.8V @ 2A and 3.3V @ 1A from a 5V PCIe slot supply in industrial edge AI accelerators. IC Role / Device Role / Timing Role: High-density, thermally efficient dual regulator with exposed-pad QFN package enabling direct thermal coupling to heatsink or copper pour. Use Value: 34°C/W θJA and low RDS(ON) sustain full 3A load at +85°C ambient without derating-reducing thermal management complexity. |
Use Scenario: Powering hot-pluggable PC Card peripherals requiring controlled startup, rail sequencing, and fault reporting. IC Role / Device Role / Timing Role: Dual regulator with independent RUN/PGOOD pins enabling hardware-enforced power-up order and safe insertion/removal detection. Use Value: TRACK/SS pins allow VOUT1 to follow VOUT2 during hot-insertion, preventing back-powering; PGOOD signals feed card controller for status monitoring. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar dual synchronous buck regulator applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TPS65270RGET | Fixed 1.2MHz/1.8MHz dual frequency; no SW1D configurability; lower max output current (2A/2A only); no Burst Mode® | Less flexible for mixed 3A/1A loads; higher light-load IQ (250µA) reduces battery runtime | Choose for cost-sensitive, fixed-frequency designs where 2A/2A suffices and thermal budget permits higher quiescent loss. |
| ISL85415IRZ-T7A | Single 5A buck (not dual); requires two ICs for dual-rail; higher RDS(ON) (0.12Ω/0.09Ω); no tracking or phase control | Increases component count, board area, and BOM cost; lacks rail coordination features essential for complex SoCs | Choose only if absolute maximum current per rail exceeds 3A and dual-channel integration is not required. |
Compared with TPS65270RGET and ISL85415IRZ-T7A, the LTC3546EUFD#TRPBF uniquely delivers field-configurable 3A/1A or 2A/2A operation in one IC, integrated Burst Mode® for ultra-low IQ, and per-channel tracking/sequencing-making it optimal for space-constrained, battery-aware, multi-rail embedded systems where flexibility and efficiency are co-prioritized.
Availability
LTC3546EUFD#TRPBF is available at Aetrix Electronics and suitable for netbooks, wireless modems, and point-of-load DC/DC conversion requiring stable component supply, long-term lifecycle support, and guaranteed lead-free compliance.
Supply support for LTC3546EUFD#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) is a global leader in high-performance analog, mixed-signal, and power management semiconductors, serving industrial, automotive, communications, and healthcare markets.
The LTC3546EUFD#TRPBF belongs to Linear's precision power management product line, designed specifically for high-efficiency, multi-rail, space-constrained embedded systems demanding configurable output capability and advanced light-load optimization.
FAQ
What output configurations does the LTC3546EUFD#TRPBF support?
The LTC3546EUFD#TRPBF supports two primary configurations: 3A/1A (by connecting SW1D to SW2A/B) and 2A/2A (by connecting SW1D to SW1). Internal auto-detection identifies the connection and adjusts current limits (ILIM2+1D = 3.75–4.8A or ILIM1+1D = 2.5–3.2A) and RDS(ON) behavior accordingly. Both configurations operate within the same 2.3–5.5V input range and use the same 28-pin QFN package.
How does the SYNC/MODE pin control operating modes on the LTC3546EUFD#TRPBF?
The SYNC/MODE pin selects among three light-load modes: > (VIN – 0.5V) enables Burst Mode® (160µA IQ, ~30mVP-P ripple), < 0.5V enables pulse-skipping (low ripple), and ≈ VIN/2 enables forced continuous (fixed frequency). When driven by an external clock, it synchronizes switching while defaulting to pulse-skipping. This single-pin interface eliminates external mode-selection logic and simplifies firmware control of efficiency/noise trade-offs in the LTC3546EUFD#TRPBF.
What is the purpose of the SW1D pin on the LTC3546EUFD#TRPBF, and how must it be handled?
The SW1D pin on the LTC3546EUFD#TRPBF is a dependent switch node that enables reconfigurable output current: tying it to SW1 creates a 2A/2A regulator; tying it to SW2A/B creates a 3A/1A regulator. It must never be connected to VIN or GND-floating disables SW1D. Internal circuitry detects the connection and scales current limits and gate drive timing automatically. This eliminates manual configuration registers and allows hardware-defined topology selection in the LTC3546EUFD#TRPBF.
Does the LTC3546EUFD#TRPBF require external Schottky diodes?
No, the LTC3546EUFD#TRPBF does not require external Schottky diodes. It integrates synchronous N-channel MOSFET bottom switches with low RDS(ON) (e.g., 0.085Ω for SW2A/B at 3.6V), eliminating reverse-recovery losses and improving efficiency across all load conditions. This reduces BOM count, board area, and thermal design complexity compared to asynchronous buck regulators requiring external diodes.
What thermal performance can be expected from the LTC3546EUFD#TRPBF in its QFN package?
The LTC3546EUFD#TRPBF in the 4mm × 5mm QFN package (UFD) has a junction-to-ambient thermal resistance (θJA) of 34°C/W with standard 2-layer PCB layout and soldered exposed pad (Pin 29 = GNDD). At full 3A load and 85°C ambient, calculated junction temperature remains within the 125°C limit, enabling reliable operation without forced air or heatsinks in most embedded applications-validated in the LTC3546EUFD#TRPBF datasheet under TA = 85°C conditions.
LTC3546EUFD#TRPBF Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc.
- Series:
- -
- Package/Case:
- 28-WFQFN Exposed Pad
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Function:
- Step-Down
- Output Configuration:
- Positive
- Topology:
- Buck
- Output Type:
- Adjustable
- Number of Outputs:
- 2
- Voltage - Input (Min):
- 2.3V
- Voltage - Input (Max):
- 5.5V
- Voltage - Output (Min/Fixed):
- 0.6V
- Voltage - Output (Max):
- 5V
- Current - Output:
- 1A, 2A
- Frequency - Switching:
- 2.25MHz, 750kHz ~ 4MHz
- Synchronous Rectifier:
- Yes
- Operating Temperature:
- -40°C ~ 125°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 28-QFN (4x5)
LTC3546EUFD#TRPBF FAQ
1.How can I place an order for LTC3546EUFD#TRPBF through Aetrix?
Please submit a Request for Quotation (RFQ) for LTC3546EUFD#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 LTC3546EUFD#TRPBF reliable?
The price and inventory of LTC3546EUFD#TRPBF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LTC3546EUFD#TRPBF is usually 5 days.
3.What payment methods are accepted for LTC3546EUFD#TRPBF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LTC3546EUFD#TRPBF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LTC3546EUFD#TRPBF?
LTC3546EUFD#TRPBF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LTC3546EUFD#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 LTC3546EUFD#TRPBF?
For technical support, including LTC3546EUFD#TRPBF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LTC3546EUFD#TRPBF requirements.
6.How does Aetrix verify that LTC3546EUFD#TRPBF is sourced from the original manufacturer or authorized distributors?
All LTC3546EUFD#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 LTC3546EUFD#TRPBF meets industry standards.
7.What is the process for return or replacement of LTC3546EUFD#TRPBF?
All LTC3546EUFD#TRPBF units undergo pre-shipment inspection (PSI). If there is an issue with LTC3546EUFD#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 LTC3546EUFD#TRPBF part is unused and in its original packaging.
Return procedure for LTC3546EUFD#TRPBF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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