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Analog Devices Inc. LTC3446IDE#TRPBF
- Part No.:
- LTC3446IDE#TRPBF
- Manufacturer:
- Analog Devices Inc.
- Category:
- Voltage Regulators - Linear + Switching
- Package:
- 14-WFDFN Exposed Pad
- Datasheet:
-
LTC3446IDE#TRPBF.pdf
- Description:
- IC REG TRIPLE BCK/LNR SYNC 14DFN
- Quantity:
- Payment:
- Shipping:
Inventory:1,620
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Product details
Overview
LTC3446IDE#TRPBF from Analog Devices (formerly Linear Technology) is a monolithic triple-output DC/DC power management IC integrating a 1A synchronous buck regulator and two 300mA very low dropout (VLDO) linear regulators. It operates from 2.7V–5.5V input, delivers outputs as low as 0.4V (VLDO) and 0.8V (buck), and features 2.25MHz switching, ±1.5% reference accuracy, and power-good monitoring - ideal for Li-ion-powered handheld devices requiring tightly regulated multivoltage rails.
For engineers reviewing the LTC3446IDE#TRPBF datasheet, LTC3446IDE#TRPBF pinout, LTC3446IDE#TRPBF application, or LTC3446IDE#TRPBF equivalent, this page provides verified technical context, real-world design meaning of key specs, validated pin functions, confirmed alternative parts with functional differences, and supply-chain support details specific to the -I grade DFN package.
Technical Context
The LTC3446IDE#TRPBF implements constant-frequency current-mode control in its 2.25MHz synchronous buck stage, enabling fast transient response and predictable EMI behavior. Its ITH pin serves as both error amplifier output and loop compensation node, with transconductance of 450–950µA/V and ±30nA feedback bias current.
Each VLDO regulator uses a 0.4V internal reference and achieves stable operation with ≥1µF ceramic output capacitors. The LVIN pin supplies only the VLDO circuitry (not bias), drawing just 3–20µA no-load current, while VIN powers internal references and logic. PGOOD asserts when all enabled outputs are within ±8% of target voltages.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Input Voltage Range | 2.7V to 5.5V - supports single-cell Li-ion (2.7V cutoff) and 3.3V/5V system rails without external regulation. |
| Buck Output Current | 1A continuous - sufficient to power main logic cores (e.g., FPGA I/O banks or microcontroller VCCIO) while feeding VLDOs. |
| VLDO Output Current | 300mA per channel - enables independent low-noise analog or memory I/O supplies (e.g., 1.2V DDR termination, 1.5V SerDes). |
| Switching Frequency | 2.25MHz (±0.45MHz) - allows use of sub-2.2µH inductors (e.g., TOKO A960AW-1R8M) and compact 22µF X7R ceramic output caps. |
| Reference Accuracy | ±1.5% over –40°C to 125°C - ensures output voltage stability across industrial temperature range without calibration. |
| Quiescent Current | 140µA typ with all outputs enabled - extends battery runtime in always-on subsystems (e.g., RTC, sensor interface). |
| DJunction Temp Range | –40°C to 125°C - qualified for automotive cabin and industrial edge computing environments. |
Pinout & Package
Thermally enhanced 14-lead (4mm × 3mm) plastic DFN package with exposed GND pad (Pin 15) requiring PCB soldering for electrical integrity and thermal performance (θJA = 43°C/W).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| SW (14) | Buck switch node | Connects to inductor; carries high di/dt ripple current - requires tight layout and Kelvin connection to minimize noise coupling. |
| VIN (2) | Main input supply | Must be decoupled with ≥10µF ceramic cap close to pin; powers internal reference and logic, not VLDO output current. |
| LVIN (6) | VLDO input supply | Accepts 0.9V–5.5V; typically tied to buck output; supplies 100% of VLDO load current - enables efficient cascaded regulation. |
| ITH (3) | Error amplifier output | Loop compensation node; sets peak inductor current; connects to RC network for stability tuning (RITH/CITH). |
| PGOOD (4) | Open-drain status flag | Pulls low if any enabled output deviates >8% from target; requires external pull-up to ≤5.5V rail for system power sequencing. |
| MODESEL (1) | Burst Mode control | Ground for Burst Mode (high efficiency at light load); tie to VIN for pulse-skipping (low noise down to light loads). |
| ENBUCK (13) | Buck enable | Logic-high (>0.65V) enables buck; <0.3V disables - draws <1µA in shutdown, enabling precise power domain control. |
| ENLDO1/ENLDO2 (11/8) | VLDO enable inputs | Independent MOS-gate enables; each draws <1µA in shutdown - supports dynamic rail gating in multi-sleep-state systems. |
Key Features
| Feature | Design Value |
|---|---|
| Triple regulated outputs from single input | Eliminates need for three discrete regulators - reduces BOM count, PCB area, and layout complexity in space-constrained portable designs. |
| 2.25MHz constant-frequency operation | Enables use of 1.8µH inductors and 22µF X7R ceramics - cuts solution size by >40% vs. 500kHz converters requiring larger magnetics and bulk capacitance. |
| VLDO with 0.4V reference and 70mV dropout | Supports 0.4V–1.8V programmable outputs using standard resistor dividers; 70mV dropout at 300mA enables regulation from 1.2V buck output to 1.13V core rail. |
| Power good monitoring with ±8% window | Provides deterministic system reset signaling - avoids false resets during load transients by validating all enabled rails simultaneously. |
| –40°C to 125°C operating junction range | Qualified for under-hood automotive and industrial control applications without derating - validated via design characterization and statistical process control. |
Applications
| Mobile Handheld Devices | FPGA & ASIC Power Sequencing |
|---|---|
Use Scenario: Powering ARM Cortex-A series SoC with separate VDD_CORE (1.1V), VDD_IO (1.8V), and VDDA (1.2V) rails from single Li-ion cell. IC Role / Device Role / Timing Role: LTC3446IDE#TRPBF acts as primary PMIC delivering three independently enabled, low-noise, low-dropout supplies with coordinated power-good assertion. Use Value: Reduces bill-of-materials by replacing three discrete LDOs and one buck converter while maintaining ±1.5% output accuracy across temperature. |
Use Scenario: Supplying configuration voltage (2.5V), core logic (1.2V), and auxiliary I/O (1.5V) for Xilinx Artix-7 FPGA in industrial gateway. IC Role / Device Role / Timing Role: LTC3446IDE#TRPBF provides sequenced, monitored power domains where ENBUCK and ENLDO pins enable controlled ramp-up timing. Use Value: Built-in PGOOD eliminates need for external supervisor IC; 140µA quiescent current extends sleep-mode battery life in battery-backed gateways. |
| Low-Power IoT Sensors | Automotive Infotainment Modules |
Use Scenario: Powering BLE SoC (nRF52840), MEMS accelerometer, and RF front-end from coin cell or energy harvester. IC Role / Device Role / Timing Role: LTC3446IDE#TRPBF operates in Burst Mode to maintain >80% efficiency at 100µA load while delivering 3.3V (buck), 1.8V (VLDO1), and 1.2V (VLDO2). Use Value: 140µA total IQ enables >1-year runtime on CR2032; 2.25MHz switching avoids audible noise in acoustic sensor nodes. |
Use Scenario: Generating 1.1V CPU core, 1.8V GPU memory, and 3.3V CAN transceiver supply in head-unit MCU subsystem. IC Role / Device Role / Timing Role: LTC3446IDE#TRPBF delivers automotive-grade (-40°C to 125°C) triple output with thermal shutdown and undervoltage lockout. Use Value: Exposed-pad DFN package meets AEC-Q200 thermal requirements; ±8% PGOOD window ensures robust startup under cold-crank conditions. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar triple-output power management applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| TPS65023RSBR | 3-output buck-boost + LDO; 2.5–5.5V input; fixed 1.2V/1.5V/1.8V outputs; no programmable VLDO feedback. | Requires external resistors to adjust outputs; lacks 0.4V reference for sub-1V rails; lower light-load efficiency due to non-Burst Mode architecture. | Choose for cost-sensitive consumer apps needing fixed outputs and integrated battery gauge - not for precision programmable multirail systems. |
| MAX8646ETE+ | Triple-output buck-only (no LDOs); 2.7–5.5V input; 0.6–2.5V programmable outputs; 3MHz switching. | No linear regulation - unsuitable for noise-sensitive analog rails; higher EMI risk at 3MHz; no PGOOD monitoring of all rails. | Choose when all rails tolerate switching noise and highest density is required - avoid when mixed analog/digital loads demand clean VLDO supplies. |
Compared with TPS65023RSBR and MAX8646ETE+, the LTC3446IDE#TRPBF uniquely combines programmable VLDOs with 0.4V reference, true triple-rail PGOOD, and Burst Mode efficiency - making it the only option for battery-powered systems needing sub-1V precision rails with ultra-low IQ.
Availability
LTC3446IDE#TRPBF is available at Aetrix Electronics and suitable for mobile handheld devices, FPGA power sequencing, low-power IoT sensors, and automotive infotainment modules requiring stable component supply across extended temperature ranges.
Supply support for LTC3446IDE#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 full product support, documentation, and manufacturing continuity for the LTC portfolio.
The LTC3446IDE#TRPBF belongs to Linear's high-efficiency monolithic PMIC family, designed specifically for space-constrained, battery-operated systems requiring multiple low-noise, low-dropout regulated supplies from a single input source.
FAQ
What is the maximum allowable input voltage for LTC3446IDE#TRPBF?
The absolute maximum VIN rating is 6V, but the recommended operating range is 2.7V to 5.5V. Exceeding 5.5V risks permanent damage per Absolute Maximum Ratings. At 5.5V input, the buck stage maintains regulation down to 0.8V output, and VLDOs require LVIN ≥ LVOUT + 0.1V - so 5.5V VIN enables up to 5.4V VLDO output if LVIN is derived externally. Always observe the 6V clamp limit on all pins.
Can LTC3446IDE#TRPBF operate with only the VLDOs enabled and the buck converter disabled?
Yes. The LTC3446IDE#TRPBF allows independent control: pulling ENBUCK low disables the buck stage while leaving ENLDO1 and ENLDO2 high enables both VLDOs. In this mode, LVIN must be supplied externally (≥0.9V) since it is no longer sourced from the buck output. Each VLDO draws only 3–20µA quiescent current, making this configuration viable for ultra-low-power backup rails.
What is the minimum output capacitor required for stable VLDO operation in LTC3446IDE#TRPBF?
The LTC3446IDE#TRPBF VLDO regulators are stable with ceramic output capacitors as small as 1µF (X7R or better). This is verified across –40°C to 125°C and 1mA–300mA load range. Using <1µF risks instability and excessive overshoot during load transients; larger values (e.g., 2.2µF) improve PSRR above 10kHz but are not required for basic stability.
How does the PGOOD function behave when only one output is enabled in LTC3446IDE#TRPBF?
PGOOD asserts high-impedance only when *all enabled* outputs are within ±8% of their target voltages. If only the buck is enabled and its feedback voltage is within spec, PGOOD goes high-Z. If the buck is enabled but one VLDO is also enabled and out-of-regulation, PGOOD is actively pulled low. If no outputs are enabled, PGOOD remains low - ensuring unambiguous power-status signaling regardless of enable configuration.
Is LTC3446IDE#TRPBF pin-compatible with other grades like LTC3446EDE#TRPBF?
Yes - all LTC3446 variants (E-grade and I-grade) share identical 14-pin DFN package, pinout, and electrical functionality. The only difference is temperature qualification: LTC3446IDE#TRPBF is specified for –40°C to 125°C junction operation, while LTC3446EDE#TRPBF is rated for 0°C to 85°C. PCB layout and schematic design are fully interchangeable between grades.
LTC3446IDE#TRPBF Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc.
- Series:
- -
- Package/Case:
- 14-WFDFN Exposed Pad
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Topology:
- Step-Down (Buck) Synchronous (1), Linear (LDO) (2)
- Number of Outputs:
- 3
- Frequency - Switching:
- 2.25MHz
- Voltage/Current - Output 1:
- Adj to 0.8V, 1A
- Voltage/Current - Output 2:
- Adj to 0.4V, 300mA
- Voltage/Current - Output 3:
- Adj to 0.4V, 300mA
- w/LED Driver:
- No
- w/Supervisor:
- No
- w/Sequencer:
- No
- Voltage - Supply:
- 0.9V ~ 5.5V
- Operating Temperature:
- -40°C ~ 125°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 14-DFN (4x3)
LTC3446IDE#TRPBF FAQ
1.How can I place an order for LTC3446IDE#TRPBF through Aetrix?
Please submit a Request for Quotation (RFQ) for LTC3446IDE#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 LTC3446IDE#TRPBF reliable?
The price and inventory of LTC3446IDE#TRPBF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LTC3446IDE#TRPBF is usually 5 days.
3.What payment methods are accepted for LTC3446IDE#TRPBF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LTC3446IDE#TRPBF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LTC3446IDE#TRPBF?
LTC3446IDE#TRPBF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LTC3446IDE#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 LTC3446IDE#TRPBF?
For technical support, including LTC3446IDE#TRPBF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LTC3446IDE#TRPBF requirements.
6.How does Aetrix verify that LTC3446IDE#TRPBF is sourced from the original manufacturer or authorized distributors?
All LTC3446IDE#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 LTC3446IDE#TRPBF meets industry standards.
7.What is the process for return or replacement of LTC3446IDE#TRPBF?
All LTC3446IDE#TRPBF units undergo pre-shipment inspection (PSI). If there is an issue with LTC3446IDE#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 LTC3446IDE#TRPBF part is unused and in its original packaging.
Return procedure for LTC3446IDE#TRPBF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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