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Analog Devices Inc. LTC3351IUFF#TRPBF
- Part No.:
- LTC3351IUFF#TRPBF
- Manufacturer:
- Analog Devices Inc.
- Category:
- Power Management - Specialized
- Package:
- 44-WFQFN Exposed Pad
- Datasheet:
-
LTC3351IUFF#TRPBF.pdf
- Description:
- HOT SWAPPABLE HIGH CURRENT SUPER
- Quantity:
- Payment:
- Shipping:
Inventory:706
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Product details
Overview
LTC3351IUFF#TRPBF from Analog Devices is a hot-swappable supercapacitor backup power controller that charges, balances, and monitors 1–4 series supercapacitors with synchronous step-down/step-up conversion. It delivers >10A charge/backup current, supports 4.5V–35V input, regulates VCAP up to 5V per capacitor, and integrates 16-bit ADC-based capacitance and ESR measurement for server ride-through UPS applications.
For engineers reviewing the LTC3351IUFF#TRPBF datasheet, LTC3351IUFF#TRPBF pinout, LTC3351IUFF#TRPBF application, or LTC3351IUFF#TRPBF equivalent, this page provides verified functional identity, validated QFN-44 pin roles, confirmed I²C/SMBus monitoring capability, and real-world backup timing behavior in high-current 12V systems.
Technical Context
The LTC3351IUFF#TRPBF implements a bidirectional synchronous buck-boost converter using external N-channel MOSFETs, enabling constant-current/constant-voltage charging and reverse-mode energy delivery from supercapacitor stack to VOUT. Its integrated shunt balancers eliminate external balancing resistors while providing per-capacitor overvoltage protection via dedicated CAPx pins.
It features four independent voltage measurement channels (CAP1–CAP4 vs CAPRTN), programmable UV/OV thresholds up to 35V, and a 16-bit ADC that digitizes VIN, VOUT, VCAP, ISNSP_HS, ISNSP_CHG, ISNSM, GPI, and internal DAC outputs - all accessible via I²C/SMBus interface with SMBALERT interrupt signaling.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VIN Range | 4.5V to 35V - supports wide-input industrial and telecom power rails without external pre-regulation |
| Charge/Backup Current | >10A - enables rapid supercapacitor recharge and high-power backup delivery in short-duration outages |
| Supercapacitor Stack | 1 to 4 series cells - configurable via CAP_SLCT0/CAP_SLCT1 pins with per-cell voltage monitoring and shunt regulation |
| ADC Resolution | 16-bit - provides ±1.5% full-scale accuracy for VCAP, VIN, VOUT, and current sense measurements |
| Switching Frequency | 200kHz to 1MHz - adjustable via RT resistor for optimized efficiency vs. size trade-off in inductor selection |
| Package | 44-lead 4mm × 7mm × 0.75mm QFN - thermally enhanced with exposed PGND pad (θJC = 2.6°C/W) for high-power operation |
| I²C/SMBus Interface | 400kHz max clock - supports system-level telemetry, fault logging, and dynamic threshold reprogramming in live systems |
Pinout & Package
Package: 44-lead plastic QFN (UFF), 4mm × 7mm × 0.75mm, exposed thermal pad (Pin 45 = PGND), rated for –40°C to 125°C junction temperature.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| CAP1–CAP4 | Per-capacitor top-plate sensing | Enables individual voltage measurement and active shunt balancing for each supercapacitor in stack |
| CAPRTN | Stack bottom-plate reference | Common return for shunt regulators and differential VCAP1–VCAP4 measurements |
| OUTFET | N-FET gate drive for ideal diode path | Drives external N-MOSFET between VCAP and VOUT to minimize forward drop during backup |
| TGATE/BGATE | High-side/low-side MOSFET drivers | Control external N-FETs in synchronous buck-boost power stage with 50ns non-overlap timing |
| ICAP/VCAP | Charge current sense inputs | Measure voltage across RSNSC to regulate charge/discharge current with 32mV setpoint |
| ISNSP_CHG/ISNSM | Input current sense inputs | Regulate input current during charging with 32mV setpoint; shared with hot-swap current limit |
| SCL/SDA/SMBALERT | I²C/SMBus interface | Provide read/write access to 16-bit ADC registers, fault status, and programmable thresholds |
Key Features
| Feature | Design Value |
|---|---|
| Bidirectional synchronous converter | Operates as buck charger (VIN→VCAP) and boost backup source (VCAP→VOUT), maximizing usable stored energy |
| Integrated per-cell shunt balancers | Eliminates need for external balancing resistors; each CAPx pin includes overvoltage clamp and regulator |
| 16-bit system monitor ADC | Measures VIN, VOUT, VCAP, ISNSP_HS, ISNSP_CHG, ISNSM, GPI, and internal DAC outputs with <±1.5% error |
| Programmable hot-swap current limit | Configurable foldback curve via ISNSP_HS/ISNSM; supports circuit breaker function with retry timing on CTIMER |
| Ideal diode controller | Drives external N-FET on VCAP→VOUT path with fast turn-on (<65mV threshold) and reverse blocking |
Applications
| Server Ride-Through UPS | PCIe NVM Swappable Card |
|---|---|
Use Scenario: Maintains DRAM refresh and NVMe controller state during brief AC mains interruption in rack-mounted servers. IC Role / Device Role / Timing Role: Backup power controller managing supercapacitor stack discharge into 12V system rail with <100µs switchover latency. Use Value: Enables zero-data-loss failover without battery maintenance; >10A discharge sustains critical loads for 20–100ms depending on stack size. |
Use Scenario: Powers volatile cache and controller logic during hot-plug insertion/removal of PCIe add-in cards with persistent memory. IC Role / Device Role / Timing Role: Hot-swap supervisor and backup source ensuring uninterrupted power during connector mating/unmating transients. Use Value: Prevents configuration corruption by maintaining VOUT during mechanical insertion delay; I²C telemetry logs event timing and voltage droop. |
| Industrial PLC Power Holdup | Telecom Line Card Backup |
Use Scenario: Sustains programmable logic controller operation during brownout events on 24V DC distribution bus. IC Role / Device Role / Timing Role: Monitors VIN UV/OV thresholds and initiates controlled backup from 4-cell supercapacitor stack to 24V output rail. Use Value: Provides deterministic 50–200ms holdup time with programmable undervoltage lockout at 18V and overvoltage cutoff at 32V. |
Use Scenario: Supplies backup power to Ethernet PHY and control logic during redundant power supply switchover in carrier-grade line cards. IC Role / Device Role / Timing Role: Dual-role controller performing hot-swap inrush limiting on primary supply and seamless step-up backup from supercapacitors. Use Value: Achieves <1ms switchover with no packet loss; SMBALERT signals switchover event to host processor for diagnostics. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar supercapacitor backup controller applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LTC3350IUF#TRPBF | Single-cell only; no CAP2–CAP4 pins; lacks shunt balancers and per-cell monitoring | Suitable only for 1-supercapacitor systems; cannot support stacked architectures or ESR measurement | Select when cost-sensitive single-cell backup suffices and per-cell telemetry is unnecessary |
| MAX34441ETL+ | No integrated switching controller; requires external buck/boost ICs; relies on discrete FETs for power path | Higher BOM count and layout complexity; no native step-up backup mode or internal balancers | Choose when existing power stage must be reused or when analog monitoring-only functionality is sufficient |
Compared with LTC3350IUF#TRPBF and MAX34441ETL+, the LTC3351IUFF#TRPBF uniquely integrates bidirectional conversion, per-cell shunt regulation, and 16-bit telemetry in one QFN package - eliminating external balancers, reducing PCB area by >35%, and enabling full-stack health monitoring without additional ICs.
Availability
LTC3351IUFF#TRPBF is available at Aetrix Electronics and suitable for server ride-through UPS, PCIe NVM card backup, and industrial PLC holdup requiring stable component supply across extended temperature and long-life deployments.
Supply support for LTC3351IUFF#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 is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, serving precision instrumentation, industrial automation, and power management markets.
The LTC3351IUFF#TRPBF belongs to Analog Devices' Power by Linear™ supercapacitor management portfolio, designed specifically for high-reliability, maintenance-free backup power in mission-critical infrastructure where batteries are impractical.
FAQ
What is the maximum supercapacitor stack voltage supported by the LTC3351IUFF#TRPBF?
The LTC3351IUFF#TRPBF supports up to four series supercapacitors with a maximum of 5V per cell, yielding a total stack voltage of 20V. The absolute maximum rating for VCAP is 22V, and the CAPFB feedback loop is programmable from 0.625V to 1.212V, scaling to full-stack regulation via external resistor divider.
Does the LTC3351IUFF#TRPBF support step-up (boost) mode during backup operation?
Yes, the LTC3351IUFF#TRPBF operates its synchronous controller in step-up mode to deliver power from the supercapacitor stack to VOUT when VIN fails. It regulates VOUT using OUTFB feedback, supports >10A backup current, and maintains output stability down to VCAP = 4.5V in boost mode.
How does the LTC3351IUFF#TRPBF perform supercapacitor capacitance and ESR measurement?
The LTC3351IUFF#TRPBF measures capacitance by discharging the stack with a precise current programmed via ITST pin (20Ω minimum), then timing voltage decay via 16-bit ADC. ESR is derived from instantaneous voltage drop under known charge/discharge current measured across ICAP/VCAP and ISNSP_CHG/ISNSM.
What is the purpose of the CAPGD pin on the LTC3351IUFF#TRPBF?
CAPGD is an open-drain "Capacitor Power Good" output on the LTC3351IUFF#TRPBF that pulls low when the regulated VCAP feedback voltage (CAPFB) falls below 90–94% of its DAC-set target. It signals stack under-voltage condition to system controllers and can trigger graceful shutdown sequences.
Can the LTC3351IUFF#TRPBF operate without external MOSFETs?
No - the LTC3351IUFF#TRPBF is a controller IC requiring external N-channel MOSFETs for both the synchronous buck-boost power stage (TGATE/BGATE) and ideal diode path (OUTFET). It does not integrate power switches; all high-current paths are implemented externally for thermal and voltage scalability.
LTC3351IUFF#TRPBF Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc.
- Series:
- -
- Package/Case:
- 44-WFQFN Exposed Pad
- Packaging:
- Tape & Reel (TR)
- Product Status:
- Active
- Applications:
- Supercapacitor Backup Controller
- Current - Supply:
- 2.25mA
- Voltage - Supply:
- 4.5V ~ 35V
- Operating Temperature:
- -40°C ~ 125°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 44-QFN (4x7)
LTC3351IUFF#TRPBF FAQ
1.How can I place an order for LTC3351IUFF#TRPBF through Aetrix?
Please submit a Request for Quotation (RFQ) for LTC3351IUFF#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 LTC3351IUFF#TRPBF reliable?
The price and inventory of LTC3351IUFF#TRPBF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LTC3351IUFF#TRPBF is usually 5 days.
3.What payment methods are accepted for LTC3351IUFF#TRPBF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LTC3351IUFF#TRPBF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LTC3351IUFF#TRPBF?
LTC3351IUFF#TRPBF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LTC3351IUFF#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 LTC3351IUFF#TRPBF?
For technical support, including LTC3351IUFF#TRPBF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LTC3351IUFF#TRPBF requirements.
6.How does Aetrix verify that LTC3351IUFF#TRPBF is sourced from the original manufacturer or authorized distributors?
All LTC3351IUFF#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 LTC3351IUFF#TRPBF meets industry standards.
7.What is the process for return or replacement of LTC3351IUFF#TRPBF?
All LTC3351IUFF#TRPBF units undergo pre-shipment inspection (PSI). If there is an issue with LTC3351IUFF#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 LTC3351IUFF#TRPBF part is unused and in its original packaging.
Return procedure for LTC3351IUFF#TRPBF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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