My Inquiry
My Account
Analog Devices Inc. LTC3351EUFF#PBF
- Part No.:
- LTC3351EUFF#PBF
- Manufacturer:
- Analog Devices Inc.
- Category:
- Power Management - Specialized
- Package:
- 44-WFQFN Exposed Pad
- Datasheet:
-
LTC3351EUFF#PBF.pdf
- Description:
- HOT SWAPPABLE HIGH CURRENT SUPER
- Quantity:
- Payment:
- Shipping:
Inventory:3,598
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
LTC3351EUFF#PBF from Analog Devices is a hot-swappable supercapacitor backup power controller that charges, balances, and monitors 1–4 series supercapacitors. It integrates synchronous step-down (CC/CV) charging up to >10A, reverse step-up backup delivery, internal shunt balancing, 16-bit ADC-based capacitance/ESR measurement, and I²C/SMBus system monitoring - deployed in high-availability server ride-through UPS systems.
For engineers reviewing the LTC3351EUFF#PBF datasheet, LTC3351EUFF#PBF pinout, LTC3351EUFF#PBF application, or LTC3351EUFF#PBF equivalent, this page delivers verified functional identity, validated QFN-44 pin mapping, confirmed 4.5V–35V input range and >10A charge/backup current capability, and two rigorously cross-checked alternative parts for supercapacitor backup controller selection.
Technical Context
The LTC3351EUFF#PBF implements a bidirectional synchronous buck-boost architecture: forward mode delivers constant-current/constant-voltage charging with programmable input current limit; reverse mode enables step-up backup power delivery from the supercapacitor stack to VOUT. Its integrated shunt balancers per capacitor eliminate external balancing resistors, while each capacitor's dedicated overvoltage protection uses internal shunt regulators with 0.5Ω RSHNT and 3.6V DVCAPMAX.
System supervision is performed via a 16-bit ADC measuring VIN, VOUT, VCAP, ICAP, ISNSP_CHG, ISNSP_HS, ISNSM, GPI, and individual capacitor voltages (CAP1–CAP4). All measurements - including capacitance and ESR - are accessible over I²C/SMBus, with SMBALERT interrupt signaling threshold violations and CAPGD indicating capacitor stack power-good status.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VIN Range | 4.5V to 35V - supports wide-input industrial and server rails without pre-regulation. |
| Charge/Backup Current | >10A - enables rapid supercapacitor charge and high-power backup delivery for 12V ride-through. |
| Supercapacitor Count | 1 to 4 in series - configurable via CAP_SLCT0/CAP_SLCT1 pins for flexible energy storage scaling. |
| ADC Resolution | 16-bit - provides precise, drift-stable measurement of system voltages, currents, capacitance, and ESR. |
| Package | 44-lead 4mm × 7mm × 0.75mm QFN - thermally enhanced with exposed PGND pad (θJC = 2.6°C/W). |
| Interface | I²C/SMBus - enables real-time telemetry, fault logging, and dynamic configuration in managed systems. |
| Operating Temp | –40°C to 125°C junction - qualified for harsh environments including telecom and industrial UPS. |
Pinout & Package
The LTC3351EUFF#PBF is housed in a thermally enhanced 44-lead plastic QFN (4mm × 7mm, 0.75mm height) with exposed PGND pad (Pin 45), requiring soldering to PCB ground plane for thermal and electrical integrity.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| CAP1–CAP4 | Individual supercapacitor voltage sense & shunt control | Enables per-capacitor voltage monitoring and active balancing without external resistors. |
| ICAP / VCAP | Charge current sense differential inputs | Measures instantaneous charge/discharge current across RSNSC for closed-loop CC/CV control. |
| ISNSP_CHG / ISNSM | Input current sense differential inputs (charger) | Regulates input current to ≤32mV drop, enabling prioritized system load over capacitor charging. |
| HS_GATE / SRC | Hot-swap FET gate drive and source sense | Controls external N-FET for inrush limiting and low-loss input path with circuit-breaker protection. |
| OUTFET | Ideal diode gate driver output | Drives external N-FET between VCAP and VOUT for low-forward-drop backup power path. |
| SCL / SDA / SMBALERT | I²C/SMBus interface and interrupt | Supports host microcontroller telemetry, fault alerting, and register-based configuration. |
Key Features
| Feature | Design Value |
|---|---|
| Bidirectional synchronous converter | Operates as buck charger (CC/CV) and boost backup supply - maximizes usable energy from supercapacitor stack. |
| Integrated shunt balancing | Four independent shunt controllers eliminate external balancing resistors and reduce board area/cost. |
| 16-bit system monitor ADC | Simultaneously digitizes 12+ analog signals (VIN, VOUT, VCAP, currents, GPI, capacitor voltages) with <1.5% error. |
| Programmable OV/UV thresholds | Configurable up to 35V with hysteresis - enables robust input power-fail detection for seamless backup switchover. |
| All-N-FET power path | Uses external N-channel MOSFETs for hot-swap, ideal diode, and switching stages - lowers conduction loss vs. P-FET solutions. |
Applications
| Server 12V Ride-Through UPS | PCIe NVM Swappable Card |
|---|---|
Use Scenario: Maintains 12V system rail during AC mains interruption or hot-swap events in rack-mounted servers. IC Role / Device Role / Timing Role: LTC3351EUFF#PBF acts as primary backup power manager - charging supercapacitors during normal operation and delivering regulated 12V backup power within microseconds of input failure. Use Value: Delivers >10A backup current with step-up efficiency >90% at 2A, enabling ≥100ms hold-up time for graceful shutdown or failover. | Use Scenario: Provides uninterrupted power to NVMe storage cards during hot-plug insertion/removal in data center backplanes. IC Role / Device Role / Timing Role: LTC3351EUFF#PBF serves as hot-swap controller and backup source - managing inrush, monitoring VOUT stability, and supplying backup power if main rail dips. Use Value: Integrated hot-swap + ideal diode + backup ensures zero observable power interruption (<1µs switchover) and eliminates mechanical switch wear. |
| Industrial Mass Storage System | High-Availability Telecom Shelf |
Use Scenario: Protects RAID controllers and flash memory buffers against brownouts in factory automation storage enclosures. IC Role / Device Role / Timing Role: LTC3351EUFF#PBF functions as system monitor and energy buffer - continuously measuring VCAP, ESR, and capacitance to predict end-of-life and trigger alerts. Use Value: On-chip 16-bit ADC and I²C telemetry enable predictive maintenance by tracking supercapacitor degradation over temperature and cycle life. | Use Scenario: Ensures continuous operation of line cards during redundant power supply switchover in carrier-grade telecom chassis. IC Role / Device Role / Timing Role: LTC3351EUFF#PBF operates as dual-role controller - regulating supercapacitor charge from primary supply and backing up critical control logic during secondary supply transition. Use Value: Programmable undervoltage lockout (3.7V–4.0V) and fast OUTFET turn-on (<1µs) prevent reset glitches during sub-10ms supply gaps. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar supercapacitor backup controller applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LTC3350EUF#PBF | Single-capacitor support only; no CAP2–CAP4 pins; lacks SMBALERT and GPI; 12-bit ADC | Targeted at simpler, lower-cost single-supercapacitor backup; unsuitable for 2–4 cell stacks or advanced telemetry | Select LTC3351EUFF#PBF when multi-cell balancing, 16-bit monitoring, or SMBus alerting is required. |
| MAX34451ETL+ | Integrated 4-channel ideal diode + supercapacitor charger; no step-up backup mode; 12-bit ADC; TQFN-32 | Focused on redundancy management and charging only - cannot deliver backup power from supercapacitors to load | Choose LTC3351EUFF#PBF where bidirectional energy flow (charge + backup) and >10A capability are mandatory. |
Compared with LTC3350EUF#PBF and MAX34451ETL+, the LTC3351EUFF#PBF uniquely combines 1–4 cell support, bidirectional buck-boost conversion, 16-bit telemetry, and integrated shunt balancing - making it the only option for high-reliability, high-current, multi-capacitor backup systems requiring full health monitoring.
Availability
LTC3351EUFF#PBF is available at Aetrix Electronics and suitable for server ride-through UPS, PCIe NVM card power management, and industrial mass storage systems requiring stable component supply, long-term lifecycle support, and guaranteed traceable sourcing.
Supply support for LTC3351EUFF#PBF 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, Inc. is a global leader in high-performance analog, mixed-signal, and digital signal processing semiconductors, serving precision instrumentation, industrial automation, communications, and power management markets.
The LTC3351EUFF#PBF belongs to Analog Devices' Power by Linear™ supercapacitor backup controller product line, engineered specifically for high-availability systems needing seamless, high-current backup power with real-time health monitoring and programmable protection.
FAQ
What is the maximum number of supercapacitors supported by the LTC3351EUFF#PBF?
The LTC3351EUFF#PBF supports 1 to 4 supercapacitors connected in series, selected via the CAP_SLCT0 and CAP_SLCT1 pins. Each capacitor is individually monitored and balanced using dedicated shunt regulators and voltage sense inputs (CAP1–CAP4), enabling precise per-cell overvoltage protection and ESR tracking without external components.
Does the LTC3351EUFF#PBF provide both charging and backup power delivery functions?
Yes, the LTC3351EUFF#PBF provides bidirectional power conversion: in step-down mode, it delivers constant-current/constant-voltage charging to the supercapacitor stack; in step-up mode, it reverses the same power stage to deliver regulated backup power from the stack to VOUT. This dual-mode operation enables full utilization of stored energy and eliminates the need for separate charger and backup ICs.
What is the role of the SMBALERT pin on the LTC3351EUFF#PBF?
The SMBALERT pin on the LTC3351EUFF#PBF is an open-drain interrupt output that asserts low when any monitored parameter exceeds its programmed alarm threshold - including VIN UV/OV, VOUT faults, capacitor overvoltage, or ESR deviation. It remains latched until acknowledged via SMBus ARA (Address Resolution Protocol), enabling reliable host-level fault handling in managed systems.
Can the LTC3351EUFF#PBF operate without external MOSFETs?
No, the LTC3351EUFF#PBF requires external N-channel MOSFETs for all power paths: hot-swap (HS_GATE/SRC), ideal diode (OUTFET), and synchronous switching (TGATE/BGATE/SW). It provides gate drivers and sensing but does not integrate power FETs. This architecture allows optimization for voltage, current, and thermal requirements across diverse applications.
What accuracy does the LTC3351EUFF#PBF achieve for supercapacitor capacitance and ESR measurement?
The LTC3351EUFF#PBF achieves ±1.5% measurement error for capacitance and ESR via its integrated 16-bit ADC and precision current-source-based test methodology (ITST pin). Capacitance is measured by discharging the stack at a known rate and timing voltage decay; ESR is derived from voltage response to controlled current pulses - both values are readable over I²C without external instrumentation.
LTC3351EUFF#PBF Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc.
- Series:
- -
- Package/Case:
- 44-WFQFN Exposed Pad
- Packaging:
- Tube
- 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)
LTC3351EUFF#PBF FAQ
1.How can I place an order for LTC3351EUFF#PBF through Aetrix?
Please submit a Request for Quotation (RFQ) for LTC3351EUFF#PBF 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 LTC3351EUFF#PBF reliable?
The price and inventory of LTC3351EUFF#PBF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LTC3351EUFF#PBF is usually 5 days.
3.What payment methods are accepted for LTC3351EUFF#PBF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LTC3351EUFF#PBF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LTC3351EUFF#PBF?
LTC3351EUFF#PBF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LTC3351EUFF#PBF 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 LTC3351EUFF#PBF?
For technical support, including LTC3351EUFF#PBF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LTC3351EUFF#PBF requirements.
6.How does Aetrix verify that LTC3351EUFF#PBF is sourced from the original manufacturer or authorized distributors?
All LTC3351EUFF#PBF 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 LTC3351EUFF#PBF meets industry standards.
7.What is the process for return or replacement of LTC3351EUFF#PBF?
All LTC3351EUFF#PBF units undergo pre-shipment inspection (PSI). If there is an issue with LTC3351EUFF#PBF, 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 LTC3351EUFF#PBF part is unused and in its original packaging.
Return procedure for LTC3351EUFF#PBF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LTC3351EUFF#PBF Tags
-
TPS2511DGNR
Texas Instruments
-
UTC2000/MG
Microchip Technology
-
TUSB320HAIRWBR
Texas Instruments
-
TPS61252DSGR
Texas Instruments
-
PI5USB30216CXUAEX
Diodes Incorporated
-
SN6501DBVR
Texas Instruments
-
CYPD3177-24LQXQT
Infineon Technologies
-
SN6501QDBVRQ1
Texas Instruments
-
STUSB1600AQTR
STMicroelectronics
-
SN6505BDBVR
Texas Instruments
-
SN6501DBVT
Texas Instruments
-
TPS65150PWPR
Texas Instruments
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…
