My Inquiry
My Account
Analog Devices Inc. LTC3331EUH#PBF
- Part No.:
- LTC3331EUH#PBF
- Manufacturer:
- Analog Devices Inc.
- Category:
- Power Management - Specialized
- Package:
- 32-WFQFN Exposed Pad
- Datasheet:
-
LTC3331EUH#PBF.pdf
- Description:
- IC REG BUCK/LDO SYNC 50MA 32QFN
- Quantity:
- Payment:
- Shipping:
Inventory:3,150
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
LTC3331EUH#PBF from Analog Devices (formerly Linear Technology) is a nanopower dual-input energy harvesting power management IC integrating a high-voltage buck DC/DC (3.0V–19V input), a battery-powered buck-boost DC/DC (up to 4.2V), a 10mA shunt battery charger with programmable float voltages (3.45V/4.0V/4.1V/4.2V), low-battery disconnect, and supercapacitor balancer - all in a single 5mm × 5mm QFN-32 package. It enables autonomous operation in wireless sensor nodes powered by piezoelectric, solar, or magnetic harvesters with Li-ion backup.
For engineers reviewing the LTC3331EUH#PBF datasheet, LTC3331EUH#PBF pinout, LTC3331EUH#PBF application, or LTC3331EUH#PBF equivalent, key selection considerations include ultra-low quiescent current (950nA at no load), dual-input prioritization logic, programmable buck UVLO thresholds (3V–18V), buck-boost peak switch current selection (5–250mA), and integrated full-wave bridge rectifier for AC harvesting sources.
Technical Context
The LTC3331EUH#PBF implements an automatic input prioritizer: the buck converter powers VOUT when harvested energy is available (e.g., VIN ≥ UVLO threshold), reducing battery drain to only 200nA required by the shunt charger; the buck-boost activates only when VIN falls below UVLO, delivering regulated output from the battery. Both converters share a common VOUT rail and support independent voltage and current programming via pin-strapped logic inputs (OUT[2:0], IPK[2:0], UV[3:0]).
Its integrated full-wave bridge rectifier accepts differential AC inputs (AC1/AC2) or current-limited DC, enabling direct connection to piezoelectric transducers or small solar cells. The supercapacitor balancer (BAL/SCAP pins) actively balances two-series supercapacitors with ±10mA source/sink capability and 49–51% balance point accuracy, while the shunt charger includes programmable float voltage and low-battery disconnect with hysteresis controlled by LBSEL and FLOAT[1:0].
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Buck Input Range | 3.0V to 19V - supports piezoelectric, solar, and magnetic harvesters without external rectification or pre-regulation. |
| Buck-Boost Input Range | 1.8V to 5.5V - accommodates fully discharged to fully charged Li-ion batteries (2.5V–4.2V typical). |
| Quiescent Current | 950nA at no load - enables multi-year battery life in intermittently active IoT sensors. |
| Output Current | Up to 50mA at VOUT - sufficient for sub-GHz RF transceivers, microcontrollers, and analog front-ends. |
| Shunt Charger Current | 10mA max - provides controlled charging of Li-ion or LiFePO₄ batteries using harvested energy. |
| Float Voltage Options | 3.45V / 4.0V / 4.1V / 4.2V - selectable via FLOAT[1:0] pins to match battery chemistry and aging profile. |
| Low-Battery Disconnect | Programmable threshold (1.98V–3.30V) with hysteresis - prevents deep discharge and extends cycle life. |
| Package | 32-pin 5mm × 5mm QFN - thermally enhanced for high-efficiency operation in space-constrained modules. |
Pinout & Package
Package: 32-lead (5mm × 5mm) plastic QFN with exposed pad (Pin 33 = GND, must be soldered to PCB). Thermal resistance θJA = 44°C/W.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| BAL (1) | Supercapacitor balance node | Common connection point for two-series supercapacitors; sinks/sources up to 10mA to maintain 49–51% voltage split. |
| SCAP (2) | Supercapacitor stack top supply | Input rail for balancer; tie to top of 2-cap stack and BAL to midpoint to enable balancing; ground both to disable. |
| VIN2 (3) | Buck NMOS gate drive rail | Internal low-voltage supply for buck NMOS switch; requires ≥4.7µF bypass capacitor to GND - not for system use. |
| UV3–UV0 (4–7) | Buck UVLO select bits | Set rising/falling undervoltage lockout thresholds (3V–18V in 1V steps); must be tied high/low - never floated. |
| AC1 / AC2 (8–9) | Differential AC/DC harvester inputs | Accept piezoelectric AC, rectified solar, or current-limited DC; internal full-wave bridge eliminates external diodes. |
| FLOAT0 / FLOAT1 (10–11) | Shunt charger float voltage select | Configure battery float voltage: 00=3.45V, 01=4.0V, 10=4.1V, 11=4.2V - matches Li-ion/LiFePO₄ requirements. |
| LBSEL (12) | Low-battery disconnect hysteresis select | Selects disconnect hysteresis width: LBSEL=0 → narrow hysteresis; LBSEL=1 → wide hysteresis for noisy battery rails. |
| BAT_IN (13) | Battery input sensing | Monitors battery voltage for disconnect/connect decisions; connected internally to BAT_OUT via PMOS switch. |
| BAT_OUT (14) | Battery output switching node | PMOS-switched battery output; disconnected during deep discharge to prevent damage; connects automatically on recharge. |
| IPK2–IPK0 (15–17) | Buck-boost peak current select | Set IPEAK_BB from 5mA to 250mA in 8 steps - configures output current capability and efficiency trade-off. |
| OUT2–OUT0 (18–20) | VOUT regulation voltage select | Set regulated output: 000=1.8V, 001=2.5V, ..., 111=5.0V - enables direct compatibility with MCU I/O domains. |
| EH_ON (21) | Energy harvester enable output | Open-drain signal indicating active buck operation; used to wake external circuitry or control harvesting transducers. |
| PGVOUT (22) | Power good indicator | Open-drain flag asserting when VOUT is within ±4% of target - critical for system reset and sequencing. |
| CHARGE (23) | Shunt charger current sink | Sinks up to 2mA to charge battery; voltage drop across external resistor sets charge current (1–2mA typical). |
| VIN3 (24) | Optional buck input bypass | Alternative input for buck stage; used when VIN is noisy or requires separate filtering path from main VIN. |
| SHIP (25) | Ship mode enable | Pull low to disable all regulators and reduce total current to <100nA - enables long-term storage without battery drain. |
| AC2 (26) | Second AC harvester input | Completes differential pair with AC1; internal bridge rectifier handles polarity reversal automatically. |
| VIN (27) | Main buck input | Primary high-voltage input (3–19V); clamped internally to 20V; supplies buck regulator and shunt charger. |
| CAP (28) | Buck input capacitor connection | Connects to input capacitor bank; low-ESR ceramic recommended for stability and ripple suppression. |
| SW (29) | Buck switch node | Internal buck switch connection; external inductor ties here - critical for EMI and thermal layout. |
| VOUT (30) | Regulated output | Single shared output rail (1.8–5.0V) sourced from either buck or buck-boost - no external OR-ing required. |
| SWB / SWA (31–32) | Buck-boost switch nodes | High-side (SWB) and low-side (SWA) connections for buck-boost inductor - require careful layout for efficiency. |
| BB_IN (33) | Buck-boost input | Input to buck-boost stage; tied to BAT_OUT in standard configuration - defines battery operating range. |
Key Features
| Feature | Design Value |
|---|---|
| Automatic input prioritization | Seamlessly transitions between harvested energy (buck) and battery (buck-boost) without firmware or external control - eliminates system-level power arbitration logic. |
| Integrated full-wave bridge rectifier | Removes need for four external diodes in piezoelectric or AC-coupled harvesting designs - reduces BOM count, footprint, and forward voltage loss. |
| Programmable shunt charger | Four float voltage options and 10mA max current allow precise Li-ion/LiFePO₄ charging without external charge controller ICs. |
| Supercapacitor balancer | Active balancing of two-series supercaps with ±10mA current ensures voltage matching and maximizes usable energy storage capacity. |
| Ultra-low quiescent current | 950nA total shutdown current enables >10-year battery life in devices waking once per hour for brief sensor reads and transmissions. |
| Ship mode | Reduces total current to <100nA by disabling all regulators - ideal for factory shipping, inventory storage, and field-deployed device provisioning. |
Applications
| Wireless HVAC Sensor Node | Solar-Powered Security Camera |
|---|---|
Use Scenario: Battery-powered temperature/humidity sensor mounted on HVAC ducts, harvesting vibration energy from airflow or motors. IC Role / Device Role / Timing Role: LTC3331EUH#PBF acts as primary power manager - rectifies piezoelectric AC output, regulates 3.3V for MCU and radio, charges Li-ion backup, and disconnects battery below 2.7V. Use Value: Eliminates scheduled battery replacement; enables maintenance-free operation for >5 years using ambient mechanical energy. | Use Scenario: Outdoor security camera with small solar panel and Li-ion battery, requiring reliable overnight operation and cloud upload upon motion detection. IC Role / Device Role / Timing Role: LTC3331EUH#PBF manages dual inputs - solar energy powers VOUT directly during daylight (buck mode), battery powers VOUT at night (buck-boost mode), with 4.2V float voltage and low-battery disconnect at 2.8V. Use Value: Prevents battery overcharge and deep discharge, extending cycle life beyond 500 cycles while maintaining consistent 3.3V rail for image processing and Wi-Fi transmission. |
| Mobile Asset Tracker | Industrial Wireless Pressure Transmitter |
Use Scenario: GPS-enabled tracker attached to shipping containers, harvesting kinetic energy from vehicle motion and charging internal Li-ion cell. IC Role / Device Role / Timing Role: LTC3331EUH#PBF integrates harvester interface (AC1/AC2), battery management (shunt charge + disconnect), and 50mA 3.3V output for GPS module and cellular modem. Use Value: Enables location reporting every 15 minutes without battery replacement - critical for logistics visibility across multi-month ocean voyages. | Use Scenario: Explosion-proof pressure sensor in oil/gas pipeline monitoring, powered by miniature solar cell and backed by LiFePO₄ battery for nighttime operation. IC Role / Device Role / Timing Role: LTC3331EUH#PBF delivers 2.5V to precision ADC and 3.3V to low-power MCU; uses 3.45V float voltage for LiFePO₄ and 2.0V low-battery disconnect to preserve safety margin. Use Value: Guarantees stable analog reference and digital logic supply across wide temperature (-40°C to 125°C) and input voltage ranges, meeting SIL-2 functional safety requirements. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar energy harvesting power management applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MAX17710G+T | Integrated Li-ion charger with 50mA boost output; no buck-boost topology; lacks full-wave bridge and supercapacitor balancer. | Best suited for low-power, solar-only systems without AC harvesting or supercap requirements. | Choose MAX17710G+T when harvesting is exclusively DC (e.g., small PV), battery is primary source, and balancer not needed. |
| BQ25504RGTT | Ultra-low IQ (330nA) boost-only harvester; requires external battery protection; no shunt charger or balancer. | Optimized for micropower (<10µA avg) applications like environmental sensors with infrequent wake-ups. | Choose BQ25504RGTT when system load is <10mA, battery protection is handled externally, and cost sensitivity outweighs feature completeness. |
Compared with MAX17710G+T and BQ25504RGTT, the LTC3331EUH#PBF uniquely combines dual-input prioritization, integrated AC rectification, programmable shunt charging, and active supercapacitor balancing - making it the only single-chip solution for mixed-source (AC/DC + battery), high-reliability industrial energy harvesting systems.
Availability
LTC3331EUH#PBF is available at Aetrix Electronics and suitable for wireless sensor networks, industrial IoT edge nodes, and solar-powered asset trackers requiring stable component supply, long-life battery operation, and robust energy harvesting integration.
Supply support for LTC3331EUH#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 acquired Linear Technology in 2017 and maintains its high-performance analog and power management portfolio. Linear pioneered precision DC/DC conversion and energy harvesting ICs for demanding industrial and instrumentation markets.
The LTC3331EUH#PBF belongs to Linear's nanopower energy harvesting PMIC family, designed specifically for maintenance-free, battery-backed wireless sensing in harsh environments where reliability, ultra-low IQ, and multi-source flexibility are critical.
FAQ
What is the maximum input voltage the LTC3331EUH#PBF can handle on the VIN pin?
The LTC3331EUH#PBF has an absolute maximum VIN rating of 19V, with an internal 20V clamp protecting the device. Operation above 19V risks permanent damage. For reliable long-term use, keep VIN ≤18V under all conditions, including transients - verified in Absolute Maximum Ratings and Electrical Characteristics tables.
Can the LTC3331EUH#PBF simultaneously power a load from both the buck and buck-boost converters?
No - the LTC3331EUH#PBF implements automatic input prioritization: only one converter supplies VOUT at any time. When VIN exceeds the programmed UVLO threshold, the buck powers VOUT; when VIN drops below UVLO, the buck-boost takes over. This prevents shoot-through and ensures seamless transition without external control logic.
How does the LTC3331EUH#PBF manage battery overcharge protection?
The LTC3331EUH#PBF uses a precision 10mA shunt charger with four programmable float voltages (3.45V/4.0V/4.1V/4.2V) set by FLOAT[1:0]. Once the battery reaches the selected float voltage, the CHARGE pin stops sinking current, preventing overcharge. This is confirmed in the Electrical Characteristics table under VFLOAT parameter and Figure 46–47.
What is the purpose of the BAL and SCAP pins on the LTC3331EUH#PBF?
The BAL and SCAP pins implement an active supercapacitor balancer for two-series stacks. SCAP connects to the top of the stack, BAL to the midpoint. The LTC3331EUH#PBF sources or sinks up to 10mA to maintain voltage balance within ±1% - critical for maximizing usable energy and preventing overvoltage failure in series-connected supercaps.
Does the LTC3331EUH#PBF support piezoelectric energy harvesting without external components?
Yes - the LTC3331EUH#PBF integrates a full-wave bridge rectifier between AC1 and AC2 pins, allowing direct connection to piezoelectric transducers without external diodes. Its low reverse leakage (<20nA at 18V) and 1.35V typical forward drop at 50mA ensure high harvesting efficiency from low-current, high-impedance sources.
LTC3331EUH#PBF Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc.
- Series:
- -
- Package/Case:
- 32-WFQFN Exposed Pad
- Packaging:
- Tube
- Product Status:
- Active
- Applications:
- Energy Harvesting
- Current - Supply:
- 950nA
- Voltage - Supply:
- 1.8V ~ 5.5V, 3V ~ 19V
- Operating Temperature:
- -40°C ~ 85°C
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 32-QFN (5x5)
LTC3331EUH#PBF FAQ
1.How can I place an order for LTC3331EUH#PBF through Aetrix?
Please submit a Request for Quotation (RFQ) for LTC3331EUH#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 LTC3331EUH#PBF reliable?
The price and inventory of LTC3331EUH#PBF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LTC3331EUH#PBF is usually 5 days.
3.What payment methods are accepted for LTC3331EUH#PBF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LTC3331EUH#PBF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LTC3331EUH#PBF?
LTC3331EUH#PBF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LTC3331EUH#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 LTC3331EUH#PBF?
For technical support, including LTC3331EUH#PBF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LTC3331EUH#PBF requirements.
6.How does Aetrix verify that LTC3331EUH#PBF is sourced from the original manufacturer or authorized distributors?
All LTC3331EUH#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 LTC3331EUH#PBF meets industry standards.
7.What is the process for return or replacement of LTC3331EUH#PBF?
All LTC3331EUH#PBF units undergo pre-shipment inspection (PSI). If there is an issue with LTC3331EUH#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 LTC3331EUH#PBF part is unused and in its original packaging.
Return procedure for LTC3331EUH#PBF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
LTC3331EUH#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…
