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Analog Devices Inc. LT8491EUKJ#PBF
- Part No.:
- LT8491EUKJ#PBF
- Manufacturer:
- Analog Devices Inc.
- Category:
- Battery Chargers
- Package:
- 64-WFQFN Exposed Pad
- Datasheet:
-
LT8491EUKJ#PBF.pdf
- Description:
- IC BATT CHG LEAD ACID 1CEL 64QFN
- Quantity:
- Payment:
- Shipping:
Inventory:1,544
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Product details
Overview
LT8491EUKJ#PBF from Analog Devices is a high-voltage buck-boost battery charge controller with integrated MPPT, I²C telemetry, and four feedback loops for solar or DC-powered charging of SLA, gel, flooded, and Li-ion batteries. It operates across 6V–80V input and 1.3V–80V battery voltage ranges, supports automatic temperature compensation via external thermistor, and delivers CCCV charging profiles with programmable stage transitions.
For engineers reviewing the LT8491EUKJ#PBF datasheet, LT8491EUKJ#PBF pinout, LT8491EUKJ#PBF application, or LT8491EUKJ#PBF equivalent, key selection criteria include its single-inductor buck-boost topology enabling VIN above/below/equal to VBAT, 100kHz–400kHz synchronizable switching frequency, internal EEPROM for persistent configuration storage, and dual current-sense architecture (IMON_IN/IMON_OUT) for precise input/output current regulation.
Technical Context
The LT8491EUKJ#PBF implements a perturb-and-observe MPPT algorithm directly in hardware, using real-time panel voltage (VINR) and current (IMON_IN) measurements to dynamically adjust FBIN setpoint via FBIW PWM output. Its dual-loop control simultaneously regulates input power (MPPT), output voltage (FBOUT), output current (IMON_OUT), and battery temperature (TEMPSENSE).
It integrates an internal 6.35V INTVCC regulator powered from either VIN or EXTVCC (≥6.4V), drives external NMOS switches via TG1/TG2 and BG1/BG2 gate drivers, and provides I²C-compliant serial interface (100kHz, 3.3V logic) with 10-bit ADC, CRC-protected telemetry registers, and configurable startup behavior stored in on-chip EEPROM.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| VIN Range | 6V to 80V - supports wide-input solar panels and industrial DC supplies without pre-regulation. |
| VBAT Range | 1.3V to 80V - enables charging of single-cell Li-ion up to 24S lead-acid stacks. |
| Switching Frequency | 100kHz to 400kHz - adjustable via RT resistor; synchronizable to external clock for EMI reduction. |
| I²C Interface | Standard-mode (100kHz), 3.3V logic - enables real-time telemetry (VIN, VBAT, IIN, IOUT, POUT, TBAT) and full configuration via 128-byte register map. |
| EEPROM | 100,000 write cycles, 20-year data retention at 85°C - stores user-defined charge profiles, MPPT settings, and fault thresholds persistently. |
| Thermal Range | –40°C to +125°C junction - qualified for automotive under-hood and industrial outdoor deployment. |
| Package | 64-lead 7mm × 11mm × 0.75mm QFN with exposed GND pad - optimized for high-power thermal dissipation in compact solar chargers. |
Pinout & Package
LT8491EUKJ#PBF is housed in a low-profile 64-lead plastic QFN (7mm × 11mm × 0.75mm) with exposed thermal pad (Pin 65 = GND). The package supports high-current switching and efficient heat transfer to PCB copper.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| SW1, SW2 | Power Switch Nodes | Connect to external NMOS drains; tolerate up to 81V; enable buck-boost topology with single inductor. |
| TG1, TG2, BG1, BG2 | Gate Drivers | Drive external NMOS gates; TGx sources current, BGx sinks current; support 100% duty cycle operation. |
| CSP/CSN, CSPOUT/CSNOUT | Current Sense Inputs | Dual differential inputs for input (CSPIN/CSNIN) and output (CSPOUT/CSNOUT) current monitoring with ±0.3V common-mode range. |
| FBIW, FBOW | PWM Outputs | 8-bit PWM outputs for MPPT (FBIW → FBIN) and temperature-compensated VBAT regulation (FBOW → FBOUT). |
| TEMPSENSE | Analog Temperature Input | ADC input for thermistor network; used for automatic VBAT compensation and thermal fault detection. |
| SDA, SCL | I²C Serial Interface | Standard-mode bidirectional bus; supports telemetry readback, register writes, and EEPROM programming. |
| STATUS | Charger State Indicator | Open-drain output driving LED; signals charging stage, fault conditions, and C/10 termination. |
Key Features
| Feature | Design Value |
|---|---|
| Single-inductor buck-boost topology | Eliminates need for separate boost/buck converters; enables seamless transition between VIN > VBAT, VIN < VBAT, and VIN ≈ VBAT operating modes. |
| Hardware-based MPPT engine | Real-time perturb-and-observe algorithm executed autonomously; no host MCU required for solar optimization. |
| Four independent feedback loops | Simultaneously regulates input power (MPPT), output voltage (VBAT), output current (IBAT), and battery temperature (TBAT) for robust multi-parameter control. |
| Integrated 3.3V LDO (LDO33) | Supplies VDD and AVDD; delivers up to 22mA with ±1% load regulation; includes UVLO (2.96V–3.12V) for clean system reset. |
| Configurable charge staging | Four-stage CCCV algorithm (trickle → constant current → constant voltage → reduced CV) with programmable timeouts and termination thresholds. |
Applications
| Solar-Powered Off-Grid Battery Charger | Lithium-Ion Battery Charging System |
|---|---|
|
Use Scenario: Standalone solar charger for remote telecom base stations using 48V Li-ion backup battery and 60–75V solar array. IC Role / Device Role / Timing Role: Primary charge controller managing MPPT, CCCV profile, thermal derating, and telemetry reporting over I²C to local MCU. Use Value: Delivers >94% peak efficiency across 20–100% solar irradiance; maintains full charge current down to 15% panel output via dynamic MPPT re-scan. |
Use Scenario: Portable medical device with 3S Li-ion pack charged from variable-input solar panel or USB-C PD adapter. IC Role / Device Role / Timing Role: Dual-source battery manager handling both solar MPPT and regulated DC supply mode with automatic source arbitration. Use Value: Enables safe 4.2V/cell charging with ±0.5% voltage accuracy and C/10 termination detection; supports hot-plug battery insertion without latch-up. |
| Industrial Lead-Acid UPS Charger | Military Ruggedized Power System |
|
Use Scenario: 24V/48V sealed lead-acid battery charger in oilfield SCADA cabinet powered by 24–72V DC rail. IC Role / Device Role / Timing Role: High-reliability charge controller implementing temperature-compensated absorption/floating voltages per IEEE 1188. Use Value: Uses TEMPSENSE input to adjust VBAT by –3mV/°C per cell; stores custom float voltage and timeout values in EEPROM for field calibration. |
Use Scenario: Manpack radio battery charger operating in desert (-40°C to +70°C ambient) with solar panel and vehicle alternator inputs. IC Role / Device Role / Timing Role: Mission-critical power management IC providing fault-tolerant charging, brownout recovery, and tamper-proof configuration storage. Use Value: Qualified to –40°C to +125°C junction; survives 1000hr 85°C/85% RH bias life test; EEPROM CRC validation prevents corrupted firmware updates. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar battery charge controller applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| LT8705EFE#PBF | Step-down only; no MPPT; no I²C; wider 2.8V–80V VIN; supports higher output current (8A typical). | Best for fixed-rail DC-DC battery charging where solar MPPT and telemetry are unnecessary. | Select when cost, BOM count, or thermal footprint are prioritized over solar intelligence and remote configurability. |
| BQ24650RTWR | Fixed-frequency buck-only; no MPPT; no EEPROM; 4.5V–28V VIN; integrated MOSFETs; lower voltage range. | Suitable for low-voltage portable Li-ion charging with minimal external components. | Choose for space-constrained consumer devices requiring integrated power FETs and simplified layout - not for solar or high-VIN systems. |
Compared with LT8491EUKJ#PBF, LT8705EFE#PBF lacks MPPT and telemetry but offers higher current capability in a smaller package, while BQ24650RTWR integrates power stages but sacrifices voltage range, solar functionality, and configurability - making LT8491EUKJ#PBF uniquely suited for high-voltage, solar-optimized, field-programmable battery charging.
Availability
LT8491EUKJ#PBF is available at Aetrix Electronics and suitable for solar-powered battery chargers, industrial UPS systems, military portable power units, and Li-ion energy storage applications requiring stable component supply, long-term lifecycle assurance, and traceable sourcing.
Supply support for LT8491EUKJ#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 aerospace markets.
The LT8491 product line was designed specifically for high-voltage, multi-source battery charging in harsh environments - integrating MPPT, telemetry, and robust protection features into a single monolithic IC for solar, vehicle, and grid-tied energy systems.
FAQ
What battery chemistries does the LT8491EUKJ#PBF support?
The LT8491EUKJ#PBF supports sealed lead-acid (SLA), flooded, gel, and lithium-ion batteries through its programmable four-stage CCCV charging algorithm. It allows independent configuration of trickle, constant-current, constant-voltage, and reduced-voltage stages - including temperature-compensated voltage setpoints via the TEMPSENSE pin and FBOW PWM output. This flexibility makes LT8491EUKJ#PBF suitable for diverse chemistries without hardware changes.
How does the LT8491EUKJ#PBF implement Maximum Power Point Tracking?
The LT8491EUKJ#PBF executes hardware-based perturb-and-observe MPPT using real-time measurements from VINR and IMON_IN pins. It autonomously adjusts the FBIN reference via the FBIW PWM output to maximize panel power - no external microcontroller is required. Full-panel scans and partial-shading recovery are supported, and MPPT parameters (scan rate, perturbation step) are configurable via I²C registers. This ensures LT8491EUKJ#PBF delivers optimal solar harvest under dynamic lighting conditions.
Can the LT8491EUKJ#PBF operate from both solar and DC supply inputs?
Yes, the LT8491EUKJ#PBF automatically detects and selects between solar panel and DC supply inputs using the VINR pin and internal power-supply-mode detection circuitry. When VINR falls below 174mV, it enters solar mode with active MPPT; above that threshold, it switches to DC supply mode with fixed-voltage regulation. This dual-input capability is built into LT8491EUKJ#PBF's core architecture and requires no external logic or switching components.
What is the role of the internal EEPROM in the LT8491EUKJ#PBF?
The LT8491EUKJ#PBF includes 128 bytes of on-chip EEPROM rated for 100,000 write cycles and 20-year data retention at 85°C. It stores critical configuration data - including charge stage voltages, current limits, MPPT parameters, temperature compensation coefficients, and startup defaults - ensuring consistent behavior after power cycles or resets. This persistent memory eliminates the need for external nonvolatile storage and makes LT8491EUKJ#PBF ideal for unattended solar installations.
Does the LT8491EUKJ#PBF require external MOSFETs?
Yes, the LT8491EUKJ#PBF is a controller IC and requires external NMOS power switches. It provides dedicated gate drive outputs (TG1/TG2 for sourcing, BG1/BG2 for sinking) to drive high-side and low-side FETs in a synchronous buck-boost configuration. This architecture allows optimization for voltage/current/power requirements - unlike integrated-FET solutions - and enables LT8491EUKJ#PBF to scale from 10W to >500W designs using discrete MOSFETs selected for specific RDS(on), Qg, and thermal performance.
LT8491EUKJ#PBF Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc.
- Series:
- -
- Package/Case:
- 64-WFQFN Exposed Pad
- Packaging:
- Tube
- Product Status:
- Active
- Battery Chemistry:
- Lead Acid
- Number of Cells:
- 1
- Current - Charging:
- Constant
- Programmable Features:
- Current, Voltage
- Fault Protection:
- Over Temperature, Over Voltage
- Charge Current - Max:
- -
- Battery Pack Voltage:
- 1.3V ~ 80V
- Voltage - Supply (Max):
- 80V
- Interface:
- I2C
- Operating Temperature:
- -40°C ~ 125°C (TJ)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 64-QFN (7x11)
LT8491EUKJ#PBF FAQ
1.How can I place an order for LT8491EUKJ#PBF through Aetrix?
Please submit a Request for Quotation (RFQ) for LT8491EUKJ#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 LT8491EUKJ#PBF reliable?
The price and inventory of LT8491EUKJ#PBF are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for LT8491EUKJ#PBF is usually 5 days.
3.What payment methods are accepted for LT8491EUKJ#PBF?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for LT8491EUKJ#PBF transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for LT8491EUKJ#PBF?
LT8491EUKJ#PBF orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your LT8491EUKJ#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 LT8491EUKJ#PBF?
For technical support, including LT8491EUKJ#PBF datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your LT8491EUKJ#PBF requirements.
6.How does Aetrix verify that LT8491EUKJ#PBF is sourced from the original manufacturer or authorized distributors?
All LT8491EUKJ#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 LT8491EUKJ#PBF meets industry standards.
7.What is the process for return or replacement of LT8491EUKJ#PBF?
All LT8491EUKJ#PBF units undergo pre-shipment inspection (PSI). If there is an issue with LT8491EUKJ#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 LT8491EUKJ#PBF part is unused and in its original packaging.
Return procedure for LT8491EUKJ#PBF:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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