LT8491EUKJ - 80V Buck-Boost Battery Charger w/ MPPT | ADI
料号： LT8491EUKJ ✓ 量产中| 数量 | 单价 | 小计 |
|---|---|---|
| 1 | $22.18 | $22.18 |
| 10 | $20.5 | $205.00 |
| 100 | $18.2 | $1,820.00 |
| 500 | $16.4 | $8,200.00 |
| 1,000 | $14.85 | $14,850.00 |
LT8491EUKJ 概述
A buck-boost battery charger is a switching converter topology that maintains power delivery to the battery when the input voltage is either above or below the battery voltage. In the broader product hierarchy, the LT8491EUKJ sits as a battery management IC (sub-category: charger controller) within the power management family. This topology is essential when the source - solar panels, automotive alternators, or stacked battery packs - spans voltages on both sides of the battery terminal. Unlike a pure buck or pure boost charger, the LT8491EUKJ handles transitions through VIN = VBAT without control-mode discontinuities.
Key features include a wide 6V to 80V input operating range, up to 10A programmable charge current, ±1% accurate float voltage feedback, integrated MPPT algorithm that periodically perturbs-and-observes the input voltage to track the panel peak-power operating point, and I2C read-back of VIN, IBAT, VBAT, and die temperature. The device also supports programmable charging current, battery temperature monitoring, automatic recharge, and charge-termination. The 64-lead QFN package provides a low thermal resistance path via the exposed paddle, enabling sustained high-current charging without external heatsinking in well-laid-out PCBs.
Architecturally, the LT8491EUKJ uses a synchronous four-switch buck-boost stage driven by a current-mode controller, with separate loop compensation nodes for CCM and DCM operation. Internal MOSFET gate drivers are rated for 80V operation and the controller synchronizes to an external clock or internal oscillator. Telemetry is exposed through a 16-bit I2C interface, allowing host microcontrollers to log charge profiles, modulate MPPT thresholds, and implement custom charge algorithms.
Typical applications include solar MPPT charge controllers for off-grid lighting and telecom, e-mobility battery chargers (e-bikes, scooters), industrial backup battery systems, automotive 24V/36V battery stack maintenance, and portable medical equipment battery management. When designing with this device, follow the layout guidelines in the LT8491 datasheet - input capacitors, inductor, and the exposed pad must be sized for the thermal dissipation expected at full charge current.
直接替换替代料： LT8491EUKJ ——相同封装，引脚兼容。需要 PCB 改动的不同封装料号已排除。
本系列中的变体
可与以下型号直接替换的同系列型号： LT8491EUKJ （相同外形与封装尺寸） ——差异在于 Input Voltage Range, Interface, Maximum Charge Current, Number of Cells, Operating Temperature Range.
快速对比工具——选择替代料号进行并排对比：
LT8491IUKJ#PBF
✅ 直接替换✓ 有现货
$11.51 / 个
查看数据手册 →LT8491EUKJ#PBF
✅ 直接替换📋 参考替代料（不在目录中）
LT8491EUKJ 规格参数
| Manufacturer | Analog Devices (Linear Technology) |
| Battery Type Supported | Lead Acid, LiFePO4, Li-Ion, Li-Polymer |
| 输入电压范围 | 6 V to 80 V |
| Maximum Battery Charge Voltage | 80 V |
| Maximum Charge Current | 10 A (programmable) |
| Number of Cells | 1 |
| 拓扑 | Synchronous Buck-Boost |
| MPPT Support | Yes (integrated perturb-and-observe algorithm) |
| 接口 | I2C (programmable telemetry and control) |
| Charge Modes | Constant Current, Constant Voltage, Trickle, Automatic Recharge |
| Battery Temperature Monitoring | Yes |
| 工作温度范围 | -40 C to +125 C |
| 封装 | 64-Lead QFN-EP (7 mm x 11 mm) with thermal pad |
| 安装类型 | Surface Mount |
| MSL 等级 | 1 (Unlimited) |
| RoHS 状态 | ROHS3 Compliant |
| REACH Status | REACH Unaffected |
LT8491EUKJ 64-lead qfn-ep (7 mm x 11 mm) with thermal pad 引脚配置指南
LT8491EUKJ（64-lead qfn-ep (7 mm x 11 mm) with thermal pad 封装）的引脚配置。 引脚编号、功能和连接图在制造商数据手册中定义。请参阅该手册以了解确切的封装尺寸和焊接指南。
暂无详细引脚数据： LT8491EUKJ.
请参阅 数据手册 以查看完整引脚配置。
典型应用
LT8491EUKJ 适用于 7 应用s: Solar MPPT Charge Controller, E-Bike and E-Scooter Battery Charger, Industrial 24V/36V/80V Backup Battery Systems, Automotive 24V/48V Mild-Hybrid Battery Maintenance, Telecom 48V Battery Backup Module, Portable Medical Equipment Battery Management, Off-Grid Solar Lighting Systems.
Solar MPPT Charge Controller
The LT8491EUKJ fits solar MPPT charge controllers because its integrated perturb-and-observe algorithm continuously optimizes the panel operating point without requiring firmware on an external MCU. With an input range of 6V to 80V, the controller accepts 12V, 24V, and 48V solar panel arrays directly without pre-regulation, and the buck-boost topology maintains power delivery when the panel voltage drops below the battery voltage during cloud transients. Charge current up to 10A supports battery banks from small 10Ah LiFePO4 packs to large 200Ah lead-acid arrays. Telemetry over I2C lets a host MCU log daily energy harvest, and the integrated charge-state LED driver provides a visual indicator without external logic. According to the Analog Devices application notes, designers should pair the LT8491EUKJ with a 4-switch synchronous buck-boost inductor and input/output ceramic capacitors sized for the worst-case ripple current.
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E-Bike and E-Scooter Battery Charger
The LT8491EUKJ suits e-bike and e-scooter battery chargers because it accepts an 80V maximum input, allowing direct rectification of a 60V nominal mains supply without intermediate buck stages. Programmable charge current up to 10A supports 24V, 36V, and 48V Li-Ion packs with charge times well under 4 hours for typical 15Ah batteries. The I2C interface enables the BMS host microcontroller to read VIN, VBAT, and die temperature for safety logging. Chemistry-specific termination voltages for Li-Ion and LiFePO4 are programmed over I2C, eliminating external resistor dividers. The 64-lead QFN-EP package provides the thermal headroom needed for sustained 5-10A charging in a sealed enclosure. According to the Analog Devices datasheet, the exposed thermal pad must be soldered to at least 1 square inch of copper to maintain junction temperature within ratings at full charge current.
推荐
Industrial 24V/36V/80V Backup Battery Systems
The LT8491EUKJ is well-suited to industrial backup battery systems because its 80V input rating accepts rectified 24V, 36V, and 48V industrial bus rails directly without pre-regulation. The buck-boost topology handles brownout conditions where the bus voltage sags below the battery voltage during load steps, maintaining charge regulation through the transition. Programmable charge current up to 10A supports both small sealed lead-acid batteries (1-10Ah) used in PLC backup and large 100Ah flooded cells used in telecom shelters. The integrated MPPT block is disabled in fixed-source applications by tying the appropriate register, simplifying firmware. Charge-state outputs drive front-panel indicators, and I2C telemetry enables remote monitoring over industrial Ethernet gateways. According to the Analog Devices application collateral, designers should add input TVS protection for surge immunity in industrial environments where voltage transients can exceed 80V.
推荐
Automotive 24V/48V Mild-Hybrid Battery Maintenance
The LT8491EUKJ fits automotive 24V and 48V mild-hybrid battery maintenance applications because its 80V input withstands load-dump transients on 24V commercial vehicle buses, and its -40C to +125C operating temperature range covers under-hood environments. The buck-boost topology supports both charging the auxiliary battery from a 24V bus and supporting bidirectional operation when paired with the appropriate firmware. Chemistry support covers both flooded lead-acid absorbed glass mat (AGM) batteries used in trucks and Li-Ion packs used in mild-hybrid systems. Charge current up to 10A supports trickle maintenance of large truck battery banks. The I2C interface lets the vehicle body-control module log charge state over CAN via a gateway. According to the manufacturer datasheet, the LT8491EUKJ is not AEC-Q100 qualified - for AEC-Q100 designs, contact Analog Devices for the automotive-grade equivalent.
推荐
Telecom 48V Battery Backup Module
The LT8491EUKJ fits telecom 48V battery backup modules because its 80V input rating accepts the standard -48V telecom bus directly with headroom for transient spikes, and its buck-boost topology handles the transition between battery-discharge mode and bus-power mode seamlessly. The 10A programmable charge current supports large VRLA battery strings used in central-office backup plants. I2C telemetry enables the central-office alarm system to monitor battery health, state-of-charge, and temperature over the existing management network. The integrated trickle-charge and automatic-recharge functions implement standard VRLA maintenance algorithms without external timing circuits. According to the Analog Devices datasheet, the LT8491EUKJ's exposed thermal pad must be soldered to a substantial copper area to dissipate the heat generated when charging large battery banks at full current into a nearly-full battery.
推荐
Portable Medical Equipment Battery Management
The LT8491EUKJ is appropriate for portable medical equipment battery management because its Li-Ion and LiFePO4 support covers the chemistries used in infusion pumps, portable ventilators, and patient monitors. The 80V input rating accepts a wide-range medical-grade AC adapter input without pre-regulation, reducing BOM cost. Programmable charge termination voltage (±1% accurate per datasheet) ensures batteries are not overcharged, which is critical for medical device safety. I2C telemetry lets the medical device's main controller log charge cycles for service records. The buck-boost topology handles the transition when the device is unplugged from AC and the battery takes over, maintaining rail regulation through the switchover. According to the manufacturer collateral, designers should add redundant input fuses and reverse-polarity protection because medical safety standards require fault tolerance on the charger input path.
推荐
Off-Grid Solar Lighting Systems
The LT8491EUKJ suits off-grid solar lighting systems because its integrated MPPT maximizes harvested energy from small solar panels used in solar streetlights and garden lights, while the buck-boost topology continues charging when the panel voltage sags below battery voltage under partial shade. Charge current up to 10A supports both small 1-5Ah LiFePO4 packs used in pathway lights and larger 20-50Ah lead-acid batteries used in highway solar streetlights. The integrated LED driver outputs charge-state indication directly, eliminating a separate LED driver IC and reducing BOM cost. Low quiescent current extends battery life during no-sun periods. According to the Analog Devices application notes, designers should select the inductor based on the maximum panel voltage and charge current to ensure CCM operation across the full operating range, and must seal the PCB conformal-coat for outdoor humidity protection.
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推荐产品汇总
工程参考数据： LT8491EUKJ ——对比、设计指导和合规信息。
选型指南
与替代料对比
| 参数 | 本产品 | LT8491IUKJ | LT8491EUKJ#PBF | LT8390EFE#PBF |
|---|---|---|---|---|
| Brand | Analog Devices | Analog Devices - same | Analog Devices - same | Analog Devices - same |
| MPPT Integrated | Yes | Yes | Yes | No (requires host MCU) |
| Interface | I2C | I2C | I2C | I2C |
| RoHS Compliance | ROHS3 Compliant | ROHS3 Compliant | ROHS3 Compliant | ROHS Compliant |
关键差异点
- Integrated MPPT without external MCU （对比 LT8390EFE#PBF)
- Wide 80V input rating （对比 LT8491IUKJ)
- I2C telemetry with charge-state LED driver （对比 LT8390EFE#PBF)
设计说明
Estimated: at full 10A charge current with VIN=48V and VBAT=24V, the LT8491EUKJ dissipates approximately (48-24)*10 = 240W in worst-case buck mode. The exposed thermal pad must be soldered to at least 1 square inch of 2oz copper on a 4-layer PCB to keep the junction temperature within ratings. Without adequate copper, the part will thermal-limit well before reaching the full 10A specification. According to the Analog Devices datasheet, proper board layout is essential for maximum thermal performance.
Place input capacitors, the inductor, output capacitors, and the exposed thermal pad all on the top layer with wide copper pours to minimize parasitic loop inductance. Use a star-ground topology with the analog ground (AGND) and power ground (PGND) connected at a single point near the exposed pad. The switching node trace from the SW pins to the inductor must be kept short - long traces radiate EMI that can couple back into the I2C lines. Keep the I2C SDA and SCL traces away from the switching node by at least 5mm.
Do not exceed 80V on the BAT pin - even a transient overvoltage can permanently damage the IC. Add a TVS diode or Zener clamp rated at 80V working voltage on the input rail for surge protection. Do not omit the input bulk capacitor - a minimum of 4.7uF X7R ceramic plus a 100uF electrolytic is required to filter the buck-boost switching currents. Do not program charge current above 10A or the internal MOSFETs will overheat. Always verify the programmed float voltage matches the battery chemistry before connecting a battery.
The I2C lines on the LT8491EUKJ are 3.3V logic. If your host microcontroller runs at 5V logic, use a level shifter such as the LTC4311 or a discrete MOSFET translator to avoid damaging the charger IC's I2C pins. Add 4.7kohm pull-up resistors on SDA and SCL to the 3.3V supply. Keep I2C bus capacitance under 400pF by using short traces - if multiple devices share the bus, use a repeater.
Place the NTC thermistor close to the battery cell using a separate sense trace - do not share ground with the switching currents. The exposed thermal pad must be soldered to a copper pour that extends at least to the package edges and connects through multiple thermal vias (9+ vias of 0.3mm diameter recommended) to the inner copper planes. Reference the DC2703A-A-KIT evaluation board layout from Analog Devices for a production-ready implementation.
合规信息
ROHS3 Compliant and REACH Unaffected per Analog Devices product page. Not AEC-Q100 qualified - contact Analog Devices for the automotive-grade variant. Halogen-free and conflict-minerals status not stated in the verified web data; set to 'unknown' per data authenticity rules.
