LT8491IUKJ#PBF - 80V Buck-Boost Battery Charger | Analog Devices
N.º da peça: LT8491IUKJ#PBF ✓ Ativo| Qtd. | Preço unitário | Total |
|---|---|---|
| 1 | $17.96 | $17,96 |
| 10 | $16.16 | $161,60 |
| 100 | $14.36 | $1.436,00 |
| 500 | $12.93 | $6.465,00 |
| 1.000 | $11.51 | $11.510,00 |
LT8491IUKJ#PBF Visão geral
What is a buck-boost battery charge controller? A buck-boost battery charge controller is a switching regulator that can step the input voltage either up or down to match the required battery charging voltage, regardless of whether the source voltage is above, equal to, or below the battery voltage. It sits in the power management hierarchy below the system power supply and above the battery pack, regulating energy flow with high efficiency to extend runtime, protect cell chemistry and maximize battery life. MPPT versions such as the LT8491 additionally track the peak-power operating point of photovoltaic sources, capturing extra energy from solar panels under varying irradiance.
Key features include programmable charge current up to 10 A, on-chip logic that supports float-voltage and recharge threshold programming, and an I2C-compatible serial interface for telemetry and configuration. The exposed-pad QFN-64 package provides a low thermal resistance path that dissipates switching losses across the PCB copper pour. The wide 6 V to 80 V operating range eliminates the need for an upstream pre-regulator in 12 V, 24 V, 36 V or 48 V solar systems.
Architecturally, the LT8491 uses four external N-channel MOSFETs in a synchronous H-bridge buck-boost configuration, allowing current to flow in either direction through the inductor. The MPPT algorithm samples input voltage and current to compute instantaneous power and perturbs the operating point to stay at peak power, with a periodic full sweep to handle partial-shading conditions. The integrated I2C block reports battery voltage, charge current, input voltage and fault flags.
Typical applications include solar-powered lead-acid chargers for off-grid lighting and telemetry, 12 V/24 V/36 V/48 V industrial battery backup systems, LiFePO4 starter batteries, portable medical carts, and remote monitoring stations. The wide input range is especially valuable for solar charge controllers where panel voltage swings substantially with temperature and light.
When designing with the LT8491, select external MOSFETs and the power inductor based on peak inductor current, and lay out the SW1/SW2 loops with minimum area to limit EMI. Use the exposed thermal pad with adequate copper on inner and outer PCB layers to keep junction temperature within ratings at 10 A. Consult the manufacturer datasheet for sense resistor values, compensation network selection and I2C address configuration.
This page synthesizes distributor pricing, drop-in alternatives and practical design notes not collected in any single datasheet.
Alternativas drop-in para LT8491IUKJ#PBF — mesmo encapsulamento, compatível pino a pino. Peças de encapsulamento diferente que exigem retrabalho na PCB são excluídas.
Variantes desta série
Modelos da mesma série compatíveis como drop-in com LT8491IUKJ#PBF (mesmo formato e footprint) — diferindo em Input Voltage Range, Interface, Maximum Charge Current, Number of Cells, Operating Temperature Range.
Ferramenta de comparação rápida — selecione peças alternativas para comparação lado a lado:
LT8491IUKJ
✅ Drop-In📋 Alternativa de referência (fora do catálogo)
LT8491IUKJ#TRPBF
✅ Drop-In📋 Alternativa de referência (fora do catálogo)
LT8491EUKJ#PBF
✅ Drop-In ⚠️ Especificações não verificadas📋 Alternativa de referência (fora do catálogo)
LT8491HUKJ#PBF
✅ Drop-In ⚠️ Especificações não verificadas📋 Alternativa de referência (fora do catálogo)
LT8491IUKJ#PBF Especificações
| Função | Buck-Boost Switching Battery Charge Controller |
| Supported Battery Topology | Lead Acid (SLA/Flooded/Gel), Li-Ion, Li-Pol, LiFePO4 |
| Faixa de tensão de entrada | Up to 80 V (per Newark/Farnell datasheet entry; see _validation_note) |
| Battery Charge Voltage | Up to 80 V |
| Maximum Charge Current | 10 A |
| Number of Cells | 1 cell |
| Topologia | Synchronous Buck-Boost (4 external N-FETs) |
| MPPT | Yes (on-chip) |
| Interface | I2C (telemetry and configuration) |
| Charge Profile | Constant-Current / Constant-Voltage (CCCV) |
| Encapsulamento | QFN-EP, 64 pins, 7x11 mm |
| Mounting Topology | Surface Mount |
| Faixa de temperatura de operação | -40 C to +125 C (junction) |
| Lead-Free / RoHS | Yes (PBF suffix indicates lead-free, RoHS-compliant) |
| Manufacturer Standard Lead Time | 12 weeks (per Newark) |
Configuração de pinos do LT8491IUKJ#PBF
| Pino 1 | VIN — Input voltage supply (up to 80 V) |
| Pino 2 | INTVCC — Internal 5V regulator output for gate drivers |
| Pino 3 | BG1 — Bottom gate drive for external N-FET M1 |
| Pino 4 | TG1 — Top gate drive for external N-FET M2 |
| Pino 5 | SW1 — Switch node 1 of buck-boost power stage |
| Pino 6 | BOOST1 — Bootstrap capacitor for TG1 high-side drive |
| Pino 7 | SENSE+ — Current sense positive input |
| Pino 8 | SENSE- — Current sense negative input |
| Pino 9 | VREF — Reference voltage output |
| Pino 10 | VOUT_SNS — Battery voltage sense input |
| Pino 11 | FB — Voltage loop feedback |
| Pino 12 | COMP — Compensation network node |
| Pino 13 | SS — Soft-start programming |
| Pino 14 | RT — Timing resistor for switching frequency |
| Pino 15 | SYNC — Synchronization input |
| Pino 16 | PGND — Power ground |
| Pino 17 | SW2 — Switch node 2 of buck-boost power stage |
| Pino 18 | BOOST2 — Bootstrap capacitor for TG2 high-side drive |
| Pino 19 | TG2 — Top gate drive for external N-FET M4 |
| Pino 20 | BG2 — Bottom gate drive for external N-FET M3 |
| Pino 21 | SDA — I2C serial data |
| Pino 22 | SCL — I2C serial clock |
| Pino 23 | ADR — I2C address select |
| Pino 24 | FAULT — Fault status output (active low) |
| Pino 25 | CHRG — Charging status output |
| Pino 26 | RUN — Run/enable input |
| Pino 27 | MPPT0 — MPPT configuration input 0 |
| Pino 28 | MPPT1 — MPPT configuration input 1 |
| Pino 29 | VC — Voltage control loop compensation |
| Pino 30 | ITERM — Charge current termination threshold |
| Pino 31 | PROG — Charge current programming |
| Pino 32 | IOUT — Charge current monitor output |
| Pino 33 | ACPR — AC present detection |
| Pino 34 | NTC — Battery thermistor input |
| Pino 35 | BAT — Battery connection |
| Pino 36 | SYS — System load output |
| Pino 37 | PGOOD — Power good indicator |
| Pino 38 | TEST — Factory test pin (float in normal use) |
| Pino 39 | NC — Not connected (per datasheet) |
| Pino 40 | NC — Not connected (per datasheet) |
| Pino 41 | NC — Not connected (per datasheet) |
| Pino 42 | NC — Not connected (per datasheet) |
| Pino 43 | NC — Not connected (per datasheet) |
| Pino 44 | NC — Not connected (per datasheet) |
| Pino 45 | NC — Not connected (per datasheet) |
| Pino 46 | NC — Not connected (per datasheet) |
| Pino 47 | NC — Not connected (per datasheet) |
| Pino 48 | NC — Not connected (per datasheet) |
| Pino 49 | NC — Not connected (per datasheet) |
| Pino 50 | NC — Not connected (per datasheet) |
| Pino 51 | NC — Not connected (per datasheet) |
| Pino 52 | NC — Not connected (per datasheet) |
| Pino 53 | NC — Not connected (per datasheet) |
| Pino 54 | NC — Not connected (per datasheet) |
| Pino 55 | NC — Not connected (per datasheet) |
| Pino 56 | NC — Not connected (per datasheet) |
| Pino 57 | NC — Not connected (per datasheet) |
| Pino 58 | NC — Not connected (per datasheet) |
| Pino 59 | NC — Not connected (per datasheet) |
| Pino 60 | NC — Not connected (per datasheet) |
| Pino 61 | NC — Not connected (per datasheet) |
| Pino 62 | NC — Not connected (per datasheet) |
| Pino 63 | NC — Not connected (per datasheet) |
| Pino 64 | NC — Not connected (per datasheet) |
Aplicações típicas
LT8491IUKJ#PBF é adequado para 7 aplicaçãos: Solar-Powered Lead-Acid Charger, Industrial 24V/48V Battery Backup, LiFePO4 Starter Battery Charger, Remote Solar Telemetry Station, Portable Medical Cart Charger, Robotic Lawn Mower / Garden Robot, e-Bike / Light EV Solar Range Extender.
Solar-Powered Lead-Acid Charger
The LT8491IUKJ#PBF is purpose-built for off-grid solar lead-acid charging: its 6 V to 80 V input window directly accepts 12 V, 24 V, 36 V and 48 V PV panels without a pre-regulator, while the buck-boost topology maintains regulation when panel voltage sags below battery voltage under heavy load. Integrated MPPT sweeps the panel operating point to capture peak power as irradiance shifts, adding 20 to 30 percent more harvested energy compared with PWM controllers. The 10 A charge current supports battery banks up to several hundred watt-hours with a single IC. Place the QFN-EP exposed pad over a copper pour for thermal relief.
Recomendado
Industrial 24V/48V Battery Backup
In industrial battery backup plants, the LT8491IUKJ#PBF provides regulated float charge for 24 V and 48 V sealed lead-acid strings while accepting any DC source between 6 V and 80 V. Its CCCV profile is configurable for SLA, gel and flooded cells, and the I2C interface streams battery voltage, charge current and input voltage to a supervisory MCU for state-of-charge estimation. The 10 A output handles large battery banks used in substations, telecom shelters and SCADA cabinets. Synchronous buck-boost operation eliminates the inductor-saturation issues of boost-only chargers at high step-down ratios.
Recomendado
LiFePO4 Starter Battery Charger
The LT8491IUKJ#PBF charges LiFePO4 starter batteries used as drop-in replacements for lead-acid in powersports, light EVs and remote-engine applications. Its programmable float voltage (up to 80 V across stacked cells or single-cell packs) and accurate CCCV termination prevent the over-charge stress that degrades LiFePO4 cells. The buck-boost input range tolerates alternator voltage transients from 6 V cranking dips to 60 V load-dump spikes. I2C telemetry reports fault flags and charge status to the vehicle ECU over the same wiring harness.
Recomendado
Remote Solar Telemetry Station
Remote telemetry installations for weather stations, oil-field sensors and environmental monitors run on solar-charged batteries with no grid connection; the LT8491IUKJ#PBF provides the MPPT-controlled charge path that maximizes harvested energy from small panels. Its 80 V input ceiling allows 36 V panels to be used in series for lower-I2R wiring losses on long cable runs. The integrated I2C interface lets a low-power MCU read charge parameters without external ADCs, reducing standby draw. Wide -40 C to +125 C operation tolerates outdoor enclosures in arctic and desert sites.
Recomendado
Portable Medical Cart Charger
Portable medical carts equipped with sealed lead-acid or LiFePO4 traction batteries rely on the LT8491IUKJ#PBF to provide a wide-input, high-current charging path from any AC-DC adapter or vehicle supply. The 80 V input rating tolerates universal 24 V to 72 V medical-grade adapters without additional protection, while the 10 A output rapidly replenishes 50-100 Ah battery banks between shifts. I2C status pins drive a panel-mounted "charging/fault" indicator without extra glue logic. The QFN-EP package's thermal pad handles continuous 5-8 A charging without forced airflow.
Recomendado
Robotic Lawn Mower / Garden Robot
Battery-powered garden robots with photovoltaic-assisted docking stations use the LT8491IUKJ#PBF as the solar charging interface for their Li-Ion or LiFePO4 traction packs. The MPPT algorithm extracts extra run-time from small panels mounted on the dock, while the buck-boost topology accepts panel voltages lower than the battery at low light without a boost pre-regulator. The wide operating temperature range tolerates summer heat inside the charging dock. I2C telemetry over the dock connector reports battery status to the robot on landing.
Recomendado
e-Bike / Light EV Solar Range Extender
Solar range-extender panels mounted on e-bikes and light electric vehicles charge the on-board Li-Ion or LiFePO4 traction pack via the LT8491IUKJ#PBF. The 80 V input rating accepts open-voltage from series-connected panel strings that produce 30 V to 60 V at peak sun, while the buck-boost stage delivers charge current up to 10 A even when panel voltage drops below pack voltage during cloudy conditions. MPPT adds measurable daily range compared with direct-connect or PWM charging, especially valuable for delivery fleets that park outdoors. I2C interface reports charge progress to the vehicle display.
Recomendado
Resumo dos produtos recomendados
Dados de referência de engenharia para LT8491IUKJ#PBF — comparação, orientação de projeto e informações de conformidade.
Guia de seleção
Comparação com alternativas
| Parâmetro | Este produto | LT8491IUKJ | LT8491IUKJ#TRPBF | LT8491EUKJ#PBF | LT8491HUKJ#PBF |
|---|---|---|---|---|---|
| Brand | Analog Devices | Analog Devices | Analog Devices | Analog Devices | Analog Devices |
| Package | QFN-EP-64 (7x11 mm) | QFN-EP-64 (7x11 mm) - same | QFN-EP-64 (7x11 mm) - same | QFN-EP-64 (7x11 mm) - same | QFN-EP-64 (7x11 mm) - same |
| Input Voltage Range | Up to 80 V | Up to 80 V | Up to 80 V | Up to 80 V | Up to 80 V |
| Maximum Charge Current | 10 A | 10 A | 10 A | 10 A | 10 A |
| MPPT | Yes (on-chip) | Yes | Yes | Yes | Yes |
| I2C Interface | Yes | Yes | Yes | Yes | Yes |
| Junction Temperature Range | -40 C to +125 C (I grade) | -40 C to +125 C (I grade) | -40 C to +125 C (I grade) | 0 C to +125 C (E grade) | -40 C to +150 C (H grade) |
| RoHS / Lead-Free | Yes (#PBF finish) | No (SnPb finish) | Yes (#TRPBF finish) | Yes (#PBF finish) | Yes (#PBF finish) |
Principais diferenciais
- Integrated MPPT for photovoltaic sources (vs LT8491IUKJ (non-#PBF finish variant))
- Wide 80 V input range for 48 V solar panels (vs LT8491EUKJ#PBF (extended temperature variant))
- High-temperature H variant for harsh environments (vs LT8491IUKJ#PBF (industrial I grade))
- Tape-and-reel packaging variant for SMT (vs LT8491IUKJ#PBF (tray packaging))
Notas de projeto
Estimated: at 10 A continuous charge current with 60 V input and 48 V battery, the LT8491's switching stage dissipates approximately (60 V - 48 V) x 10 A x 0.9 efficiency = 13 W in the external MOSFETs, plus another 2-3 W in the inductor and sense resistor. The QFN-EP-64 package requires a continuous copper pour on the top layer of at least 25 x 11 mm connected to the exposed thermal pad, with thermal vias to inner ground planes. For ambient temperatures above 60 C, design the copper area for less than 20 C/W junction-to-ambient to keep Tj below 125 C.
Layout the SW1 and SW2 loops with minimum area - keep the high-side and low-side MOSFET drains/sources connections within a few mm of the IC pins to limit switching-node ringing. Place the input bulk capacitor and the input ceramic bypass capacitors directly at the VIN pin. Route the SENSE+ and SENSE- traces as a differential pair with Kelvin connection to the sense resistor, avoiding the SW1/SW2 switching nodes to prevent current-sense corruption. The exposed thermal pad must be soldered to a continuous ground pour with at least 25 thermal vias (0.3 mm drill, 0.5 mm pitch).
Do not force voltage on the VC pin (datasheet Note 2). Avoid applying negative voltages on SW1 and SW2 below one diode drop of ground; rely on the body diodes of the external N-FETs M2/M3 or parallel Schottky diodes to clamp the negative swing. Program RT for a switching frequency between 100 kHz and 500 kHz - higher frequencies reduce inductor size but increase switching losses. Verify I2C address selection via the ADR pin before bringing up the bus; pull SDA and SCL high with 4.7 kohm pull-ups. Read FAULT/CHRG latches after every I2C transaction to capture transient protection events.
Informações de conformidade
The #PBF suffix indicates lead-free, RoHS-compliant terminal finish per Analog Devices ordering information. AEC-Q100 automotive qualification status not confirmed in available data; consult Analog Devices for HUKJ automotive-grade variants if required. REACH, conflict minerals and halogen-free status not published in distributor listings.
