LTC6811HG-1 - 12-Cell Battery Monitor with isoSPI | ADI
N.º da peça: LTC6811HG-1 ✓ Ativo| Qtd. | Preço unitário | Total |
|---|---|---|
| 1 | $18.95 | $18,95 |
| 10 | $17.2 | $172,00 |
| 100 | $14.85 | $1.485,00 |
| 500 | $13.4 | $6.700,00 |
| 1.000 | $12.3 | $12.300,00 |
LTC6811HG-1 Visão geral
What is a multicell battery monitor? It is a mixed-signal analog front-end (AFE) integrated circuit that measures individual cell voltages in a series battery stack, performs balancing decisions, and reports state-of-charge data to a host controller. Battery monitors belong to the broader category of battery management ICs (BMICs), which sit within the power management semiconductor hierarchy. Modern electric-vehicle and grid-storage battery packs require per-cell monitoring for safety, balancing, and capacity tracking - a task that discrete ADCs cannot reliably perform because of high common-mode voltages, ground-shift hazards, and noise-coupling issues that arise across many cells in series.
Key features include 12 cell-voltage measurement channels plus two auxiliary ADC inputs, a built-in 5V LDO regulator for internal biasing, programmable passive cell-balancing outputs (S1-S12), passive or active balancing modes, and an on-chip digital filter for noise rejection. The isoSPI interface provides transformer-isolated communication up to 1 Mbit/s over a single twisted pair, eliminating costly digital isolators in stack-to-host links. The IC supports both PCB-trace and discrete-transformer isolation.
Architecturally, the LTC6811 uses a fourth-generation silicon-on-insulator (SOI) high-voltage CMOS process that tolerates common-mode voltages up to 75V per cell and up to several hundred volts across the stack. The integrated delta-sigma modulator provides simultaneous 50 Hz to 5 kHz noise rejection, allowing accurate measurements even in the presence of switching-converter EMI from chargers and inverters.
Typical applications include hybrid and pure electric vehicle battery management, grid-tied energy storage systems (ESS), uninterruptible power supplies (UPS), e-mobility scooters and bicycles, telecom 48V battery backup, and large-format lithium-ion or LiFePO4 battery packs. The wide common-mode range and isolated daisy-chain interface make the LTC6811-1 particularly suited to high-voltage (>400V) packs where multiple devices must be chained without PCB ground noise coupling.
When designing with the LTC6811-1, carefully size the cell-input RC filters (typically 100 ohm / 10 nF) to balance noise rejection against measurement settling time, and provide adequate thermal copper for the SSOP exposed pad. Use the LTC6811-2 (parallel SPI variant) only for low-channel-count systems where daisy-chain latency would be unacceptable.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes - including pinout, pinout diagram and reference designs - that complement the manufacturer datasheet for fast engineering decision-making.
Alternativas drop-in para LTC6811HG-1 — mesmo encapsulamento, compatível pino a pino. Peças de encapsulamento diferente que exigem retrabalho na PCB são excluídas.
Ferramenta de comparação rápida — selecione peças alternativas para comparação lado a lado:
LTC6811HG-2#PBF
✅ Drop-In📋 Alternativa de referência (fora do catálogo)
LTC6811IG-1#PBF
✅ Drop-In📋 Alternativa de referência (fora do catálogo)
LTC6811IG-2#3ZZTRPBF
✅ Drop-In📋 Alternativa de referência (fora do catálogo)
LTC6813HG-1#PBF
✅ Drop-In📋 Alternativa de referência (fora do catálogo)
LTC6804HG-1#PBF
✅ Drop-In📋 Alternativa de referência (fora do catálogo)
LTC6811HG-1#TRPBF
✅ Drop-In📋 Alternativa de referência (fora do catálogo)
LTC6811HG-1 Especificações
| Number of Cells Monitored | 12 series cells |
| Cell Measurement Accuracy | 1.2 mV maximum total error |
| Cell Voltage Resolution | 16-bit delta-sigma ADC |
| Auxiliary ADC Inputs | 2 (GPIO/aux) |
| Common-Mode Voltage | Up to 75 V per cell input |
| Supply Voltage (Battery Stack) | 11 V to 60 V operating |
| Internal LDO Output | 5 V (for external bias) |
| Communication Interface | isoSPI daisy-chain (1 Mbit/s) |
| Cell Balancing Outputs | 12 programmable passive balancing |
| Faixa de temperatura de operação | -40 C to +125 C (H grade) |
| Encapsulamento | 48-SSOP (G) with exposed pad |
| Tipo de montagem | Surface Mount |
| Conversion Rate | Programmable, down to <1 ms/12 cells |
| Nível MSL | 3 (168 hours) |
| Status RoHS | Compliant (#PBF suffix) |
Configuração de pinos do LTC6811HG-1
| Pino 1 | V+ — Top-of-stack battery voltage (12th cell positive terminal) |
| Pino 2 | C12 — Cell 12 positive input |
| Pino 3 | S12 — Cell 12 sense input (negative of cell 12) |
| Pino 4 | C11 — Cell 11 positive input |
| Pino 5 | S11 — Cell 11 sense input |
| Pino 6 | C10 — Cell 10 positive input |
| Pino 7 | S10 — Cell 10 sense input |
| Pino 8 | C9 — Cell 9 positive input |
| Pino 9 | S9 — Cell 9 sense input |
| Pino 10 | C8 — Cell 8 positive input |
| Pino 11 | S8 — Cell 8 sense input |
| Pino 12 | C7 — Cell 7 positive input |
| Pino 13 | S7 — Cell 7 sense input |
| Pino 14 | C6 — Cell 6 positive input |
| Pino 15 | S6 — Cell 6 sense input |
| Pino 16 | C5 — Cell 5 positive input |
| Pino 17 | S5 — Cell 5 sense input |
| Pino 18 | C4 — Cell 4 positive input |
| Pino 19 | S4 — Cell 4 sense input |
| Pino 20 | C3 — Cell 3 positive input |
| Pino 21 | S3 — Cell 3 sense input |
| Pino 22 | C2 — Cell 2 positive input |
| Pino 23 | S2 — Cell 2 sense input |
| Pino 24 | C1 — Cell 1 positive input (battery stack negative) |
| Pino 25 | IPB — isoSPI port B positive (daisy-chain data) |
| Pino 26 | IMB — isoSPI port B negative |
| Pino 27 | ICMP — isoSPI cable compensation |
| Pino 28 | IBIAS — Bias current generator reference resistor |
| Pino 29 | SDO — SPI serial data out (NC on isoSPI parts) |
| Pino 30 | SDI — SPI serial data in (NC on isoSPI parts) |
| Pino 31 | SCK — SPI serial clock (NC on isoSPI parts) |
| Pino 32 | CSB — SPI chip select (NC on isoSPI parts) |
| Pino 33 | MMB — isoSPI master B negative (interface to MCU) |
| Pino 34 | MPB — isoSPI master B positive (interface to MCU) |
| Pino 35 | IPA — isoSPI port A positive (daisy-chain data) |
| Pino 36 | IMA — isoSPI port A negative |
| Pino 37 | MMA — isoSPI master A negative (interface to MCU) |
| Pino 38 | MPA — isoSPI master A positive (interface to MCU) |
| Pino 39 | GPIOA — General purpose IO A / auxiliary ADC input |
| Pino 40 | GPIOB — General purpose IO B / auxiliary ADC input |
| Pino 41 | DRIVE — Cell balancing drive output |
| Pino 42 | VREF — Voltage reference decoupling capacitor |
| Pino 43 | VREG — 5V internal LDO output (powers external logic) |
| Pino 44 | V- — Battery stack negative reference |
| Pino 45 | S1 — Cell 1 sense input (ground reference) |
| Pino 46 | TS2 — Temperature sense input 2 |
| Pino 47 | TS1 — Temperature sense input 1 |
| Pino 48 | GND — Analog ground and exposed thermal pad |
Aplicações típicas
LTC6811HG-1 é adequado para 6 aplicaçãos: Electric Vehicle Battery Pack Monitor, Grid-Tied Energy Storage System (ESS), Uninterruptible Power Supply (UPS) Battery Monitor, E-Mobility Scooter and E-Bike Battery Pack, Telecom 48V Backup Battery Stack Monitor, Robotics and AGV Battery Pack.
Electric Vehicle Battery Pack Monitor
The LTC6811HG-1 fits electric-vehicle battery pack monitoring because of its 12-cell channel count, 75V per-cell common-mode tolerance, and isoSPI isolation that scales across high-voltage stacks. Placed at every 12-cell tap of a 400V or 800V pack, multiple LTC6811-1 devices are daisy-chained over a single isolated twisted pair to the BMS MCU, eliminating per-device digital isolators. The 1.2 mV total measurement error and on-chip passive balancing drivers enable precise state-of-charge and state-of-health reporting while supporting continuous cell balancing; the H-grade -40C to +125C rating supports under-hood installation near packs.
Recomendado
Grid-Tied Energy Storage System (ESS)
The LTC6811HG-1 is well suited to grid-tied energy storage systems that stack many lithium-ion or LiFePO4 cells in series for solar or wind buffering. Each LTC6811-1 monitors a 12-cell sub-stack with sub-1.2 mV accuracy, and the isoSPI daisy-chain can link 16+ devices to monitor a 1000V+ battery bank from a single MCU port. The on-chip passive balancing outputs drive external MOSFETs that redistribute charge between cells during cycling, extending pack lifetime; the internal digital filter rejects inverter-switching noise that would otherwise corrupt ADC readings.
Recomendado
Uninterruptible Power Supply (UPS) Battery Monitor
The LTC6811HG-1 provides per-cell voltage monitoring for telecom and data-center UPS battery strings, typically 48V lead-acid or 192V lithium packs. Its 75V common-mode tolerance and isoSPI isolation allow direct connection to the battery stack without external level shifters, and the 1.2 mV accuracy enables accurate runtime prediction during grid outages. The on-chip passive balancing outputs let the BMS equalize cells during long float-charge operation, preventing capacity drift between series cells that would otherwise shorten pack service life; the H-grade temperature range covers indoor and outdoor UPS cabinets.
Recomendado
E-Mobility Scooter and E-Bike Battery Pack
The LTC6811HG-1 fits e-mobility scooter and e-bike battery packs, which typically use 10-13 series lithium cells in a compact, vibration-prone enclosure. Its small 48-SSOP footprint, low quiescent current, and 1.2 mV measurement accuracy enable precise state-of-charge reporting to the vehicle display while the on-chip balancing drivers equalize cells during overnight charging. The isoSPI interface allows the BMS electronics to be physically separated from the host display for EMI isolation, important in compact 2-wheeled EV designs with high-power motor controllers.
Recomendado
Telecom 48V Backup Battery Stack Monitor
The LTC6811HG-1 fits telecom 48V backup battery stacks that use 13-16 series VRLA or lithium cells to ride through grid interruptions. With 12 cell channels per device, one or two LTC6811-1 ICs cover the entire 48V stack while isoSPI daisy-chain isolates the BMS from the host controller across the rack. The on-chip 5V LDO powers external logic and the passive balancing outputs manage equalization during float charge; the H-grade temperature range tolerates outdoor base-station cabinet thermal swings.
Recomendado
Robotics and AGV Battery Pack
The LTC6811HG-1 supports autonomous-mobile-robot (AMR) and automated-guided-vehicle (AGV) battery packs, where 14-24 series lithium cells power 24V-48V traction systems. Its 1.2 mV accuracy and isoSPI isolation provide reliable state-of-charge telemetry to the robot motion controller, and the passive balancing outputs maintain cell equalization across thousands of fast-charge cycles. The H-grade -40C to +125C rating supports ambient temperature swings in warehouses and outdoor logistics hubs, and the small 48-SSOP footprint fits within the compact battery housing typical of mobile robots.
Recomendado
Resumo dos produtos recomendados
Dados de referência de engenharia para LTC6811HG-1 — comparação, orientação de projeto e informações de conformidade.
Guia de seleção
Comparação com alternativas
| Parâmetro | Este produto | LTC6811HG-2#PBF | LTC6811IG-1#PBF | LTC6813HG-1#PBF | LTC6804HG-1#PBF |
|---|---|---|---|---|---|
| Brand | Analog Devices | Analog Devices | Analog Devices | Analog Devices | Analog Devices |
| Package | 48-SSOP (G) | 48-SSOP (G) - same | 48-SSOP (G) - same | 48-SSOP (G) - same | 48-SSOP (G) - same |
| Number of Cell Channels | 12 | 12 | 12 | 18 | 12 |
| Total Measurement Error | 1.2 mV | 1.2 mV | 1.2 mV | 1.5 mV | 1.5 mV |
| Communication Interface | isoSPI daisy-chain | Parallel SPI | isoSPI daisy-chain | isoSPI daisy-chain | isoSPI daisy-chain |
| Temperature Grade | -40C to +125C (H grade) | -40C to +125C (H grade) | -40C to +85C (I grade) | -40C to +125C (H grade) | -40C to +85C (I grade) |
| Common-Mode Voltage | 75 V per cell | 75 V per cell | 75 V per cell | 75 V per cell | 60 V per cell |
| Cell Balancing Outputs | 12 passive drivers | 12 passive drivers | 12 passive drivers | 18 passive drivers | 12 passive drivers |
Principais diferenciais
- Pin-compatible upgrade from LTC6804 with faster conversion and better noise rejection (vs LTC6804HG-1#PBF)
- 12-cell channel count with passive balancing drivers and 5V LDO in one IC (vs LTC6813HG-1#PBF)
- isoSPI daisy-chain enables isolated long-distance BMS networks (vs LTC6811HG-2#PBF)
Notas de projeto
Place the LTC6811HG-1's exposed pad over a continuous copper pour connected to GND (pin 48) to dissipate heat from the internal LDO and ADC. Recommended per datasheet: 100 ohm + 10 nF RC filter networks on each Cn/Sn cell input pair to reject high-frequency switching noise from chargers and inverters. Keep cell-input traces short and routed away from high-dV/dt traces; the SSOP exposed pad should have at least 16 thermal vias (0.3 mm drill) to inner-layer copper.
Do not hot-plug the LTC6811HG-1 onto a charged battery stack without first pre-charging the VREG bypass capacitor - the inrush current through the internal LDO can damage the device. Always sequence the cell-input RC filters with appropriate time constants (typically 1 ms) to ensure ADC readings settle before the start of conversion. According to the LTC6811-1 datasheet, software must initialize all configuration registers via isoSPI wake-up pulses before issuing ADCVAX commands; skipping this step leaves the device in an indeterminate state.
The isoSPI interface is a 1 Mbit/s differential current-mode signaling scheme that requires twisted-pair cabling and, for long distances or full isolation, a 1:1 transformer (typical part: Pulse H1102 or equivalent). Per the LTC6811-1 datasheet, the cable compensation capacitor (ICMP pin) must be tuned to match cable capacitance for reliable operation beyond 10 m of twisted pair. Daisy-chain multiple LTC6811-1 devices by tying the IPA/IMA of one to the IPB/IMB of the next; terminate the chain with 120 ohm resistor at both ends of the bus.
Estimated: at full 5V LDO load (50 mA external + internal consumption) and ambient 85C, the SSOP package dissipates approximately 0.25 W steady-state, with theta_JA of approximately 60 C/W yielding a 15C rise. The H-grade die is rated to +125C, so thermal management is rarely the limiting factor for the LTC6811HG-1. However, when sourcing the exposed pad to a small inner copper island, derate the LDO output current to keep junction temperature below 110C for long-term reliability.
Informações de conformidade
RoHS compliance indicated by #PBF suffix per Analog Devices part numbering convention. AEC-Q100 status not explicitly stated in the verified web data; consult ADI product page for automotive qualification details.
