LTC6811HG-1 - 12-Cell Battery Monitor with isoSPI | ADI
MPN: LTC6811HG-1 ✓ Hoạt độngLTC6811HG-1 Tóm tắt
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.
Bộ thay thế dễ dàng lắp đặt cho LTC6811HG-1 — cùng gói, chân-to-chân tương thích. Các bộ phận yêu cầu hàn PCB bị loại trừ.
LTC6811HG-2#PBF
✅ Drop-In📋 Tham chiếu thay thế (không có trong danh mục)
LTC6811IG-1#PBF
✅ Drop-In📋 Tham chiếu thay thế (không có trong danh mục)
LTC6811IG-2#3ZZTRPBF
✅ Drop-In📋 Tham chiếu thay thế (không có trong danh mục)
LTC6813HG-1#PBF
✅ Drop-In📋 Tham chiếu thay thế (không có trong danh mục)
LTC6804HG-1#PBF
✅ Drop-In📋 Tham chiếu thay thế (không có trong danh mục)
LTC6811HG-1#TRPBF
✅ Drop-In📋 Tham chiếu thay thế (không có trong danh mục)
LTC6811HG-1 Thông số kỹ thuật
| 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 |
| Khoảng nhiệt độ hoạt động | -40 C to +125 C (H grade) |
| Hộp | 48-SSOP (G) with exposed pad |
| Kiểu lắp đặt | Surface Mount |
| Conversion Rate | Programmable, down to <1 ms/12 cells |
| Cấp MSL | 3 (168 hours) |
| Trạng thái RoHS | Compliant (#PBF suffix) |
Cấu hình chân LTC6811HG-1
| Chân 1 | V+ — Top-of-stack battery voltage (12th cell positive terminal) |
| Chân 2 | C12 — Cell 12 positive input |
| Chân 3 | S12 — Cell 12 sense input (negative of cell 12) |
| Chân 4 | C11 — Cell 11 positive input |
| Chân 5 | S11 — Cell 11 sense input |
| Chân 6 | C10 — Cell 10 positive input |
| Chân 7 | S10 — Cell 10 sense input |
| Chân 8 | C9 — Cell 9 positive input |
| Chân 9 | S9 — Cell 9 sense input |
| Chân 10 | C8 — Cell 8 positive input |
| Chân 11 | S8 — Cell 8 sense input |
| Chân 12 | C7 — Cell 7 positive input |
| Chân 13 | S7 — Cell 7 sense input |
| Chân 14 | C6 — Cell 6 positive input |
| Chân 15 | S6 — Cell 6 sense input |
| Chân 16 | C5 — Cell 5 positive input |
| Chân 17 | S5 — Cell 5 sense input |
| Chân 18 | C4 — Cell 4 positive input |
| Chân 19 | S4 — Cell 4 sense input |
| Chân 20 | C3 — Cell 3 positive input |
| Chân 21 | S3 — Cell 3 sense input |
| Chân 22 | C2 — Cell 2 positive input |
| Chân 23 | S2 — Cell 2 sense input |
| Chân 24 | C1 — Cell 1 positive input (battery stack negative) |
| Chân 25 | IPB — isoSPI port B positive (daisy-chain data) |
| Chân 26 | IMB — isoSPI port B negative |
| Chân 27 | ICMP — isoSPI cable compensation |
| Chân 28 | IBIAS — Bias current generator reference resistor |
| Chân 29 | SDO — SPI serial data out (NC on isoSPI parts) |
| Chân 30 | SDI — SPI serial data in (NC on isoSPI parts) |
| Chân 31 | SCK — SPI serial clock (NC on isoSPI parts) |
| Chân 32 | CSB — SPI chip select (NC on isoSPI parts) |
| Chân 33 | MMB — isoSPI master B negative (interface to MCU) |
| Chân 34 | MPB — isoSPI master B positive (interface to MCU) |
| Chân 35 | IPA — isoSPI port A positive (daisy-chain data) |
| Chân 36 | IMA — isoSPI port A negative |
| Chân 37 | MMA — isoSPI master A negative (interface to MCU) |
| Chân 38 | MPA — isoSPI master A positive (interface to MCU) |
| Chân 39 | GPIOA — General purpose IO A / auxiliary ADC input |
| Chân 40 | GPIOB — General purpose IO B / auxiliary ADC input |
| Chân 41 | DRIVE — Cell balancing drive output |
| Chân 42 | VREF — Voltage reference decoupling capacitor |
| Chân 43 | VREG — 5V internal LDO output (powers external logic) |
| Chân 44 | V- — Battery stack negative reference |
| Chân 45 | S1 — Cell 1 sense input (ground reference) |
| Chân 46 | TS2 — Temperature sense input 2 |
| Chân 47 | TS1 — Temperature sense input 1 |
| Chân 48 | GND — Analog ground and exposed thermal pad |
Ứng dụng tiêu biểu
LTC6811HG-1 phù hợp cho 6 Áp dụngs: 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.
Được đề xuất
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.
Được đề xuất
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.
Được đề xuất
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.
Được đề xuất
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.
Được đề xuất
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.
Được đề xuất
Tóm tắt các sản phẩm được đề xuất
Dữ liệu tham khảo kỹ thuật cho LTC6811HG-1 — so sánh, hướng dẫn thiết kế và thông tin tuân thủ.
Hướng dẫn chọn lựa
So sánh với các sản phẩm thay thế
| Tham số | Sản phẩm này | 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 |
Bảo phân biệt quan trọng
- Pin-compatible upgrade from LTC6804 with faster conversion and better noise rejection (vsLTC6804HG-1#PBF)
- 12-cell channel count with passive balancing drivers and 5V LDO in one IC (vsLTC6813HG-1#PBF)
- isoSPI daisy-chain enables isolated long-distance BMS networks (vsLTC6811HG-2#PBF)
Ghi chú thiết kế
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.
Thông tin tuân thủ
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.
