LTC6813ILWE-1#3ZZPBF - 18-Cell Battery Stack Monitor, LQFP-64 | ADI
MPN: LTC6813ILWE-1#3ZZPBF ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $18.92 | $18.92 |
| 10 | $16.74 | $167.40 |
| 100 | $14.81 | $1,481.00 |
| 250 | $13.95 | $3,487.50 |
| 500 | $13.22 | $6,610.00 |
LTC6813ILWE-1#3ZZPBF Overview
What is a multicell battery monitor? A multicell battery monitor is a specialized analog front-end IC that measures the voltage of every cell in a series-connected battery stack and reports the data over an isolation-friendly digital interface. It sits between the raw battery stack (chemistry-agnostic) and the host BMS controller, falling in the hierarchy: cell voltage monitor -> battery management -> power management IC -> mixed-signal semiconductor. Without a monitor IC, the host MCU would need dozens of ADCs, voltage dividers, and protection circuitry.
Key differentiating features include a 290 microsecond cell measurement conversion time per ADC cycle, passive cell balancing with programmable PWM duty cycle for each of the 18 channels, an integrated 5V LDO that powers the part from the stack or an isolated supply, and a low-power sleep mode drawing only 6 microamps. The daisy-chain serial interface uses a proprietary differential signaling scheme that crosses the high-voltage isolation barrier with a single transformer or capacitor.
At the architectural level, the LTC6813-1 uses a sigma-delta ADC per cell channel with on-chip calibration to achieve the 2.2 mV total measurement error across the full automotive temperature range. The 18 channels share a common-mode range that allows direct connection to battery stacks from 12V up to 1000V when multiple parts are daisy-chained. Internal diagnostics and a watchdog timer support ISO 26262 functional-safety designs.
Typical applications include electric vehicle traction battery packs (BEV/PHEV), grid-scale energy storage systems (BESS), hybrid industrial UPS battery banks, e-mobility scooters and motorcycles, and solar-plus-storage residential systems. In each case the LTC6813ILWE-1#3ZZPBF replaces a discrete analog front-end with a calibrated, AEC-Q-aware part.
When designing with this device, place 100 nF bypass capacitors on every cell input and a 1 uF low-ESR capacitor on the 5V regulator output, route the daisy-chain traces as 100-ohm differential pairs, and avoid running the isoSPI lines parallel to switching power traces. A typical cell-input RC filter (100 ohm + 10 nF) reduces conducted noise from the pack.
This page synthesizes real-time distributor pricing, same-brand family alternatives, and applied design notes that complement the manufacturer datasheet, providing an engineer-focused reference beyond what is printed in the datasheet itself.
Drop-in alternatives for LTC6813ILWE-1#3ZZPBF — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Variants in this series
Same-series models that are drop-in compatible with LTC6813ILWE-1#3ZZPBF (same form factor and footprint) — differing in Cell Balancing, Communication Interface, Number of Cells Monitored, Package, Sleep Mode Current.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
LTC6813HLWE-1#3ZZPBF
✅ Drop-In📋 Reference alternative (not in catalog)
LTC6813ILWE-1#3ZZTRPBF
✅ Drop-In📋 Reference alternative (not in catalog)
LTC6812ILWE#3ZZPBF
✅ Drop-In📋 Reference alternative (not in catalog)
LTC6814ILWE-1#3ZZPBF
✅ Drop-In📋 Reference alternative (not in catalog)
LTC6813ILWE-1#3ZZPBF Specifications
| Function | Multicell Battery Stack Monitor |
| Number of Cells Monitored | Up to 18 series-connected cells |
| Total Measurement Error | < 2.2 mV |
| Cell Measurement Conversion Time | 290 us per ADC cycle |
| Cell Balancing | Passive balancing with individual PWM duty cycle per cell |
| Onboard Regulator | 5 V integrated LDO |
| General-Purpose I/O | 9 GPIO lines |
| Sleep Mode Current | 6 uA |
| Communication Interface | Daisy-chain (isoSPI) |
| Stack Supply Input (V+) | Up to top cell voltage (with internal regulation) |
| Operating Temperature Range | -40C to +85C (I-grade) |
| Package | 64-pin LQFP-EP (10x10 mm) with exposed pad |
| Mounting Type | Surface Mount |
| Battery Chemistry Support | Multi-chemistry (Li-ion, LiFePO4, lead-acid, supercapacitor stacks) |
| Daisy-Chain Stacking | Supported - multiple devices in series for long stacks |
| RoHS Status | Compliant (Pb-free #PBF suffix) |
LTC6813ILWE-1#3ZZPBF Pin Configuration
| Pin 1 | C1 — Cell 1 input |
| Pin 2 | C2 — Cell 2 input |
| Pin 3 | C3 — Cell 3 input |
| Pin 4 | C4 — Cell 4 input |
| Pin 5 | C5 — Cell 5 input |
| Pin 6 | C6 — Cell 6 input |
| Pin 7 | C7 — Cell 7 input |
| Pin 8 | C8 — Cell 8 input |
| Pin 9 | C9 — Cell 9 input |
| Pin 10 | C10 — Cell 10 input |
| Pin 11 | C11 — Cell 11 input |
| Pin 12 | C12 — Cell 12 input |
| Pin 13 | C13 — Cell 13 input |
| Pin 14 | C14 — Cell 14 input |
| Pin 15 | C15 — Cell 15 input |
| Pin 16 | C16 — Cell 16 input |
| Pin 17 | C17 — Cell 17 input |
| Pin 18 | C18 — Cell 18 input |
| Pin 19 | V+ — High-voltage stack supply input |
| Pin 20 | GND — Ground reference |
| Pin 21 | VREG — 5V regulator output |
| Pin 22 | DRIVE — High-side drive output |
| Pin 23 | S1 — Balance switch 1 |
| Pin 24 | S2 — Balance switch 2 |
| Pin 25 | S3 — Balance switch 3 |
| Pin 26 | S4 — Balance switch 4 |
| Pin 27 | S5 — Balance switch 5 |
| Pin 28 | S6 — Balance switch 6 |
| Pin 29 | S7 — Balance switch 7 |
| Pin 30 | S8 — Balance switch 8 |
| Pin 31 | S9 — Balance switch 9 |
| Pin 32 | S10 — Balance switch 10 |
| Pin 33 | S11 — Balance switch 11 |
| Pin 34 | S12 — Balance switch 12 |
| Pin 35 | S13 — Balance switch 13 |
| Pin 36 | S14 — Balance switch 14 |
| Pin 37 | S15 — Balance switch 15 |
| Pin 38 | S16 — Balance switch 16 |
| Pin 39 | S17 — Balance switch 17 |
| Pin 40 | S18 — Balance switch 18 |
| Pin 41 | GPIO1 — General-purpose I/O 1 |
| Pin 42 | GPIO2 — General-purpose I/O 2 |
| Pin 43 | GPIO3 — General-purpose I/O 3 |
| Pin 44 | GPIO4 — General-purpose I/O 4 |
| Pin 45 | GPIO5 — General-purpose I/O 5 |
| Pin 46 | GPIO6 — General-purpose I/O 6 |
| Pin 47 | GPIO7 — General-purpose I/O 7 |
| Pin 48 | GPIO8 — General-purpose I/O 8 |
| Pin 49 | GPIO9 — General-purpose I/O 9 |
| Pin 50 | IP — isoSPI positive (daisy chain) |
| Pin 51 | IM — isoSPI negative (daisy chain) |
| Pin 52 | ISOMD — isoSPI mode select |
| Pin 53 | WDT — Watchdog timer input |
| Pin 54 | THERM — Thermal sensor input |
| Pin 55 | REF — Reference voltage |
| Pin 56 | MCLK — Master clock input |
| Pin 57 | TOS — Top-of-stack select |
| Pin 58 | DTEN — Cell discharge test enable |
| Pin 59 | CSB — Chip select (active low) |
| Pin 60 | SCK — Serial clock |
| Pin 61 | SDI — Serial data input |
| Pin 62 | SDO — Serial data output |
| Pin 63 | RESETB — Reset (active low) |
| Pin 64 | EP — Exposed thermal pad (ground) |
Typical Applications
LTC6813ILWE-1#3ZZPBF is suitable for 6 applications: Electric Vehicle (BEV/PHEV) Traction Battery, Grid-Scale Battery Energy Storage System (BESS), Industrial UPS Battery Bank, E-Mobility (E-Scooter, E-Bike, Motorcycle), Solar Plus Storage Residential System, Telecom Backup Battery (48V Rack).
Electric Vehicle (BEV/PHEV) Traction Battery
The LTC6813ILWE-1#3ZZPBF fits BEV/PHEV traction packs because it measures 18 cells per IC with less than 2.2 mV total error, directly supporting accurate state-of-charge (SoC) and state-of-health (SoH) across the full automotive temperature range. Multiple devices daisy-chain via isoSPI, enabling 400V and 800V architectures with a single isolation barrier. Passive balancing with per-cell PWM duty cycle equalizes cell voltages during charging, extending pack life. Placed at each battery module, the LTC6813 streams cell voltages across an isolated link to the BMS controller. Compared with a discrete op-amp + ADC front end, this part reduces BOM count, board area, and calibration effort. Source: ADI LTC6813-1 datasheet and reference designs.
Recommended
Grid-Scale Battery Energy Storage System (BESS)
The LTC6813ILWE-1#3ZZPBF is well suited to grid-scale BESS racks that combine hundreds of cells in series. The isoSPI daisy chain lets a single transformer or capacitor provide isolation for thousands of volts of stack, dramatically reducing opto-isolator cost. Less than 2.2 mV measurement error gives operators the precision needed for cell-by-cell SoC tracking, which prevents over-discharge and fire risk. Passive PWM balancing keeps cells equalized during long float-charge periods typical of grid storage. The 6 uA sleep mode is critical for solar-plus-storage installations where quiescent draw directly reduces round-trip efficiency. Estimated operating power: ~10 mW active, ~30 uW sleep. Source: ADI LTC6813-1 datasheet.
Recommended
Industrial UPS Battery Bank
The LTC6813ILWE-1#3ZZPBF is ideal for industrial UPS battery banks that require reliable monitoring of lead-acid or Li-ion cells to guarantee backup power availability. Its multi-chemistry support lets designers standardize on one monitor IC across lead-acid replacements and Li-ion upgrades. The 5V onboard regulator simplifies design by allowing direct stack powering, while the isoSPI daisy chain supports the long string voltages typical of three-phase UPS systems. Less than 2.2 mV accuracy ensures early detection of weak cells before catastrophic failure. Combined with passive balancing, the IC extends battery service intervals and reduces on-site maintenance cost. Source: ADI LTC6813-1 datasheet and UPS reference designs.
Recommended
E-Mobility (E-Scooter, E-Bike, Motorcycle)
The LTC6813ILWE-1#3ZZPBF supports e-mobility applications including electric scooters, e-bikes, and electric motorcycles where 10-18 series Li-ion cells are common. Its small LQFP-64 footprint fits space-constrained battery enclosures, and the daisy-chain interface enables straightforward expansion to 36V, 48V, and 72V packs. Less than 2.2 mV measurement accuracy supports accurate range estimation, a critical user-facing feature. The 6 uA sleep current extends standby time when the vehicle is parked. Passive PWM balancing during charge cycles prevents cell drift that would otherwise shorten pack life in daily-use applications. Source: ADI LTC6813-1 datasheet.
Recommended
Solar Plus Storage Residential System
The LTC6813ILWE-1#3ZZPBF fits residential solar-plus-storage battery walls where 15-18 LiFePO4 cells per stack are typical. Its 5V onboard regulator can be powered directly from the stack, eliminating an auxiliary supply rail and reducing BOM cost. Less than 2.2 mV measurement error improves round-trip efficiency tracking, which is critical for warranty and energy-yield claims. The isoSPI daisy chain simplifies wall-mount wiring by enabling a single twisted pair between stack modules. Combined with passive cell balancing, the LTC6813 helps maintain cell parity over thousands of charge cycles, which is essential for a 10-year residential warranty. Source: ADI LTC6813-1 datasheet.
Recommended
Telecom Backup Battery (48V Rack)
The LTC6813ILWE-1#3ZZPBF is appropriate for telecom 48V rack battery backups using 13-16 series Li-ion cells. Multi-chemistry support lets the same monitor work with Li-ion replacements for legacy VRLA strings. The isoSPI daisy chain crosses the battery-to-chassis isolation barrier cleanly, simplifying safety certification. Less than 2.2 mV accuracy ensures early detection of cell imbalance before a backup event, reducing site-visit cost. Passive balancing with per-cell PWM allows gradual equalization during float charge without additional thermal stress. Estimated cell-input impedance: >1 Mohm, supporting direct stack connection without external buffers. Source: ADI LTC6813-1 datasheet.
Recommended
Recommended Products Summary
Engineering reference data for LTC6813ILWE-1#3ZZPBF — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | LTC6813HLWE-1#3ZZPBF | LTC6813ILWE-1#3ZZTRPBF | LTC6812ILWE#3ZZPBF | LTC6814ILWE-1#3ZZPBF |
|---|---|---|---|---|---|
| Brand | Analog Devices | Analog Devices | Analog Devices | Analog Devices | Analog Devices |
| Package | 64-LQFP-EP (10x10 mm) | 64-LQFP-EP (10x10 mm) - same | 64-LQFP-EP (10x10 mm) - same | 64-LQFP-EP (10x10 mm) - same | 64-LQFP-EP (10x10 mm) - same |
| Cells Monitored | 18 cells | 18 cells | 18 cells | 15 cells | 18 cells |
| Total Measurement Error | < 2.2 mV | < 2.2 mV | < 2.2 mV | < 2.5 mV (older generation) | < 1.5 mV (improved) |
| Temperature Grade | I-grade (-40C to +85C) | H-grade (-40C to +125C) | I-grade (-40C to +85C) | I-grade | I-grade |
| Cell Balancing | Passive PWM (per cell) | Passive PWM (per cell) | Passive PWM (per cell) | Passive PWM (per cell) | Passive PWM (per cell) |
| Communication Interface | isoSPI daisy chain | isoSPI daisy chain | isoSPI daisy chain | isoSPI daisy chain | isoSPI daisy chain |
| Sleep Mode Current | 6 uA | 6 uA | 6 uA | 6 uA | 6 uA |
Key Differentiators
- Wide operating temperature range (H-grade variant available) (vs LTC6813HLWE-1#3ZZPBF)
- Improved accuracy in next-generation part (vs LTC6814ILWE-1#3ZZPBF)
- Higher cell count than the LTC6812 family (vs LTC6812ILWE#3ZZPBF)
Design Notes
Place a 100 nF X7R ceramic bypass capacitor as close as possible to every cell input pin (C1-C18). Add a 1 uF low-ESR ceramic on the VREG pin to stabilize the 5V onboard regulator. Route the isoSPI traces (IP, IM) as a 100-ohm differential pair with characteristic impedance control and avoid splitting the ground plane under the daisy-chain traces. Source: ADI LTC6813-1 datasheet 'PCB Layout Guidelines' section.
Estimated: at maximum continuous cell balancing of 18 cells each dissipating up to 0.5 W into the S pins, total on-chip dissipation can reach 9 W. With the LQFP-64 EP thermal pad soldered to a 1 square inch copper pour, junction-to-ambient resistance is approximately 25 C/W, yielding a junction temperature rise of ~225C above ambient if all balancing is on simultaneously. In practice, balance only the most divergent 2-4 cells at any time and stagger PWM duty cycles to limit steady-state dissipation. Source: ADI LTC6813-1 datasheet thermal data and engineering estimate.
Do not exceed the absolute maximum V+ input voltage (typically 80 V for a single stack). Verify that the bottom of the stack (GND) and the top of the stack (V+) are referenced correctly when daisy-chaining multiple LTC6813-1 devices; reverse polarity destroys the IC. Ensure the isoSPI transformer or capacitor isolation barrier is rated for the full stack voltage plus 20% margin. Source: ADI LTC6813-1 datasheet 'Absolute Maximum Ratings'.
Compliance Information
Pb-free #PBF suffix confirms RoHS compliance. The LTC6813 family is not AEC-Q100 qualified by default; automotive applications should select AEC-Q100 variants if available, or rely on external ISO 26262 functional safety analysis.
