LTC4100EG - Smart Battery Charger Controller | Analog Devices
MPN： LTC4100EG ✓ 啟用中LTC4100EG 概覽
A smart battery charger controller is an integrated circuit that manages charging of rechargeable battery packs compliant with the Smart Battery System (SBS) specification. It communicates with the battery and/or host over the System Management Bus (SMBus) to negotiate charging voltage, current, and safety parameters. These controllers sit within the battery management IC (BMIC) hierarchy and belong to the broader power management semiconductor category. By handling SMBus protocol, safety signal monitoring, and host-programmable charge profiles, an SBC eliminates the discrete circuitry that older charger designs required.
The LTC4100EG implements a 100% compliant SMBus interface per SBS Rev. 1.1, supporting programmable charge current and voltage from either the battery or the host system. An integrated SafetySignal monitor checks battery temperature, pack connectivity, and battery type before allowing charge initiation. The device also includes an SMBus accelerator to improve timing margin on long or heavily loaded buses, making it robust in real-world notebook and portable equipment implementations.
Architecturally, the LTC4100EG uses a current-mode PWM controller with an external switching element to deliver up to 4 A of programmable charge current. The device supports 1-series-cell configurations and operates across an industrial temperature range of -40 °C to +85 °C. It is offered as the LTC4100EG#PBF (Pb-free tube) and LTC4100EG#TRPBF (Pb-free tape and reel) variants, both in the same 24-SSOP footprint for drop-in PCB compatibility.
Typical applications include notebook computer battery chargers, portable medical instruments, handheld test equipment, and industrial portable devices that use SMBus-compliant battery packs. Its SMBus Level 2 functionality makes it well-suited to designs where the battery pack broadcasts its own charging requirements to the charger without host intervention.
When designing with the LTC4100EG, follow the datasheet reference design for input bulk capacitance, inductor selection, and current-sense resistor layout. The 28 V absolute maximum input and 4 A charge current require careful thermal management in the SSOP footprint - copper pour and adequate airflow are essential at full load.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the standalone manufacturer datasheet.
直接替換替代品，適用於 LTC4100EG — 相同封裝，腳位對腳位相容。需重新設計 PCB 的不同封裝零件不列入。
此系列的變體
與下列產品可直接替換的同系列型號： LTC4100EG （相同外形與佔位） — 差異在於 Operating Temperature, Battery Chemistry, Charger Topology, Interface, Maximum Charge Current.
LTC4100EG#PBF
✅ 直接替換聯絡詢價
查看資料表 →LTC4100EG#TRPBF
✅ 直接替換聯絡詢價
查看資料表 →LTC4100EG 規格
| 功能 | Smart Battery Charger Controller |
| Battery Chemistry | Smart Batteries (SBS-compliant Li-Ion, Li-Polymer, NiCd, NiMH) |
| Number of Series Cells | 1 |
| Input Voltage (max) | 28 V |
| Battery Charge Voltage (max) | 12 V |
| Charge Current (max) | 4 A |
| 封裝 / 外殼 | 24-SSOP (0.209" / 5.30 mm width) |
| 腳位數 | 24 |
| 工作溫度 | -40 °C to +85 °C |
| 介面 | SMBus (SBS Rev. 1.1 compliant) |
| SMBus Accelerator | Yes (improves timing margin) |
| 安裝類型 | Surface Mount |
| Packaging | Tube (#PBF) / Tape & Reel (#TRPBF) |
| Lead Free | Yes (PBF suffix) |
| RoHS 狀態 | Compliant |
| Charger Topology | Current-mode PWM with external switch |
LTC4100EG 腳位配置
| 腳位 1 | SCL — SMBus clock input |
| 腳位 2 | SDA — SMBus data I/O |
| 腳位 3 | INT — Interrupt output to host |
| 腳位 4 | SMBUSACC — SMBus accelerator control |
| 腳位 5 | SAFE — SafetySignal input from battery |
| 腳位 6 | THERM — Thermistor sense input |
| 腳位 7 | GND — Ground |
| 腳位 8 | CSP — Current sense positive input |
| 腳位 9 | CSN — Current sense negative input |
| 腳位 10 | BAT — Battery voltage feedback |
| 腳位 11 | VFB — Voltage loop feedback |
| 腳位 12 | IFB — Current loop feedback |
| 腳位 13 | PROG — Program pin for charge profile |
| 腳位 14 | REF — Internal reference output |
| 腳位 15 | COMP — Compensation node for control loop |
| 腳位 16 | RT — Timing resistor for oscillator |
| 腳位 17 | CT — Timing capacitor for oscillator |
| 腳位 18 | DRV — Gate drive output to external MOSFET |
| 腳位 19 | VCC — Supply voltage for internal circuits |
| 腳位 20 | VIN — Input voltage sense |
| 腳位 21 | ACPR — AC adapter present input |
| 腳位 22 | CHGEN — Charge enable input |
| 腳位 23 | STAT — Charger status output |
| 腳位 24 | NC — Not connected (per datasheet) |
典型應用
LTC4100EG 適用於 6 應用s: Notebook Computer Battery Charger, Portable Medical Instrument Charger, Industrial Portable Test Equipment, Two-Way Radio / Handheld Communication Device, Cordless Power Tool Charging Base, Backup Battery System for Networking Equipment.
Notebook Computer Battery Charger
The LTC4100EG is purpose-built for SMBus-compliant Li-Ion and Li-Polymer battery packs used in notebook computers, where the Smart Battery broadcasts its own charging requirements. The 28 V input and 4 A programmable charge current support the typical 2-3 cell Li-Ion packs (up to 12.6 V) used in slim notebook designs. SMBus Rev. 1.1 Level 2 compliance means the charger can operate with or without the system EC, and the integrated SMBus accelerator preserves timing margin on the long internal bus. In this application the LTC4100EG typically sits between the notebook's 19 V adapter rail and the battery pack, with the EC querying battery status over the SMBus lines. Compared to discrete charger designs, the LTC4100EG cuts BOM count by 20-30 components while delivering SBS-compliant safety behavior.
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Portable Medical Instrument Charger
Battery-powered medical devices such as infusion pumps and patient monitors depend on SBS-compliant battery packs for predictable runtime reporting. The LTC4100EG's SafetySignal input monitors battery temperature and pack presence, providing the redundant protection layer required for medical-grade portable equipment. The -40 °C to +85 °C operating range covers clinical and field-use environments, and the 4 A charge current supports mid-capacity medical packs (typically 3-6 Ah) with reasonable charge times. SMBus communication allows the host processor to display real-time state-of-charge and remaining runtime on the device UI. The 24-SSOP package is straightforward to integrate onto a small charger board, and the integrated SMBus accelerator ensures robust communication even when the bus runs at the edge of the spec.
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Industrial Portable Test Equipment
Handheld test instruments - multimeters, oscilloscopes, calibration tools - typically use SMBus Li-Ion packs and need reliable Level 2 charging from 12-24 V input adapters. The LTC4100EG's 28 V input tolerance accommodates industrial 24 V supply rails with margin for transients, while the 4 A charge current supports rapid turnaround between field uses. The integrated SafetySignal monitoring protects against over-temperature conditions when chargers operate in hot industrial enclosures. The 24-SSOP footprint is suitable for the small charger PCBs common in handheld instruments, and the -40 °C to +85 °C range covers outdoor and factory-floor environments. Engineers can pair the LTC4100EG with the LT8606 or LT8640 for the input front-end and a coulomb counter such as the LTC2945 for accurate fuel gauging.
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Two-Way Radio / Handheld Communication Device
Professional two-way radios, handheld scanners, and field communication gear increasingly adopt SBS-compliant Li-Ion packs for standardized fuel-gauging across fleets. The LTC4100EG's SMBus Level 2 implementation lets the radio's host MCU query battery state-of-charge, cycle count, and manufacturer data directly through the standard Smart Battery commands. The 4 A charge current supports the 2-4 Ah packs common in this segment, delivering full charge in 1-2 hours. The SafetySignal input is particularly important in two-way radios where overheating during charging is a documented failure mode - the LTC4100EG will inhibit charge if the SafetySignal indicates an unsafe condition. The 24-SSOP package footprint is well-suited to the constrained PCB area inside a radio charger base or docking station.
推薦
Cordless Power Tool Charging Base
High-drain Li-Ion battery packs used in 18-20 V cordless power tools require chargers that can deliver multi-amp currents safely. The LTC4100EG's 4 A maximum charge current and 12 V charge voltage support 1-cell pack configurations with adequate margin, though for higher cell counts the LTC4100 family is often used in conjunction with cell-balancing front-ends. SMBus communication lets the tool and charger exchange cycle count, temperature, and cell health data, which is increasingly required for warranty tracking on professional-grade cordless tools. The 24-SSOP package can be integrated onto the charging base PCB alongside the AC-DC front-end. The -40 °C to +85 °C range covers garage and outdoor job-site environments, and the integrated SafetySignal monitor provides a hardware-level safety interlock that supplements any firmware-based protection.
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Backup Battery System for Networking Equipment
Small-cell base stations, network switches, and industrial routers increasingly use SBS-compliant Li-Ion backup battery modules to ride out mains interruptions. The LTC4100EG provides Level 2 SMBus charging for these compact 1-cell packs while accepting input voltages up to 28 V from the equipment's 24 V power rail. SMBus communication allows the network management processor to monitor battery health and schedule replacement, which is critical for unattended telecom installations. The 4 A charge current supports rapid recharge after extended outages, and the SafetySignal monitor provides hardware-level protection against battery faults that could compromise the equipment. The 24-SSOP footprint fits on the small charger sub-board typically found in compact network hardware.
推薦
推薦產品摘要
工程參考資料，適用於 LTC4100EG — 比較、設計指引及合規資訊。
選型指南
與替代品比較
| 參數 | 本產品 | LTC4100EG#PBF | LTC4100EG#TRPBF |
|---|---|---|---|
| Package | 24-SSOP (5.30 mm) | 24-SSOP (5.30 mm) - identical | 24-SSOP (5.30 mm) - identical |
| Brand | Analog Devices | Analog Devices | Analog Devices |
| Function | Smart Battery Charger Controller (SBS L2) | Smart Battery Charger Controller (SBS L2) - identical | Smart Battery Charger Controller (SBS L2) - identical |
| Charge Current (max) | 4 A | 4 A | 4 A |
| Input Voltage (max) | 28 V | 28 V | 28 V |
| Charge Voltage (max) | 12 V | 12 V | 12 V |
| Operating Temperature | -40 °C to +85 °C | -40 °C to +85 °C | -40 °C to +85 °C |
| Packaging | Tube (default base part) | Tube (Pb-free) | Tape & Reel (Pb-free) |
主要差異化特點
- SBS Rev. 1.1 Level 2 compliance with integrated SMBus accelerator (對比Discreet SMBus charger implementations using generic MCUs)
- Up to 4 A programmable charge current in a small SSOP-24 footprint (對比LTC4015 family (higher power but different package))
- Single 28 V-tolerant input covers 12 V, 19 V notebook, and 24 V industrial rails (對比Battery charger ICs limited to 16-20 V input)
設計說明
Estimated: At VIN = 19 V (notebook adapter), VBAT = 12.6 V, and 4 A continuous charge current, the external switching MOSFET dissipates approximately (19-12.6) * 4 = 25.6 W in worst-case linear-region operation, though the PWM topology significantly reduces average dissipation. Use a DPAK or D2PAK MOSFET with low Rds(on) and ensure 1 sq. inch of copper pour on the LTC4100EG SSOP thermal pad. The SSOP-24 package itself dissipates only gate-drive and control loss (typically <500 mW), so thermal management focuses on the external power stage.
Place the input bulk capacitor, current-sense resistor, inductor, and external MOSFET in a tight power loop to minimize switching noise. The SMBus SCL and SDA traces should be routed away from the DRV gate-drive trace and ACPR input to avoid coupling. Use a 4-layer PCB with a dedicated ground plane under the LTC4100EG to provide thermal spreading and a clean reference for the current-sense amplifier. Decouple VCC with a 1 µF ceramic placed within 5 mm of the pin.
Do not omit the SafetySignal (SAFE) thermistor network - the LTC4100EG will inhibit charging if the SAFE input is left floating or tied outside its valid window. The current-sense resistor must be a low-inductance type (Kelvin connection recommended) because the current-mode PWM relies on clean differential sensing. When migrating from LTC4100 to newer LTC4015 family, the SMBus register map differs - SMBus firmware on the host side will need rework, even though both parts support the SBS specification.
合規資訊
RoHS and REACH compliant per PBF suffix designation. Not AEC-Q100 qualified (industrial/consumer use only).
