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Texas Instruments BQ2018TS-E1
- Part No.:
- BQ2018TS-E1
- Manufacturer:
- Texas Instruments
- Category:
- Battery Management
- Package:
- 8-TSSOP (0.173", 4.40mm Width)
- Datasheet:
-
BQ2018TS-E1.pdf
- Description:
- IC BAT MON MULT-CHEM 1-4C 8TSSOP
- Quantity:
- Payment:
- Shipping:
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Product details
Overview
BQ2018TS-E1 from Texas Instruments is a multifunction charge/discharge counter IC for rechargeable battery state-of-charge (SoC) monitoring. It measures voltage drop across a sense resistor with 12.5µV resolution, integrates internal temperature sensing for self-discharge estimation, and provides 1024-bit NVRAM (128 × 8) for capacity and status storage. It operates in battery packs with NiCd/NiMH or Li-ion chemistries.
For engineers reviewing the BQ2018TS-E1 datasheet, BQ2018TS-E1 pinout, BQ2018TS-E1 application, or BQ2018TS-E1 equivalent, key selection considerations include its single-wire HDQ interface, <80µA operating current, ±200mV differential sense range, REG output for microregulated supply, and 8-pin TSSOP package optimized for compact battery pack integration.
Technical Context
The BQ2018TS-E1 implements a dynamically balanced voltage-to-frequency converter (VFC) architecture to integrate charge/discharge current over time using SR1/SR2 differential inputs. Its precision oscillator (±3.0% accuracy) and internal bandgap reference enable stable timing without external components.
It features dual-mode operation-normal mode (<80µA) and sleep mode (<10µA)-triggered by HDQ state and |VSRO| vs. programmable WOE threshold. The internal temperature sensor (±2°C typical at 25°C) scales self-discharge count rate exponentially (×2 per +10°C above 25°C), and the OFR register stores an 8-bit two's complement offset value for calibration against system-level VOS up to ±500µV.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Resolution | 12.5µV per hour - enables precise coulomb counting for sub-mAh battery capacity tracking |
| Sense Range | ±200mV differential - supports low-value sense resistors (e.g., 10–50mΩ) without signal conditioning |
| Operating Current | <80µA - minimizes parasitic drain during active SoC monitoring in always-on battery systems |
| Sleep Current | <10µA - extends shelf life during storage while preserving NVRAM via RBI backup (<100nA) |
| NVRAM Size | 1024 bits (128 × 8) - stores capacity data, serial number, chemistry ID, and user-defined parameters |
| Temperature Sensor | 8-step 10°C resolution (0–60°C), ±2°C typical accuracy - enables temperature-compensated self-discharge modeling |
| Interface | Single-wire HDQ (open-drain) - reduces pack wiring to one signal plus ground, compatible with simple microcontroller GPIO |
| REG Output | 3.7V nominal (±200mV) - drives external n-JFET for low-cost regulated VCC from unregulated battery input |
Pinout & Package
Package: 8-pin TSSOP (TS suffix) - surface-mount, 3.0mm × 4.4mm footprint, 0.65mm pitch, suitable for A-size cell crevices or prismatic pack width constraints.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| REG | Regulator output | Drives external n-JFET gate to generate stable 3.7V supply; eliminates need for dedicated LDO in cost-sensitive battery packs |
| VCC | Supply voltage input | Accepts 2.8–5.5V (direct battery) or 3.7V ±200mV (REG-derived); powers all internal circuitry including VFC and RAM |
| VSS | Ground reference | Common return for all analog and digital functions; must be low-impedance connection to pack ground |
| HDQ | Data I/O | Single-wire asynchronous serial interface (open-drain); requires external pull-up; handles command/data exchange and sleep/wake control |
| WAKE | Wake-up output | Open-drain indicator asserting low when |VSRO| exceeds programmable WOE threshold - signals host to resume SoC polling |
| SR1 / SR2 | Differential current sense inputs | Measure voltage drop across series sense resistor; polarity determines charge (SR1 > SR2) vs. discharge (SR1 < SR2) counting direction |
| RBI | Register backup input | Provides <100nA backup power to retain NVRAM contents when VCC drops below 2.4V (e.g., deep discharge or short-circuit) |
Key Features
| Feature | Design Value |
|---|---|
| Internal offset calibration | Stores 8-bit two's complement offset (OFR) to cancel up to ±500µV VOS, enabling high-resolution current measurement without external trimming |
| Self-discharge estimation | Uses integrated temperature sensor to scale SCR count rate (1 count/hour @25°C, ×2 per +10°C), supporting accurate SoC hold-time prediction |
| Dual operating modes | Switches autonomously between <80µA active mode and <10µA sleep mode based on HDQ state and current activity, minimizing standby drain |
| Single-wire HDQ interface | Reduces interconnect to one signal line plus ground - simplifies battery pack wiring, lowers connector cost, and improves mechanical reliability |
| REG output for microregulation | Provides 3.7V reference to drive external JFET, enabling ultra-low-quiescent-current regulation from raw battery voltage without discrete LDO |
Applications
| Smart Power Tools | Medical Portable Devices |
|---|---|
Use Scenario: Cordless drill/driver battery packs require real-time SoC reporting to prevent unexpected shutdown mid-operation and support fuel-gauge UI. IC Role / Device Role / Timing Role: BQ2018TS-E1 acts as coulomb counter and self-discharge estimator, interfacing with host MCU via HDQ to deliver accumulated DCR/CCR/SCR values. Use Value: Enables accurate runtime prediction (±5% typical) and safe low-voltage cutoff by resolving 12.5µV/h sense signals and compensating for temperature-dependent self-discharge. | Use Scenario: Battery-powered infusion pumps and portable monitors must maintain SoC accuracy over long shelf life and variable ambient temperatures. IC Role / Device Role / Timing Role: BQ2018TS-E1 serves as autonomous battery monitor, using internal temperature sensor and SCR to adjust self-discharge model during storage and clinical use. Use Value: Extends usable shelf life by 30–50% through temperature-compensated SoC hold-time estimation and retains critical NVRAM data via RBI during deep discharge events. |
| Consumer Electronics Battery Packs | Industrial Handheld Scanners |
Use Scenario: Rechargeable battery modules for cordless headphones, Bluetooth speakers, and wearables demand minimal footprint and ultra-low power consumption. IC Role / Device Role / Timing Role: BQ2018TS-E1 functions as compact SoC peripheral in 8-pin TSSOP, communicating via HDQ to host controller while drawing <10µA in sleep mode. Use Value: Fits within tight mechanical constraints (e.g., between AA cells), reduces BOM cost via REG-driven JFET regulation, and preserves battery capacity with sub-10µA quiescent current. | Use Scenario: Rugged handheld scanners used in warehouses and logistics require reliable SoC tracking across wide temperature ranges (-20°C to +70°C). IC Role / Device Role / Timing Role: BQ2018TS-E1 provides temperature-aware charge/discharge accounting, with TMP/CLR register reporting 8-step thermal zones and scaling SCR accordingly. Use Value: Maintains SoC accuracy within ±3% over -20°C to +60°C by doubling SCR count rate every 10°C above 25°C and halving it below, ensuring consistent runtime estimates in varying environments. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar charge/discharge counter applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| BQ2019TS-E1 | Same pinout and core functionality; adds EEPROM write-protection bit and enhanced WAKE debounce logic | Preferred for new designs requiring improved data integrity in high-noise industrial environments | Select BQ2019TS-E1 if firmware-level EEPROM lockout and robust wake signaling are required; otherwise BQ2018TS-E1 remains optimal for cost-sensitive, high-volume consumer packs |
| MAX1660EAP+ | Different interface (I²C), higher quiescent current (120µA), no internal temperature sensor or self-discharge compensation | Suitable for simpler SoC applications where temperature drift is negligible and host has I²C available | Choose MAX1660EAP+ only when existing platform uses I²C and thermal compensation is handled externally; BQ2018TS-E1 offers superior integration and lower power for standalone battery monitoring |
Compared with BQ2019TS-E1 and MAX1660EAP+, the BQ2018TS-E1 delivers the lowest system-level BOM cost and smallest footprint for basic coulomb counting, with unique advantages in temperature-compensated self-discharge modeling and sub-10µA sleep current - making it ideal for consumer and medical battery packs prioritizing size, power, and thermal accuracy.
Availability
BQ2018TS-E1 is available at Aetrix Electronics and suitable for smart power tools, medical portable devices, consumer electronics battery packs, and industrial handheld scanners requiring stable component supply and long-term lifecycle support.
Supply support for BQ2018TS-E1 includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.
Manufacturer
Texas Instruments is a global semiconductor company specializing in analog and embedded processing technologies, with leadership in battery management, power conversion, and signal chain solutions.
The BQ2018TS-E1 belongs to TI's Power Minder™ family of battery fuel-gauge ICs, designed specifically for low-cost, high-accuracy state-of-charge monitoring in rechargeable battery packs using NiCd, NiMH, or Li-ion chemistries.
FAQ
What is the primary function of the BQ2018TS-E1 in a battery management system?
The BQ2018TS-E1 is a dedicated coulomb-counting fuel-gauge IC that measures charge and discharge current via differential sense inputs (SR1/SR2), accumulates counts in 16-bit registers (DCR/CCR), and estimates self-discharge using its internal temperature sensor. It does not manage charging or protection; instead, it provides SoC data to an external host controller via the HDQ interface. The BQ2018TS-E1 enables accurate runtime prediction and battery health tracking in compact, low-power battery packs.
How does the BQ2018TS-E1 achieve high measurement resolution despite low supply current?
The BQ2018TS-E1 achieves 12.5µV resolution through a precision differential amplifier front-end and a dynamically balanced voltage-to-frequency converter (VFC) architecture, which integrates small voltage signals over time rather than relying on high-speed ADC sampling. Its internal bandgap reference and temperature-compensated oscillator ensure stability at <80µA operating current. This design allows the BQ2018TS-E1 to resolve minute sense voltages without increasing power consumption - a key advantage over conventional current-sense amplifiers in battery-constrained applications.
Can the BQ2018TS-E1 operate without an external regulator?
Yes, the BQ2018TS-E1 can operate directly from 2.8V to 5.5V battery sources (e.g., 3–4 NiCd/NiMH cells or 1 Li-ion cell). Its REG pin is optional: when unused, VCC is supplied directly from the battery. When enabled, REG drives an external n-JFET to create a low-cost, micro-power 3.7V regulated supply - useful when battery voltage varies widely or noise sensitivity demands cleaner VCC. The BQ2018TS-E1 functions identically in both configurations, with no performance trade-off.
What role does the RBI pin play during battery deep discharge or short-circuit conditions?
The RBI (Register Backup Input) pin maintains the contents of the BQ2018TS-E1's 1024-bit NVRAM when VCC falls below 2.4V - such as during battery short-circuit, deep discharge, or removal from the host system. Connected to a storage capacitor or auxiliary cell, RBI supplies <100nA to preserve critical data (capacity, cycle count, chemistry ID) across extended periods. This ensures SoC history and calibration values remain intact, allowing the BQ2018TS-E1 to resume accurate tracking immediately upon re-powering - a vital capability for mission-critical battery applications.
How does the BQ2018TS-E1 handle temperature variations in self-discharge estimation?
The BQ2018TS-E1 uses its integrated temperature sensor (±2°C typical accuracy) to dynamically scale the self-discharge count register (SCR) rate: 1 count/hour at 20–30°C, doubling every +10°C up to 60°C (reaching 16 counts/hour), and halving every −10°C down to 0°C (as low as 1 count/8 hours). This exponential scaling, mapped to 8 discrete thermal steps in the TMP/CLR register, allows the BQ2018TS-E1 to model realistic battery shelf-life degradation without external computation - delivering accurate SoC hold-time estimates across environmental conditions.
BQ2018TS-E1 Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Texas Instruments
- Series:
- Power Minder™
- Package/Case:
- 8-TSSOP (0.173", 4.40mm Width)
- Packaging:
- Tube
- Product Status:
- Active
- Function:
- Battery Monitor
- Battery Chemistry:
- Multi-Chemistry
- Number of Cells:
- 1 ~ 4
- Fault Protection:
- -
- Interface:
- HDQ
- Operating Temperature:
- -20°C ~ 70°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 8-TSSOP
BQ2018TS-E1 FAQ
1.How can I place an order for BQ2018TS-E1 through Aetrix?
Please submit a Request for Quotation (RFQ) for BQ2018TS-E1 on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for BQ2018TS-E1 reliable?
The price and inventory of BQ2018TS-E1 are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for BQ2018TS-E1 is usually 5 days.
3.What payment methods are accepted for BQ2018TS-E1?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for BQ2018TS-E1 transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for BQ2018TS-E1?
BQ2018TS-E1 orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your BQ2018TS-E1 order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for BQ2018TS-E1?
For technical support, including BQ2018TS-E1 datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your BQ2018TS-E1 requirements.
6.How does Aetrix verify that BQ2018TS-E1 is sourced from the original manufacturer or authorized distributors?
All BQ2018TS-E1 products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that BQ2018TS-E1 meets industry standards.
7.What is the process for return or replacement of BQ2018TS-E1?
All BQ2018TS-E1 units undergo pre-shipment inspection (PSI). If there is an issue with BQ2018TS-E1, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The BQ2018TS-E1 part is unused and in its original packaging.
Return procedure for BQ2018TS-E1:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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