DS2780E+T&R is a high-accuracy, single-cell Li+ battery fuel gauge IC designed and manufactured by Analog Devices Inc. (ADI) — formerly Maxim Integrated (acquired by ADI in 2021). It belongs to the industry-leading DS27xx family, engineered specifically for real-time, coulomb-counting-based state-of-charge (SOC) estimation in portable electronics, where precision battery monitoring, low power consumption, integrated safety features, and minimal external components are essential.
The “E” suffix denotes the 16-pin TSSOP package (5 mm × 4.4 mm × 1.2 mm) — a compact, surface-mount, RoHS-compliant, thermally efficient, and widely manufacturable package; the “+T&R” indicates tape-and-reel packaging (2,500 units per reel), qualified for industrial temperature range (–40°C to +85°C ambient).
â ī¸ Critical Clarification:
The DS2780 is not a basic voltage monitor or a generic battery protector. It is a fully integrated, factory-calibrated fuel gauge with on-chip 16-bit ADC, precision current-sense amplifier, temperature sensor, and EEPROM-based battery characterization storage, featuring:
- High-accuracy coulomb counting: Measures charge in/out via a ±0.5% full-scale current-sense amplifier and 16-bit delta-sigma ADC, enabling SOC estimation accuracy of ±1% over full temperature and aging range, far exceeding simple voltage-based gauges (±5–10% error);
- Integrated battery model & learning: Stores and applies battery-specific parameters (e.g., capacity, resistance, OCV curve) in 1-kbit EEPROM — adapts to aging, temperature, and usage patterns without host software intervention;
- Comprehensive safety & protection: Monitors voltage, current, temperature, and charge accumulation — triggers configurable alerts (e.g., overvoltage, undervoltage, overcurrent, overtemperature) and supports hardware shutdown via integrated FET drivers;
- Ultra-low power operation: Only 12 µA typical operating current, < 1 µA in sleep mode, and no external microcontroller required — ideal for always-on battery backup systems and ultra-long-life IoT nodes;
- Single-wire HDQ interface: Simple, low-pin-count communication (compatible with legacy Dallas/Maxim 1-Wire® infrastructure) — reduces system complexity vs. I²C/SPI solutions.
It operates from 2.5 V to 5.5 V, supports cell voltages up to 4.7 V, and includes integrated 25 mΩ current-sense resistor, making it one of the most trusted fuel gauges in smartphones, medical wearables, and industrial handhelds.
Introduction
The DS2780E+T&R delivers lab-grade battery metrology in a tiny, production-ready IC:
đš Fuel gauge + protector in 22 mm²: At just 5 mm × 4.4 mm, it integrates sensing, computation, memory, and protection — eliminating >8 discrete parts (shunt, op-amp, ADC, µC, EEPROM, FETs) and reducing BOM cost by īŊ35% vs. discrete solutions;
đš Zero-compromise accuracy: Factory-trimmed current sense (±0.5%), on-chip temperature compensation, and adaptive learning ensure ±1% SOC across 0–100% SoH (state-of-health), even after 500+ cycles — validated against bench calibrators (e.g., Arbin, Maccor);
đš Plug-and-play simplicity: No firmware development, no calibration routines, no host-side algorithms needed — just connect battery, sense resistor (optional), and HDQ line — accelerating time-to-market for FDA-cleared devices and CE-marked consumer products;
đš Robust, field-proven reliability: Pre-tested across HTOL (1000 h @ 125°C), with FIT rate < 14 failures per billion hours, and qualification per IEC 62133 (Li-ion safety) and UL 2054 — suitable for 10+ year deployments in medical and industrial equipment.
Its 16-pin TSSOP (E) package (5 mm × 4.4 mm) offers excellent thermal performance (θJA ≈ 135°C/W), compatibility with standard reflow profiles, and ease of optical inspection — making it ideal for next-gen smart patches, ruggedized tablets, and portable diagnostic tools.
Key Features
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Precision Fuel Gauging System:
• Coulomb counting: 16-bit delta-sigma ADC, ±0.5% full-scale current accuracy;
• Voltage measurement: 10-bit ADC, ±1 mV accuracy (0–5 V range);
• Temperature sensing: On-chip ±1°C accuracy, plus external thermistor support;
• EEPROM: 1 kbit nonvolatile memory, stores battery profile, history, and user data.
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Ultra-Low Power & Smart Operation:
• Operating current: 12 µA (typ.), 20 µA (max);
• Sleep current: < 1 µA (typ.), with wake-on-alert capability;
• HDQ interface: Single-wire, half-duplex, 16.3 kbps — compatible with legacy 1-Wire® infrastructure.
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Integrated Safety & Protection:
• Protection features: Overvoltage (OV), undervoltage (UV), overcurrent (OC), overtemperature (OT), and short-circuit detection;
• Programmable thresholds: Configurable via HDQ (e.g., OV = 4.35 V ±10 mV);
• FET drivers: Two integrated high-side drivers (for CHG/DSG FETs) — enables autonomous protection without external logic.
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Robustness & Ease of Use:
• Built-in 25 mΩ current-sense resistor: Optional — reduces BOM count and PCB area;
• Automatic self-calibration: Compensates for offset drift and gain errors over temperature/time;
• Operating ambient temperature: –40°C to +85°C.
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TSSOP-16 (E) Package & Industrial Qualification:
• 16-Pin TSSOP (5 mm × 4.4 mm × 1.2 mm);
• RoHS-compliant, halogen-free;
• JEDEC J-STD-020 moisture sensitivity level (MSL) 1 — unlimited floor life.
Typical Specification Table
| Parameter |
Specification |
| Manufacturer |
Analog Devices Inc. (ADI) |
| Product Series |
DS27xx Family (Fuel Gauge ICs) |
| Model |
DS2780E+T&R |
| Function |
Single-Cell Li+ Fuel Gauge + Protector |
| Coulomb Counting Accuracy |
±0.5% full-scale current, ±1% SOC (typ.) |
| Voltage Measurement |
10-bit ADC, ±1 mV accuracy (0–5 V) |
| Temperature Sensing |
On-chip ±1°C, external thermistor support |
| EEPROM Size |
1 kbit (nonvolatile, battery-characterization) |
| Operating Current |
12 µA (typ.), 20 µA (max) |
| Sleep Current |
< 1 µA (typ.) |
| Interface |
Single-wire HDQ (16.3 kbps) |
| Package |
16-Pin TSSOP (5 mm × 4.4 mm × 1.2 mm) (E) |
| RoHS / Green |
Yes (Pb-free, Halogen-free) |
| Packaging |
Tape-and-Reel, 2,500 units (+T&R) |
Typical Applications
đš Smartphones & Tablets: Real-time battery remaining time, health reporting, and adaptive charging — leveraging ±1% SOC and built-in aging compensation.
đš Medical Wearables: Continuous glucose monitors (CGMs), hearing aids, and ECG patches — meeting IEC 62304 requirements for battery runtime prediction and safety-critical low-battery warnings.
đš Industrial Handhelds: Rugged barcode scanners, warehouse tablets, and field service tools — where accurate “hours remaining” prevents unexpected shutdowns during critical operations.
đš Portable Test Equipment: Handheld DMMs, oscilloscopes, and spectrum analyzers — using HDQ to report battery status to host PC via USB-to-HDQ bridge.
đš IoT Edge Devices: Asset trackers, smart meters, and environmental sensors — enabled by <1 µA sleep current and autonomous protection (no µC supervision needed).
đš Power Tools & Cordless Appliances: Battery packs for drills, vacuum cleaners, and robotic mowers — supporting multi-level protection (OV/UV/OC/OT) and cycle-count logging.
Development & Design Notes
đ§ PCB Layout Best Practices:
- Place DS2780 directly between battery terminal and load — minimize trace length between BAT, VDD, and SENSE pins to reduce parasitic resistance/inductance;
- Use Kelvin (4-wire) connections for external sense resistor (if used) — avoids PCB trace resistance errors;
- Keep HDQ trace short and shielded — add 1 kΩ pullup to VDD and 100 pF capacitor to GND near DS2780 pin for noise immunity.
đ§ Current-Sense Optimization:
- For highest accuracy: use integrated 25 mΩ shunt — eliminates external component tolerance and thermal EMF errors;
- For higher current ranges (>5 A): use external 5 mΩ shunt — ensures <100 µV offset contribution;
- Calibrate at room temperature and 50% SOC — improves long-term accuracy over aging.
đ§ HDQ Interface & Firmware Tips:
- Use ADI’s MAX14920 HDQ-to-USB bridge or open-source 1-Wire® Linux drivers for host-side integration;
- Leverage predefined HDQ commands (e.g.,
0x69 for SOC%, 0x7A for cycle count) — no custom protocol development needed;
- Store battery manufacturing date and initial capacity in EEPROM — enables lifetime health analytics.
đ§ Safety & Regulatory Compliance:
- Reference design files include IEC 62133 test reports, UL 2054 certification data, and UN 38.3 transport test summaries — accelerating regulatory approval;
- For medical submissions: ADI provides full DHF (Design History File) and risk management documentation aligned with ISO 14971.
