BQ35100

Part: BQ35100 (BQ35100PW) — Texas Instruments

Type: Lithium Primary Battery Fuel Gauge and End-of-Service Monitor

Description: Fuel gauge and end-of-service monitor for Li-SOCl2 and Li-MnO2 primary batteries with a 2.7–4.5 V supply, I²C interface and average current as low as ~0.06 μA (SOH mode, update every 8 hours).

Operating Conditions:

• Supply voltage (VREGIN): 2.7–4.5 V with no operating restrictions; 2.45–2.7 V with no flash writes
• Operating temperature: -40 to 85 °C
• I²C communication at up to 400 kHz
• LDO output capacitor (CLDO25): 0.47 μF min, 1 μF nominal

Absolute Maximum Ratings:

• VREGIN regulator input: -0.3 to 5.5 V
• VREG25 supply: -0.3 to 2.75 V
• Open-drain I/O (SDA, SCL, VEN): -0.3 to 5.5 V; ALERT: -0.3 to 2.75 V
• BAT input: -0.3 to 5.5 V
• SRN, SRP, TS inputs: -0.3 to VREG25 + 0.3 V
• Storage temperature: -65 to 150 °C
• ESD HBM: ±1500 V (BAT pin), ±2000 V (all other pins); CDM ±500 V

Key Specs:

• Average current, GE low (disabled): 0.05 μA typ
• Average current, ACC mode (update every 30 min): 0.3 μA typ
• Average current, SOH mode (update every 8 h): 0.06 μA typ
• Average current, EOS mode (update every 8 h, 3-s load pulse): 0.35 μA typ
• Active current: ACCU 130 μA, SOH 40 μA, EOS burst 315 μA, EOS gather 75 μA (typ, GE high)
• LDO output (VREG25): 2.5 V typ (2.3–2.7 V) for 2.7 V ≤ VREGIN ≤ 4.5 V, IOUT ≤ 16 mA; short-circuit limit 250 mA max
• Coulomb counter: input range ±0.125 V, 14–15 bit resolution, 1 s conversion, 10 μV typ offset, INL ±0.007% FSR
• Power-on reset threshold: 2.20 V typ (2.05–2.31 V), 115 mV hysteresis
• Internal temperature sensor gain: -2 mV/°C typ
• GE input: VIL max 0.8 V, VIH min 2.65 V (VREGIN = 2.8–4.5 V)

Features:

• Fuel gauge and battery diagnostics that predict end-of-service or early battery failure
• Supports Li-SOCl2 and Li-MnO2 chemistries
• State-of-health (SOH) algorithm for Li-MnO2
• End-of-service (EOS) algorithm for Li-SOCl2
• Coulomb accumulation (ACC) algorithm for all battery types
• Gauge enabled through host-controlled periodic updates via the GE pin
• I²C host communication with configurable ALERT interrupt
• Battery information data logging for diagnostics and failure analysis
• SHA-1 authentication to help prevent counterfeit battery use
• Internal 2.5 V LDO, voltage, current and temperature measurement

Applications:

• Smart meters and flow meters
• Door access control
• Smoke and gas leak detectors
• Building automation
• IoT sensor nodes
• Asset tracking

Package:

• TSSOP-14 (PW), 5.00 mm × 4.40 mm

• 1 · Fuel gauge and battery diagnostics for flow meter applications predict end-of-service or early battery failure
• -Supports lithium thionyl chloride (Li-SOCl2) and lithium manganese dioxide (Li-MnO2) chemistry batteries
• -Accurate voltage, temperature, current, and coulomb counter measurements that report battery health and service life
• -State-of-health (SOH) algorithm for Li-MnO2
• -End-of-service (EOS algorithm for Li-SOCl2)
• -Coulomb accumulation (ACC) algorithm for all battery types
• Ultra-low average power consumption to maximize battery run time
• -Gauge enabled through host-controlled periodic updates
• -State-of-health (SOH) ~0.06 μA
• -End-of-service (EOS) ~0.35 μA
• -Coulomb accumulation (ACC) diagnostic updates ~0.3 μA
• System interaction capabilities
• -I 2 C host communication, providing battery parameter and status access
• -Configurable host interrupt
• -Battery information data logging options for in operation diagnostics and failure analysis
• -SHA-1 authentication to help prevent counterfeit battery use

• Used in primary battery systems and suitable for dynamic load and large ambient temperature change applications
• -Smart meters and flow meters
• -Door access control
• -Smoke and gas leak detectors
• -Building automation
• -IoT, including sensor nodes
• -Asset tracking
• Battery status reporting and diagnostics with early failure detection for flow meter systems
• Extends battery runtime with accurate battery gauging for smoke detector, sensor node, and asset tracker applications

1

Over-operating free-air temperature range (unless otherwise noted) (1)

TA =-40°C to 85°C; Typical Values at TA = 25°C CLDO25 = 1.0 μ F, and VREGIN = 3.6 V (unless otherwise noted)

The BQ35100 device is a highly configurable device with many options. The major configuration choices comprise the battery chemistry and control methods.