8.3.17 1.8-V Low Dropout Regulator

The BQ28Z610-R1 AFE contains an integrated 1.8-V LDO that provides regulated supply voltage for the device

CPU and internal digital logic.

8.3.18 Internal Voltage References

The BQ28Z610-R1 AFE provides two internal voltage references with VREF1, used by the ADC and CC, while

VREF2 is used by the LDO, LFO, current wake comparator, and OCD/SCC/SCD1/SCD2 current protection

circuitry.

8.3.19 Overcurrent in Discharge Protection

The overcurrent in discharge (OCD) function detects abnormally high current in the discharge direction.

The overload in discharge threshold and delay time are configurable via the OCD_CONTROL register. The

thresholds and timing can be fine-tuned even further based on a sense resistor with lower resistance or wider

tolerance via the PROTECTION_CONTROL register. The detection circuit also incorporates a filtered delay

before disabling the CHG and DSG FETs. When an OCD event occurs, the LATCH_STATUS[OCD] bit is set to

1 and is latched until it is cleared and the fault condition has been removed.

8.3.20 Short-Circuit Current in Charge Protection

The short-circuit current in charge (SCC) function detects catastrophic current conditions in the charge direction.

The short-circuit in charge threshold and delay time are configurable via the SCC_CONTROL register. The

thresholds and timing can be fine-tuned even further based on a sense resistor with lower resistance or wider

tolerance via the PROTECTION_CONTROL register. The detection circuit also incorporates a blanking delay

before disabling the CHG and DSG FETs. When an SCC event occurs, the LATCH_STATUS[SCC] bit is set to 1

and is latched until it is cleared and the fault condition has been removed.

8.3.21 Short-Circuit Current in Discharge 1 and 2 Protection

The short-circuit current in discharge (SCD) function detects catastrophic current conditions in the discharge

direction. The short-circuit in discharge thresholds and delay times are configurable via the SCD1_CONTROL

and SCD2_CONTROL registers. The thresholds and timing can be fine-tuned even further based on a sense

resistor with lower resistance or wider tolerance via the PROTECTION_CONTROL register. The detection circuit

also incorporates a blanking delay before disabling the CHG and DSG FETs. When an SCD event occurs, the

LATCH_STATUS[SCD1] or LATCH_STATUS[SCD2] bit is set to 1 and is latched until it is cleared and the fault

condition has been removed.

8.3.22 Primary Protection Features

The BQ28Z610-R1 gas gauge supports the following battery and system level protection features, which can be

configured using firmware:

• Cell Undervoltage Protection

• Cell Overvoltage Protection

• Overcurrent in CHARGE Mode Protection

• Overcurrent in DISCHARGE Mode Protection

• Overload in DISCHARGE Mode Protection

• Short Circuit in CHARGE Mode Protection

• Overtemperature in CHARGE Mode Protection

• Overtemperature in DISCHARGE Mode Protection

• Precharge Timeout Protection

• Fast Charge Timeout Protection

8.3.23 Gas Gauging

This device uses the Impedance Track™ technology to measure and determine the available charge in battery

cells. The accuracy achieved using this method is better than 1% error over the lifetime of the battery. There

is no full charge/discharge learning cycle required. See the Theory and Implementation of Impedance Track

Battery Fuel-Gauging Algorithm Application Report for further details.

BQ28Z610-R1

SLUSE07B – JANUARY 2020 – REVISED JANUARY 2022

www.ti.com

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