SLUUBY2 User guide

SLUUBY2B September 2020 – May 2022 BQ76952

4.6 Subcommands 0x0075–0x0077 DASTATUS5–7(), Additional Measurements

The 0x0075 DASTATUS5() subcommand provides voltage measurements of the REG18 LDO voltage, the VSS pin, as well as calculated values for the minimum, maximum, and sum of cell-voltage measurements. It also provides the readings used for cell and FET temperature, minimum, maximum, and average cell temperature, and both CC1 and CC3 current values.

Since the VREF2 measurement is measured by the voltage ADC using VREF1, the REG18 voltage measurement provides information on the ratio of one reference versus the other and should stay approximately constant. This measurement can be used as a diagnostic check to determine if one reference changes value versus the other.

The VSS measurement is included as an additional diagnostic measurement to ensure that the ADC input mux is working properly. This measurement should normally result in a value near 0. If an internal fault were to occur that caused the ADC input mux to be stuck at a particular setting, such as a cell input, then the VSS measurement would be significantly higher. If the mux were stuck at a setting such as an interconnect measurement or VSS, the cell voltage measurements would be reported as very low voltage.

The battery voltage Ssum is the sum of all enabled cell voltage measurements, reported in units of cV (10 mV). This value can be compared with the 0x34 Stack Voltage() and used as a diagnostic check.

Note: Because the measurements are taken by the same ADC at different times, transient changes in the cell voltages can cause differences in the sum versus the stack measurement, and will need to be considered.

The 32-bit raw CC2 counts and raw CC3 counts data has an LSB value of approximately V_REF2 / (5 × 2²³) ≅ 1.24 V / (5 × 2²³) ≅ 29.56 nV.

Note: This data has not been processed for gain or offset, which are used for calculation of the 16-bit current data provided by the CC2 Current() and CC3 Current() commands.

Table 5-5 provides further details.

Table 4-5 0x0075 DASTATUS5() Subcommand Detail

Subcommand Address	Bytes Within Block	Name	Unit
0x0075	0–1	V_REG18	16-bit ADC counts
	2–3	VSS	16-bit ADC counts
	4–5	Max Cell Voltage	mV
	6–7	Min Cell Voltage	mV
	8–9	Battery Voltage Sum	cV
	10–11	Avg Cell Temperature	0.1 K
	12–13	FET Temperature	0.1 K
	14–15	Max Cell Temperature	0.1 K
	16–17	Min Cell Temperature	0.1 K
	18–19	Avg Cell Temperature	0.1 K
	20–21	CC3 Current	userA
	22–23	CC1 Current	userA
	24–27	CC2 Counts	32-bit ADC counts
	28–31	CC3 Counts	32-bit ADC counts

The 0x0076 DASTATUS6() subcommand provides the accumulated charge value and associated timer. It also includes the 32-bit raw ADC count for the CFETOFF, DFETOFF, ALERT, TS1, and TS2 pin measurements, which can be used for customer calibration of the general purpose ADC input measurement capability of the device.

The 32-bit raw ADC counts data for the CFETOFF, DFETOFF, ALERT, TS1, TS2, TS3, HDQ, DCHG, and DDSG pins has a different LSB value depending on whether the pin is configured for thermistor measurement mode or general purpose ADC (ADCIN) input mode. When configured for thermistor measurement, the raw ADC counts have an LSB of approximately 5 / 3 × 1.8 V / 2²³ ≅ 0.358 μV. When configured for ADCIN measurement, the raw ADC counts have an LSB of approximately 5 / 3 × V_REF1 / 2²³ ≅ 5 / 3 × 1.212 V / 2²³ ≅ 0.241 μV. Note that this data has not been processed using gain and offset trim corrections, which are used for calculation of the 16-bit data provided in ADCIN mode by the temperature commands, such as TS1 Temperature().

The details of this subcommand are shown below.

Table 4-6 0x0076 DASTATUS6() Subcommand Details

Subcommand Address	Bytes Within Block	Name	Unit
0x0076	0–3	Accumulated charge (integer portion)	32-bit signed integer portion in userAh
	4–7	Accumulated charge (fractional portion), initialized to 0.5 userAh when reset	32-bit fractional portion in userAh
	8–11	Accumulated Time	32-bit unsigned integer in seconds
	12–15	CFETOFF Counts	32-bit ADC counts
	16–19	DFETOFF Counts	32-bit ADC counts
	20–23	ALERT Counts	32-bit ADC counts
	24–27	TS1 Counts	32-bit ADC counts
	28–31	TS2 Counts	32-bit ADC counts

The 0x0077 DASTATUS7() subcommand provides the 32-bit raw ADC count for the TS3, HDQ, DCHG, and DDSG pin measurement, which can be used for customer calibration of the general purpose ADC input measurement capability of the device. The details of this subcommand are shown below.

Table 4-7 0x0077 DASTATUS7() Subcommand Detail

Subcommand Address	Bytes Within Block	Name	Unit
0x0077	0–3	TS3 Counts	32-bit ADC counts
	4–7	HDQ Counts	32-bit ADC counts
	8–11	DCHG Counts	32-bit ADC counts
	12–15	DDSG Counts	32-bit ADC counts
	16–31	Reserved	-