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AS8515

Datasheet - AS8515 Bottom Die Overvi ew

8.8.5 Standby Mode - Power Consumption

In Standby Mode 1 there is a timer based accurate measurement every Ta seconds. The device itself stays in idle-mode as long as it does not

get a different command from the SPI interface. Internal oscillator frequency is typically foscint=262 kHz to reduce power consumption as long as

the timer runs. After every time out of Ta seconds, it performs accurate measurement of current, voltage/ temperature. Data ready is signaled to

microcontroller through an interrupt signal on INT and goes into STOP state.

In the SBM the following equations hold:



Tsbm1 = Ta= 10s (default value is 10secs); the power consumption is valid for this setting. This is the period of the repetition rate in SBM 1

and SBM2.



sett ≈ 2ms (depending on external capacitors). This is the time required by the analog part to settle when the new measuring period is

started. Any measurements performed during T

sett produce invalid results.



T1 = 3ms (by default setting, every third measurement is sent to microcontroller in the SBM mode 1) is the time needed to perform the first

measurement.



meas =Tsett +T1 is the total active time needed to get a valid result.



DRSBM = T

meas/Tsbm ≈ 5ms/10s. This is the ratio of repetition time versus the active time (Device in NOM mode).

Power consumption = (DRSBM*NOM mode power consumption) + ((10s-5ms)/10s)*Stop mode power consumption)

8.9 Bottom Die Block Specifications

This section provides specification of design related key parameters.

8.9.1 Current Measurement Ranges (across 100µ

Ω (±5%) shunt resistor)

Note:

The Data Rate at the output can be calculated according to the formula:

fsout=2*fchop /R2 (R2 is down sampling ratio taking values 1, 2, 4 up to 32768 as powers of 2)

Table 30. Current Measurement Ranges

Symbol

Parameter

Imax

[A]

Vsh

[mV]

PGA

Gain

Nominal

Data Rate

(fOUT)

VINADC

[mV]

1. VINADC = Vsh * Gain, gain deviations to be considered according to Table 32 and Table 33.

PSR

[dB]

2. AVDD, DVDD of 3.3V with ±5% variation.

I70

Input current range of 70A in NOM

±77

±8.1

100

@ 1 kHz

890

I200

Input current range of 200A in NOM

±235

±24.7

@ 1 kHz

1088

I400

Input current range of 400A in NOM

±400

±42

@ 1 kHz

1137

I1500

Input current range of 1500A in NOM

+2076/-1523

+218/-160

@ 1 kHz

1204

Table 31. Valid Combinations of the Chopper Clock, Oversampling Clock and Decimation Ratios

Over Sampling Frequency

Chopper Frequency

Decimation Ratio

1.024MHz

2kHz

2.048MHz

2kHz

2.048MHz

2kHz

128

2.048MHz

4kHz

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