General information

STPA002

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DocID024368 Rev 3

5.2

Battery variations

5.2.1

Low voltage operation

The most recent OEM specifications require automatic stop of car engine at traffic lights, in

order to reduce emissions of polluting substances. The STPA002, thanks to its innovating

design, allows a continuous operation when battery falls down. At 6 V it is still fully

operational, only the maximum output power is reduced accordingly to the available voltage

supply.

If the battery voltage drops below the minimum operating voltage of 6 V the amplifier is fast

muted, the capacitor on SVR is discharged and the amplifier restarts when the battery

voltage returns to the correct voltage.

5.2.2

Cranks

STPA002 can sustain worst case cranks from 16 V to 6 V, continuing to play and without

producing any pop noise.

Examples of battery cranking curves are shown below, indicating the shape and duration of

allowed battery transitions.

Figure 21. Battery cranking curve example 1

V1 = 16 V; V2 = 6 V; V3 = 7 V; V4 = 8 V

t1 = 2 ms; t2 = 50 ms; t3 = 5 ms; t4 = 300 ms; t5 =10 ms; t6 = 1 s; t7 = 2 ms