Typical application

VT5376

24/30

8.1

Overall 2.4 GHz mouse power consumption example

Assumptions

●

VCSEL, MCU and 2.4 GHz Tx operate from 2.2 V

●

MCU consumes 1 mA in running mode and 50 uA in standby mode. In no motion

period, it remains in standby until it receives an interrupt from the VT5376, indicating

that MOTION has been detected.

●

2.4 GHz Tx consumes 10 mA, but data is sent by bursts of 500 µs every 5 ms (that is

Nordic nRF2402).

●

Maximum current is delivered to VCSEL (10 mA strobed).

●

DCDC efficiency is 70%

●

Ambient temperature

Using STMicroelectronics battery life model, these values would enable the mouse to

operate for 12 months from two AA batteries in parallel.

Table 8.

Power supply and typical power consumption

Run

IDLE1

IDLE2

SLEEP

4000 fps

2000 fps

1000 fps

Total @Vbat (1.25 V)

18 mA

12 mA

9.3 mA

0.59 mA

0.29 mA

0.24 mA