ST VL53L3CX - Timing Considerations

The handshake must be performed by the user of the bare driver. The delay to enable a new ranging after a new
measurement has been received is key to overall system measurement rate.
2.2 Timing considerations
Timings are presented in Figure 3. Ranging sequence and timing targets.
The host can get the latest available ranging during the duration (ranging timing budget) of the current range.
If a delay to clear the interrupt is introduced by the host, the next ranging will be stalled until the pending interrupt
is cleared.
Note: Timings indicated in Figure 3. Ranging sequence and timing targets are typical timings.
The host can change the default timing budget by using a dedicated driver function described in Chapter 5.1:
Timing budget on page 14. Host can decide to change timing budget either to synchronize on the application or to
increase ranging accuracy.
In the following figure, the “Boot”, “SW standby” and “Init” lasts 40ms. This time is needed to perform a correct
initialization of the device, and it is independent from the platform or the used timing budget. The first range,
“Range1”, is not valid, being the wrap-around check not possible. This means that the first valid ranging value is
“Range2”, available after 40 ms plus two time the timing budget duration.
Figure 3. Ranging sequence and timing targets
Get Range2 Get Range3
DataInit
Start
POWER
SUPPLY
XSHUT
PIN
Range1Boot
Get Range1
40ms
Ranging
Timing
Budget
Ranging
Timing
Budget
NOT TO SCALE
Ranging
Timing
Budget
INTERRUPT
PIN
HOST
DRIVER
CALLS
Setup range3
Clear interrupt1
Setup range1
Clear interrupt
SW
standby
Setup range4
Clear interrupt2
HW
standby
SYSTEM
STATE
Range3Range2Init
UM2778
Timing considerations
UM2778 - Rev 1
page 5/25