A111 Pulsed Coherent Radar (PCR)

Datasheet, v2.8

© 2022 Copyright by Acconeer

2022-06-22

Page 20 of 35

The power up sequence is initiated by turning on VIO_3a,b. It must be turned on before or

simultaneously with ENABLE and VIO_1-2a,b. ENABLE and VIO_1-2a,b can be turned on in any

order and independently of each other. A111 should however not be considered as in state “ON” until

all supply voltage levels are stable and ENABLE is high. The time constant t1 in figure 7.4 denotes

this time. The actual value of t1 depends on the power supply and the decoupling capacitors used. If

the CTRL signal is used, it must be held at 0V during time t1.

Next step in the power up sequence is to have a settling time for the XTAL oscillator to stabilize,

shown as time t2 in Figure 8.4. This may take up to several milliseconds depending on the XTAL

performance. It is advised to have the clock inactive at 0 V while ENABLE is inactive.

Now the A111 radar sensor is ready for SPI communication.

Time

VIO_3a,b

ENABLE

t1

t2

XIN

VIO_1-2a,b

CTRL

Figure 8.4. Power up sequence.