MB90351ASPMC1 datasheet(24/83 Pages) CYPRESS

24 / 83 page

Document Number: 002-07872 Rev. *A

Page 24 of 83

MB90350 Series

9.9 Turning-on Sequence of Power Supply to A/D Converter and Analog Inputs

Make sure to turn on the A/D converter power supply (AVCC, AVRH) and analog inputs (AN0 to AN14) after turning-on the digital power

supply (VCC) .

Turn-off the digital power after turning off the A/D converter power supply and analog inputs. In this case, make sure that the voltage

does not exceed AVRH or AVCC (turning on/off the analog and digital power supplies simultaneously is acceptable).

9.10 Connection of Unused Pins of A/D Converter if A/D Converter is not used

Connect unused pins of A/D converter to AVCC  VCC, AVSS  AVRH  VSS.

9.11 Notes on Energization

To prevent the internal regulator circuit from malfunctioning, set the voltage rise time during energization at

50 μs or more (0.2 V to 2.7 V) .

9.12 Stabilization of power supply voltage

A sudden change in the power supply voltage may cause the device to malfunction even within the specified VCC power supply voltage

operating range. Therefore, the VCC power supply voltage should be stabilized.

For reference, the power supply voltage should be controlled so that VCC ripple variations (peak-to-peak value) at commercial

frequencies (50 Hz to 60 Hz) fall below 10% of the standard VCC power supply voltage and the coefficient of fluctuation does not

exceed 0.1 V/ms at instantaneous power switching.

9.13 Initialization

In the device, there are internal registers which are initialized only by a power-on reset. To initialize these registers, turn on the power

again.

9.14 Port 0 to port 3 output during Power-on (External-bus mode)

As shown below, when power is turned on in external-bus mode, there is a possibility that output signal of

Port 0 to Port 3 might be unstable.

9.15 Notes on using CAN Function

To use CAN function, please set “1” to DIRECT bit of CAN direct mode register (CDMR).

If DIRECT bit is set to “0” (initial value), wait states will be performed when accessing CAN registers.

Note : Please refer to section “22.15 CAN Direct Mode Register” in Hardware Manual of MB90350 series for detail of CAN direct mode

Port0 to Port3

Port0 to Port3 outputs

might be unstable.

Port0 to Port3 outputs = Hi-Z

VCC

1/2 VCC

MB90351ASPMC1 Datasheet(PDF) 24 Page - Cypress Semiconductor