MB91F587LD datasheet(37/177 Pages) SPANSION

37 / 177 page

D at aS h ee t

MB91F587LA_DS705-00012-2v0-E, August 22, 2014

CONFIDENTIAL



HANDLING DEVICES

The latch-up prevention and pin processing are explained below.

•

For latch-up prevention

If a voltage higher than VCC or a voltage lower than VSS is applied to an I/O pin, or if a voltage exceeding

the ratings is applied between VCC and VSS pins, a latch-up may occur in CMOS IC. If the latch-up occurs,

the power supply current increases excessively and device elements may be damaged by heat. Take care to

prevent any voltage from exceeding the maximum ratings in device application.

Also, the analog power supplies (AVCC0*, AVCC3, AVRH0*, AVRH1, AVRH2, AVRH3) and analog input

must not exceed the digital power supply (VCC5) when the power supply to the analog system is turned on

or off.

In the correct power-on sequence, turn on the digital power supply voltage (VCC5) and analog power

supply voltages (AVCC0*, AVCC3, AVRH0*, AVRH1, AVRH2, AVRH3) simultaneously. Alternatively,

turn on the digital power supply voltage (VCC5) first, and then turn on the analog power supplies (AVCC0*,

AVCC3, AVRH0*, AVRH1, AVRH2, AVRH3).

*: MB91F585LA/F586LA/F587LA/F585LC/F586LC/F587LC only

•

Treatment of unused pins

If unused input pins are left open, they may cause a permanent damage to the device due to device

malfunction or latch-up. Connect a 2kΩ or higher resistor to each of unused input pins for pull-up or

pull-down processing.

Also, if I/O pins are not used, they must be set to the output state for releasing or they must be set to the

input state and treated in the same way as for the input pins.

•

Power supply pins

The device is designed to ensure that if the device contains multiple VCC or VSS pins, the pins that should

be at the same potential are interconnected to prevent latch-up or other malfunctions. Further, connect these

pins to an external power supply or ground to reduce unwanted radiation, prevent strobe signals from

malfunctioning due to a raised ground level, and fulfill the total output current standard, etc. As shown

below, all VSS power supply pins must be treated in the similar way. If multiple VCC or VSS systems are

connected, the device cannot operate correctly even within the guaranteed operating range.

Power Supply Input Pins

The power supply pins should be connected to VCC and VSS of this device at the low impedance from the

power supply source.

In the area close to this device, a ceramic capacitor having the capacitance larger than the capacitor of C pin

is recommended to use as a bypass capacitor between VCC and VSS pins.

VSS

MB91F587LD датащи(PDF) 37 Page - SPANSION