Supply pins and decoupling

AN2871

18/25

Doc ID 15304 Rev 3

4.1.1

Internal supply decoupling capacitors

The external ballast needs output bypass capacitance for stability. Three 10 µF capacitors

are recommended for transient capability. In addition, for decoupling (that is, supply

variations) a pair of ceramic capacitors is required for each supply/GND pair. The general

rule for decoupling capacitors is to share equally the CDEC2 value (refer to device’s

datasheet), and the 1880 pF capacitance value among all the supply pins

VDD_LV_CORx/VSS_LV_CORx.

VDD_HV_IO0

Input/Output supply voltage

VSS_HV_IO0

Input/Output ground

VDD_HV_IO1

Input/Output supply voltage

VSS_HV_IO1

Input/Output ground

VDD_HV_IO2

Input/Output supply voltage

VSS_HV_IO2

Input/Output ground

VDD_HV_IO3

Input/Output supply voltage

VSS_HV_IO3

Input/Output ground

VDD_HV_FL

Code and data Flash supply voltage

VSS_HV_FL

Code and data Flash supply ground

VDD_HV_OSC

Crystal oscillator amplifier supply voltage

VSS_HV_OSC

Crystal oscillator amplifier ground

VDD_LV_COR0

1.2 V decoupling pins for core logic. Decoupling capacitor must be connected

between these pins and the nearest VSS_LV_COR0 pin.

VSS_LV_COR0

1.2 V decoupling pins for core logic. Decoupling capacitor must be connected

between these pins and the nearest VDD_LV_COR0 pin.

VDD_LV_COR1

1.2 V decoupling pins for core logic. Decoupling capacitor must be connected

between these pins and the nearest VSS_LV_COR1 pin.

VSS_LV_COR1

1.2 V decoupling pins for core logic. Decoupling capacitor must be connected

between these pins and the nearest VDD_LV_COR1 pin.

VDD_LV_COR2

1.2 V decoupling pins for core logic. Decoupling capacitor must be connected

between these pins and the nearest VSS_LV_COR2 pin.

VSS_LV_COR2

1.2 V decoupling pins for core logic. Decoupling capacitor must be connected

between these pins and the nearest VDD_LV_COR2 pin.

VDD_LV_COR3

1.2 V decoupling pins for core logic. Decoupling capacitor must be connected

between these pins and the nearest VDD_LV_COR3.

VSS_LV_COR3

1.2 V decoupling pins for on-chip core logic. Decoupling capacitor must be

connected between this pin VSS_LV_COR3.

1.

Analog supply/ground and high/low reference lines are internally physically separate, but are shorted via a double-bonding

connection on VDD_HV_ADx/VSS_HV_ADx pins.

Table 7.

Supply pins on SPC560P50XX LQFP144 (continued)

Supply

Symbol

Description