Power. Infineon CY8C4045LQI-S412, CY8C4045LQI-S413, CY8C4025AZI-S413T, CY8C4024LQI-S412, CY8C4025AZQ-S403, CY8C4024LQI-S403T, CY8C4025LQI-S412, CY8C4025LQI-S402T, CY8C4045LQI-S411, CY8C4024AXI-S412

PSoC 4: PSoC 4000S Datasheet

Power

The following power system diagram shows the set of power supply pins as implemented for the PSoC 4000S. The system has one regulator in Active mode for the digital circuitry. There is no analog regulator; the analog circuits run directly from the V

DD input.

Figure 4. Power Supply Connections

Mode 1: 1.8 V to 5.5 V External Supply

In this mode, the PSoC 4000S is powered by an external power supply that can be anywhere in the range of 1.8 to 5.5 V. This range is also designed for battery-powered operation. For example, the chip can be powered from a battery system that starts at 3.5 V and works down to 1.8 V. In this mode, the internal regulator of the PSoC 4000S supplies the internal logic and its output is connected to the V

CCD

pin. The VCCD pin must be bypassed to ground via an external capacitor (0.1 µF; X5R ceramic or better) and must not be connected to anything else.

VDDA

VDDA

VSSA

Analog

Domain

Digital

Domain

1.8 Volt

Regulator

VDDD

VSSD

VCCD

VDDD

Mode 2: 1.8 V ±5% External Supply

In this mode, the PSoC 4000S is powered by an external power supply that must be within the range of 1.71 to 1.89 V; note that this range needs to include the power supply ripple too. In this mode, the VDD and VCCD pins are shorted together and bypassed. The internal regulator can be disabled in the firmware.

Bypass capacitors must be used from VDDD to ground. The typical practice for systems in this frequency range is to use a capacitor in the 1-µF range, in parallel with a smaller capacitor

(0.1 µF, for example). Note that these are simply rules of thumb and that, for critical applications, the PCB layout, lead inductance, and the bypass capacitor parasitic should be simulated to design and obtain optimal bypassing.

An example of a bypass scheme is shown in the following diagram.

There are two distinct modes of operation. In Mode 1, the supply voltage range is 1.8 V to 5.5 V (unregulated externally; internal regulator operational). In Mode 2, the supply range is1.8 V ±5%

(externally regulated; 1.71 to 1.89, internal regulator bypassed).

Figure 5. External Supply Range from 1.8 V to 5.5 V with Internal Regulator Active

Power supply bypass connections example

1.8V to 5.5V

0.1

 F

V

DD

PSoC 4000S

V

DDA

 F

1.8V to 5.5V

0.1

 F

V

CCD

0.1

 F

V

SS

Document Number: 002-00123 Rev. *N Page 14 of 42