Freescale Semiconductor, Inc

FRDM-KL46Z

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5 FRDM-KL46Z Hardware Description

5.1.1 Power Supply

There are multiple power supply options on the FRDM-KL46Z. It can be powered from either of the USB

regulator to produce the main power supply. The other two sources are not regulated on-board. Table 2

provides the operational details and requirements for the power supplies.

Table 2. FRDM-KL46 Power Requirements

Supply Source

Valid Range

OpenSDA Operational?

Regulated on-

board?

OpenSDA USB

5V

Yes

Yes

K20 USB

5V

No

Yes

4.3-9V

No

Yes

3.3V Pin

1.71-3.6V

No

No

Coin Cell

Battery

1.71-3.6V

No

No

Note that the OpenSDA circuit is only operational when a USB cable is connected and supplying power to

OpenSDA USB. However, protection circuitry is in place to allow multiple sources to be powered at once.

Figure 3- Power Supply Schematic