Microchip Technology MCP2200EV-VCP データシート

 2011 Microchip Technology Inc.

DS22228B-page 7

1.5.2.3

3.3V Self Powered

Typically, many embedded applications are using 3.3V
power supplies. When such an option is available in the
target system, MCP2200 can be powered up from the
existing 3.3V power supply rail. The typical connections
for MCP2200 are shown in 

In this example MCP2200 has both V

DD

 and V

USB

 lines

tied to the 3.3V rail. These tied connections disable the
internal USB transceiver LDO of the MCP2200  to reg-
ulate the power supply on V

USB

 pin. Another conse-

quence is that the ‘1’ logical level on the GPIO pins will
be at the 3.3V level, in accordance with the variations
specified in 

The GPIO Module is a standard 8-bit I/O port.

1.6.1

CONFIGURABLE PIN FUNCTIONS

The pins can be configured as:
• GPIO – individually configurable general purpose 

input or output

• SSPND – USB Suspend state
• USBCFG – indicates USB configuration status
• RxLED – indicates USB receive traffic
• TxLED – indicates USB transmit traffic

1.6.1.1

SSPND Pin Function

The SSPND pin (if enabled) reflects the USB state
(Suspend/Resume). The pin is active ‘low’ when the
Suspend state has been issued by the USB host.
Likewise, the pin drives ‘high’ after the Resume state is
achieved.
This pin allows the application to go into Low Power
mode when USB communication is suspended, and
switches to a full active state when USB activity is
resumed.

1.6.1.2

USBCFG Pin Function

The USBCFG pin (if enabled) starts out ‘low’ during
power-up or after Reset, and goes ‘high’ after the
device successfully configures to the USB. The pin will
go ‘low’ when in Suspend mode and ‘high’ when the
USB resumes.

LDO

3.3V

USB

Transceiver

D+

V

DD

V

USB

D-

IN

OUT

5V (USB Bus)

or external 

power supply

LDO
3.3V

D+

V

DD

V

USB

D-

IN

OUT

5V (USB Bus)

or external 

power supply

External

USB

Transceiver

3.3V
LDO