MCP2200 datasheet(6/34 Pages) MICROCHIP

6 / 34 page

MCP2200

DS22228A-page 6

 2010 Microchip Technology Inc.

1.5

USB Transceiver

The MCP2200 has a built-in, USB 2.0, full-speed

transceiver internally connected to the USB module.

The USB transceiver obtains power from the VUSB pin,

which is internally connected to the 3.3V regulator. The

best electrical signal quality is obtained when VUSB is

locally bypassed with a high quality ceramic capacitor.

1.5.1

INTERNAL PULL-UP RESISTORS

The MCP2200 devices have built-in pull-up resistors

designed to meet the requirements for full-speed USB.

1.5.1.1

Bus Power Only

In Bus Power Only mode, all power for the application

is drawn from the USB (Figure 1-2). This is effectively

the simplest power method for the device.

In order to meet the inrush current requirements of the

USB 2.0 specifications, the total effective capacitance

appearing across VBUS and ground must be no more

than 10 µF. If not, some kind of inrush limiting is

required. For more details, see Section 7.2.4 of the

“Universal Serial Bus Specification”.

According to the USB 2.0 specification, all USB devices

must also support a Low-Power Suspend mode. In the

USB Suspend mode, devices must consume no more

than 500 µA (or 2.5 mA for high powered devices that

are remote wake-up capable) from the 5V VBUS line of

the USB cable.

The host signals the USB device to enter Suspend

mode by stopping all USB traffic to that device for more

than 3 ms.

During USB Suspend mode, the D+ or D- pull-up

resistor must remain active, which will consume some

of the allowed suspend current budget (500 µA/

2.5 mA).

FIGURE 1-2:

BUS POWER ONLY

1.6

GPIO Module

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.

1.6.1.3

RxLED Pin Function (IN Message)

The ‘Rx’ in the pin name is in respect to the USB host.

The RxLED pin is an indicator for USB ‘IN’ messages.

This pin will either pulse low for a period of time

(configurable for ~100 ms or ~200 ms), or toggle to the

opposite

state

for

every

message

received

(IN message) by the USB host. This allows the

application to count messages or provide a visual

indication of USB traffic.

1.6.1.4

TxLED Pin Function (OUT Message)

The ‘Tx’ in the pin name is in respect to the USB host.

The TxLED pin is an indicator for USB ‘OUT’

messages.

This pin will either pulse low for a period of time

(configurable for ~100 ms or ~200 ms), or toggle to the

opposite state for every message transmitted (OUT

message) by the USB host. This allows the application

to count messages or provide a visual indication of

USB traffic.

VDD

VUSB

VSS

VBUS

MCP2200 Datasheet(PDF) 6 Page - Microchip Technology

MCP2200 Datasheet(HTML) 6 Page - Microchip Technology

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34

Datasheet Download

Link URL