Datasheet

 2015 Microchip Technology Inc. DS20005292B-page 3
MCP2221
1.0 FUNCTIONAL DESCRIPTION
The MCP2221 is a USB-to-UART serial converter that
enables USB connectivity in applications that have
UART and/or I
2
C interfaces. The device reduces
external components by integrating the USB
termination resistors and the oscillator needed for USB
operation.
The MCP2221 has four GP pins for miscellaneous
functionalities (including GPIO, USBCFG, SSPND,
Clock Output, ADC, DAC and interrupt detector).
See Table 1-1 and Section 1.7 “Pin Mux Module” for
details about the pin functions.
TABLE 1-1: PINOUT DESCRIPTION
Pin
Name
PDIP,
SOIC,
SSOP
QFN
Pin
Type
Standard Function Alternate Functions
GP0 2 1 I/O General-purpose I/O or alternate
function pin
SSPND (OUT)
LED_UR
X (OUT)
Signals when the host has
entered Suspend mode
UART R
X LED activity output
(factory default)
GP1 3 2 I/O General-purpose I/O or alternate
function pin
CLKR (OUT)
ADC1 (IN)
LED_UT
X (OUT)
IOC (IN)
Clock Reference Output
ADC Channel 1
UART TX Led activity output
(factory default)
External interrupt edge detector
RST
4 3 I Reset input (with internal pull-up) N/A
URX 54IUART RX pin (input) N/A
UTX 65OUART TX pin (output) N/A
GP2 7 6 I/O General-purpose I/O or alternate
function pin
USBCFG (OUT)
ADC2 (IN)
DAC1 (OUT)
USB device configured status
(factory default)
ADC Channel 2
DAC Output 1
GP3 8 7 I/O General-purpose I/O or alternate
function pin
LED_I2C (OUT)
ADC3 (IN)
DAC2 (OUT)
USB-I
2
C traffic indicator (factory
default)
ADC Channel 3
DAC Output 2
SDA 9 8 I/O
I
2
C Data line
N/A
SCL 10 9 I/O
I
2
C Clock line
N/A
V
USB 11 10 USB USB Power pin (internally
connected to 3.3V)
Should be locally bypassed with
a high-quality ceramic capacitor
D- 12 11 USB USB D-
D+ 13 12 USB USB D+
V
SS 14 13 P Ground
NC — 14
15
— Not Connected
V
DD 116PPower
EP — 17 — Exposed Thermal Pad (EP)
Do not electrically connect.