1³

DCD

Data Carrier Detect control input (active   low)

2³

RI

Ring Indicator control input (active low)

3

GND

Ground

4

D+

USB D+

5

D–

USB D–

6

VDD

3.0–3.6 V Power Supply   Voltage Input.3.3 V Voltage Regulator Output.See "10. Voltage   Regulator" on page 19.

7

REGIN

5 V Regulator Input. This pin is the   input to the on-chip voltage regu-lator.

8

VBUS

VBUS Sense Input. This pin should be   connected to the VBUS signal of a USB network. A 5 V signal on this pin   indicates a USB network connection.

9

RST

Device Reset. Open-drain output of   internal POR or VDD monitor. An external source can initiate a system reset   by driving this pin low for at least 15 ?s.

11³

SUSPEND

This pin is driven low when the CP2102/9   enters the USB suspend state.

12³

SUSPEND

This pin is driven high when the CP2102/9   enters the USB suspend state.

18

NC1 /

This pin should be left unconnected or   tied to VDD. This pin is unused on the CP2102 and may be connected to the Vpp   programming capacitor to maintain board compatibility with the CP2109.

18

VPP2

VPP Programming Supply Voltage

23³

CTS

Clear To Send control input (active low)

24³

RTS

Ready to Send control output (active low)

25

RXD

Asynchronous data input (UART Receive)

26

TXD

Asynchronous data output (UART Transmit)

27³

DSR

Data Set Ready control input (active low)

28³

DTR

Data Terminal Ready control output   (active low)

10, 13–22

NC

These pins should be left unconnected or   tied to VDD.