CP2103 Datasheet, PDF (12/18 Pages) List of Unclassifed Manufacturers – SINGLE-CHIP USB TO UART BRIDGE

CP2103
5. USB Function Controller and Transceiver
The Universal Serial Bus function controller in the CP2103 is a USB 2.0 compliant full-speed device with integrated
transceiver and on-chip matching and pull-up resistors. The USB function controller manages all data transfers
between the USB and the UART as well as command requests generated by the USB host controller and
commands for controlling the function of the UART.
The USB Suspend and Resume signals are supported for power management of both the CP2103 device as well
as external circuitry. The CP2103 will enter Suspend mode when Suspend signaling is detected on the bus. On
entering Suspend mode, the CP2103 asserts the SUSPEND and SUSPEND signals. SUSPEND and SUSPEND
are also asserted after a CP2103 reset until device configuration during USB Enumeration is complete.
The CP2103 exits the Suspend mode when any of the following occur: (1) Resume signaling is detected or
generated, (2) a USB Reset signal is detected, or (3) a device reset occurs. On exit of Suspend mode, the
SUSPEND and SUSPEND signals are de-asserted.
Both SUSPEND and SUSPEND temporarily float high during a CP2103 reset. If this behavior is undesirable, a
strong pulldown (10 kΩ) can be used to ensure SUSPEND remains low during reset. See Figure 6 for other
recommended options.
I/O Voltage
5
VIO
1 µF
USB
CONNECTOR
VBUS ¹
D- ²
D+ ³
GND ⁴
C1
1 µF
7 _REGIN
C4
4.7 µF
TANT
Option 2
C2
0.1 µF
6 _VDD
2 _GND
8 _VBUS
4
D-
3
D+
D1 D2 D3
Option 3
CP2103
VDD
R1
4.7 kΩ
Option 1
RST
9
SUSPEND ¹²
SUSPEND ¹¹
R2
10 kΩ
RI
1
DCD
28
DTR
27
DSR
26
TXD
25
RXD
24
RTS
23
CTS
22
(to external circuitry
for USB suspend
states)
Option 4
External RS-232
transceiver or
UART circuitry
GPIO.0 ¹⁹
GPIO.1 ¹⁸
GPIO.2 ¹⁷
GPIO.3 ¹⁶
External
Application
Circuitry
Option 1: A 4.7 kΩ pull-up resistor can be added to increase noise immunity.
Option 2: A 4.7 µF tantalum capacitor can be added if powering other devices from the on-chip regulator.
Option 3: Avalanche transient voltage suppression diodes should be added for ESD protection.
Option 3: Use Littlefuse p/n SP0503BAHT or equivalent.
Option 4: 10 kΩ resistor to ground to hold SUSPEND low on initial power on or device reset.
Figure 6. Typical Connection Diagram
12
Preliminary Rev. 0.2