CP2101EK Silicon Laboratories Inc, CP2101EK Datasheet - Page 12

• Manufacturer Part Number: CP2101EK
• Description: KIT DEVELOPMENT RS232 TO USB
• Manufacturer: Silicon Laboratories Inc

Specifications of CP2101EK

• Processor To Be Evaluated: CP2101
• Interface Type: RS-232, USB
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Contains lead / RoHS non-compliant
• Other names: 336-1076; CP2101EK; Q1572300

CP2101
5.
The Universal Serial Bus function controller in the CP2101 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 CP2101 device
as well as external circuitry. The CP2101 will enter Suspend mode when Suspend signaling is detected
on the bus. On entering Suspend mode, the CP2101 asserts the SUSPEND and SUSPEND signals.
SUSPEND and SUSPEND are also asserted after a CP2101 reset until device configuration during USB
Enumeration is complete
The CP2101 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 CP2101 reset. If this behavior is undesir-
able, a strong pulldown (10 kΩ) can be used to ensure SUSPEND remains low during reset. See
Figure 5.1 for other recommended options.
6.
The CP2101 UART interface consists of the TX (transmit) and RX (receive) data signals as well as the
RTS, CTS, DSR, DTR, DCD and RI control signals. The UART supports RTS/CTS, DSR/DTR and X-On/X-
Off handshaking.
12
CONNECTOR
USB
Option 1: A 4.7 kΩ pull-up resistor can be added to increase noise immunity.
Option 2: A 4.7 µF capacitor can be added if powering other devices from the on-chip regulator.
Option 3: Avalanche transient voltage suppression diodes can be added for ESD protection .
Option 3:
Option 4: 10 kΩ resistor to ground to hold SUSPEND low on initial power on or device reset.
USB Function Controller and Transceiver
Asynchronous Serial Data Bus (UART) Interface
VBUS
GND
D+
D-
1
3
4
Use Littlefuse p/n SP0503BAHT or equivalent.
4.7 µF
Option 2
C4
D1
0.1 µF
D2
1 µF
C1
C2
Figure 5.1. Typical Connection Diagram
D3
Option 3
7
6
3
8
5
4
REGIN
VBUS
GND
VDD
D+
D-
CP2101
Rev. 1.8
SUSPEND
SUSPEND
RST
DCD
DTR
DSR
TXD
RXD
RTS
CTS
RI
9
12
11
2
1
28
27
26
25
24
23
4.7 kΩ
10 kΩ
R1
R2
VDD
Option 1
Option 4
External RS-232
(to external circuitry
for USB suspend
states)
UART circuitry
transceiver or