Datasheet

Application Note AN-1006
Rev. A | Page 7 of 16
CIRCUIT SCHEMATICS
USB CONNECTOR
The connection between the host PC and the Cypress USB
interface device is via a standard USB cable that carries D+ and
D− signals for data communications, a 5 V power supply, and
ground. The D+ and D− lines are a one-wire communication
interface carried by half-duplex differential signals on a twisted
pair. The clock is embedded in the data using the nonreturn-to-
zero inverted (NRZI) line code. These signal lines connect
directly to pins on the Cypress USB interface.
A surface-mounted USB miniature Type B jack was selected for
its low profile and increasing ubiquity in consumer electronics.
1
VCC
2
D–
3
D+
4
GND
J3
USB-MINI-B-SMD
DMINUS
DPLUS
5V0DD
08093-018
Figure 18. USB Connector Schematic
POWER REGULATOR
The Cypress USB Interface I/O ports are capable of operating in
both 1.8 V and 3.3 V modes, depending on the target device in
the system. Two regulators, one for 5 V to 3.3 V regulation and
the other for 5 V to 1.8 V regulation, run simultaneously when
the board is powered. A switch (S1) is provided to easily switch
the IOVDD supply between the two regulators. LED D4 provides
visual feedback that the board is being supplied with 5 V power
from the PC USB port.
The position of switch S1 should not be changed when the
board is connected to the USB bus.
C21
1.0uF
C20
1.0uF
C19
1.0uF
C17
1.0uF
+
C14
10uF
+
C13
10uF
+
C22
15uF
1
2
3
S1
SPDT
3
EN
2
GND
1
IN
5
OUT
4
BYP
U7
ADP1711AUJZ-1.8-R7
3
EN
2
GND
1
IN
5
OUT
4
BYP
U8
ADP1711AUJZ-3.3-R7
C18
10nF
C16
10nF
D4
Red Diffused
R10
475R
TP1
IOVDD
3V3DD1V8DD
5V0DD
3V3DD
1V8DD
08093-019
Figure 19. Power Regulator Schematic