CY7C65213 Datasheet, PDF (21/29 Pages) Cypress Semiconductor – USB-UART LP Bridge Controller

CY7C65213
CY7C65213A
In a battery charger system, a 9-V spike on the VBUS is possible. The CY7C65213 VCC pin is intolerant to voltage above 6 V. In the
absence of over-voltage protection (OVP) on the VBUS line, the VBUS should be connected to BUSDETECT (GPIO configured) using
the resistive network and the output of the battery charger to the VCC pin of CY7C65213, as shown in the following figure.
Figure 8. GPIO VBUS Detect (BUSDETECT)
VCC
USB-UART LP
CY7C65213 /
CY7C65213A
SYS
Battery Charger _BAT
BUSDETECT
GPIO
A
B
A
Rs
B
Rs = 10 K
VBUS = VCCIO
A
R1 ^B _{R1 = 10 K}
R2
R2/(R1+R2) = VCCIO/VBUS
VBUS
VBUS > VCCIO
When VBUS and VCCIO are at the same voltage potential, the
VBUS can be connected to GPIO using a series resistor (Rs).
This is shown in the following figure. If there is a charger failure
and the VBUS becomes 9 V, then the 10-k resistor plays two
roles. It reduces the amount of current flowing into the now
forward-biased diodes in the GPIO, and it reduces the voltage
seen on the pad.
Figure 9. GPIO VBUS Detection, VBUS = VCCIO
VCCIO
CY7C65213 /
CY7C65213A
BUSDETECT
Rs ^VBUS
LED Interface
Any GPIO can be configured to drive an LED. Three
configuration options (TXLED#, RXLED#, and TX or RX LED#)
are available for driving LEDs. Refer to Table 13 on page 14.
The following figure shows an example of the CY7C65213 drive
single-LED configuration and dual-LED configurations,
respectively. In the single-LED configuration, the GPIO pin is
used to indicate when data is transmitted or received over USB
by the device (TX or RX LED#). In the dual-LED configuration,
when data is transmitted or received over USB, the respective
GPIO pins will drive the LED to indicate the transfer.
Figure 11. Single-LED Configuration
VCCIO
When VBUS > VCCIO, a resistor voltage divider is required to
reduce the voltage from the VBUS down to VCCIO for the GPIO
sensing the VBUS voltage. This is shown in Figure 10.
The resistors should be sized as follows:
■ R1 ≥ 10 k
■ R2 / (R1 + R2) = VCCIO / VBUS
The first condition limits the voltage and current for the charger
failure situation, as described in the previous paragraph, while
the second condition allows for normal-operation VBUS
detection.
Figure 10. GPIO VBUS Detection, VBUS > VCCIO
VCCIO
CY7C65213 /
CY7C65213A
BUSDETECT
R1 ^VBUS
R2
CY7C65213 /
CY7C65213A
GPIO[0..7]
270R
TX or RX
LED#
Figure 12. Double-LED Configuration
VCCIO
CY7C65213 /
CY7C65213A
1K
1K
GPIO[0..7]
TXLED#
GPIO[0..7]
RXLED#
Document Number: 001-81011 Rev. *M
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