FUSB3317

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9

APPLICATIONS INFORMATION

FUSB3317 has the entire Power Delivery (PD)

communication stack within hardware including the

optional Programmable Power Supply (PPS). No external

processor is needed. This enables turnkey solutions for PD

with PPS and makes this solution tamper proof unlike other

firmware−based solutions.

VBAT Supply Input

Connect the automotive battery supply directly to the

VBAT pin of the FUSB3317. The battery voltage can vary

from 5.5 V to 36 V in normal operation but can be up to 45 V

for short periods of time when an automotive load dump

event occurs. Similarly, the battery voltage could dip to

4.5 V momentarily. If there is significant dropout of VBAT

for tens of microseconds or milliseconds, an input holdup

capacitor is needed to stabilize VBAT to be within the above

voltage range.

Low Standby Current

With the FUSB3317 connected directly to the battery,

there is no need to turn on the DC/DC unless there is

something attached to the USB−C port. The FUSB3317 will

attach allowing for a very low system standby current.

Local Power Generated

FUSB3317 generates its own power from VBAT via an

integrated LDO. The total current generated can be

consumed by the FUSB3317 and by external low−power

2.2

Figure 4. VDD LDO Supply Generation

VDD

VBAT

Type C Attach

Figure 5. Type C Source

Figure 6. Type C Sink

The FUSB3317 implements the Rp pull up resistors in

default current capability. When the Sink’s CC1 or CC2 pins

as shown in Figure 6 with Rd as 5.1 k

W resistor connect with

either with CC1 or CC2 of the FUSB3317 in a flipped or

straight connection, an attach occurs when the voltage on the

CC1 or CC2 pin (only one CCx connects through the cable)

FUSB3317 enables a DC/DC controller via DC_EN pin to

source VBUS provided the connector VBUS pin is initially

discharged to ground (VBUS not source if VBUS already

present).