USB375x

DS00001824A-page 12

 2011 - 2014 Microchip Technology Inc.

4.0

GENERAL OPERATION

The USB375x is an integrated USB protection device, battery charger detection device, and High Speed USB mux

(USB3750 only). The USB375x is designed to protect a USB product from electrical overstress on the USB connector.

The USB375x includes several features designed to improve the reliability and speed the design of products designed

with a USB interface.

The USB3750 includes a high bandwidth HS USB mux. The mux allows high speed signals to pass through and still

meet HS USB signaling requirements.

The USB375x will protect the system from ESD stress events on VBUS, DP, and DM. The USB375x provides ESD pro-

tection to the IEC-61000 ESD specification.

The low resistance VBUS overvoltage protection switch protects the internal circuitry from VBUS over voltage events.

When VBUS is outside the safe operating range VBUS switch will automatically open.

The USB375x also includes the capability to detect various USB battery chargers, including those defined in the USB

Battery Charging Specification, Revision 1.2.

To support the device dead battery conditions as defined in the USB Battery Charging Specification, Revision 1.2, the

USB host. This will allow a device to charge a dead battery without violating the USB specifications. The USB375x-1

also includes a current limit to prevent the unconfigured current from exceeding 100mA. Note, this feature is not avail-

able with the USB375x-2.

The USB3750 block diagram is shown Figure 4-1 and the USB3751 block diagram is shown Figure 4-2.

FIGURE 4-1:

USB3750 BLOCK DIAGRAM

SCL

SDA

VBUS

VOUT

I

Interface

INT_B

DP

DM

HS USB

Switch

DM_2

DP_2

USB 2.0 PHY,

Processor, or

Accessory

Processor

Charger

Detection

Battery

Charger/

PMU

GND

DM_1

DP_1

USB 2.0 PHY,

Processor, or

Accessory

Over-Voltage/Under-Voltage

Protection and Current

Limiting

DP

DM

VBUS

VBUS

DP

DM

VBUS

DP

DM

USB3750