USB375x

DS00001824A-page 14

 2011 - 2014 Microchip Technology Inc.

4.2.1

CHARGER DETECTION CIRCUITRY

The charger detection circuitry shown Figure 4-3 is used to detect the type charger attached to the USB connector.

The VdatDet output is qualified with the Linestate[1:0] value. If the Linestate is not equal to 00b the VdatDet signal will

not assert.

TABLE 4-1:

VALID CHARGERS

USB Charger Type

DP/DM

Profile

Bits[7:5]

(ChargerType)

DCP

(Dedicated Charging Port, defined in Battery Charging

1.2 specification)

Shorted < 200ohm

001

CDP

(Charging Downstream Port, defined in Battery Charging

1.2 specification)

010

(EnhancedChrgDet = 1)

SDP

(Standard Downstream Port)

USB Host or downstream hub port

15Kohm

pull-down on DP and DM

011

SE1 Charger Low Current Charger

DP = 2.0V

DM = 2.0V

100

(SE1ChrgDet =1)

SE1 Charger High Current Charger

DP = 2.0V

DM = 2.7V

101

(SE1ChrgDet =1)

FIGURE 4-3:

USB CHARGER DETECTION BLOCK DIAGRAM

Note:

DP

VBUS

To USB Con.

en

DM

To USB Con.

IdatSinkEn

HostChrgEn

VdatDet

VdatSrcEn

en

VdatSrc

ContactDetectEn

en

DpPulldownEn

DmPulldownEn

MUX

I

Registers

Charger

State

Machine

DpSeRx

DmSeRx

SeRxEn

I

HiCurrent