34708 datasheet(103/159 Pages) FREESCALE

103 / 159 page

Analog Integrated Circuit Device Data



103

Freescale Semiconductor

MC34708

Functional Block Description

7.8.4.14 5-Wire Charger or A/V Charger Mode

When the attached accessory is a 5-Wire Charger or A/V Charger, the MC34708 enables the appropriate device type 5.0 W CHG

or A/V in the USB device type register.

The VBUS detector is used to monitor the detachment of the charger. The falling edge of USBDETS is an indication of the charger

detachment. Both unplugging the mini-USB connector and unplugging the ac side lead to the same detachment conclusion. The

Detach bit is set to inform the host. Then the MC34708 USB detection enters the Standby mode.

7.8.4.15 Charger Input Current Limit Setting

When the Manual SW_B bit is set to 1, the MC34708 automatically detects what device is attached.

7.8.4.16 Unknown Accessory Operation Mode

When an unknown accessory is attached, the ID_FLOAT bit is cleared or the USBDETS bit is set to '1'. Only the Unknown_Atta

bit is set to interrupt the baseband. The Attach bit is not set to distinguish the unknown accessory from the known accessory. No

other actions are taken.The falling edge of the USBDETS or the rising edge of the ID_FLOAT signals can trigger the detachment

detection. The Detach bit is set to inform the detachment of the unknown accessory. The USB detection then enters the Standby

mode.

7.8.4.17 Software Reset

The USB detection supports a software reset, which is realized by writing the Reset bit in the USB Control register to 1. The

consequence of the software reset is the same as the hardware reset. All register bits reset by the Mini-USB will be reset.

7.8.4.18 ID Resistance Value Assignment

The ID resistors used are standard 1% resistors. Table 95 lists the complete 32 ID resistor assignment. Those with the Assigned

Functions filled are ones that are already used with special functions. The ones reserved can be assigned to other functions.

Table 94. ID Detection Thresholds

UID Pin External

Connection

UID Pin Voltage (68)

IDFLOATS IDGNDS IDFACTORYS

Accessory

Resistor to Ground

0.18 * VCORE < UID < 0.77 * VCORE

Non-USB accessory is attached (per

CEA-936-A spec)

Grounded

0 < UID < 0.12 * VCORE

A type plug (USB default slave) is

attached (per CEA-936-A spec)

Floating

0.89 * VCORE < UID < VCORE

B type plug (USB Host, OTG default

master or no device) is attached.

Voltage Applied

3.6 V < UID (1)

Factory mode

Notes

68.

UID maximum voltage is 5.25 V

Table 95. ID Resistance Assignment

Item#

ADC Result

ID Resistance K



Assignment

00000

<1.9

Reserved

00001

2.0

00010

2.604

00011

3.208

00100

4.014

34708 Datasheet(PDF) 103 Page - Freescale Semiconductor, Inc

34708 Datasheet(HTML) 103 Page - Freescale Semiconductor, Inc

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 ...More

Datasheet Download

Link URL