Analog Integrated Circuit Device Data
Freescale Semiconductor
108
PC34708
Functional Block Requirements and Behaviors
Mini/Micro USB Interface Description and Application Information
7.10.2.1 VUSB Specifications
7.10.3 Accessory Identification
The PC34708 monitors both the ID pin and the VBUS pin. When an accessory attachment is detected, the accessory
identification state machine will enter Active mode to start the identification flow. The ID detection state machine will determine
what ID resistor is attached and the Power Supply Type Identification or PSTI circuit will determine what type of power supply is
connected.
An identification conclusion is made when the identification flow is finished. The corresponding bit in the USB Device Type/Status
register is set to indicate the device type, and the ATTACH bit in the USB Interrupt Status register is set to inform the baseband.
If the attached accessory can't be identified, the Unknown_Atta bit in the USB Interrupt Status register is set.
There are three types of accessories that the PC34708 will automatically detect.
Table 113. VUSB Electrical Characteristics
Characteristics noted under conditions BP = 3.6 V, VBUS = 5.0 V, -40°C ≤ TA ≤ 85°C, unless otherwise noted. Typical values at
BP = 3.6 V and TA = 25°C under nominal conditions, unless otherwise noted.
Symbol
Characteristic
Min
Typ
Max
Unit
Notes
VUSB REGULATOR
VUSBIN
Operating Input Voltage Range VINMIN to VINMAX
Supplied by VBUS
Supplied by SWBST
4.4
-
5.0
-
5.25
5.75
V
IUSB
Operating Current Load Range ILMIN to ILMAX
0
-
100
mA
COVUSB
Bypass Capacitor Value Range
0.65
2.2
-
μF
ESRVUSB
Bypass Capacitor ESR
10 kHz - 1.0 MHz
0
-
0.1
Ω
VUSB ACTIVE MODE - DC
VUSB
Output Voltage VOUT
VINMIN < VIN < VINMAX ILMIN < IL < ILMA
VNOM - 4%
3.3
VNOM + 4%
V
VUSBLOPP Load Regulation
0 < IL < ILMAX from DM / DP, For any VINMIN < VIN < VINMAX
-
1.0
-
mV/mA
VUSBLIPP
Line Regulation
VINMIN < VIN < VINMAX, For any ILMIN < IL < ILMAX
-
20
mV
VUSBSCTH Short-circuit Protection threshold
VINMIN < VIN < VINMAX, Short-circuit VOUT to ground
IMAX+20%
-
mA
tOFF-VUSB Turn-off Time
Disable to 0.8 V, per USB OTG specification parameter
VA_SESS_VLD VIN = VINMIN, VINMAX IL = 0
-
1.3
sec
VUSB ACTIVE MODE - AC
VUSBPSRR PSRR - IL = 75% of ILMAX 20 Hz to 20 kHz
VIN = VINMIN + 100 mV
35
40
-
dB
VUSBNOISE Output Noise - VIN = VINMIN IL = 75% of ILMAX
100 Hz – 50 kHz
> 50 kHz – 1.0 MHz
-
1.0
0.2
μV/√Hz