Datasheet
Analog Integrated Circuit Device Data
Freescale Semiconductor 70
MC34708
Functional Block Description
7.5.6.7 VUSB2
VUSB2 has an internal PMOS pass FET which will support loads up to 65 mA. To support load currents an external PNP is
provided. The external PNP configuration is offered to avoid excess on-chip power dissipation at higher loads and large
differentials between BP and output settings. For lower current requirements, an integrated PMOS pass FET is included. The
input pin for the integrated PMOS option is shared with the base current drive pin for the PNP option. The external PNP
configuration must be committed as a hardwired board level implementation. The recommended PNP device is the ON
Semiconductor™ NSS12100XV6T1G, which is capable of handling up to 250
mW of continuous dissipation, at minimum footprint
and 75 °C of ambient. For use cases where up to 500 mW of dissipation is required, the recommended PNP device is ON
Semiconductor NSS12100UW3TCG. For stability reasons, a total resistance of 50 m 20% in series with the output
capacitance is required. The total resistance includes the ESR of the capacitor plus an external resistance provided by a discrete
resistor or PCB circuit trace.
A short-circuit condition will shut down the VUSB2 regulator and generate an interrupt for SCPI, if REGSCPEN is set.
The nominal output voltage of this regulator is SPI configurable, and can be 2.5 V, 2.6 V, 2.75 V, or 3.0 V. The output current
when working with the internal pass FET is 65
mA, and could be up to 350 mA when working with an external PNP.
Table 59. VUSB2 Voltage Control
Parameter Value
Output
Voltage
ILoad max
VUSB2CONFIG = 0
Internal Pass FET
VUSB2CONFIG = 1
External PNP
VUSB2[1:0] 00 2.5 V 65 mA 350 mA
01 2.6 V 65 mA 350 mA
10 2.75 V 65 mA 350 mA
11 3.00 V 65 mA 350 mA
Table 60. VUSB2 Electrical Specification
Characteristics noted under conditions BP = 3.6 V, V
BUS
= 5.0 V, - 40 C T
A
85 C, unless otherwise noted. Typical values
at BP = 3.6 V and T
A
= 25 °C under nominal conditions, unless otherwise noted.
Symbol Characteristic Min Typ Max Unit Notes
GENERAL
V
USB2IN
Operating Input Voltage Range V
INMIN
to V
INMAX
V
NOM
+
0.25
- 4.5 V
I
USB2
Operating Current Load Range IL
MIN
to IL
MAX
• Internal pass FET
• External PNP Not exceeding PNP max power
0.0
0.0
-
-
65
350
mA
V
USB2IN
Extended Input Voltage Range
• Performance may be out of specification
UVDET - 4.5
V
VUSB2 ACTIVE MODE - DC
V
USB2
Output Voltage V
OUT
•V
INMIN
< V
IN
< V
INMAX
IL
MIN
< IL < IL
MAX
V
NOM
- 3% V
NOM
V
NOM
+ 3%
V
V
USB2LOPP
Load Regulation
•1.0 mA < IL < IL
MAX
For any V
INMIN
< V
IN
< V
INMAX
- 0.25 -
mV/mA
V
USB2LIPP
Line Regulation
•V
INMIN
< V
IN
< V
INMAX
For any IL
MIN
< IL < IL
MAX
- 8.0 -
mV
I
USB2Q
Active Mode Quiescent Current, V
INMIN
< V
IN
< V
INMAX
•IL = 0, Internal PMOS configuration
•V
INMIN
< V
IN
< V
INMAX
IL = 0, External PNP configuration
-
-
25
30
-
-
µA