Datasheet

Power-Supply Input Options
Electrostatic Discharge (ESD)
TUSB2551A
www.ti.com ...................................................................................................................................................................................................... SCES790 – JUNE 2009
The TUSB2551A has two power-supply input options.
• Internal regulator – V
CC(5.0)
is connected to 4 V to 5.5 V. The internal regulator is used to supply the internal
circuitry with 3.3 V (nominal). V
reg(3.3)
becomes a 3.3-V output reference.
• Regulator bypass – V
CC(5.0)
and V
reg(3.3)
are connected to the same supply. The internal regulator is bypassed,
and the internal circuitry is supplied directly from the V
reg(3.3)
power supply. The voltage range is
3 V to 3.6 V to comply with the USB specification.
The supply-voltage range for each input option is specified in Table 3 .
Table 3. Power-Supply Input Options
INPUT OPTION V
CC(5.0)
V
reg(3.3)
V
CC(I/O)
Supply input for internal regulator Voltage-reference output Supply input for digital I/O pins
Internal regualtor
(4 V to 5.5 V) (3.3 V, 300 µ A) (1.4 V to 3.6 V)
Connected to V
reg(3.3)
with
Supply input Supply input for digital I/O pins
Regulator bypass maximum voltage drop of 0.3 V
(3 V to 3.6 V) (1.4 V to 3.6 V)
(2.7 V to 3.6 V)
PIN NAME ESD TYP UNIT
IEC61000-4-2, Air-Gap Discharge ± 9
D+, D – , V
CC(5.0)
IEC61000-4-2, Contact Discharge ± 9 kV
Human-Body Model ± 15
All other pins Human-Body Model ± 2 kV
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Product Folder Link(s): TUSB2551A