ISP1105/1106
Advanced USB transceivers
7.4 Power supply input options
The ISP1105/1106 range has two power supply input options.
Internal regulator — VCC(5.0) is connected to 4.0 V to 5.5 V. The internal regulator is
used to supply the internal circuitry with 3.3 V (nominal). The Vreg(3.3) pin becomes a 3.3 V
output reference.
Regulator bypass — VCC(5.0) and Vreg(3.3) are connected to the same supply. The internal
regulator is bypassed and the internal circuitry is supplied directly from the Vreg(3.3) power
supply. The voltage range is 3.0 V to 3.6 V to comply with the USB specification.
The supply voltage range for each input option is specified in Table 10.
Table 10. Power supply input options
Input option
VCC(5.0)
Vreg(3.3)
VCC(I/O)
Internal regulator supply input for internal voltage reference output supply input for digital
regulator (4.0 V to 5.5 V) (3.3 V, 300 μA)
I/O pins (1.65 V to 3.6 V)
Regulator bypass connected to Vreg(3.3)
supply input
supply input for digital
with maximum voltage
drop of 0.3 V
(3.0 V to 3.6 V)
I/O pins (1.65 V to 3.6 V)
(2.7 V to 3.6 V)
ISP1105_1106_10
© ST-ERICSSON 2009. All rights reserved.
Product data sheet
Rev. 10 — 28 September 2009
9 of 25
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