
Philips Semiconductors
ISP1104
Advanced USB transceiver
Product data
Rev. 01 — 26 August 2002
6 of 21
9397 750 09784
Koninklijke Philips Electronics N.V. 2002. All rights reserved.
7.3 Power supply congurations
The ISP1104 can be used with different power supply congurations, which can be
changed dynamically.
Table 8 provides an overview of the power supply
conguration.
Normal mode — Both VCC(I/O) and VCC(5.0) are connected. For 5 V operation,
VCC(5.0) is connected to a 5 V source (4.0 to 5.5 V). The internal voltage regulator
then produces 3.3 V for USB connections. VCC(I/O) is independently connected to a
voltage source (1.65 to 3.6 V), depending on the supply voltage of the external circuit.
Disable mode — VCC(I/O) is not connected and VCC(5.0) is connected. In this mode,
the internal circuits of the ISP1104 ensure that the (D
+, D) pins are in three-state
and the power consumption drops to the low-power (suspended) state level. Some
hysteresis is built into the detection of VCC(I/O) lost.
Sharing mode — VCC(I/O) is connected and VCC(5.0) is below 3.6 V. In this mode,
pins (D
+, D) are made three-state and the ISP1104 allows external signals of up to
3.6 V to share the (D
+, D) lines. The internal circuits of the ISP1104 ensure that
virtually no current (maximum 10
A) is drawn via the (D+, D) lines. The power
consumption through pin VCC(I/O) and pin VCC(5.0) drops to the low-power
(suspended) state level. Pins VP and VM are driven HIGH and pins VBUSDET and
RCV are driven LOW to indicate this mode. Some hysteresis is built into the detection
of VCC(5.0) lost.
[1]
High impedance or driven LOW.
[1]
High impedance or driven LOW.
Table 7:
Pin states in the Disable or Sharing mode
Pins
Disable mode
Sharing mode
VCC(5.0)
5 V input
below 3.6 V
Vreg(3.3)
3.3 V output
pulled-down
VCC(I/O)
not present
1.65 to 3.6 V input
Vpu(3.3)
high impedance (off)
D
+, D
high impedance
VP, VM
H
RCV
L
VBUSDET
L
VPO/VO, VMO/FSE0, MODE,
SUSPND, OE, SOFTCON
high impedance
Table 8:
Power supply conguration overview
VCC(5.0)
VCC(I/O)
Conguration
Special characteristics
connected
Normal mode
-
connected
not connected
Disable mode
(D
+, D) and Vpu(3.3) high
impedance; VP, VM, RCV: invalid
[1]not connected
connected
Sharing mode
(D
+, D) and V
pu(3.3) high
impedance; VP, VM driven HIGH;
RCV driven LOW; VBUSDET
driven LOW; Vreg(3.3) pulled-down