ISP1105/1106
Advanced USB transceivers
7.3 Power supply configurations
The ISP1105/1106 can be used with different power supply configurations, which can be
changed dynamically. An overview is given in Table 9.
Normal mode — Both VCC(I/O) and VCC(5.0) or (VCC(5.0) and Vreg(3.3)) are connected. For
5 V operation, VCC(5.0) is connected to a 5 V source (4.0 V to 5.5 V). The internal voltage
regulator then produces 3.3 V for the USB connections. For 3.3 V operation, both VCC(5.0)
and Vreg(3.3) are connected to a 3.3 V source (3.0 V to 3.6 V). VCC(I/O) is independently
connected to a voltage source (1.65 V to 3.6 V), depending on the supply voltage of the
external circuit.
Disable mode — VCC(I/O) is not connected, VCC(5.0) or (VCC(5.0) and Vreg(3.3)) are
connected. In this mode, the internal circuits of the ISP1105/1106 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, (VCC(5.0) and Vreg(3.3)) are not connected. In this
mode, the (D+, D−) pins are made three-state and the ISP1105/1106 allows external
signals of up to 3.6 V to share the (D+, D−) lines. The internal circuits of the ISP1105/1106
ensure that virtually no current (maximum 10 μA) is drawn via the (D+, D−) lines. The
power consumption through pin VCC(I/O) drops to the low-power (suspended) state level.
Both the VP and VM pins are driven HIGH to indicate this mode. Pin RCV is made LOW.
Some hysteresis is built into the detection of Vreg(3.3) lost.
Table 8.
Pins
Pin states in disable or sharing mode
Disable mode state
Sharing mode state
VCC(5.0) / Vreg(3.3)
5 V input / 3.3 V output;
3.3 V input / 3.3 V input
not present
VCC(I/O)
Vpu(3.3)
(D+, D−)
(VP, VM)
RCV
not present
1.65 V to 3.6 V input
high impedance (off)
high impedance
H
high impedance (off)
high impedance
invalid[1]
invalid[1]
L
Inputs (VO/VPO, FSE0/VMO, SPEED, high impedance
MODE[2], SUSPND, OE, SOFTCON)
high impedance
[1] High impedance or driven LOW.
[2] ISP1105 only.
Table 9.
Power supply configuration overview
VCC(5.0) or Vreg(3.3) VCC(I/O)
Configuration
normal mode
disable mode
Special characteristics
Connected
Connected
connected
-
not connected
(D+, D−) and Vpu(3.3) high
impedance; VP, VM, RCV:
invalid[1]
Not connected
connected
sharing mode
(D+, D−) and Vpu(3.3) high
impedance;
VP, VM driven HIGH; RCV driven
LOW
[1] High impedance or driven LOW.
ISP1105_1106_10
© ST-ERICSSON 2009. All rights reserved.
Product data sheet
Rev. 10 — 28 September 2009
8 of 25
ERICSSON [ ERICSSON ]
