MIC2529 Datasheet, PDF (1/11 Pages) Micrel Semiconductor – Single-Channel USB Power Controller Advance Information

MIC2529
Micrel
MIC2529
Single-Channel USB Power Controller
Advance Information
General Description
The MIC2529 is a high-side power switch optimized for self-
powered (individual port switching) and bus-powered (ganged
port switching) Universal Serial Bus (USB) hub applications.
An on-board voltage regulator provides the 3.3V supply
voltage needed for many USB microcontrollers reducing
board component count.
The MIC2529 satisfies the following USB requirements: it
supplies up to 500mA as required by USB downstream
devices; the switch’s low on-resistance meets USB voltage
drop requirements; fault current is limited to typically 750mA,
well below the UL 25VA safety requirement; and a flag output
is available to indicate fault conditions to the local USB
controller. Soft start eliminates the momentary voltage drop
on the upstream port that may occur when the switch is
enabled in bus-powered applications.
A low-dropout (LDO) regulator provides 3.3V at loads up to
100mA and includes an enable pin for low current shutdown.
Both enable inputs are compatible with 3.3V and 5V logic.
Thermal shutdown prevents catastrophic failure from high-
current loads.
The MIC2529 is available in an 8-pin SOIC package with
active-high or active-low enable circuitry on switch.
Features
• Compliant to USB specifications
• UL Recognized Component
• On-board 3.3V, 100mA low-dropout regulator
• 500mA minimum continuous switch load current
• 160mΩ maximum on-resistance
• 750mA typical current limit
• Open-drain fault flag pin for switch
• Output can be forced higher than input (off-state)
• Thermal shutdown
• 1ms turn-on (soft-start) and fast turnoff
• Available with active-high or active-low switch enable
• Active-high enable on 3.3V regulated output
• 8-pin SOIC package
Applications
• USB self-powered hubs
• USB bus-powered hubs
• USB keyboard hubs
Typical Applications
Upstream V_BUS
D+
D–
GND
4.40V to 5.25V
3.3V USB Controller
4.7 0.1
µF µF
V+
ON/OFF
10k
OVERCURRENT
D–
0.1µF
D+ _GND
10k
1.5k*
5%
MIC2529
8
EN
3
IN
1
FLG
2
OUT
6
7
3VEN OUT
5
4
GND 3VOUT
1µF
Bold lines indicate
0.1" wide, 1-oz. copper
high-current traces.
* Speed sense termination resistor. Must be connected
between V_3VOUT and D+ to indicate high speed operation.
† _{33µF tantalum or 100µF electrolytics are recommended.}
33µF^†
33µF^†
33µF^†
33µF^†
Ferrite
Bead
0.01µF
V_BUS
D+
D–
GND
0.01µF
V_BUS
D+
D–
GND
0.01µF
V_BUS
D+
D–
GND
0.01µF
V_BUS
D+
D–
GND
Downstream
USB
Port 1
100mA max.
Downstream
USB
Port 2
100mA max.
Downstream
USB
Port 3
100mA max.
Downstream
USB
Port 4
100mA max.
UL Recognized Component
June 1999
4-Port Ganged Bus-Powered Hub
1
MIC2529