MIC2027-1BWM Micrel Inc, MIC2027-1BWM Datasheet - Page 15

• Manufacturer Part Number: MIC2027-1BWM
• Description: IC USB DISTRIB SW QUAD 16-SOIC
• Manufacturer: Micrel Inc
• Type: High Side Switchr

Specifications of MIC2027-1BWM

• Number Of Outputs: 4
• Rds (on): 150 mOhm
• Internal Switch(s): Yes
• Current Limit: 900mA
• Voltage - Input: 2.7 ~ 5.5 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 16-SOIC (0.300", 7.5mm Width)
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

Application Information
Supply Filtering
A 0.1µF to 1µF bypass capacitor positioned close to V
and GND of the device is strongly recommended to
control supply transients. Without a bypass capacitor, an
output short may cause sufficient ringing on the input
(from supply lead inductance) to damage internal control
circuitry.
Printed Circuit Board Hot-Plug
The MIC2027/77 are ideal inrush current-limiters for hot-
plug applications. Due to the integrated charge pump,
the MIC2027/77 present a high impedance when off and
slowly becomes a low impedance as it turns on. This
“soft-start” feature effectively isolates power supplies
from highly capacitive loads by reducing inrush current.
In cases of extremely large capacitive loads (>400µF),
the length of the transient due to inrush current may
exceed the delay provided by the integrated filter. Since
this inrush current exceeds the current-limit flag delay
specification, FLG will be asserted during this time. To
prevent the logic controller from responding to FLG
Micrel, Inc.
September 2006
Figure 3. Transient Filter
IN
15
being asserted, an external RC filter, as shown in Figure
3, can be used to filter out transient FLG assertion. The
value of the RC time constant should be selected to
match the length of the transient, less t
MIC2027/77.
Universal Serial Bus (USB) Power Distribution
The MIC2027/77 is ideally suited for USB (Universal
Serial Bus) power distribution applications. The USB
specification defines power distribution for USB host
systems such as PCs and USB hubs. Hubs can either
be self-powered or bus-powered (that is, powered from
the bus). The requirement for USB self-powered hubs is
that the port must supply a minimum of 500mA at an
output voltage of 5V ±5%. In addition, the output power
delivered must be limited to below 25VA. Upon an
overcurrent condition, the host must also be notified. To
support hot-plug events, the hub must have a minimum
of 120µF of bulk capacitance, preferably low ESR
electrolytic or tantulum. Please refer to Application Note
17 for more details on designing compliant USB hub and
host systems.
MIC2027/2077
M9999-091506
D(min)
of the