June 2010 1 MIC2025/2075
MIC2025/2075 Micrel, Inc.
MIC2025/2075
Single-Channel Power Distribution Switch MM8®
General Description
The MIC2025 and MIC2075 are high-side MOSFET switches
optimized for general-purpose power distribution requiring
circuit protection.
The MIC2025/75 are internally current limited and have
thermal shutdown that protects the device and load. The
MIC2075 offers “smart” thermal shutdown that reduces cur-
rent consumption in fault modes. When a thermal shutdown
fault occurs, the output is latched off until the faulty load is
removed. Removing the load or toggling the enable input will
reset the device output.
Both devices employ soft-start circuitry that minimizes inrush
current in applications where highly capacitive loads are em-
ployed. A fault status output ag is provided that is asserted
during overcurrent and thermal shutdown conditions.
The MIC2025/75 is available in the MM8® 8-lead MSOP
and 8-lead SOP.
Typical Application
EN OUT
FLG IN
ON/OFF
OVERCURRENT
MIC2025/75Logic Controller
GND OUT
NC
V
CC
2.7V to 5.5V
0.1µF
10k
1µF
VIN
GND
NC
Load
Features
• 140mΩ maximum on-resistance
• 2.7V to 5.5V operating range
• 500mA minimum continuous output current
• Short-circuit protection with thermal shutdown
• Fault status ag with 3ms lter eliminates false asser-
tions
• Undervoltage lockout
• Reverse current ow blocking (no “body diode”)
• Circuit breaker mode (MIC2075) reduces power
consumption
• Logic-compatible input
• Soft-start circuit
• Low quiescent current
• Pin-compatible with MIC2525
• UL File # E179633
Applications
• USB peripherals
• General purpose power switching
• ACPI power distribution
• Notebook PCs
• PDAs
• PC card hot swap
Micrel, Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel + 1 (408) 944-0800 • fax + 1 (408) 474-1000 • http://www.micrel.com
MM8 is a registered trademark of Micrel, Inc.
UL Recognized Component
MIC2025/2075 Micrel, Inc.
MIC2025/2075 2 June 2010
Pin Description
Pin Number Pin Name Pin Function
1 EN Switch Enable (Input): Active-high (-1) or active-low (-2).
2 FLG Fault Flag (Output): Active-low, open-drain output. Indicates overcurrent or
thermal shutdown conditions. Overcurrent condition must exceed tD in order
to assert FLG.
3 GND Ground
4 NC not internally connected
5 NC not internally connected
6, 8 OUT Supply (Output): Pins must be connected together.
7 IN Supply Voltage (Input).
Pin Conguration
1
2
3
4
8
7
6
5
OUT
IN
OUT
NC
EN
FLG
GND
NC
MIC2025/75
8-Lead SOIC (BM)
8-Lead MSOP (BMM)
Ordering Information
Part Number Enable Temperature Range Package
Standard Pb-Free
MIC2025-1BM MIC2025-1YM Active High -40°C to +85°C 8-Lead SOIC
MIC2025-2BM MIC2025-2YM Active Low -40°C to +85°C 8-Lead SOIC
MIC2025-1BMM MIC2025-1YMM Active High -40°C to +85°C 8-Pin MSOP
MIC2025-2BMM MIC2025-2YMM Active Low -40°C to +85°C 8-Pin MSOP
MIC2075-1BM MIC2075-1YM Active High -40°C to +85°C 8-Lead SOIC
MIC2075-2BM MIC2075-2YM Active Low -40°C to +85°C 8-Lead SOIC
MIC2075-1BMM MIC2075-1YMM Active High -40°C to +85°C 8-Pin MSOP
MIC2075-2BMM MIC2075-2YMM Active Low -40°C to +85°C 8-Pin MSOP
June 2010 3 MIC2025/2075
MIC2025/2075 Micrel, Inc.
Electrical Characteristics
VIN = +5V; TA = 25°C, bold values indicate –40°C ≤ TA ≤ +85°C; unless noted
Symbol Parameter Condition Min Typ Max Units
IDD Supply Current MIC20x5-1, VEN ≤ 0.8V, (switch off), 0.75 5 µA
OUT = open
MIC20x5-2, VEN ≥ 2.4V, (switch off), 0.75 5 µA
OUT = open
MIC20x5-1, VEN ≥ 2.4V, (switch on), 160 µA
OUT = open
MIC20x5-2, VEN ≤ 0.8V, (switch on), 160 µA
OUT = open
VEN Enable Input Voltage low-to-high transition 2.1 2.4 V
high-to-low transition 0.8 1.9 V
Enable Input Hysteresis 200 mV
IEN Enable Input Current VEN = 0V to 5.5V –1 0.01 1 µA
Control Input Capacitance 1 pF
RDS(on) Switch Resistance VIN = 5V, IOUT = 500mA 90 140 mΩ
V
IN = 3.3V, IOUT = 500mA 100 160 mΩ
Output Leakage Current MIC2025/2075 (output off) 10 µA
OFF Current in Latched MIC2075 50 µA
Thermal Shutdown (during thermal shutdown state)
tON Output Turn-On Delay RL = 10Ω, CL = 1µF, see “Timing Diagrams” 1 2.5 6 ms
tR Output Turn-On Rise Time RL = 10Ω, CL = 1µF, see “Timing Diagrams” 0.5 2.3 5.9 ms
tOFF Output Turnoff Delay RL = 10Ω, CL = 1µF, see “Timing Diagrams” 50 100 µs
tF Output Turnoff Fall Time RL = 10Ω, CL = 1µF, see “Timing Diagrams” 50 100 µs
ILIMIT Short-Circuit Output Current VOUT = 0V, enabled into short-circuit. 0.5 0.7 1.25 A
Current-Limit Threshold ramped load applied to output, Note 4 0.60 0.85 1.25 A
Short-Circuit Response Time VOUT = 0V to IOUT = ILIMIT 24 µs
(Short applied to output)
tD Overcurrent Flag Response VIN = 5V, apply VOUT = 0V until FLG low 1.5 3 7 ms
Delay V
IN = 3.3V, apply VOUT = 0V until FLG low 1.5 3 8 ms
Undervoltage Lockout VIN rising 2.2 2.5 2.7 V
Threshold V
IN falling 2.0 2.3 2.5 V
Absolute Maximum Ratings (Note 1)
Supply Voltage (VIN) ..........................................–0.3V to 6V
Fault Flag Voltage (VFLG) ..............................................+6V
Fault Flag Current (IFLG)............................................. 25mA
Output Voltage (VOUT) ...................................................+6V
Output Current (IOUT) ............................... Internally Limited
Enable Input (IEN) ..................................... –0.3V to VIN +3V
Storage Temperature (TS) ........................ –65°C to +150°C
ESD Rating, Note 3
Operating Ratings (Note 2)
Supply Voltage (VIN) ................................... +2.7V to +5.5V
Ambient Temperature (TA) .......................... –40°C to +85°C
Junction Temperature (TJ) ........................ Internally Limited
Thermal Resistance
SOP (θJA) .......................................................... 160°C/W
MSOP(θJA) ........................................................ 206°C/W
MIC2025/2075 Micrel, Inc.
MIC2025/2075 4 June 2010
Test Circuit
Device
Under
Test
C
L
OUT
R
L
V
OUT
I
OUT
Timing Diagrams
90%
VOUT
10%
90%
10%
tRtF
Output Rise and Fall Times
VEN
50%
90%
VOUT
10%
tOFF
tON
Active-Low Switch Delay Times (MIC20x5-2)
V
EN
50%
90%
V
OUT
10%
t
OFF
t
ON
Active-High Switch Delay Times (MIC20x5-1)
Symbol Parameter Condition Min Typ Max Units
Error Flag Output IL = 10mA, VIN = 5V 8 25 Ω
Resistance I
L = 10mA, VIN = 3.3V 11 40 Ω
Error Flag Off Current VFLAG = 5V 10 µA
Overtemperature Threshold TJ increasing 140 °C
T
J decreasing 120 °C
Note 1. Exceeding the absolute maximum rating may damage the device.
Note 2. The device is not guaranteed to function outside its operating rating.
Note 3. Devices are ESD sensitive. Handling precautions recommended.
Note 4. See “Functional Characteristics: Current-Limit Response” graph.
June 2010 5 MIC2025/2075
MIC2025/2075 Micrel, Inc.
0
20
40
60
80
100
120
140
160
180
-40 -20 020406080 100
CURRENT (µA)
TEMPERATURE (°C)
SupplyOn-Current
vs.Temperature
5V
3.3V
0
20
40
60
80
100
120
140
160
-40 -20 020406080 100
ON-RESISTANCE (mΩ)
TEMPERATURE (°C)
On-Resistance
vs.Temperature
5V
3.3V
I
OUT
=500mA
0
50
100
150
200
2.5 3.0 3.5 4.0 4.5 5.0 5.5
RESISTANCE (mΩ)
INPUT VOLTAGE (V)
On-Resistance
vs.InputVoltage
I
OUT
=500mA
+85°C
+25°C
-40°C
0
50
100
150
200
2.5 3.0 3.5 4.0 4.5 5.0 5.5
CURRENT (µA)
INPUT VOLTAGE (V)
SupplyOn-Current
vs.InputVoltage
+85°C
+25°C
-40°C
0
200
400
600
800
1000
1200
-40 -20 020406080 100
CURRENT LIMIT THRESHOLD (mA)
TEMPERATURE (°C)
Current-Limit Threshold
vs.Temperature
V
IN
=3.3V
V
IN
=5V
0
200
400
600
800
1000
-40 -20 020406080 100
CURRENT LIMIT (mA)
TEMPERATURE (°C)
Short-CircuitCurrent-Limit
vs.Temperature
V
IN
=3.3V
V
IN
=5V
0
1.0
2.0
3.0
4.0
5.0
2.5 3.0 3.5 4.0 4.5 5.0 5.5
RISE TIME (ms)
INPUT VOLTAGE (V)
Turn-OnRiseTime
vs.InputVoltage
RL=10Ω
CL=1µF
+85°C
+25°C
-40°C
0
100
200
300
400
500
600
700
800
2.5 3.0 3.5 4.0 4.5 5.0 5.5
CURRENT LIMIT (mA)
INPUT VOLTAGE (V)
Short-CircuitCurrent-Limit
vs.InputVoltage
+85°C
+25°C
-40°C
0
100
200
300
400
500
600
700
800
900
1000
1100
1200
2.5 3.0 3.5 4.0 4.5 5.0 5.5
CURRENT LIMIT THRESHOLD (mA)
INPUT VOLTAGE (V)
Current-Limit Threshold
vs.InputVoltage
+85°C+25°C-40°C
0
0.5
1.0
1.5
2.0
2.5
2.5 3.0 3.5 4.0 4.5 5.0 5.5
ENABLE THRESHOLD (V)
INPUT VOLTAGE (V)
Enable Threshold
vs.InputVoltage
TA=25°C
VEN
FALLING
VEN
RISING
0
0.5
1.0
1.5
2.0
2.5
-40 -20 020406080 100
ENABLE THRESHOLD (V)
TEMPERATURE (°C)
Enable Threshold
vs.Temperature
V
IN
=5V
V
EN
RISING
V
EN
FALLING
MIC2025/2075 Micrel, Inc.
MIC2025/2075 6 June 2010
0
1
2
3
4
5
2.5 3.0 3.5 4.0 4.5 5.0 5.5
DELAY TIME (ms)
INPUT VOLTAGE (V)
Flag Delay
vs.InputVoltage
+85°C
+25°C
-40°C
0
0.5
1.0
1.5
2.0
2.5
3.0
-40 -20 020406080 100
UVLO THRESHOLD (V)
TEMPERATURE (°C)
UVLOThreshold
vs.Temperature
V
IN
RISING
V
IN
FALLING
June 2010 7 MIC2025/2075
MIC2025/2075 Micrel, Inc.
Functional Characteristics
MIC2025/2075 Micrel, Inc.
MIC2025/2075 8 June 2010
June 2010 9 MIC2025/2075
MIC2025/2075 Micrel, Inc.
Block Diagram
1.2V
REFERENCE
THERMAL
SHUTDOWN
OSC.
CHARGE
PUMP
OUT
UVLO
GATE
CONTROL
IN
FLG
EN
CURRENT
LIMIT
GND
FLAG
RESPONSE
DELAY
Functional Description
Input and Output
IN is the power supply connection to the logic circuitry and
the drain of the output MOSFET. OUT is the source of the
output MOSFET. In a typical circuit, current ows from IN to
OUT toward the load. If VOUT is greater than VIN, current will
ow from OUT to IN since the switch is bidirectional when
enabled. The output MOSFET and driver circuitry are also
designed to allow the MOSFET source to be externally forced
to a higher voltage than the drain (VOUT > VIN) when the
switch is disabled. In this situation, the MIC2025/75 avoids
undesirable current ow from OUT to IN.
Thermal Shutdown
Thermal shutdown is employed to protect the device from
damage should the die temperature exceed safe margins
due mainly to short circuit faults. Each channel employs its
own thermal sensor. Thermal shutdown shuts off the output
MOSFET and asserts the FLG output if the die temperature
reaches 140°C. The MIC2025 will automatically reset its output
should the die temperature cool down to 120°C. The MIC2025
output and FLG signal will continue to cycle on and off until
the device is disabled or the fault is removed. Figure 2 depicts
typical timing. If the MIC2075 goes into thermal shutdown, its
output will latch off and a pull-up current source is activated.
This allows the output latch to automatically reset when the
load (such as a USB device) is removed. The output can also
be reset by toggling EN. Refer to Figure 1 for details.
Depending on PCB layout, package, ambient temperature,
etc., it may take several hundred milliseconds from the in-
cidence of the fault to the output MOSFET being shut off.
The worst-case scenario of thermal shutdown is that of a
short-circuit fault and is shown in the in the “Function Char-
acteristics: Thermal Shutdown Response” graph.
Power Dissipation
The device’s junction temperature depends on several fac-
tors such as the load, PCB layout, ambient temperature
and package type. Equations that can be used to calculate
power dissipation of each channel and junction temperature
are found below.
P
D = RDS(on) × IOUT2
Total power dissipation of the device will be the summation of
PD for both channels. To relate this to junction temperature,
the following equation can be used:
T
J = PD × θJA + TA
where:
T
J = junction temperature
T
A = ambient temperature
θJA = is the thermal resistance of the package
Current Sensing and Limiting
The current-limit threshold is preset internally. The preset
level prevents damage to the device and external load but
still allows a minimum current of 500mA to be delivered to
the load.
The current-limit circuit senses a portion of the output MOSFET
switch current. The current-sense resistor shown in the block
diagram is virtual and has no voltage drop. The reaction to
an overcurrent condition varies with three scenarios:
Switch Enabled into Short-Circuit
If a switch is enabled into a heavy load or short-circuit, the
switch immediately enters into a constant-current mode,
reducing the output voltage. The FLG signal is asserted
indicating an overcurrent condition. See the Short-Circuit
Response graph under Functional Characteristics.
MIC2025/2075 Micrel, Inc.
MIC2025/2075 10 June 2010
Short-Circuit Applied to Enabled Output
When a heavy load or short-circuit is applied, a large transient
current may ow until the current-limit circuitry responds. Once
this occurs the device limits current to less than the short-cir-
cuit current limit specication. See the Short-Circuit Transient
Response graph under Functional Characteristics.
Current-Limit Response—Ramped Load
The MIC2025/75 current-limit prole exhibits a small foldback
effect of about 200mA. Once this current-limit threshold is
exceeded the device switches into a constant current mode.
It is important to note that the device will supply current until
the current-limit threshold is exceeded. See the Current-Limit
Response graph under Functional Characteristics.
Fault Flag
The FLG signal is an N-channel open-drain MOSFET output.
FLG is asserted (active-low) when either an overcurrent
or thermal shutdown condition occurs. In the case where
an overcurrent condition occurs, FLG will be asserted only
after the ag response delay time, tD, has elapsed. This
ensures that FLG is asserted only upon valid overcurrent
conditions and that erroneous error reporting is eliminated.
For example, false overcurrent conditions can occur during
hot-plug events when a highly capacitive load is connected
and causes a high transient inrush current that exceeds the
current-limit threshold. The FLG response delay time tD is
typically 3ms.
Undervoltage Lockout
Undervoltage lockout (UVLO) prevents the output MOS-
FET from turning on until VIN exceeds approximately 2.5V.
Undervoltage detection functions only when the switch is
enabled.
VEN
VOUT
IOUT
Short-Circuit Fault
Thermal Shutdown
Reached
Load Removed
(Output Reset)
VFLG
ILIMIT
IDC
tD
Figure 1. MIC2075-2 Timing: Output Reset by Removing Load
VEN
VOUT
IOUT
Short-Circuit Fault
Thermal Shutdown
Reached
Load/Fault
Removed
VFLG
IDC
ILIMIT
tD
Figure 2. MIC2025-2 Timing
June 2010 11 MIC2025/2075
MIC2025/2075 Micrel, Inc.
Applications Information
Supply Filtering
A 0.1µF to 1µF bypass capacitor positioned close to VIN and
GND of the device is strongly recommended to control sup-
ply transients. Without a bypass capacitor, an output short
may cause sufcient ringing on the input (from supply lead
inductance) to damage internal control circuitry.
Printed Circuit Board Hot-Plug
The MIC2025/75 are ideal inrush current-limiters suitable for
hot-plug applications. Due to the integrated charge pump,
the MIC2025/75 presents 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 during hot-plug
events. Figure 3 shows how the MIC2075 may be used in a
hot-plug application.
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 lter. Since this inrush cur-
rent exceeds the current-limit delay specication, FLG will
be asserted during this time. To prevent the logic controller
from responding to FLG being asserted, an external RC lter,
as shown in Figure 4, can be used to lter out transient FLG
assertion. The value of the RC time constant will be selected
to match the length of the transient.
Universal Serial Bus (USB) Power Distribution
The MIC2025/75 is ideally suited for USB (Universal Serial
Bus) power distribution applications. The USB specication
denes 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). Figure 5 below
shows a typical USB Host application that may be suited for
mobile PC applications employing USB. The requirements
for USB host systems 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 notied. To
support hot-plug events, the hub must have a minimum of
120µF of bulk capacitance, preferably low-ESR electrolytic
or tantulum. Refer to Application Note 17 for more details on
designing compliant USB hub and host systems.
For bus-powered hubs, USB requires that each downstream
port be switched on or off under control by the host. Up to four
downstream ports each capable of supplying 100mA at 4.4V
minimum are allowed. In addition, to reduce voltage droop on
the upstream VBUS, soft-start is necessary. Although the hub
can consume up to 500mA from the upstream bus the hub
must consume only 100mA max at start-up, until it enumer-
ates with the host prior to requesting more power. The same
requirements apply for bus-powered peripherals that have no
downstream ports. Figure 6 shows a bus-powered hub.
MIC2025-2
EN OUT
FLG
GND OUT
NC
IN
1 8
2 7
3 6
5
NC
4
Adaptor Card
to "Hot"
Receptacle
C
BULK
GND
V
CC
0.1
µF Backend
Function
Figure 3. Hot Plug Application
10k
V+
MIC2025
EN OUT
FLG
GND OUT
NC NC
IN
1 8
2 7
3 6
4 5
OVERCURRENT
Logic Controller
R
C
Figure 4. Transient Filter
MIC2025/2075 Micrel, Inc.
MIC2025/2075 12 June 2010
V
BUS
D+
D–
GND
USB
Port
Data
EN OUT
FLG IN
ON/OFF
OVERCURRENT
MIC2025/753.3V USB Controller
GND OUT
NC
V
CC
5.0V
0.1µF
10k
IN OUT
GND
4.50V to 5.25V
Upstream V
BUS
100mA max.
Ferrite
Beads
120µF
V
BUS
D+
D–
GND
Data
1µF 1µF
VIN
GND
3.3V
NC
MIC5203-3.3
0.01µF
Figure 5 USB Host Application
V
BUS
D+
D–
GND
USB Downstream
Connector
(Up to four
ganaged ports)
Data
EN OUT
FLG IN
ON/OFF
OVERCURRENT
MIC2025/75
USB Logic Controller
GND OUT
NC
0.1µF
1.5k
IN OUT
GND
USB Upstream
Connector
Ferrite
Beads
120µF
V
BUS
D+
D–
GND
Data
0.1µF 0.1µF
VIN
GND
3.3V
NC
MIC5203-3.3
(LDO)
0.01µF
1.5K
Figure 6. USB Bus-Powered Hub
June 2010 13 MIC2025/2075
MIC2025/2075 Micrel, Inc.
Package Information
8-Lead SOIC (M)
MM8™ 8-Pin MSOP (MM)
MIC2025/2075 Micrel, Inc.
MIC2025/2075 14 June 2010
MICREL INC. 2180 FORTUNE DRIVE SAN JOSE, CA 95131 USA
te l + 1 (408) 944-0800 f a x + 1 (408) 474-1000 w e b http://www.micrel.com
This information furnished by Micrel in this data sheet is believed to be accurate and reliable. However no responsibility is assumed by Micrel for its use.
Micrel reserves the right to change circuitry and specications at any time without notication to the customer.
Micrel Products are not designed or authorized for use as components in life support appliances, devices or systems where malfunction of a product can
reasonably be expected to result in personal injury. Life support devices or systems are devices or systems that (a) are intended for surgical implant into
the body or (b) support or sustain life, and whose failure to perform can be reasonably expected to result in a signicant injury to the user. A Purchaser's
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