MIC2072-1CQS - Micrel Semiconductor, Inc.

September 2000 1 MIC2012/2072

MIC2012 Micrel

MIC2012/MIC2072

USB Power Controller

Advance Information

General Description

The MIC2012 is a dual channel USB power switch designed

to support the power distribution requirements for USB Wakeup

from the ACPI S3 state. The MIC2012 will directly switch its

two outputs between a 5V main supply and a 5V auxiliary

supply normally provided in ATX style power supplies.

The MIC2012 will adjust its current-limit threshold according

to the ACPI state it is in. In the normal active S0 state the

current-limit is set at 500mA minimum per channel satisfying

the USB continuous output current specification. In the S3

state the current-limit can be reduced to only 100mA per

channel to minimize the current that is supplied by the

auxiliary supply thereby ensuring that voltage regulation is

maintained even during fault conditions.

The MIC2012 provides make-before-break switching to en-

sure glitch-free transitions between the S3 and S0 states.

Each channel is also thermally isolated from the other so that

a fault in one channel does not effect the other. FAULT status

output signals are also provided indicating overcurrent and

thermal shutdown conditions.

The MIC2072 option latches the output off upon detecting an

overcurrent condition for more than 5ms minimum. The

output can be reset by either toggling the EN inputs of the

MIC2072-1, -2 or by removing the load. Latching the output

off provides a circuit breaker mode of operation which re-

duces power consumption during fault conditions.

Typical Application

MIC2012P

BUS

D+

D–

GND

MAIN

AUX OUT1

Downstream

USB

Port 1

100µF

5V MAIN

ATX Power Supply

S3#

FAULT1#

FAULT2#

BUS

D+

D–

GND

Downstream

USB

Port 2

OUT2

GND

5V STANDBY

82801AA or Equivalent

SLP S3#

SLP S5#

OC0

OC1

Overcurrent Port 1

S3 Control

Overcurrent Port 1

100µF

Figure 1. USB Wakeup with Control Input

Features

• Compliant to USB power distribution specifications

• Two completely independent switches

• Integrated switching matrix supports ACPI S0/S3 state

transitions without external FET circuits

• Make-before-break switching ensures glitch-free

transitions

• No back-feed of auxiliary supply onto main supply

during standby mode

• Bi-level current-limit preserves auxiliary supply voltage

regulation in standby mode

• Thermally isolated channels

• Thermal shutdown protection

• Fault status outputs with filter prevents false assertions

during hot-plug events

• Latched thermal shutdown options with auto-reset

(MIC2072)

• Undervoltage lockout

Applications

• Desktop PCs

• Notebook PCs

• Notebook Docking stations

• LAN Servers

• PC Motherboards

Micrel, Inc. • 1849 Fortune Drive • San Jose, CA 95131 • USA • tel + 1 (408) 944-0800 • fax + 1 (408) 944-0970 • http://www.micrel.com

MIC2012 Micrel

MIC2012/2072 2 September 2000

Pin Configuration

1FAULT1

S3#

AUX

GND

8FAULT2

OUT1

MAIN

OUT2

8-Pin SOIC (M)

Ordering Information

Fault Circuit Breaker Temperature

Part Number Enable Output Function Range Package

MIC2012CM n/a Open-Drain 0°C to +70°C 8-lead SOIC

MIC2012PCM* n/a Internal Pull-Up 0°C to +70°C 8-lead SOIC

MIC2012-1CQS* Active High Open-Drain 0°C to +70°C 16-lead QSOP

MIC2012-1PCQS* Active High Internal Pull-Up 0°C to +70°C 16-lead QSOP

MIC2012-2CQS* Active Low Open-Drain 0°C to +70°C 16-lead QSOP

MIC2012-2PCQS* Active Low Internal Pull-Up 0°C to +70°C 16-lead QSOP

MIC2072CM* n/a Open-Drain ✓0°C to +70°C 8-lead SOIC

MIC2072PCM* n/a Internal Pull-Up ✓0°C to +70°C 8-lead SOIC

MIC2072-1CQS* Active High Open-Drain ✓0°C to +70°C 16-lead QSOP

MIC2072-1PCQS* Active High Internal Pull-Up ✓0°C to +70°C 16-lead QSOP

MIC2072-2CQS Active Low Open-Drain ✓0°C to +70°C 16-lead QSOP

MIC2072-2PCQS* Active Low Internal Pull-Up ✓0°C to +70°C 16-lead QSOP

* Contact factory for availability.

1FAULT1

EN1

S3#

AUX

GND

16 FAULT2

EN2

OUT1

MAIN

OUT2

16-Pin QSOP (QS)

September 2000 3 MIC2012/2072

MIC2012 Micrel

Pin Description

Pin Number Pin Number Pin Name Pin Function

(MIC2012)

(MIC2012-1, -2)

1 1 FAULT1 Fault Status (Output): Internal pull-up or open-drain. Asserted LOW when

Channel is in a thermal shutdown state or overcurrent condition for more

than 5ms. MIC2072 latches this output in its asserted state upon an

overcurrent condition. Toggling EN1 or removing the load will reset the

circuit breaker latch and deassert FAULT1.

n/a 2 EN1 Enable (Input): Channel 1, active-high (–1) or active-low (–2). Toggling this

input also resets the latched output of the MIC2072.

2 3 S3# Control (Input): When this input is HIGH, the MAIN inputs are connected to

OUT1 and OUT2 via 100mΩ MOSFET switches. When this input is LOW the

AUX inputs are connected to OUT1 and OUT2 via 500mΩ MOSFET

switches.

3 5 AUX Auxiliary 5V Supply (Input): Also used as power supply for internal circuitry.

n/a 4, 6, 7 NC No Connection: This pin may be connected to other pins without restriction.

4 8 GND Ground

5 9, 10 OUT2 Channel 2 (Output): For MIC2012-1, -2 both pins must be externally

connected together.

6 11, 12 MAIN 5V Main Supply (Input): All MAIN inputs must be connected together

externally.

7 13, 14 OUT1 Channel 1 (Output): For MIC2012-1, -2 both pins must be externally

connected together.

n/a 15 EN2 Enable (Input): Channel 2, active-high (–1) or active-low (–2). Toggling this

input also resets the latched output of the MIC2072.

8 16 FAULT2 Fault Status (Output): Internal pull-up or open-drain. Asserted LOW when

Channel 2 is in a thermal shutdown state or overcurrent condition for more

than 5ms. MIC2072 latches this output in its asserted state upon an

overcurrent condition. Toggling EN2 or removing the load will reset the

circuit breaker latch and deassert FAULT2.

MIC2012 Micrel

MIC2012/2072 4 September 2000

Absolute Maximum Ratings (Note 1, Note 4)

Supply Voltage (VIN, VMAIN, VAUX) ................... –0.3V to 6V

EN1, EN2, S3# Input Pins................................ –0.3V to 6V

FAULT#, OUT1, OUT2 Output Pins................. –0.3V to 6V

FAULT Output Current ...............................................25mA

ESD Rating, Note 3 ......................................................2kV

Operating Ratings (Note 2)

Supply Voltage (VMAIN, VAUX) ..................... +4.5V to +5.5V

Ambient Temperature (TA)........................... –0°C to +70°C

Junction Temperature (TJ) ....................... Internally Limited

Package Thermal Resistance

QSOP (θJA) .......................................................163°C/W

SOIC (θJA).........................................................160°C/W

Electrical Characteristics

VMAIN = 5V; AUX = 5V; TA = 25°C; unless noted

Symbol Parameter Condition Min Typ Max Units

VMAIN MAIN Supply Voltage 4.5 5.0 5.5 V

IMAIN (ON) MAIN Supply Current Switches On S3# = 1, no load 16 22 µA

Note 5

IMAIN (OFF) MAIN Supply Current Switches Off S3# = 1, no load 5 µA

Note 5, (MIC20x2-1, MIC20x2-2 only)

ILEAK MAIN Reverse Leakage Current, S3# = 0, both switches ON, VMAIN = 0V –10 +10 µA

VAUX AUX Supply Voltage 4.5 5.0 5.5 V

IAUX ON AUX Supply Current, No load .6 1 mA

both switches on, Note 5 S3# = 0

IAUX OFF AUX Supply Current, switches No load 5 µA

off. (MIC20x2-1, MIC20x2-2 only) S3# = 0

VUV/AUX AUX Undervoltage Lockout VAUX increasing 3.5 3.7 4.0 V

Threshold VAUX decreasing 3.3 3.5 3.8 V

VHYS AUX Undervoltage Lockout 200 mV

Hysteresis

RDSMAIN MAIN On-Resistance, Each Output S3# = 1, IOUT = 500mA 100 140 mΩ

RDSAUX AUX On-Resistance, Each Output S3# = 0, IOUT = 100mA 500 700 mΩ

ILIMIT(MAIN) MAIN Current-Limit Threshold S3# = 1, VOUT = 4.0V, ramped load 0.5 1.25 A

MAIN Short-Circuit Current-Limit VOUT = 0V 0.5 1.25 A

ILIMIT(AUX) AUXCurrent-Limit Threshold S3# = 0, VOUT = 4.0V, ramped load 105 150 195 mA

AUX Short-Circuit Current-Limit VOUT = 0V, COUT = 100µF80mA

VTH S3#, EN1, EN2. Input High-to-Low transition .8 1.5 V

Threshold Voltage Low-to-High transition 1.7 2.0 V

(EN1, EN2, for MIC20x2-x only)

VHYS EN1, EN2 and S3# Input Hysteresis 200 mV

(EN1, EN2, for MIC20x2-x only)

IIN S3#, EN1, EN2 Input Current VS3/EN = 5V, 0V –11µA

(EN1, EN2, for MIC20x2-x only)

IOFF OUT1, OUT2 Leakage Current Outputs are off, VOUT = 0 –10 10 µA

(MIC2012-x, MIC2072-x only)

Pull-Up Current During Latched Outputs latched off 1 mA

Output State (MIC2072-1, -2)

September 2000 5 MIC2012/2072

MIC2012 Micrel

Symbol Parameter Condition Min Typ Max Units

VTH LATCH Latch Reset Threshold VOUT Rising 1.95 V

(MIC2072, MIC2072-x only)

Minimum Output Slew Rate .4 V/s

to Reset Latch

(MIC2072, MIC2072-x only), Note 6

Overtemperature Threshold TJ increasing, single channel 140 °C

TJ decreasing, single channel 120 °C

TJ increasing, both channels 160 °C

TJ decreasing, both channels 150 °C

VOL FAULT Output Low Voltage IFAULT = 5mA 0.2 V

VOH FAULT Output High Voltage IFAULT = –20µA4V

(MIC2012-1P,-2P),(MIC2072-1P,-2P)

FAULT Output Off Current VFAULT = 5V .2 10 µA

(Not Applicable to 'P' Options)

THMAIN to S3# Hold Time, Note 6 Figure 5 5 ms

TSMAIN to S3# Set-up Time, Note 6 Figure 5 0 ms

tDLY FAULT Delay Filter Response Time Output shorted to ground, Figure 4 5 10 20 ms

(Overcurrent only), Note 7

tOC Overcurrent Response Time Output shorted to ground, Figure 4

MAIN output 2 µs

AUX output 2 µs

tON(MAIN) MAIN Output Turn-On Time RL = 10Ω, CL = 1µF, Figure 3 2 ms

tOFF(MAIN) MAIN Output Turn-Off Time RL = 10Ω, CL = 1µF, Figure 3 35 µs

(MIC20x2-x only)

tr(MAIN) MAIN Output Rise Time RL = 10Ω, CL = 1µF, Figure 3 2 ms

tf(MAIN) MAIN Output Fall Time RL = 10Ω, CL = 1µF, Figure 3 32 µs

(MIC20x2-x only)

tON(AUX) AUX Output Turn-On Time RL = 50Ω, CL = 1µF, Figure 3 0.6 ms

tOFF(AUX) AUX Output Turn-Off Time RL = 50Ω, CL = 1µF, Figure 3 120 µs

(MIC20x2-x only)

tr(AUX) AUX Output Rise Time RL = 50Ω, CL = 1µF, Figure 3 0.5 ms

tf(AUX) AUX Output Fall Time RL = 50Ω, CL = 1µF, Figure 3 115 µs

(MIC20x2-x only)

tXMA MAIN to AUX S3# transition to 0 5 7.5 ms

Cross Conduction Time, Note 8

tXAM AUX to MAIN S3# transition to 1 5 7.5 ms

Cross Conduction Time, Note 8

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. Human body model, 1.5k in series with 100pF.

Note 4. All voltages are referenced to ground.

Note 5. For MIC20x2-1(P) OFF occurs when VEN < 0.8V and ON occurs when VEN > 2.4V. For MIC20x2-2(P) OFF occurs when VEN > 2.4V and ON

occurs when VEN < 0.8V.

Note 6. Guaranteed by design. Not production tested.

Note 7. Assumes only one channel in current-limit. Delay circuitry is shared among channels so it is possible for tDLY to be 40ms max if one channel

enters current-limit as the other is about to time-out.

Note 8. Cross conduction time is the duration in which both MAIN and AUX internal switches are on subsequent to S3# transitioning.

MIC2012 Micrel

MIC2012/2072 6 September 2000

Test Circuit

Device

Under

Test CL

OUT

VOUT

IOUT

90%

OUT

10%

90%

10%

September 2000 7 MIC2012/2072

MIC2012 Micrel

Timing Diagrams

50%

90%

OUT

10%

OFF

Figure 2. MIC2012/72-1

50%

90%

OUT

10%

OFF

Figure 3. MIC2012/72-2

Output shorted to ground

VOUT

FAULT#

ILIMIT

tOC tDLY

IOUT

Figure 4. Overcurrent Response Timing

MAIN

S3# 1.5V

1.5V

Figure 5. MAIN to S3# Timing

MIC2012 Micrel

MIC2012/2072 8 September 2000

Functional Description

The MIC2012/2072 are designed to support the power distri-

bution requirements for USB wakeup from the ACPI S3 state.

It integrates two independent channels under control of input

S3#. When S3# is asserted LOW (S3 state) the MIC2012/

2072 will switch a 500mΩ, 100mA MOSFET switch from the

AUX input to each of its two outputs. Conversely when the

S3# input is HIGH (S0 state) the MIC2012/72 will switch a

100mΩ, 500mA MOSFET switch from the MAIN input to each

of its two outputs. The lower current limit during the ACPI S3

state helps to ensure that the standby supply maintains

regulation even during fault conditions.

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. Thermal shutdown shuts off

the output MOSFET and asserts the FAULT output if the die

temperature reaches 140°C and the overheated channel is in

current limit. The other channel is not affected. If, however,

the die temperature exceeds 160°C, both channels will be

shut off even if neither channel is in current limit.

Power Dissipation

The device’s junction temperature depends on several fac-

tors such as the load, PCB layout, ambient temperature and

package type. The power dissipated in each channel is

PD = RDS(on) × IOUT2 where RDS(on) is the on-resistance of the

internal MOSFETs and IOUT is the continuous output current.

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:

TJ = PD × θJA + TA

where:

Functional Diagram

Current

Limit

10ms

Timer

Charge Pump

Gate Control

S3#

Current

Limit

MAIN

OUT

AUX

/FAULT

AUX

Latch

To Other Channel

MAIN

FET

AUX

FET

*MIC2070-1/2 Only

Thermal

Sense

* 'P' options only

TJ = junction temperature

TA = ambient temperature

θJA = is the thermal resistance of the package

Current Sensing and Limiting

The current-limit thresholds are preset internally for each

state. The preset level prevents damage to the device and

external load but still allows a minimum current of 100mA or

500mA to be delivered to the load depending on the state of

the device according to the S3# input. When S3# is LOW the

current-limit is set at 100mA minimum. When S3# is HIGH the

current-limit is set at 500mA minimum.

Should an over-current condition last longer than tDLY, the

MIC2072 will latch the faulty output off. The output will remain

off until either the load is removed or the EN signal (MIC2072-

1, -2) is toggled. When the MIC2072 enters a latched output

condition a 1mA pull-up current source is activated. This

provides a way to automatically reset the output once the load

is removed without the need to toggle the enable input such

as in the MIC2072. Please refer to Figure 7 for timing details.

The MIC2012 will automatically reset its output when the die

temperature cools down to 120°C. The MIC2012 output and

FAULT signal will continue to cycle on and off until the device

is disabled or the fault is removed. Figure 6 depicts typical

timing. Depending on PCB layout, package, ambient tem-

perature, etc., it may take several hundred milliseconds from

the incidence of the fault to the output MOSFET being shut

off. This time duration will be shortest in the case of a dead

short on the output.

September 2000 9 MIC2012/2072

MIC2012 Micrel

Fault Status Output

The FAULT signal is an active-low output with an open-drain

or weak pull-up configuration. FAULT is asserted (active-low)

when either an overcurrent or thermal shutdown condition

occurs. In the case of an overcurrent condition, FAULT will be

asserted only after the flag response delay time, tDLY, has

elapsed. This ensures that FAULT 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 FAULT response

delay time tDLY is typically 10ms.

Undervoltage Lockout

Undervoltage lockout (UVLO) prevents the output MOSFET

from turning on until the AUX input exceeds approximately

3.5V. UVLO ensures that the output MOSFETs remain off to

prevent high transient inrush current due to stray or bulk load

capacitance. This helps to ensure that the power supply

voltage regulation is preserved and also prevents possible

damage to sensitive components.

(MIC2010-2)

VOUT

Overcurrent Fault

Thermal Shutdown

Reached

FAULT

Figure 6. MIC2012 System Timing

(MIC2070-2)

OUT

Overcurrent Fault

Load Removed–

Output Reset

FAULT

Figure 7. MIC2072 System Timing—

Output Resets When Load is Removed

MIC2012 Micrel

MIC2012/2072 10 September 2000

Package Information

45°

0.2284 (5.801)

0.2240 (5.690)

SEATING

PLANE

0.009 (0.2286)

REF 0.012 (0.30)

0.008 (0.20)

0.157 (3.99)

0.150 (3.81)

0.050 (1.27)

0.016 (0.40)

0.0688 (1.748)

0.0532 (1.351)

0.196 (4.98)

0.189 (4.80)

0.025 (0.635)

BSC

PIN 1

DIMENSIONS:

INCHES (MM)

0.0098 (0.249)

0.0040 (0.102) 0.0098 (0.249)

0.0075 (0.190) 8°

0°

16-Pin QSOP (QS)

45°

0°–8°

0.244 (6.20)

0.228 (5.79)

0.197 (5.0)

0.189 (4.8) SEATING

PLANE

0.026 (0.65)

MAX)

0.010 (0.25)

0.007 (0.18)

0.064 (1.63)

0.045 (1.14)

0.0098 (0.249)

0.0040 (0.102)

0.020 (0.51)

0.013 (0.33)

0.157 (3.99)

0.150 (3.81)

0.050 (1.27)

TYP

PIN 1

DIMENSIONS:

INCHES (MM)

0.050 (1.27)

0.016 (0.40)

8-Pin SOIC (M)

MICREL INC. 1849 FORTUNE DRIVE SAN JOSE, CA 95131 USA

TEL + 1 (408) 944-0800 FAX + 1 (408) 944-0970 WEB http://www.micrel.com

This information is believed to be accurate and reliable, however no responsibility is assumed by Micrel for its use nor for any infringement of patents or

other rights of third parties resulting from its use. No license is granted by implication or otherwise under any patent or patent right of Micrel Inc.