Datasheet MIC2524-1BN, MIC2524-1BWM, MIC2524-2BN, MIC2524-2BWM, MIC2527-2BWM Datasheet (MICREL)

MIC2524/2527 Micrel

MIC2524/2527

Quad USB Power Control Switch

Not Recommended for New Designs

Refer to MIC2027

General Description

The MIC2524 and MIC2527 are cost-effective high-side
power switches with four independently controlled channels,
optimized for self-powered and bus-powered Universal Se­rial Bus (USB) applications. Few external components are
necessary to satisfy USB requirements.

The MIC2524/7 satisfies the following USB requirements:
each switch channel 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 require­ments; 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.

Additional features include thermal shutdown to prevent
catastrophic switch failure from high-current loads,
undervoltage lockout (UVLO) to ensure that the device re­mains off unless there is a valid input voltage present, and

3.3V and 5V logic compatible enable inputs.
The MIC2524/7 is available in active-high and active-low

versions in 16-pin DIP and SOIC packages.

Features

• Compliant to USB specifications

• UL Recognized Component

• 4 independent switches

• 3V to 5.5V input

• 500mA minimum continuous load current per port

• 140mΩ maximum on-resistance (MIC2524)

• 1.25A maximum short circuit current limit

• Individual open-drain fault flag pins

• 220µA on-state supply current

• 1µA typical off-state supply current

• Output can be forced higher than input (off-state)

• Thermal shutdown

• 2.4V typical undervoltage lockout (UVLO)

• 1ms turn-on (soft-start) and fast turnoff

• Active-high or active-low enable versions

• 16-pin SOIC and DIP packages

Applications

• USB bus-powered hubs

• USB self-powered hubs

• USB monitors

• USB printers

Typical Application

MIC2527

5.1V ± 3%
5V ± 1%

or

MIC2524

5V ±3%

MIC5207-3.3

LDO Regulator

IN OUT

4.7
µF

GND

Bold lines indicate

0.1" wide, 1-oz. copper
high-current traces.

* 33µF, 16V tantalum or 100µF, 10V electrolytic per port

3.3V USB Controller

V+

1µF

OVERCURRENT

D+
D–

10k

GND

ON/OFF

27k

MIC2524
MIC2527

ENA
FLGA IN
ENB OUTA
FLGB

OUTB

ENC

OUTC

OUTDFLGC
END
FLGD GND

GND

Ferrite

Bead

V

BUS

33µF*

IN

0.1
µF

33µF*

33µF*

33µF*

0.01µF

0.01µF

0.01µF

0.01µF

D+

D–

GND

V

BUS

D+

D–

GND

V

BUS

D+

D–

GND

V

BUS

D+

D–

GND

Downstream

USB

Port 1

500mA max.

Downstream

USB

Port 2

500mA max.

Downstream

USB

Port 3

500mA max.

Downstream

USB

Port 4

500mA max.

UL Recognized Component

Micrel, Inc. • 1849 Fortune Drive • San Jose, CA 95131 • USA • tel + 1 [phone] • fax + 1 [phone] • http://www.micrel.com

June 1999 1 MIC2524/2527

4-Port Self-Powered Hub

MIC2524/2527 Micrel

Ordering Information

Part Number On-Resistance Enable Temperature Range Package

MIC2524-1BWM 100mΩ typ. Active High –40°C to +85°C 16-Pin SOIC
MIC2524-1BN 100mΩ typ. Active High –40°C to +85°C 16-pin DIP
MIC2524-2BWM 100mΩ typ. Active Low –40°C to +85°C 16-Pin SOIC
MIC2524-2BN 100mΩ typ. Active Low –40°C to +85°C 16-pin DIP
MIC2527-1BWM 200mΩ typ. Active High –40°C to +85°C 16-Pin SOIC
MIC2527-1BN 200mΩ typ. Active High –40°C to +85°C 16-pin DIP
MIC2527-2BWM 200mΩ typ. Active Low –40°C to +85°C 16-Pin SOIC
MIC2527-2BN 200mΩ typ. Active Low –40°C to +85°C 16-pin DIP

Pin Configuration

FLGA

ENA

OUTA

GND

IN(C/D)

OUTC

ENC

FLGC

1
2
3
4
5
6
7
8

16
15
14
13
12
11
10

9

FLGB
ENB
OUTB
IN(A/B)
GND
OUTD
END
FLGD

16-Pin SOIC (WM)

16-Pin DIP (N)

Pin Description

Pin Number Pin Name Pin Function

1 FLGA Flag A: (Output): Channel A open-drain fault flag output.
2 ENA Enable A (Input): Channel A control input.
3 OUTA Output A: Channel A switch output.

4, 12 GND Ground: Supply return. Connect both pins to ground.

5 IN(C/D) Supply Input: Channel C and D switch, logic, and charge-pump supply input.
6 OUTC Output C: Channel C switch output.
7 ENC Enable C (Input): Channel C control input.
8 FLGC Flag C (Output): Channel C open-drain fault flag output.

9 FLGD Flag D (Output): Channel D open-drain fault flag output.
10 END Enable D (Input): Channel D control input.
11 OUTD Output D: Channel D switch output.
13 IN(A/B) Supply Input: Channel A and B switch, logic, and charge-pump supply input.
14 OUTB Output B: Channel B switch output.
15 ENB Enable B (Input): Channel B control input.
16 FLGB Flag B (Output): Channel B open-drain fault flag output.

ENA 2

FLGA 1
ENB 15

FLGB 16

ENC 7

FLGC 8
END 10

FLGD 9

Functional Pinout

LOGIC,

CHARGE

PUMP

LOGIC,

CHARGE

PUMP

LOGIC,

CHARGE

PUMP

LOGIC,

CHARGE

PUMP

3 OUTA

13 IN(A/B)

14 OUTB

6 OUTC

5 IN(C/D)

11 OUTD

124 GND

MIC2524/2527 2 June 1999

MIC2524/2527 Micrel

Absolute Maximum Ratings (Note 1)

Supply Voltage (V
Fault Flag Voltage (V
Fault Flag Current (I
Output Voltage (V
Output Current (I
Control Input (V

) .....................................................+6V

IN

)..............................................+6V

FLG

) ............................................50mA

FLG

) ..................................................+6V

OUT

)...............................Internally Limited

OUT

)......................................... –0.3V to 12V

EN

Operating Ratings (Note 2)

Supply Voltage (V
Ambient Operating Temperature (T
Thermal Resistance

SOIC (θ

).........................................................120°C/W

JA

DIP(θJA).............................................................130°C/W

) ...................................... +3V to +5.5V

IN

) ........ –40°C to +85°C

A

Storage Temperature (TS) ....................... –65°C to +150°C

Lead Temperature (Soldering 5 sec.) ....................... 260°C

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

Electrical Characteristics

VIN = +5V; TA = 25°C; unless noted.

Parameter Condition Min Typ Max Units
Supply Current Note 4, switch off, OUT = open 1.5 10 µA

Note 4, all switches on, OUT = open 220 320 µA

Enable Input Threshold low-to-high transition 2.1 2.4 V

high-to-low transition, Note 4 0.8 1.9 V
Enable Input Current VEN = 0V to 5.5V –1 ±0.01 1 µA
Enable Input Capacitance 1pF
Switch Resistance MIC2524, I

MIC2527, I
Output Turn-On Delay RL = 10Ω each output 0.5 ms
Output Turn-On Rise Time RL = 10Ω each output 1 ms
Output Turnoff Delay RL = 10Ω each output 1 20 µs
Output Turnoff Fall Time RL = 10Ω each output 1 20 µs
Output Leakage Current each output (output disabled) 10 µA
Continuous Load Current each output 0.5 A
Short-Circuit Current Limit each output (enable into load), V
Current-Limit Threshold ramped load applied to enabled output, V
Overtemperature Shutdown TJ increasing 135 °C

Threshold
Error Flag Output Resistance VIN = 5V, IL = 10mA 10 Ω

Error Flag Off Current V
UVLO Threshold VIN = increasing 2.5 V

TJ decreasing 125 °C

VIN = 3.3V, IL = 10mA 15 Ω

= 5V 0.01 1 µA

FLAG

VIN = decreasing 2.3 V

= 500mA, each switch 100 140 mΩ

OUT

= 500mA, each switch 200 300 mΩ

OUT

= 4.0V 0.5 0.75 1.25 A

OUT

≤ 4.0V, Note 5 1.6 2.2 A

OUT

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. Off is ≤ 0.8V and on is ≥ 2.4V for the MIC252x-1. Off is ≥ 2.4V and on is ≤ 0.8V for the MIC252x-2. The enable input has approximately 200mV

Note 5. See “Functional Characteristics: Current-Limit Response” photo.

of hysteresis. See control threshold charts.

June 1999 3 MIC2524/2527

MIC2524/2527 Micrel

Typical Characteristics

VIN = 5V; TA = 25°C; one switch section; unless noted.

Output On-Resistance

vs. Supply Voltage

110

100

90

OUTPUT RESISTANCE (mΩ)

80

3.0 3.5 4.0 4.5 5 5.5

Awaiting Full

Characterization

Data

RL = 44Ω

T = 25°C

SUPPLY VOLTAGE (V)

On-State Supply Current

vs. Supply Voltage

500

400

300

200

100

SUPPLY CURRENT (µA)

ALL SWITCHES ON

0

02468

SUPPLY VOLTAGE (V)

Output On-Resistance

140

120

100

ON-RESISTANCE (mΩ)

vs. Temperature

80

60

-40 -20 0 20 40 60 80 100

TEMPERATURE (°C)

RL = 44Ω

VIN = 5V

Off-State Supply Current

vs. Supply Voltage

2.0

1.5

1.0

0.5

SUPPLY CURRENT (µA)

0

2345678

ALL SWITCHES OFF

SUPPLY VOLTAGE (V)

UVLO Threshold Voltage

3.0

2.5

2.0

THRESHOLD VOLTAGE (V)

1.5

vs. Temperature

RISING

FALLING

-40 -20 0 20 40 60 80 100

TEMPERATURE (°C)

Control Threshold

vs. Supply Voltage

2.5

2.0

1.5

THRESHOLD VOLTAGE (V)

1.0
2345

V

RISING

CTL

V

FALLING

CTL

SUPPLY VOLTAGE (V)

On-State Supply Current

400
350
300
250
200
150
100

SUPPLY CURRENT (µA)

vs. Temperature

50

0

-40 -20 0 20 40 60 80 100

ALL SWITCHES ON

TEMPERATURE (°C)

Output Rise Time

vs. Temperature

5

4

3

2

TIME (µs)

1

0

-40 -20 0 20 40 60 80 100

Awaiting Full

Characterization

Data

TEMPERATURE (°C)

Off-State Supply Current

2.0

1.5

1.0

0.5

SUPPLY CURRENT (µA)

vs. Temperature

ALL SWITCHES OFF

0

-40 -20 0 20 40 60 80 100

TEMPERATURE (°C)

Output Fall Time

1.0

0.8

0.6

0.4

TIME (ms)

0.2

vs. Temperature

Awaiting Full

Characterization

Data

0

-40 -20 0 20 40 60 80 100

TEMPERATURE (°C)

Control Threshold

2.5

2.0

1.5

ENABLE VOLTAGE (V)

1.0

vs. Temperature

VEN RISING

VEN FALLING

VIN = 5V

-40 -20 0 20 40 60 80 100

TEMPERATURE (°C)

Current-Limit Threshold

2.0

1.8

1.6

1.4

CURRENT (A)

1.2

1.0

vs. Temperature

CURRENT LIMIT
THRESHOLD

SHORT CIRCUIT
CURRENT LIMIT

-25 0 25 50 75 100

TEMPERATURE (°C)

MIC2524/2527 4 June 1999

MIC2524/2527 Micrel

Functional Characteristics

V

V

V

I

V

V

EN

OUT

FLG

OUT

EN

FLG

Input V oltage

Response

EN

V

(5V/div.)

2.6V (UVLO) Threshold

(2V/div.)

V

V

FLG

(5V/div.)

OUT

(2V/div.)

T urn-On, T urnoff

Characteristics

(2V/div.)

= 5.0V

V

(5V/div.)

(200mA/div.)

TIME (100ns/div.)

T urn-On, T urnoff

Characteristics

(5V/div.)

IN

RL = 35Ω

= 15µF

C

L

I

V

OUT

(100mA/div.)

TIME (2.5ms/div.)

Short Circuit Response

(Short Applied to Output)

FLG

(5V/div.)

144mA

V

IN

RL = 35Ω

CL = 10µF

= 5.0V

(5V/div.)

V

I

OUT

OUT

OUT

V

I

OUT

(2V/div.)

1A Short Circuit Current Limit

(1A/div.)

Thermal Shutdown

TIME (500ms/div.)

(2V/div.)

144mA

RL = 35Ω

= 150µF

C

L

(100mA/div.)

TIME (2.5ms/div.)

Short Circuit Response

Enable into Short Circuit

EN

V

(5V/div.)

FLG

V

(5V/div.)

OUT

V

I

OUT

(2V/div.)

1.1A Short Circuit

(1A/div.)

Current-Limiting

TIME (250ms/div.)

Thermal

Shutdown

June 1999 5 MIC2524/2527

MIC2524/2527 Micrel

OUT

V

(5V/div.)

FLG

V

(5V/div.)

OUT

I

(1A/div.)

Test Circuit

Short Circuit Transient Response

(Short Applied to Output)

2.76A

1A Current Limit

TIME (500µs/div.)

5V

10k

0.1µF

MIC2524/7

ENA
FLGA NC
ENB OUTA
FLGB

OUTB

ENC

OUTC

OUTDFLGC
END
FLGD

NC

GND

Current-Limit Response

(Ramped Load)

FLG

V

(5V/div.)

OUT

V

(2V/div.)

Current Limit

Threshold

OUT

I

(1A/div.)

TIME (1ms/div.)

(1 output shown)

Ferrite

IN

Bead

I

OUT

I

C

L

R

L

LOAD

(for Current
Limit Response)

1A Current

Limit

Functional Characteristics Test Circuit

MIC2524/2527 6 June 1999

MIC2524/2527 Micrel

Block Diagrams

FLGA

OUTA

ENA

CHARGE

PUMP

GATE

CONTROL

CURRENT

LIMIT

ENB

ENC

OSC.

CHARGE

PUMP

CHARGE

PUMP

OSC.

THERMAL

SHUTDOWN

THERMAL

SHUTDOWN

UVLO

UVLO

REFERENCE

GATE

CONTROL

GATE

CONTROL

REFERENCE

1.2V

1.2V

CURRENT

LIMIT

CURRENT

LIMIT

IN (A/B)

OUTB
FLGB

FLGC

OUTC

IN (C/D)

END

MIC2527

CHARGE

PUMP

GND

GATE

CONTROL

CURRENT

LIMIT

OUTD
FLGD

June 1999 7 MIC2524/2527

MIC2524/2527 Micrel

Functional Description

The MIC2524/7-1 and MIC2524/7-2 are quad high-side
switches with active-high and active-low enable inputs, re­spectively. Fault conditions turn off or inhibit turn-on of one or
more of the output transistors, depending upon the type of
fault, and activate the open-drain error flag transistors mak­ing them sink current to ground.

Input and Output

IN (input) is the power supply connection to the logic circuitry
and the drain of the output MOSFET. OUTx (output) is the
source of its respective MOSFET. In a typical circuit, current
flows through the switch from IN to OUT toward the load. If
V

is greater than VIN, current will flow from OUT to IN

OUT

since the MOSFET is bidirectional when on.
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 (V
this situation, the MIC2524/7 prevents reverse current flow.
If VIN < 2.5V, UVLO disables both switches.

Thermal Shutdown

Thermal shutdown shuts off the affected output MOSFETs
and signals all fault flags if the die temperature exceeds
135°C. 10°C of hysteresis prevents the switch from turning on
until the die temperature drops to 125°C. Overtemperature
detection functions only when at least one switch is enabled.

Current Limit Induced Thermal Shutdown

Internal circuitry increases the output MOSFET on-resis­tance until the series combination of the MOSFET on-resis­tance and the load impedance limit current to typically 850mA.
The increase in power dissipation, in most cases, will cause
the MIC2524/7 to go into thermal shutdown, disabling af­fected channels. When this is undesirable, thermal shutdown
can be avoided by externally responding to the fault and
disabling the current limited channel before the shutdown
temperature is reached. The delay between the flag indica­tion of a current limit fault and thermal shutdown will vary with
ambient temperature, board layout, and load impedance, but
is typically several hundred milliseconds. The USB controller
must therefore recognize a fault and disable the appropriate
channel within this time. If the fault is not removed or the
switch is not disabled within this time, then the device will
enter into a thermal oscillation of about 2Hz. This does not
cause any damage to the device. Refer to “Functional Char­acteristics: Thermal Shutdown Response.”

> VIN) when the output is off. In

OUT

Undervoltage Lockout

UVLO (undervoltage lockout) prevents the output MOSFET
from turning on until VIN exceeds approximately 2.5V. In the
undervoltage state, the FLAG will be low. After the switch
turns on, if the voltage drops below approximately 2.3V,
UVLO shuts off the output MOSFET and signals fault flag.
Undervoltage detection functions only when at least one
switch is enabled.

Current Sensing and Limiting

The current-limit threshold is preset internally. The preset
level prevents damage to the output MOSFET and external
load but allows a minimum current of 0.5A through the output
MOSFET of each channel.

The current-limit circuit senses a portion of the output FET
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 powered on or enabled into a heavy load or short­circuit, the switch immediately goes into a constant-current
mode, reducing the output voltage. The fault flag goes low
until the load is reduced. See the “Functional Characteristics:
Short Circuit Response, Enabled into Short Circuit” photo.

Short Circuit Applied to Output

When a heavy load is applied, a large transient current may
flow until the current limit circuitry will respond. Once this
occurs, the device limits current to less than the short-circuit
current limit specification. See the “Short Circuit Transient
Response, Short Applied to Output” graph.

Current-Limit Response

The MIC2524/7 current-limit profile exhibits a small foldback
effect of approximately 500mA. Once this current-limit thresh­old is exceeded the device enters constant-current mode.
This constant current is specified as the short circuit current
limit in the “Electrical Characteristics” table. It is important to
note that the MIC2524/7 will deliver load current up to the
current-limit threshold which is typically 1.6A. Refer to “Func-
tional Characteristics: Current-Limit Response” photo for
details.

Fault Flag

FLG is an N-channel, open-drain MOSFET output. The fault­flag is active (low) for one or more of the following conditions:
undervoltage (while 2V < VIN < 2.7), current limit, or thermal
shutdown. The flag output MOSFET is capable of sinking a
10mA load to typically 100mV above ground. Multiple FLG
pins may be “wire NORed” to a common pull-up resistor.

MIC2524/2527 8 June 1999

MIC2524/2527 Micrel

Applications Information

Supply Filtering

A 0.1µF to 1µF bypass capacitor from IN to GND, located at
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.

Input or output transients must not exceed the absolute
maximum supply voltage (V
duration.

V

IN

2.7V to 5.5V

0.1µF to 1µF

MIC2524/7

FLGA FLGB
ENA
OUTA OUTB
GND IN
IN GND
OUTC
ENC END
FLGC FLGD

Figure 1. Supply Bypassing

= 7V) even for a short

IN max

ENB

0.1µF to 1µF

OUTD

Transient Overcurrent Filter

When the MIC2524/7 is enabled, large values of capacitance
at the output of the device will cause inrush current to exceed
the short circuit current-limit threshold of the device and
assert the flag. The duration of this time will depend on the
size of the output capacitance. Refer to the “Functional
Characteristics” turn-on and turnoff behaviors for details.
During the capacitance charging time, the device enters into
constant-current mode. As the capacitance is charged, the
current decreases below the short circuit current-limit thresh­old, and the flag will then be deasserted.

In USB applications, it is required that output bulk capaci­tance is utilized to support hot-plug events. When the
MIC2524/7 is enabled, the flag may go active for about 1ms
due to inrush current exceeding the current-limit setpoint.
Additionally, during hot-plug events, inrush currents may also
cause the flag to go active for 30µs. Since these conditions
are not valid overcurrent faults, the USB controller must
ignore the flag during these events. To prevent this erroneous
overcurrent reporting, a 1ms RC filter as shown in Figure 2
may be used. Alternatively, a 1ms debounce routine may be
programmed into the USB logic controller, eliminating the
need for the RC filter.

Enable Input

EN must be driven logic high or logic low for a clearly defined
input. Floating the input may cause unpredictable operation.
EN should not be allowed to go negative with respect to GND.

Soft Start

The MIC2524/7 presents a high impedance when off, and
slowly becomes a low impedance as it turns on. This reduces
inrush current and related voltage drop that results from
charging a capacitive load, satisfying the USB voltage droop
requirements.

USB Controller

OVERCURRENT

10k

10k

0.1µF

Figure 2. Transient Filter

FLGA
FLGB
FLGC
FLGD

June 1999 9 MIC2524/2527

MIC2524/2527 Micrel

Package Information

PIN 1

0.157 (3.99)

0.150 (3.81)

0.020 (0.51)
REF

0.0648 (1.646)

0.0434 (1.102)

.250±0.005

(6.350±0.127)

0.025±0.015

(0.635±0.381)

0.130±0.005

(3.302±0.127)

0.050 (1.27)
BSC

0.394 (10.00)

0.386 (9.80)

0.020 (0.51)

0.013 (0.33)

16-Pin SOP (M)

0.780
MAX

(19.812)

0.040

(1.016)

0.0098 (0.249)

0.0040 (0.102)

SEATING

PLANE

TYP

DIMENSIONS:

INCHES (MM)

0.050 (1.27)

0.016 (0.40)

PIN 1

0.030-0.110

(0.762-2.794)

0.020

(0.508)

45°

0°–8°

0.244 (6.20)

0.228 (5.79)

RAD

0.290-0.320

(7.336-8.128)

0.020

(0.508)

MIN

0.018±0.003

(0.457±0.076)

16-Pin Plastic DIP (N)

0.100±0.010

(2.540±0.254)

0.125

(3.175)

MIN

0°-10°

0.009-0.015

(0.229-0.381)

+0.025

0.325
–0.015

+0.635

8.255

()

–0.381

MIC2524/2527 10 June 1999

MIC2524/2527 Micrel

June 1999 11 MIC2524/2527

MIC2524/2527 Micrel

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

TEL + 1 [phone] FAX + 1 [phone] 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.

© 1999 Micrel Incorporated

MIC2524/2527 12 June 1999