February 2000
1
MIC2526
MIC2526
Micrel
MIC2526
Dual USB Power Control Switch
Not Recommended for New Designs
Refer to MIC2026
General Description
The MIC2526 is a dual integrated high-side power switch with
independent enable and flag functions, optimized for self-
powered and bus-powered Universal Serial Bus (USB) appli-
cations. Few external components are necessary to satisfy
USB requirements.
The MIC2526 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 require-
ments; and a flag output is available to indicate fault condi-
tions 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 re-
mains off unless there is a valid input voltage present, and
3.3V and 5V logic compatible enable inputs.
The MIC2526 is available in active-high and active-low ver-
sions in 8-pin DIP and SOIC packages.
Typical Application
ENA
OUTA
FLGA
IN
FLGB
GND
ENB
OUTB
ON/OFF
OVERCURRENT
OVERCURRENT
ON/OFF
MIC2526-2
3.3V USB Controller
V
CC
5.0V
0.1F
V
BUS
D+
D
GND
Data
(Two Pair)
V
BUS
D+
D
GND
USB
Port 2
USB
Port 1
10k
100k
MIC5207-3.3
IN
OUT
GND
47F
47F
Ferrite
Beads
4.50V to 5.25V
Upstream V
BUS
100mA max.
V
BUS
D+
D
GND
Data
1F
1F
10k
100k
VIN
to USB
Controller
2-Port USB Self-Powered Hub
Features
Compliant to USB specifications
UL Recognized Component
2 independent switches
3V to 5.5V input
500mA minimum continuous load current per port
140m
maximum on-resistance
1.25A maximum short circuit current limit
Individual open-drain fault flag pins
110
A typical on-state supply current
1
A 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
8-pin SOIC and DIP packages
Applications
USB host and self-powered hubs
USB bus-powered hubs
Hot plug-in power supplies
Battery-charger circuits
UL Recognized Component
Micrel, Inc. 1849 Fortune Drive San Jose, CA 95131 USA tel + 1 (408) 944-0800 fax + 1 (408) 944-0970 http://www.micrel.com
MIC2526
Micrel
MIC2526
2
February 2000
Pin Description
Pin Number
Pin Name
Pin Function
1 / 4
EN(A/B)
Enable (Input): Logic-compatible enable input. High input > 2.1V typical.
Low input <1.9V typical (-1 active high, -2 active low). Do not float.
2 / 3
FLG(A/B)
Fault Flag (Output): Active-low, open-drain output. Indicates overcurrent,
UVLO, and thermal shutdown.
6
GND
Ground: Supply return.
7
IN
Supply Input: Output MOSFET drain. Also supplies IC's internal circuitry.
Connect to positive supply.
8 / 5
OUT(A/B)
Switch Output: Output MOSFET source. Typically connect to switched side
of load.
Pin Configuration
1
2
3
4
8
7
6
5
OUTA
IN
GND
OUTB
ENA
FLGA
FLGB
ENB
MIC2526
8-Pin SOIC (M)
8-Pin DIP (N)
LOGIC,
CHARGE
PUMP
LOGIC,
CHARGE
PUMP
8 (OUTA)
5 (OUTB)
7 (IN)
6 (GND)
(ENA) 1
(FLGA) 2
(FLGB) 3
(ENB) 4
MIC2526
Ordering Information
Part Number
Enable
Temperature Range
Package
MIC2526-1BM
Active High
40
C to +85
C
8-Pin SOIC
MIC2526-2BM
Active Low
40
C to +85
C
8-Pin SOIC
MIC2526-1BN
Active High
40
C to +85
C
8-pin DIP
MIC2526-2BN
Active Low
40
C to +85
C
8-pin DIP
February 2000
3
MIC2526
MIC2526
Micrel
Electrical Characteristics
V
IN
= +5V; T
A
= 25
C; unless noted.
Parameter
Condition
Min
Typ
Max
Units
Supply Current
Note 4, switch off, OUT = open
0.75
5
A
Note 4, all switches on, OUT = open
110
160
A
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
V
EN
= 0V to 5.5V
1
0.01
1
A
Enable Input Capacitance
1
pF
Switch Resistance
V
IN
= 5V, I
OUT
= 500mA, each switch
100
140
m
V
IN
= 3.3V, I
OUT
= 500mA, each switch
140
180
m
Output Turn-On Delay
R
L
= 10
each output
0.5
ms
Output Turn-On Rise Time
R
L
= 10
each output
1
ms
Output Turnoff Delay
R
L
= 10
each output
1
20
s
Output Turnoff Fall Time
R
L
= 10
each output
1
20
s
Output Leakage Current
each output (output disabled)
10
A
Continuous Load Current
each output
0.5
A
Short-Circuit Current Limit
each output (enable into load), V
OUT
= 4.0V
0.5
0.75
1.25
A
Current-Limit Threshold
ramped load applied to enabled output, V
OUT
4.0V, Note 5
1.6
2.2
A
Overtemperature Shutdown
T
J
increasing
135
C
Threshold
T
J
decreasing
125
C
Error Flag Output Resistance
V
IN
= 5V, I
L
= 10mA
10
25
V
IN
= 3.3V, I
L
= 10mA
15
40
Error Flag Off Current
V
FLAG
= 5V
0.01
1
A
UVLO Threshold
V
IN
= increasing
2.5
V
V
IN
= decreasing
2.3
V
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 MIC2526-1. Off is
2.4V and on is
0.8V for the MIC2526-2. The enable input has approximately
200mV of hysteresis. See control threshold charts.
Note 5.
See "Functional Characteristics: Current-Limit Response" photo.
Absolute Maximum Ratings
(Note 1)
Supply Voltage (V
IN
) ..................................................... +6V
Fault Flag Voltage (V
FLG
) .............................................. +6V
Fault Flag Current (I
FLG
) ............................................ 50mA
Output Voltage (V
OUT
) .................................................. +6V
Output Current (I
OUT
) ............................... Internally Limited
Control Input (V
EN
) ......................................... 0.3V to 12V
Storage Temperature (T
S
) ....................... 65
C to +150
C
Lead Temperature (Soldering 5 sec.) ....................... 260
C
ESD Rating, Note 3 ...................................................... 2kV
Operating Ratings
(Note 2)
Supply Voltage (V
IN
) ...................................... +3V to +5.5V
Ambient Operating Temperature (T
A
) ........ 40
C to +85
C
Thermal Resistance
SOIC (
JA
) ......................................................... 120
C/W
DIP(
JA
) ............................................................. 130
C/W
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