MIC2042/2043
Micrel
MIC2042/2043
Single Channel, High Current, Low Voltage,
Protected Power Distribution Switch
General Description
The MIC2042 and MIC2043 are high-side MOSFET switches
optimized for general purpose power distribution applications
which require circuit protection. The devices switch up to 5.5V
and as low as 0.8V while offering both programmable current
limiting and thermal shutdown to protect the device and the
load. A fault status output is provided in order to detect
overcurrent and thermal shutdown fault conditions. Both
devices employ soft-start circuitry to minimize the inrush
current in applications that employ highly capacitive loads.
Additionally, for tighter control over inrush current during
start-up, the output slew-rate may be adjusted by an external
capacitor.
The MIC2043 features a auto-reset circuit breaker mode that
latches the output off upon detecting an overcurrent condition
lasting more than 28ms. The output is reset by removing or
reducing the load.
All support documentation can be found on Micrel’s web
site at www.micrel.com.
Features
•
•
•
•
•
•
•
•
•
•
•
60mΩ max. on-resistance
0.8V to 5.5V operating range
Adjustable current limit
Power-Good detection
Up to 3A continuous output current
Short-circuit protection with thermal shutdown
Adjustable slew-rate control
Circuit breaker mode (MIC2043)
Fault status flag
Undervoltage lockout
Output MOSFET reverse current flow block when
disabled
• Very fast reaction to short-circuits
• Low quiescent current
Applications
•
•
•
•
•
•
•
Docking stations
Notebook PCs
PDAs
Hot swap board insertions
RAID controllers
USB hosts
ACPI power distribution
Typical Application
+3.3V
Power
Supply
OUT1
OUT2
C2
0.1µF
C1
0.1µF
C3
4.7µF
R1
20kΩ
MIC2042-1BTS
7
VBIAS
VIN
EN
/FAULT
VOUT
PGREF
10,11,14
V
OUT
3.3V@ 1.5A
R2
294kΩ
1%
R3
24.3kΩ
1%
C
LOAD
33µF
8, 12
2
13
IN
Logic
Controller
ON/OFF
3
R4
20kΩ
1
OVERCURRENT
9
MIC39100-2.5BS
IN
SLEW PWRGD
ILIM
UVLOIN
GND
5
2.5V
OUT
EN
GND
6
4
C4*
0.022µF
(OPEN)
Note:
All V
IN
pins (8, 12) must be externally tied together.
All V
OUT
pins (10, 11, 14) must be externally tied together.
I
LIMIT
≅
2A.
Output Power-Good = 3.0V.
*C4 is optional. See
"Applications Information."
R
SET
200Ω
Micrel, Inc. • 1849 Fortune Drive • San Jose, CA 95131 • USA • tel + 1 (408) 944-0800 • fax + 1 (408) 944-0970 • http://www.micrel.com
January 2005
1
M0512-112603
MIC2042/2043
Micrel
Ordering Information
Part Number
Standard
MIC2042-1BM
MIC2042-2BM
MIC2043-1BM
MIC2043-2BM
MIC2042-1BTS
MIC2042-2BTS
MIC2043-1BTS
MIC2043-2BTS
Pb-Free
MIC2042-1YM
MIC2042-2YM
MIC2043-1YM
MIC2043-2YM
MIC2042-1YTS
MIC2042-2YTS
MIC2043-1YTS
MIC2043-2YTS
Enable
Active High
Active Low
Active High
Active Low
Active High
Active Low
Active High
Active Low
X
X
X
X
X
X
X
X
Circuit Breaker
V
BIAS
V
IN
Range
1.6V to 5.5V
1.6V to 5.5V
1.6V to 5.5V
1.6V to 5.5V
0.8V to 5.5V
0.8V to 5.5V
0.8V to 5.5V
0.8V to 5.5V
Package
8-pin SOP
8-pin SOP
8-pin SOP
8-pin SOP
14-pin TSSOP
14-pin TSSOP
14-pin TSSOP
14-pin TSSOP
Pin Configuration
PWRGD 1
EN 2
/FAULT 3
UVLOIN 4
GND 5
14 VOUT
13 PGREF
12 VIN
11 VOUT
10 VOUT
9 SLEW
8 VIN
EN 1
/FAULT 2
GND 3
ILIM 4
8 VOUT
7 VIN
6 VOUT
5 VIN
8-Pin SOP (M)
ILIM 6
VBIAS 7
14-Pin TSSOP (TS)
M0512-112603
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January 2005
MIC2042/2043
Micrel
Pin Description
Pin Number
8-Pin SOP
1
2
Pin Number
14-Pin TSSOP
2
3
Pin Name
EN
/FAULT
Pin Function
Switch Enable Input: Gate control pin of the output MOSFET available as an
active high (–1) or active low (–2) input signal.
Fault Status Output: Open-drain N-Channel device, active low. This pin
indicates an overcurrent or thermal shutdown condition. For an overcurrent
event, /FAULT is asserted if the duration of the overcurrent condition lasts
longer than 28ms.
Ground Connection: Tie to analog ground.
Slew-Rate Control Input: A capacitor connected between this pin and ground
will reduce (slow) the output slew-rate. The output turn-on time must be less
than the nominal flag delay of 28ms in order to avoid nuisance tripping of the
/FAULT output since V
OUT
must be “fully on” (i.e., within 200mV of the voltage
at the input) before the /FAULT signal delay elapses. The capacitor requires a
16V rating, or greater, 25V is recommended. See
“Applications Information,”
“Output Slew-Rate Adjustment”
for further detail.
Current Limit Set: A resistor, R
SET
, connected to this pin sets the current
limit threshold as CLF/R
SET
, where CLF is the current limit factor specified in
the
“Electrical Characteristics”
table. For the MIC2042/43, the continuous
output current range is 0.5A to 3A.
Switch Input Supply: The drain of the output MOSFET. The range of input for
the switch is 0.8V to 5.5V. These pins must be externally connected together
to achieve rated performance.
Switch Output: The source of the output MOSFET. These pins must be
externally connected together to achieve rated performance.
Bias Supply Input: This input pin supplies power to operate the switch and
internal circuitry. The input range for V
BIAS
is 1.6V to 5.5V. When switched
voltage (V
IN
) is between 1.6V to 5.5V and the use of a single supply is desired,
connect VBIAS to VIN externally.
Power-Good Threshold (Input): Analog reference used to specify the
PWRGD threshold. When the voltage at this pin exceeds its threshold, V
TH
,
PWRGD is asserted high. An external resistive divider network is used to
determine the output voltage level at which V
TH
is exceeded. See
“Functional Description”
for further detail. When the PWRGD signal is not
utilized, this input should be tied to VOUT.
Power-Good Output: Active high, open-drain. This pin asserts high when the
voltage at PGREF exceeds its threshold.
Undervoltage Lockout Adjust Input: With this pin left open, the UVLO
threshold is internally set to 1.45V. When the switching voltage (V
IN
) is below
1.6V, connecting an external resistive divider to this input will lower the
UVLO threshold. The total resistance of the divider must be less than
200kΩ. See
“Applications Information”
for further detail.
3
N/A
5
9
GND
SLEW
4
6
ILIM
5,7
8,12
VIN
6,8
N/A
10,11,14
7
VOUT
VBIAS
N/A
13
PGREF
N/A
N/A
1
4
PWRGD
UVLOIN
January 2005
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M0512-112603
MIC2042/2043
Micrel
Absolute Maximum Ratings
(1)
Supply Voltage
V
IN
and V
BIAS .............................................................................
6V
/FAULT, PWRGD Output Voltage ................................... 6V
/FAULT, PWRGD Output Current .............................. 25mA
Junction Temperature (T
J
) ...................... Internally Limited
ESD Rating
(3)
Human Body Model ................................................... 3kV
Machine Model ........................................................ 200V
Operating Ratings
(2)
Supply Voltage
V
IN
............................................................... 0.8V to 5.5V
V
BIAS
........................................................... 1.6V to 5.5V
Continuous Output Current ................................ 0.5A to 3A
Ambient Temperature (T
A
) ........................... –40°C to 85°C
Package Thermal Resistance
SOP (θ
JA
) .......................................................... 160°C/W
TSSOP (θ
JA
) ....................................................... 85°C/W
Electrical Characteristics
(4)
V
IN
= V
BIAS
= 5V; T
A
= 25°C unless specified otherwise.
Bold
indicates –40°C to +85°C.
Symbol
V
IN
V
BIAS
I
BIAS
Parameter
Switch Input Voltage
Condition
V
IN
≤
V
BIAS
(14-pin TSSOP)
No load
No load
V
IL
(max)
V
IH
(min)
V
ENHYST
I
EN
R
DS(ON)
I
LEAK
CLF
Enable Input Threshold Hysteresis
Enable Input Current
Switch Resistance
Output Leakage Current
Current Limit Factor
(2)
V
EN
= 0V to 5.5V
V
IN
= V
BIAS
= 3V, 5V
I
OUT
= 500mA
Output off
V
IN
= 5V, 0.5V
≤
V
OUT
< 0.5V
IN
0.5A
≤
I
OUT
≤
3A
V
IN
= 3V, 0.5V
≤
V
OUT
< 0.5V
IN
0.5A
≤
I
OUT
≤
3A
V
TH
V
LATCH
I
LATCH
V
OL
I
OFF
V
UV
V
UVHYST
V
UVINTH
V
UVINHYST
PGREF and UVLOIN Threshold
Output Reset Threshold
Latched Output Off Current
Output Low Voltage
(/FAULT, PWRGD)
/FAULT, PWRGD Off Current
Undervoltage Lockout Threshold
V
IN
= V
BIAS
= 1.6V to 5.5V
(14-pin TSSOP)
V
IN
= 0.8V to 5.5V
V
OUT
rising (MIC2043)
Output latched off (MIC2043)
I
OL
(/FAULT) = 15mA
I
OL
(PWRGD) = 5mA
V
FAULT
= V
PWRGD
= 5V
V
IN
rising
V
IN
falling
Undervoltage Lockout
Threshold Hysteresis
UVLO Adjust Pin Threshold Voltage
V
IN
rising
V
IN
falling
UVLO Adjust Pin Threshold Hysteresis
Overtemperature Threshold
T
J
increasing
T
J
decreasing
205
185
1.30
1.20
1.45
1.35
100
225
205
20
140
120
245
225
1
1.58
1.50
µA
V
V
mV
mV
mV
mV
°C
°C
1
310
320
205
395
385
225
V
IN
–.0.2
3
5
0.4
–1
3.5
14-pin TSSOP
8-pin SOP
Bias Supply Voltage
VBIAS Supply Current - Switch OFF
VBIAS Supply Current - Switch ON
Note 5
Enable Input Voltage
Min
0.8
1.6
1.6
0.1
300
2.4
2.5
100
.01
40
1
60
10
485
450
245
Typ
Max
5.5
5.5
5.5
5
400
1.5
Units
V
V
V
µA
µA
V
V
mV
µA
mΩ
µA
A×Ω
A×Ω
mV
V
mA
V
V
EN
M0512-112603
4
January 2005
MIC2042/2043
Symbol
t
FLAG
t
ON
t
R
t
OFF
t
F
Notes:
1. Exceeding the absolute maximum rating may damage the device.
2. The device is not guaranteed to function outside its operating rating.
3. Devices are ESD sensitive. Handling precautions recommended. Human body model, 1.5k in series with 100pF.
4. Specification for packaged product only.
Micrel
Condition
V
IN
= V
BIAS
= 3V, 5V
R
LOAD
= 10Ω, C
LOAD
= 1µF
R
LOAD
= 10Ω, C
LOAD
= 1µF
R
LOAD
= 10Ω, C
LOAD
= 1µF
R
LOAD
= 10Ω, C
LOAD
= 1µF
Min
21
600
1
Typ
28
800
1.5
1
24
Max
35
1000
2
5
Units
ms
µs
ms
µs
µs
Parameter
Flag Response Delay
Output Turn-on Delay
Output Turn-on Rise Time
Output Turn-off Delay
Output Turn-off Fall Time
5. OFF is V
EN
< 1.0V for MIC2042/MIC2043-1 and V
EN
> 4.0V for MIC2042/MIC2043-2. ON is V
EN
> 4.0V for MIC2042/MIC2043-1 and V
EN
< 1.0V for
MIC2042/MIC2043-2.
6. The current limit is determined as follows: I
LIM
= CLF/R
SET
.
Timing Diagrams
50%
V
EN
0
t
ON
t
OFF
90%
10%
(a) MIC2042/43-1
V
OUT
0
50%
V
EN
0
t
ON
t
OFF
90%
V
OUT
0
10%
(b) MIC2042/43-2
Figure 1. Turn-On/Turn-Off Delay
V
EN
0
V
IN
0.2V
Increase the load
V
OUT
0
I
LIMIT
I
OUT
0
t
FLAG
/FAULT
0
Figure 2. Overcurrent Fault Response — MIC2042-2
January 2005
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M0512-112603
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