MIC2546/2547
Dual Programable Current Limit Switch
General Description
Features
The MIC2546 and MIC2547 are integrated high-side dual
•
2.7V to 5.5V input
power switches optimized for low loss dc power switching
•
Adjustable current-limit up to 1.5A
and other power management applications, including
•
Reverse current flow blocking (no “body diode”)
Advanced Configuration and Power Interface (ACPI). The
•
100μA typical on-state supply current per channel
MIC2546/47 is a cost-effective, highly integrated solution
•
2μA typical off-state supply current
that requires few external components to satisfy USB and
ACPI requirements.
•
120mΩ maximum on-resistance
Load current management features include a precision
•
Open-drain fault flag
resistor-programmable output current-limit and a soft-start
•
Thermal shutdown
circuit which minimizes inrush current when the switch is
•
Thermal shutdown output latch (MIC2547)
enabled. Thermal shutdown, along with current-limit,
•
2ms (slow) turn-on and fast turnoff
protects theswitch and the attached device.
•
Available with active-high or active-low enable
The MIC2546/47’s open-drain flag outputs are used to
indicate current-limiting or thermal shutdown to a local
controller. The MIC2547 has an additional internal latch
Applications
which turns the output off upon thermal shutdown
providing robust fault control. The enable signal is
•
USB power distribution
compatible with both 3V and 5V logic, and is also used as
•
PCI Bus Power Switching
the thermal shutdown latch reset for the MIC2547.
•
Notebook PC
The MIC2546 and MIC2547 are available in active-high
•
ACPI power distribution
and active-low enable versions in 16-pin TSSOP and SOP
•
PC card hot swap applications
packages.
•
Inrush current-limiting
Data sheets and support documentation can be found on
•
Ideal for dual supply applications
Micrel’s web site at www.micrel.com.
___________________________________________________________________________________________________________
Typical Application
Typical Advanced Configuration and Power Interface (ACPI) Application
UL Recognized Component
Micrel Inc. • 2180 Fortune Drive • San Jose, CA 95131 • USA • tel +1 (
408
) 944-0800 • fax + 1 (408) 474-1000 • http://www.micrel.com
January 2008
M9999-012508-A
Micrel, Inc.
MIC2546/2547
Ordering Information
Part Number
Standard
MIC2546-1BM
MIC2546-1BTS
MIC2546-2BM
MIC2546-2BTS
MIC2547-1BM
MIC2547-1BTS
MIC2547-2BM
MIC2547-2BTS
Note:
1. Thermal Shutdown Latch.
Pb-Free
MIC2546-1YM
MIC2546-1YTS
MIC2546-2YM
MIC2546-2YTS
MIC2547-1YM
MIC2547-1YTS
MIC2547-2YM
MIC2547-2YTS
Enable
Active High
Active High
Active Low
Active Low
Active High
Active High
Active Low
Active Low
Latch
(1)
Junction Temp. Range
(1)
–40° to +85°C
–40° to +85°C
–40° to +85°C
–40° to +85°C
Package
16-pin SOP
16-pin TSSOP
16-pin SOP
16-pin TSSOP
16-pin SOP
16-pin TSSOP
16-pin SOP
16-pin TSSOP
•
•
•
•
–40° to +85°C
–40° to +85°C
–40° to +85°C
–40° to +85°C
Pin Configuration
MIC2546/2547
(ENA)
(FLGA)
(ILIMA)
(ENB)
(FLGB)
LOGIC,
CHARGE
PUMP
LOGIC,
CHARGE
PUMP
(OUTA)
(INA)
(OUTB)
(INB)
(ILIMB) (GND)
Function Pinout
16-Pin SOP (M)
16-Pin TSSOP (TS)
January 2008
2
M9999-012508-A
Micrel, Inc.
MIC2546/2547
Pin Description
Pin Number
1
2, 16
3
Pin Name
INA
OUTA
ENA
Pin Function
Input A: Output A MOSFET drain. Also supplies internal circuitry.
Switch A (Output): Output A MOSFET source. Pins 2 and 16 must be externally
connected.
Enable A (Input): Logic-compatible enable input. Active- activelow (–2). High
input >1.7V typical; low input <1.5V typical. MIC2547 only: Also resets thermal
shutdown latch.
Not internally connected.
Fault Flag A (Output): Active-low, open-drain output. Indicates overcurrent or
thermal shutdown conditions. MIC2547 only: latched low on thermal shutdown.
Ground. Both pins must be connected to GND.
Current Limit Channel B: Sets current-limit threshold using an resistor, R
SET
,
connected to ground. 154Ω < R
SET
< 2.29kΩ.
Switch B (Output): Pins 8 and 11 must be externally connected.
Input B
Enable B (Input)
Fault Flag B (Output)
Fault Flag B (Output)
4, 10
5
6, 14
7
8, 11
9
12
13
15
NC
FLGA
GNDB,
GNDA
ILIMB
OUTB
INB
ENB
FLGB
ILIMA
January 2008
3
M9999-012508-A
Micrel, Inc.
MIC2546/2547
Absolute Maximum Ratings
(1)
Supply Voltage (V
IN
) ...................................................+6.0V
Output Voltage (V
OUT
) ................................................+6.0V
Output Current (I
OUT
) ................................Internally Limited
Enable Input (V
EN
) ................................. –0.3V to V
IN
+0.3V
Fault Flag Voltage (V
FLG
)............................................+6.0V
Fault Flag Current (I
FLG
) .............................................50mA
Storage Temperature (T
S
) ........................–65°C to +150°C
Junction Temperature (T
J
) ........................Internally Limited
Lead Temperature (soldering 5 sec.)......................... 260°C
ESD Rating,
Note 3 .......................................................
2kV
Operating Ratings
(2)
Supply Voltage (V
IN
) .................................... +2.7V to +5.5V
Current Limit Set Range......................................0.1 to 1.5A
Ambient Temperature Range (T
A
) .............. –40°C to +85°C
Package Thermal Resistance
SOP (θ
JA
) .........................................................120°C/W
TSSOP (θ
JA
) ....................................................100°C/W
Electrical Characteristics
(4)
V
IN
= +5V; T
A
= 25°C,
bold
values indicate –40°C to +85°C, unless noted.
Symbol
Parameter
Supply Current
V
EN
Enable Input Voltage
Enable Input Current
Enable Input Capacitance
R
DS(ON)
Switch Resistance
Current Limit Factor,
Note 6
Output Leakage Current
t
ON
t
R
t
OFF
t
F
Output Turn-On Delay
Output Turn-On Rise Time
Output Turn-Off Delay
Output Turn-Off Fall Time
Overtemperature Threshold
Shutdown
Error Flag Output Resisitance
Error Flag Off Current
EN Pulse Reset Width
V
IN
to EN Set-Up
Current-Limit Response Time
Overcurrent FLG Response
Time
Notes:
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 MIC2546-1 and MIC2547-1. Off is
≥
2.4V and on is
″
0.8V for the MIC2546-2 and MIC2547-2. The enable
input has about 200mV of hysteresis.
Condition
Switch off, OUT = open,
Note 4
Switch on, OUT = open,
Note 4
Enable High,
Note 4
Enable Low,
Note 4
V
EN
= V
OH(MIN)
= 2.4V
V
EN
= V
OH(MAX)
= 0.8V
Note 5
I
OUT
= 500mA
I
OUT
= 500mA to 1.5A, V
OUT
= 1.0V to 4.0V
Note 6
Swich off
R
L
= 10Ω, C
L
= 1µF,
Figure 1a and 1b
R
L
= 10Ω, C
L
= 1µF,
Figure 1a and 1b
R
L
= 10Ω, C
L
= 1µF,
Figure 1a and 1b
R
L
= 10Ω, C
L
= 1µF,
Figure 1a and 1b
T
J
increasing
T
J
decreasing
V
IN
= 5V, I
L
= 10µA
V
IN
= 3.3V, I
L
= 10µA
V
FLG
= 5V
MIC2547 Thermal Shutdown Latch
MIC2547,
Note 5
V
OUT
= oV
V
OUT
= V
IN
/2 to FLG low
Min
Typ
1.5
200
Max
10
320
0.8
1
1
120
276
10
5
5
Units
µA
µA
V
V
µA
µA
pF
mΩ
V
µA
ms
ms
µs
µs
°C
°C
2.4
1.7
1.5
0.01
0.01
1
80
184
230
1
1
1
2
2
22
21
140
130
4
5
0.01
15
20
1
Ω
Ω
µA
µs
µs
5
0
25
5
µs
µs
January 2008
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M9999-012508-A
Micrel, Inc.
Note 5.
Guaranteed by design, but not production tested.
Note 6.
Current limit threshold is determined by:
I
LIMIT
=
230V
R
SET
MIC2546/2547
, where R
SET
is in ohms.
January 2008
5
M9999-012508-A
电源技术
