MIC2546-1BM TR Micrel Inc, MIC2546-1BM TR Datasheet - Page 12

• Manufacturer Part Number: MIC2546-1BM TR
• Description: IC SW CURR LIMIT DUAL 16-SOP
• Manufacturer: Micrel Inc
• Type: High Sider

Specifications of MIC2546-1BM TR

• Input Type: Non-Inverting
• Number Of Outputs: 2
• On-state Resistance: 80 mOhm
• Current - Peak Output: 1.5A
• Voltage - Supply: 2.7 V ~ 5.5 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 16-SOIC (3.9mm Width)
• Input Voltage Range: 2.7 to 5.5V
• Mounting: Surface Mount
• Operating Temperature (max): 85C
• Operating Temperature (min): -40C
• Operating Temperature Classification: Industrial
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Current - Output / Channel: -
• Lead Free Status / RoHS Status: Not Compliant, Contains lead / RoHS non-compliant
• Other names: MIC2546-1BMTR; MIC2546-1BMTR

Functional Description
The MIC2546 and MIC2547 are dual high-side N-
channel switches available with active-high or active-low
enable inputs. Fault conditions turn off or inhibit turn-on
of the output transistor and activate the open-drain error
flag transistor making it sink current to ground.
Input and Output
INX is the power supply connection to the logic circuitry
and the drain of the output MOSFET. OUTX is the
source of the output MOSFET. In a typical circuit, current
flows from INX to OUTX toward the load. If VOUT is
greater than V
since the switch is bidirectional when enabled. 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
switch is disabled. In this situation, the MIC2546/47
avoids undesirable current flow from OUTX to INX. Both
OUT pins for a given channel must be connected
together.
Thermal Shutdown
Thermal shutdown shuts off the output MOSFET and
signals the fault flag if the die temperature exceeds
140°C. 10°C of hysteresis prevents the switch from
turning on until the die temperature drops to 130°C.
Overtemperature detection functions only when the
switch is enabled.
The MIC2547 features an internal latch which causes
the part to remain off after thermal shutdown until a reset
pulse is provided via the enable pin. While in current-
limit, the thermal shutdown latch prevents on/off cycling
of the output. Refer to Figure 2 for timing diagram. The
flag remains low until reset.
Enable Input
ENX must be driven logic high or logic low, or be pulled
high or low for a clearly defined input. Floating the input
may cause unpredictable operation. ENX should not be
allowed to go negative with respect to GND, and V
should be less than or equal to V
Micrel, Inc.
January 2008
IN
, current will flow from OUTX to INX
INX
OUT
.
> V
IN
) when the
ENX
12
Adjustable Current-Limit
The short-circuit current-limit is user-adjustable with an
external set resistor. Current-limit in the range of 100mA
to 1.5A is available with a set point accuracy of better
than ±20%. The current-limit circuit prevents damage to
the output MOSFET and external load.
The nominal current-limit value is set with an external
resistor between ILIMX and GND. For a desired current-
limit, the value of the external set resistor is given by:
where:
For example, to set a 1A nominal current-limit, R
calculated as:
Current through R
voltage across R
impedance comparator to provide an indication of output
current. R
(0.5% resistor value).
Short-Circuit Protection
In the event of a short-circuit, the output current will fold
back to approximately 80% of the short-circuit current-
limit.
Fault Flag
FLGX is an N-channel, open-drain MOSFET output. The
fault-flag is active (low) for current-limit or thermal
shutdown conditions. The flag output MOSFET is
capable of sinking a 10mA load to typically 100mV
above ground.
154Ω < R
R
⎛
⎜
⎝
230V
SETX
1A
SETX
⎞
⎟
⎠
=
=
⎛
⎜ ⎜
⎝
SET
I
230Ω
LIMITX
230V
should be between 154Ω and 2.29kΩ
< 2.29kΩ
SETX
SETX
⎞
⎟ ⎟
⎠
could be monitored with a high
increases with OUT current. The
M9999-012508-A
MIC2546/2547
SET
is