MIC2505-2BM TR Micrel Inc, MIC2505-2BM TR Datasheet - Page 9

• Manufacturer Part Number: MIC2505-2BM TR
• Description: IC SW SGL 2A HIGH SIDE 8-SOIC
• Manufacturer: Micrel Inc
• Type: High Sider

Specifications of MIC2505-2BM TR

• Input Type: Non-Inverting
• Number Of Outputs: 1
• On-state Resistance: 30 mOhm
• Current - Output / Channel: 2A
• Current - Peak Output: 4A
• Voltage - Supply: 2.7 V ~ 7.5 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 8-SOIC (3.9mm Width)
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Other names: MIC2505-2BMTR; MIC2505-2BMTR

Applications Information
Supply Filtering
A 0.1 F to 1 F bypass capacitor from IN to GND, located at
the device is strongly recommended to control supply tran-
sients. Without a bypass capacitor, an output short may
cause sufficient ringing on the input (from supply lead induc-
tance) to destroy the internal control circuitry.
Input transients must not exceed the absolute maximum
supply voltage (V
The bypass capacitor may be omitted only if board design
precautions are followed, such as using extremely short
supply leads or power and ground planes.
Control Input
CTL 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. Add a diode clamp if negative spikes
may occur. See Figure 2.
Open-Load Detection
Refer to “Typical Applications” (first page). Open-load detec-
tion is available only on the MIC2505 and MIC2506. For USB
power distribution applications, the open-load detection fea-
ture is not included in the MIC2505-1 or -2 versions.
The optional open-load detection resistor supplies a small
pull-up current to the load when the output switch is off. (A
100k resistor will draw 50 A from a 5V supply.) Normally, the
load dominates, pulling OUT low. If the load is absent, the
optional resistor pulls OUT high, activating the fault flag if CTL
is off.
When a load is switched off with CTL, capacitance on the
output may cause the open-load function to pull the flag low
until the capacitor is discharged below approximately 2.4V.
Omit the pull-up resistor when open load detection is not
required and for minimum off-state supply current.
Power Bus Switch
The MIC2505/6 family features a MOSFET reverse current
flow prevention circuit. This prevents current from flowing
backwards (from OUT to IN) when CTL is disabled as long as
V
April 2004
MIC2505/2506
IN
is above UVLO minimum. In Figure 2, when U1 is on and
OFF
ON
Figure 1. Supply Bypassing
IN max
1
2
3
4
CTL
FLG
GND
GATE
MIC2505BM
= 7.5V) even for a short duration.
OUT
OUT
IN
IN
2.7V to 7.5V
8
5
7
6
0.1µF to 1µF
9
U2 is off, this feature prevents current flow from the load (5V)
backward through U2 to the 3.3V supply. (If a discrete
MOSFET and driver were used, the MOSFET’s internal body
diode would short the 5V load to the 3.3V supply.)
FLG will be active (low) on any switch that is off whenever the
load voltage is greater than the open load threshold (approxi-
mately 1V) except for MIC2505-1 and MIC2505-2.
This circuit’s function would otherwise require a dual driver,
two MOSFETs, plus two diodes (or a dual driver plus four
MOSFETs).
Hot Plug-In Applications (Soft-Start)
The MIC2505/6 family can be used to protect the socket-side
and card-side of a supply circuit from transients caused when
a capacitive load is connected to an active supply.
The switch presents a high impedance when off, and slowly
becomes a low impedance as it turns on. This reduces the
inrush current and related voltage drop that result from
charging a capacitive load.
A gate capacitor may be added to the MIC2505 to slow the
turn on time even more, reducing the inrush current. See
“MIC2505 Turn-On Delay” graph. The UVLO feature insures
that each time the card is removed and V
of the output switch is discharged to zero volts. A controlled
turn-on is executed each time a board is plugged in, even with
multiple insertions.
(optional)
1N4148
Logic-Low = 3.3V Output
Logic-High = 5V Output
Socket
GND
3.3V
Figure 2. 5V/3.3V Switch Concept
1
2
3
4
Figure 3. Hot Plug-In Concept
CTL
FLG
GND
GATE
MIC2505BM
Card
U1
OUT
OUT
IN
IN
1
2
3
4
CTL
FLG
GND
GATE
MIC2505BM
8
5
7
6
+5V
0.1µF
OUT
OUT
IN
IN
8
5
7
6
1
2
3
4
0.1µF
CTL
FLG
GND
GATE
MIC2505BM
IN
= 0 that the gate
U2
Power Control
Circuitry
OUT
OUT
M9999-042704
Capacitive
IN
IN
Load
8
5
+3.3V
7
6
Micrel
0.1µF