MIC2025 Micrel Semiconductor, MIC2025 Datasheet - Page 10

• Manufacturer Part Number: MIC2025
• Description: Single-Channel Power Distribution Switch Preliminary Information
• Manufacturer: Micrel Semiconductor

MIC2025/2075
Short-Circuit Applied to Enabled Output
When a heavy load or short-circuit is applied, a large transient
current may flow until the current-limit circuitry responds.
Once this occurs the device limits current to less than the
short-circuit current limit specification. See the Short-Circuit
Transient Response graph under Functional Characteristics.
Current-Limit Response—Ramped Load
The MIC2025/75 current-limit profile exhibits a small foldback
effect of about 200mA. Once this current-limit threshold is
exceeded the device switches into a constant current mode.
It is important to note that the device will supply current until
the current-limit threshold is exceeded. See the Current-Limit
Response graph under Functional Characteristics.
MIC2025/2075
V
I
I
V
I
V
LIMIT
V
LIMIT
I
OUT
V
V
OUT
I
OUT
OUT
I
FLG
DC
FLG
DC
EN
EN
Figure 1. MIC2075-2 Timing: Output Reset by Removing Load
Thermal Shutdown
Thermal Shutdown
Reached
Reached
Figure 2. MIC2025-2 Timing
Short-Circuit Fault
Short-Circuit Fault
t
t
D
D
10
Load/Fault
Removed
Fault Flag
The FLG signal is an N-channel open-drain MOSFET output.
FLG is asserted (active-low) when either an overcurrent or
thermal shutdown condition occurs. In the case where an
overcurrent condition occurs, FLG will be asserted only after
the flag response delay time, t
that FLG is asserted only upon valid overcurrent conditions
and that erroneous error reporting is eliminated. For ex-
ample, false overcurrent conditions can occur during hot-plug
events when a highly capacitive load is connected and
causes a high transient inrush current that exceeds the
current-limit threshold. The FLG response delay time t
typically 3ms.
Undervoltage Lockout
Undervoltage lockout (UVLO) prevents the output MOSFET
from turning on until V
voltage detection functions only when the switch is enabled.
Load Removed
(Output Reset)
IN
exceeds approximately 2.5V. Under-
D
, has elapsed. This ensures
March 2000
Micrel
D
is