MAX1931EUB+T Maxim Integrated Products, MAX1931EUB+T Datasheet - Page 6

• Manufacturer Part Number: MAX1931EUB+T
• Description: IC SW CUR LIMIT USB 10-UMAX
• Manufacturer: Maxim Integrated Products

Specifications of MAX1931EUB+T

• Applications: USB, Peripherals
• Current - Supply: 14µA
• Voltage - Supply: 2.7 V ~ 5.5 V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 10-MSOP, Micro10™, 10-uMAX, 10-uSOP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

The MAX1931 P-channel MOSFET power switch limits
output current to 0.64A (min) to 1.06A (max). When the
output current is increased beyond the current limit
(I
switch (I
compares the voltage to the internal 1.24V reference
and regulates the current back to the I
This switch is not bidirectional; therefore, the input volt-
age must be higher than the output voltage.
Current-Limited Switch for Single USB Port
Figure 1. Functional Diagram
6
_______________Detailed Description
LIMIT
FAULT
2, 4, 8, 10
_______________________________________________________________________________________
1, 3, 9
ON
IN
PIN
), the current also increases through the replica
5
6
7
OUT
N
/ 6500). The current-limit error amplifier
FAULT
NAME
GND
OUT
ON
IN
P
P
10ms
TIMER
REPLICA
AMPLIFIER
HOT
CIRCUITRY
CONTROL
ON
ON
Input. P-channel MOSFET source. Connect all IN pins together and bypass with a 1µF
ceramic capacitor to ground.
Switch Output. P-channel MOSFET drain. Connect all OUT pins together and bypass with a
0.1µF capacitor to ground.
Active-Low Switch On Input. A logic low turns the switch on.
Ground
Fault-Indicator Output. This open-drain output goes low when the device is in thermal shut-
down, undervoltage lockout, or on a sustained (>10ms) current-limit condition.
CURRENT-LIMIT
AMPLIFIER
1.24V
LIMIT
MAX1931
P
.
GND
OUT
The MAX1931 is a foldback short-circuit-protected
switch. In the event of an output short-circuit or current-
overload condition, the current through the switch is
foldback-current-limited to 500mA continuous.
The MAX1931 features thermal shutdown. The switch
turns off and the FAULT output goes low immediately
(no fault blanking) when the junction temperature
exceeds +165°C. When the MAX1931 cools 20°C, the
switch turns back on. If the fault short-circuit condition
is not removed, the switch cycles on and off, resulting
in a pulsed output.
The MAX1931 provides a fault output (FAULT). A
100kΩ pullup resistor from FAULT to IN provides a
logic control signal. This open-drain output goes low
when any of the following conditions occur:
• The input voltage is below the undervoltage lockout
• The die temperature exceeds the thermal shutdown
• The device is in current limit and the 10ms fault-
The MAX1931 features 10ms fault blanking. Fault
blanking allows current-limit faults, including momen-
tary short-circuit faults that occur when hot-swapping a
capacitive load, and also ensures that no fault is issued
during power-up. When a load transient causes the
device to enter current limit, an internal counter starts. If
the load fault persists beyond the 10ms fault-blanking
timeout, the FAULT output asserts low. Ensure that the
MAX1931’s input is adequately bypassed to prevent
input glitches from triggering spurious FAULT outputs.
Input voltage glitches less than 150mV do not cause a
(UVLO) threshold.
temperature limit of +165°C.
blanking period is exceeded.
FUNCTION
Continuous Short-Circuit Protection
Pin Description
Thermal Shutdown
FAULT Indicator
Fault Blanking