MP62340/MP62341 –CURRENT-LIMITED POWER DISTRIBUTION SWITCHES

MP62340/MP62341 Rev.1.0

www.MonolithicPower.com

9

12/10/2013

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DETAILED DESCRIPTION

Over Current

When the load exceeds trip current (minimum

threshold current triggering constant-current

mode) or a short is present, MP62340/MP62341

switches into to a constant-current mode (current

limit value). MP62340/MP62341 will be shutdown

only if the over current condition stays long

enough to trigger thermal protection.

Trigger over current protection for different

overload conditions occurring in applications:

1) The output has been shorted or overloaded

before the device is enabled or input applied.

MP62340/MP62341 detects the short or

overload and immediately switches into a

constant-current mode.

2) A short or an overload occurs after the device

is enabled. After the current-limit circuit has

been tripped (reached the trip current

threshold), the device switches into constant-

current mode. However, high current may

flow for a short period of time before the

current-limit circuit can react.

3）Output current has been gradually increased

beyond the recommended operating current.

The load current rises until the trip current

threshold is reached or until the thermal limit

of the device is exceeded. MP62340/

MP62341 is capable of delivering current up

to the trip current threshold without damaging

the device. Once the trip threshold has been

reached, the device switches into its constant-

current mode.

Flag Response

The FLAG pin is an open drain configuration.

This FAULT will report a fail mode after an 8ms

deglitch timeout. This is used to ensure that no

false fault signals are reported. This internal

deglitch circuit eliminates the need for extend

components. The FLAG pin is not deglitched

during an over temp. or voltage lockout.

Thermal Protection

The purpose of thermal protection is to prevent

damage in the IC by allowing exceptive current to

flow and heating the junction. The die temp. is

internally monitored until the thermal limit is

reached. Once this temp. is reached, the switch

will turn off and allow the chip to cool. The switch

has a built-in hysteresis.

Under-voltage Lockout (UVLO)

This circuit is used to monitor the input voltage to

ensure that the MP62340/MP62341 is operating

correctly. This UVLO circuit also ensures that

there is no operation until the input voltage

reaches the minimum spec.

Enable

The logic pin disables the chip to reduce the

supply current. The device will operate once the

enable signal reaches the appropriate level. The

input is compatible with both COMS and TTL.