APPLICATION 1: DESIGNING ABOVE A MINIMUM CURRENT LIMIT

1.016

ILIM

OSmin

25230V

OSmin

R

k

1

1.016

ILIM

OSmin

ILIM

I

(mA) = 1000mA

I

(mA) =

25230V

R

(k ) =

I

mA

R

(k ) = 24k

W

W

W

W

æ

ö÷

ç

÷

ç

÷

ç

÷

çè

ø

(2)

ILIM

OSmax

0.94

ILIM

OSmax

0.94

OSmax

R

(k ) = 23.7k

22980V

I

(mA) =

R

k

22980V

I

(mA) =

23.7

k

I

(mA) = 1172.4mA

W

W

W

W

(3)

APPLICATION 2: DESIGNING BELOW A MAXIMUM CURRENT LIMIT

0.94

ILIM

OSmax

22980V

OSmax

R

k

1

0.94

ILIM

OSmax

ILIM

I

(mA) = 500mA

I

(mA) =

22980V

R

(k ) =

I

mA

R

(k ) = 58.7k

W

W

W

W

æ

ö÷

ç

÷

ç

÷

ç

÷

çè

ø

(4)

ILIM

OSmin

1.016

ILIM

OSmin

1.016

OSmin

R

(k ) = 59k

25230V

I

(mA) =

R

k

25230V

I

(mA) =

59

k

I

(mA) = 400.6mA

W

W

W

W

(5)

TPS2552

TPS2553, TPS2552-1, TPS2553-1

Some applications require that current limiting cannot occur below a certain threshold. For this example, assume

that 1 A must be delivered to the load so that the minimum desired current-limit threshold is 1000 mA. Use the

maximum resulting current-limit threshold.

The resulting maximum current-limit threshold is 1172.4 mA with a 23.7 k

Ω resistor.

Some applications require that current limiting must occur below a certain threshold. For this example, assume

that the desired upper current-limit threshold must be below 500 mA to protect an up-stream power supply. Use

to calculate the minimum resulting current-limit threshold.

The resulting minimum current-limit threshold is 400.6 mA with a 59 k

Ω resistor.

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