6

SD

CT

t

1.0 10

C

=

´

´

RFLT

FAULT

200k

R

I

W

=

LIM

LIM

201k

R

I

W

=

OUT

IN

OUT

V

V

0.04 I

=

-

´

TPS2590

www.ti.com

SLUS960D

– JULY 2009 – REVISED OCTOBER 2011

(2)

The nominal ratio of on-to-off times represents about a 3% duty cycle when a hard fault is present on the output

of an autoretry version part.

FLT: Open-drain output that pulls low on any condition that causes the output to open. These conditions are

either an overload with a fault time-out, or a thermal shutdown. FLT becomes operational before UV, when VIN is

greater than 1 V. IFLT may not be set below 1 A to maintain the Fault Current Limit threshold accuracy listed in

Electrical Characteristics. Some parts may not current limit or fault as expected.

GND: This is the most negative voltage in the circuit and is used as reference for all voltage measurements

unless otherwise specified.

fault current threshold and the current limit are permitted to flow unimpeded for the period set by the fault timer

programmed on CT. This permits loads to draw momentary surges while maintaining the protection provided by a

lower average-current limit.

doesn

(3)

doesn

formula:

(4)

tolerances into account.

EN: When this pin is pulled low, the IC is enabled. The input threshold is hysteretic, allowing the user to program

a startup delay with an external RC circuit. EN is pulled to VIN by a 10-M

Ω resistor, pulled to GND by 16.8 MΩ

and is clamped to ground by a 7-V Zener diode. Because high impedance pullup/down resistors are used to

reduce current draw, any external FET controlling this pin should be low leakage.

IN: Input voltage to the TPS2590. The recommended operating voltage range is 3 V to 18 V. All VIN pins should

be connected together and to the power source.

OUT: Output connection for the TPS2590. When switched on the output voltage will be approximately:

(5)

All OUT pins should be connected together and to the load.

RTRY: When pulled low the TPS2590 will attempt to restart after a fault. If left floating or pulled high the

TPS2590 will latch off after a fault. This pin is internally clamped at 3 V and is pulled to the internal 3-V supply by

a diode in series with a 100-k

Ω resistor.

Copyright

© 2009–2011, Texas Instruments Incorporated

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Product Folder Link(s): TPS2590