UD36241

Preliminary

CMOS IC

UNISONICTECHNOLOGIESCO.,LTD

7 of 7

www.unisonic.com.tw

QW-R115-022 a



APPLICATION INFORMATION (Cont.)

Under Voltage Lockout (UVLO)

To avoid mis-operation at low input voltage, when input voltage falls bellow 8.2V, and under voltage lockout is

induced and the device is disabled.

Internal Current Limit Protection

When the external RSENSE is too small and the external peak current is higher than 3.6A, the high-side switch will

turn off immediately and then turn at the next clock cycle. The inductor’s peak current will be limited at 3.6A by internal

current limit.

Output Short-Circuit Protection

The IC provides VOUT the short-circuit protection function. When the VOUT is short (VFB < 0.3V),the controller will turn

off the power MOSFET. This latch-up mode of operation does not allow circuit to resume until VIN drops to 8.2V

followed by the rise to above 8.5V.

External Current Limit Protection

The external current limit is set by outside resistance (RSENSE). The average current is limited according to the

following equation :

()

Average Current L

90mV

=

RS

imit A

ENSE

UTC assumes no responsibility for equipment failures that result from using products at values that

exceed, even momentarily, rated values (such as maximum ratings, operating condition ranges, or

other parameters) listed in products specifications of any and all UTC products described or contained

herein. UTC products are not designed for use in life support appliances, devices or systems where

malfunction of these products can be reasonably expected to result in personal injury. Reproduction in

whole or in part is prohibited without the prior written consent of the copyright owner. The information

presented in this document does not form part of any quotation or contract, is believed to be accurate

and reliable and may be changed without notice.