UCC284–5, UCC284–12, UCC284–ADJ, UCC384–5, UCC384–12, UCC384–ADJ

LOW-DROPOUT 0.5-A NEGATIVE LINEAR REGULATOR

SLUS234D – JANUARY 2000 – REVISED FEBRUARY 2002

8

POST OFFICE BOX 655303

APPLICATION INFORMATION

IOUT=0A

IOUT (NOM)

IOVER

IPEAK

VOUT = 0V

VOUT

=(IPEAK)(RL)

VOUT NOM. (–V)

CT = 0V

CT (NOM) = – 1.6V

CT = – 2.6V

NOTE: CURRENT FLOW IS INTO THE DEVICE

t ON

t OFF

t ON

t OFF

t ON

UDG–99031

~40 x tON

~40 x tON

Figure 5. Short Circuit Timing

UCC384 short circuit timing

During normal operation the output voltage is in regulation and the SD/CT pin is held to –1.5 V via a 50-k

Ω

internal-source impedance. If the output-current rises above the overcurrent threshold, the CT capacitor is

charged by a 40-

µA current sink. The voltage on the SD/CT pin moves in a negative direction with respect to

GND.