Linear Technology DC1238B - LTM8021EV Demoboard DC1238B DC1238B 데이터 시트

LTM8021

6

8021fd

For more information 

 (Bank 1): The V

IN

 pin supplies current to the LTM8021’s 

internal regulator and to the internal power switch. This 

pin must be locally bypassed with an external, low ESR 

capacitor of at least 1µF.
V

 (Bank 2): Power Output Pins. An external capacitor is 

connected from V

OUT

 to GND in most applications. Apply 

output load between these pins and GND pins.
BIAS (Pin H3): The BIAS pin connects to the internal 

boost Schottky diode and to the internal regulator. Tie to 

V

OUT

 when V

OUT

 > 3V or to another DC voltage greater 

than 3V otherwise. When BIAS > 3V the internal circuitry 

will be powered from this pin to improve efficiency. Main 

regulator power will still come from V

IN

.

RUN/SS (Pin A1): Tie RUN/SS pin to ground to shut down 

the LTM8021. Tie to 1.6V or more for normal operation. 

If the shutdown feature is not used, tie this pin to the V

IN

 

pin. The RUN/SS also provides soft-start and frequency 

foldback. To use the soft-start function, connect a resistor 

and capacitor to this pin. Do not allow the RUN/SS pin to 

rise above V

IN

. See the Applications Information section.

GND (Bank 3): The GND connections serve as the main 

signal return and the primary heat sink for the LTM8021. Tie 

the GND pins to a local ground plane below the LTM8021 

and the circuit components. Return the feedback divider 

to this signal.
ADJ (Pin A2): The LTM8021 regulates its ADJ pin to 

0.8V. Connect the adjust resistor from this pin to ground. 

The value of R

ADJ

 is given by the equation, R

ADJ

 = 80/ 

(V

OUT

 – 0.8), where R

ADJ

 is in k.

V

IN

8021 BD

BIAS

CURRENT MODE

CONTROLLER

V

OUT

10µF

15pF

10µH

0.1µF

RUN/SS

100k

1%

ADJ

GND