RT9048

2

DS9048-04

June 2019

www.richtek.com

©

Copyright

2019 Richtek Technology Corporation. All rights reserved.

is a registered trademark of Richtek Technology Corporation.

Functional Pin Description

Functional Block Diagram

Pin No.

Pin Name

Pin Function

1, 4, 5

NC

No internal connection.

2

EN

Enable control input (Active-High). Pulling this pin below 0.4V turns the regulator

off, reducing the quiescent current to a fraction of its operating value. The device

will be enabled if this pin is left open. Connect to VIN if not being used.

3

VIN

Supply voltage input. For regulation at full load, the input to this pin must be

between (VOUT + 0.5V) and 6V. The minimum input voltage is 1.4V. A large bulk

capacitance should be placed closely to this pin to ensure that the input supply

does not sag below 1.4V. Also, a minimum of 10

F ceramic capacitor should be

placed directly at this pin.

6

VOUT

Output voltage. A minimum of 10

F capacitor should be placed directly at this pin.

7

ADJ

Feedback voltage input. If connected to the VOUT pin, the output voltage will be

set at 0.5V. If external feedback resistors are used, the output voltage will be

determined by the resistor ratio.

8,

9 (Exposed pad)

GND

Ground. The exposed pad must be soldered to a large PCB and connected to GND

for maximum power dissipation.

+

-

Reference

Generator

0.5V

Thermal

Shutdown

0.5µA

VIN

VPUMP

-

+

RSENSE

EN

VIN

GND

ADJ

VOUT

VIN

+

-

VIN

VOUT

Reverse Voltage

Shutdown

Operation

The RT9048 is a low dropout voltage linear regulator

designed specially for low external components system.

Output Transistor

The RT9048 builds in a N-MOSFET output transistor which

provides a low switch-on resistance for low dropout voltage

applications.

Error Amplifier

The Error Amplifier compares the internal reference voltage

with the output feedback voltage, and controls the Gate

voltage of N-MOSFET to support good line regulation and

load regulation at output voltage.

Current-Limit Protection

The RT9048 provides current limit function to prevent the

device from damages during over-load or shorted-circuit

condition. This current is detected by an internal sensing

resistor.

Over-Temperature Protection

The over-temperature protection function will turn off the

P-MOSFET when the junction temperature exceeds

160

°C (typ.). Once the junction temperature cools down

by approximately 30

°C, the regulator will automatically

resume operation.