the feedback network must tie directly to the AGND pin. Connecting the

network to the PGND can inject noise into the system and effect

performance.

The feedback network, resistors R1 and R2 must be connected to FB pin

directly as closely as possible. And FB is a sensitive signal node, trace

area at FB pin should be small.

Please keep FB away from the inductor and SW switching node on the

PCB layout to minimize copper trace connections that can inject noise into

the system.

9

AGND

I

Analog Ground. The analog ground ties to all of the noise sensitive

signals. Provide a clean ground for the analog control circuitry and should

not be in the path of large currents.

Return for output voltage set resistor divider.

Connect this pin to PGND.

10

LBO

O

Low Battery Comparator Output (open drain).

(1) I = input; O = output; P = power

ABSOLUTE MAXIMUM RATINGS

(1)

PARAM ETER

SYM BOL

RATINGS

UNITS

CE Voltage

(2)

V

Other Pins Voltage

(2)

6

V

Power

Dissipation

(3)

QFN2.1X2.1-10

2.5

W

Package Thermal Resistance

(4)

θ

JA

50

°C/W

θ

JC

10

°C/W

Operating Junction Temperature Range

150

°C

Lead Temperature(Soldering, 10 sec)

260

°C

Storage Temperature Range

-65~150

°C

(1) Stresses beyond those listed under absolute maximum ratings may cause permanent damage to the device. These are

stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated under

recommended operating conditions is not implied. Exposure to absolute-maximum -rated conditions for extended periods

my affect device reliability.

(2) All voltages are with respect to network ground terminal.

ambient thermal resistance

θ

θ

dissipation will cause excessive die temperature, and the regulator will go into thermal shutdown. Internal thermal

shutdown circuitry protects the device from permanent damage.

(4)

θ

on a four-layer Chipower Evaluation Board

LESHAN RADIO COMPANY, LTD.

Ver0.5

4/7