REV. 0

–8–

ADP3336

In standard packages the dominant component of the heat resis-

tance path is the plastic between the die attach pad and the

individual leads. In typical thermally enhanced packages one or

more of the leads are fused to the die attach pad, significantly

decreasing this component. To make the improvement mean-

ingful, however, a significant copper area on the PCB must be

attached to these fused pins.

The proprietary paddle-under-lead frame design of the ADP3336

uniformly minimizes the value of the dominant portion of the

thermal resistance. It ensures that heat is conducted away by all

pins of the package. This yields a very low 110

°C/W thermal

resistance for an MSOP-8 package, without any special board

layout requirements, relying only on the normal traces connected

to the leads. This yields a 33% improvement in heat dissipation

capability as compared to a standard MSOP-8 package. The

thermal resistance can be decreased by, approximately, an addi-

tional 10% by attaching a few square cm of copper area to the

IN pin of the ADP3336 package.

It is not recommended to use solder mask or silkscreen on the

PCB traces adjacent to the ADP3336’s pins since it will increase

the junction-to-ambient thermal resistance of the package.

Shutdown Mode

Applying a TTL high signal to the shutdown (

SD) pin or tying

it to the input pin, will turn the output ON. Pulling

SD down to

0.4 V or below, or tying it to ground will turn the output OFF.

In shutdown mode, quiescent current is reduced to much less

than 1

µA.

OUTLINE DIMENSIONS

Dimensions shown in inches and (mm).

8-Lead mini_SO

(RM-8)

0.011 (0.28)

0.003 (0.08)

0.028 (0.71)

0.016 (0.41)

33

27

0.120 (3.05)

0.112 (2.84)

85

4

1

0.122 (3.10)

0.114 (2.90)

0.199 (5.05)

0.187 (4.75)

PIN 1

0.0256 (0.65) BSC

0.122 (3.10)

0.114 (2.90)

SEATING

PLANE

0.006 (0.15)

0.002 (0.05)

0.018 (0.46)

0.008 (0.20)

0.043 (1.09)

0.037 (0.94)

0.120 (3.05)

0.112 (2.84)