PA340

2

PA340U

High voltage considerations should be taken when designing board layouts for the PA340. The PA340 may require a

derate in supply voltage depending on the spacing used for board layout. The 14-mil minimum spacing of the 7-pin

DDPAK is adequate to standoff the 350V rating of the PA340. However, a supply voltage derate to 250V is required

if the spacing of circuit board artwork is less than 11 mils.

The metal tab of the PA340CC package is directly tied to -Vs.

TYPICAL APPLICATION

DDPAK

PKG. STYLE CC

FIGURE 2. External Connections.

PA340CC

PA340CX

A

A

1

1

For C

C values, see graph on page 4.

Note: C

C must be rated for full supply voltage.

A1

PA340

A2

PA340

20R

PIEZO

TRANSDUCER

20R

RN

20R

CN

R

VIN

–175

+175

–175

+175

10pF

10pF

LOW COST 660V p-p

PIEZO DRIVER

CC

CC

FIGURE 3. Low Cost 660V

P-P Piezo Driver

Ref: APPLICATION NOTE 20: "Bridge Mode Operation of Power Amplifiers"

Two PA340 amplifiers operated as a bridge driver for a piezo transducer provides a low cost 660 volt total drive

capability. The R

N CN network serves to raise the apparent gain of A2 at high frequencies. If RN is set equal to R the

amplifiers can be compensated identically and will have matching bandwidths.