LDMOS in PowerSO-10RF
PD5xxx Series For Private Mobile Radios

ST is introducing a new series of power transistors especially designed for PMR (Private Mobile Radio 380-512MHz) BTS (28V), Portable (12V) and handheld applications (7.5V). The PD5xxxx series combines ST’s state-of-the-art LDMOS technology with the advantages of the PowerSO-10RF plastic package. The PD5xxxx series fulfils digital PMR high linearity requirements, i.e. TETRA standard (Terrestrial Trunked Radio). TETRA is ideal for public service organisations since it allows group calling, direct communication between handset and fast call set up.

LDMOS, the path to plastic packages

In DMOS conventional vertical technology an electrical insulator is required to isolate the drain from the ground. In LDMOS technology this insulation is no longer needed.

This not only means that electrical and thermal performances are greatly improved but also that the standard DMOS BeO (beryllium oxide) ceramic package used for 1W and above devices can be replaced with a plastic package.

Plastic offers numerous advantages over ceramic: Its high tolerance (0.5%), coplanarity (± 0.1mm) and good balanced weight, make it ideal for low cost SMD (Surface Mount Device) solutions.

PowerSO-10RF Features

PowerSO-10RF is an optimised version of PowerSO-10, the first ST, JEDEC approved, high power SMD. Lateral pins have been joined in two solid leads for higher current capability and lower reactive contribution. Frame leads have also been scaled down and depressed in order to diminish wire bond length, and consequently reactive effects. These features make the PowerSO-10RF well suited for applications up to 1GHz. There are two lead versions available: formed for real SMD applications for Pdiss<5W and straight for standard RF mounting for Pdiss>15W.

PowerSO-10RF Benefits

	Balanced weight
	Good Coplanarity
	Reliable solder joint
	Good heat conduction
	Junction Temperature 165°C
	Max power dissipation. 150W
	Improved RF performances (Operation>1GHz)
	Cost effective solution

PD5xxx Solution for TETRA

The ST PD54/55xxx is a low voltage series designed to provide a high performance, low cost complete solution for mobile and portable, whereas the PD57018 is a high voltage driver (28V/18W) for SD56120, a high power 100W ceramic LDMOS for base stations.

PD5xxx Series Benefits

	Easy to bias
	High power gain and linearity
	High power dissipation
	Easy board design
	Reduced system cost
	True SMD solutions (lead formed version)