GaN vs LDMOS | Difference between GaN and LDMOS

This page compares GaN vs LDMOS and describes difference between GaN and LDMOS.

Parameter	GaN	LDMOS
Full form	Gallium Nitride	Laterally Diffused MOSFET
Applications	• GaN on SiC (50V) provides high efficiency, power density and higher gain in smaller package • Used for broadband applications due to higher output impedance and lower Cds capacitance • Advantages: GaN transistors have small parasitic capacitance and hence they have easy wideband matching compare to LDMOS transistors of identical power level.	• LDMOS is used for cellular and broadcast narrowband applications due to high power and efficiency • LDMOS(50V) is used for <1.5 GHz applications while LDMOS (28V) is used for frequencies upto 4 GHz • Disadvantages: LDMOS transistor has large Cgs/Cds capacitance due to large peripheral in its design. This will limit the bandwidth.
Fmax (GHz)	30 GHz for GaN (50V)	22 GHz for LDMOS (28V) 15 GHz for LDMOS (50V)
Power Density (W/mm)	5-10 for GaN (50V)	0.8 for LDMOS (28V) 2 for LDMOS (50V)
Efficiency at P_1dB (%)	70 for GaN (50V)	60 for LDMOS (28V) <55 for LDMOS (50V)
Bandwidth (MHz)	500-2500 for GaN (50V)	100-400 for LDMOS (28V) 100-500 for LDMOS (50V)
Cds (pF/ W) output capacitance	1/4 smaller for GaN (50V)	0.23 for LDMOS (28V) 1/2 smaller for LDMOS (50V)
Cgs (pF/ W) input capacitance	1/2 smaller for GaN (50V)	0.94 for LDMOS (28V) 1/2 smaller for LDMOS (50V)

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