F. Buballa1, S. Linnhoff1, T. Hoffmann2, A. Wentzel2, W. Heinrich2, F. Gerfers1
Proc. 16th European Microwave Integrated Circuits Conference (EuMIC 2021), London, UK, Apr. 3-4, ISBN: 978-2-87487-064-4, pp. 156-159 (2022).
This paper presents a 4 GBaud pre-driver chip for GaN-based RF digital transmitter chains providing voltage swings up to 5Vpp at typical capacitive load impedances (0.25 pF). The compact monolithic microwave integrated circuit (MMIC) driver has been fabricated using a 22nm FDSOI technology featuring 6.5V LDMOS to achieve high-voltage swings and high switching speeds at the same time. The chip exhibits an area of 710×760µm2 and consumes about 488mW of DC power. Standalone driver characterization and tests in combination with a real GaN-MMIC have been conducted. Using a high ohmic (1 kΩ), ultra-compact self-made probe the driving signal of the proposed pre-driver has been tested at the interconnection between MOS and GaN devices. For a 0.35Vpp 1GHz PWM 50% duty-cycle differential input signal the driver IC achieves 4.1Vpp of output voltage amplitude with rise/fall times of 200 ps and 150 ps, respectively, at the gate of the 4×125µm first-stage GaN-HEMT.
1 Mixed Signal Circuit Design, Technische Universität Berlin, Germany
2 Ferdinand-Braun-Institut gGmbH, Leibniz-Institut für Höchstfrequenztechnik (FBH), Berlin, Germany
CMOS, LDMOS, 22nm FDSOI, power amplifiers, digital, GaN, driver amplifier, digital Tx.
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