A pair of low-voltage single-pole, double-throw analog switches offers ultra-low and flatter on-resistance, resulting in better signal quality in battery-powered, portable, and handheld devices. The ISL54050 (dual) and ISL54056 (quad) switches from Intersil are available in µTQFN packages, which reduce board space used by up to 72% compared to TDFN and TQFN packages (see the Figure). They are also 0.5-mm thick, 33% thinner than TDFN and TQFN parts. Both switches operate from single, 1.65-V to 4.5-V dc supplies, consume less than 0.45 µW, and handle logic levels as low as 1.8 V, reducing battery drain and extending talk time while eliminating crosstalk. They are bidirectional switches that can also be used as single and dual, differential, 2:1 multiplexers, respectively.
When run off a 3.3-V supply, the ISL54050 has a typical on-resistance of 0.27 Ω and resistance flatness of 0.03 Ω. Similarly, the ISL54056 has a typical on-resistance of 0.45 Ω with a flatness of 0.05 Ω. The result is very low total harmonic distortion suitable for use in audio paths such as in MP3 players in cell phones and CD audio devices. On-resistance matching between channels is 0.06 Ω. Unlike competing switches in which significant cross conduction current is present, the ISL54050/56 exhibit low supply current when operated with logic control signals that are lower than the device supply voltage.
The chips are RoHS-compliant. The dual-switch is available in a 10-lead, 1.8- by 1.4- by 0.5-mm µTQFN package. The quad version is available in a 16-lead, 2.6- by 1.8- by 0.5-mm µTQFN package. The ISL54050 is available now in a 10-lead QFN package and is priced at $1.40 each, and the ISL54056 is available now in a 16-lead QFN package and is priced at $1.60 each in 1,000-unit quantities.