Active dual-supply bus switch for level translation
The Toshiba TC7WP3125FK,LF(CT is a bus switch configured as two independent 1:1 single-pole single-throw (SPST) switches, each with a typical on-state resistance low enough to pass digital signals with minimal attenuation. The dual-supply architecture — a VCC1 range of 1.1V to 2.7V and a VCC2 range of 1.65V to 3.6V — lets it bridge logic families operating at different voltage domains, such as a 1.8V microcontroller talking to a 3.3V peripheral.
VCC1 handles the lower-voltage side (1.1V to 2.7V), VCC2 the higher side (1.65V to 3.6V). The switch is bidirectional, so data flows from either domain to the other without direction control. This eliminates a dedicated level-shifter IC when the I/O count is low — two channels here — and the 12mA output drive on both sides is enough for CMOS logic inputs or a single LED load, but not for a bus with multiple fan-out.
Housed in an 8-VFSOP package measuring 2.30 mm wide (0.091"), the TC7WP3125FK,LF(CT uses a standard 8-SSOP footprint. The VFSOP body is thinner than a typical SSOP, so reflow profiles should be checked against the package thickness — the thin profile can heat faster than a standard SSOP, potentially affecting solder-joint quality if the profile is not adjusted.