MOSFET-controlled supply sequencer in a 4×5 mm QFN
The LTC2926CUFD#PBF is a MOSFET-controlled power supply controller from Analog Devices, designed to sequence and track multiple supply rails in a system. It operates from a 2.9V to 5.5V supply rail and draws 2.5 mA quiescent current — low enough to run from the same 3.3V or 5V bias rail it is sequencing. The part comes in a 20-WFQFN exposed pad package (20-QFN, 4×5 mm body), surface-mount only.
Supply rail and temperature envelope
The 2.9V to 5.5V input range covers both 3.3V and 5V nominal rails, but the lower end at 2.9V means a 3.3V rail with 10% tolerance (3.0V min) still fits — no separate regulator needed for the controller itself. The 2.5 mA supply current is the controller's own draw; the MOSFET gate charge current is additional and depends on the external FETs and switching frequency. This part is intended for bench equipment, servers, telecom indoor racks, and similar controlled environments — not for outdoor or under-hood automotive use. The storage range is wider, but the operating envelope is the binding constraint for ambient-temperature designs.
Package and PCB layout considerations
The 20-QFN (4×5) package has a 0.50 mm pitch and an exposed pad on the bottom. The pad must be connected to a ground plane with multiple vias to keep the junction temperature within limits during continuous gate drive. The datasheet's recommended land pattern shows a 3.2×4.2 mm pad opening — the PCB fab needs a solder-mask-defined pad to avoid solder bridging to the signal pins. The part is — no tape-and-reel carrier. For automated pick-and-place, the tubes or trays need to be loaded into a compatible feeder; verify the feeder width and tube orientation before programming the line.
Lifecycle and sourcing posture
No official successor or second-source alternate is recorded in the manufacturer's cross-reference.