Fiber optic avalanche photodiode bias supply
The MAX1932ETC+T is a controller IC designed for fiber optic network applications, specifically to generate the high-voltage bias needed for avalanche photodiodes (APDs) in optical receivers. It accepts a 2.7V to 5.5V input rail — typical of a 3.3V or 5V supply in an optical module — and produces a regulated output from 4.5V up to 90V, covering the bias range for most InGaAs APDs. The single-output architecture means one IC biases one APD; for multi-channel receivers you need one per channel.
Package, footprint, and temperature grade
Housed in a 12-WQFN with exposed pad (4x4 mm body, supplier package 12-TQFN), the thermal pad must be soldered to a ground-plane copper island on the PCB to pull heat from the switching FET inside. Rated for -40°C to +85°C operation, this covers the industrial temperature band — outdoor optical line terminals and uncontrolled enclosures are within range. Surface-mount assembly; the exposed pad requires a solder paste stencil aperture matched to the datasheet land pattern for void-free reflow.
Lifecycle, compliance, and sourcing posture
Supplied in Tape & Reel (TR) or Cut Tape (CT) — the reel format suits automated pick-and-place; cut tape works for prototype or low-volume builds. No pin-compatible second source or successor is recorded — this is a single-sourced part from Analog Devices.