Automotive-grade supervisor with adjustable reset timing
It monitors a single supply voltage and asserts an active-low, open-drain reset output when the monitored voltage falls below an adjustable threshold. The reset timeout period is also adjustable via an external capacitor, giving the designer control over the delay before the output de-asserts after the supply returns. The open-drain output allows the reset signal to be wire-ORed with other supervisors or pulled up to a different voltage rail, which is common in mixed-voltage systems. The adjustable threshold means one base part number can cover multiple supply rails (e.g., 3.3 V, 5.0 V, or custom values) by selecting the appropriate resistor divider, reducing the number of unique line items on the BOM.
Package and mounting — 6-WSON with exposed pad
The small footprint (2x2 mm) suits space-constrained automotive modules, but the pad requires a via-in-pad or at least a thermal via array to keep junction temperature in check. Surface-mount assembly is standard.
The adjustable voltage threshold and adjustable reset timeout are the two features that give this part its flexibility. Instead of stocking fixed-threshold supervisors for every rail voltage, a single TPS3808G01QDRVRQ1 can be configured with a resistor divider to monitor any voltage above its internal reference. Similarly, the reset timeout — the period the reset output stays asserted after the supply recovers — is set by an external capacitor, allowing the designer to tailor the delay to the downstream processor's power-on reset requirements. For a typical 3.3 V rail, the threshold is set by two resistors; the datasheet provides a formula. The timeout capacitor value is chosen from a table in the datasheet. This programmability means one line item on the BOM can serve multiple designs, simplifying procurement and reducing the risk of a shortage on a fixed-threshold variant.