General Description
The KB809 is a power supply supervisor that provides under-voltage monitoring and power-on reset generation in an industry standard 3-pin SOT package and pinout. The reset output is asserted at power-on and any time the input voltage drops below the programmed threshold. It remains asserted for 180ms (typ.) after the input subsequently rises back above the threshold boundary. The KB809 has an active-low reset output. Hysteresis is included to prevent chattering due to noise, and the KB809 is inherently immune to brief power supply transients. Typical supply current is a low 3µA. For those applications that require a manual reset function, see the KB811/812. For those applications that require a longer reset timeout, see the KB809. (The KB809 is identical to the industry-standard KB809 with the exception of a shorter reset timout.)

FEATUREs
• Under-voltage monitor
• Power-on reset generation (180ms Typ)
• Choice of threshold voltages (contact Kingbor regarding
   availability)
• Active-low reset output
• No external components required
• Rejects brief input transients
• Industry standard package and pinout
• 3-pin SOT23-3 package

APPLICATIONs
• Monitoring processor, ASIC, or FPGA core and I/O
   voltages
• PDAs, hand-held PCs
• Embedded controllers
• Telecommunications systems
• Power supplies
• Wireless / Cellular systems
• Networking hardware