TECH PUBLIC MAX811L

The MAX811/812 are cost-effective system supervisory circuits designed to monitor the supply voltage in digital systems and assert a reset signal to the host processor when necessary. A manual reset input is provided as an alternative to dedicated reset supervisors, making these devices suitable for pushbutton reset applications. No external components are required. The reset output asserts within 20μs of VCC falling below the reset threshold voltage. After VCC rises above the reset threshold, the reset signal remains asserted for a minimum of 140ms. The MAX812 features an active-high reset output, while the MAX811 features an active-low reset output. Valid output is maintained even when VCC drops below 1.1V. Both devices are available in a 4-pin SOT-143 package and operate over a temperature range of -40°C to +85°C. The devices are optimized to reject fast transient glitches on the VCC supply rail. Adding a 0.1μF capacitor near the VCC pin further improves transient noise rejection performance.

• High-precision monitoring circuit for power supplies with rated voltages of 2.0V, 2.8V, 3.0V, 3.3V, and 5.0V
• Manual reset input
• 140ms minimum reset output period
• Reset output remains valid with Vcc as low as 1.1V
• Low supply current, 8μA (typical)
• Vcc transient suppression
• Compact 4-pin SOT-143 package
• No external components required
• Direct replacement for MAX811/812 with lower threshold voltage options
• Push-pull reset output
• Temperature range: -40°C to +85°C

• Computers
• Servers
• Laptops
• Cable modems
• Wireless communications
• Embedded control systems
• White goods
• Power meters
• Smart instruments
• PDAs and handheld devices
• Smart meters