1FEATURES

2• Precise Monitoring of 2.5V, 3.3V, and 5V

Supply Voltages

• Fully Specified Over Temperature

– Industrial: −40°C to +85°C

– Extended: −40°C to +125°C

• 100 ms Minimum Power-On Reset pulse Width, factory190

ms Typical:

– Active-Low RESET Output (LM3722)

– Active-High RESET Output (LM3723)

– Active-Low RESET Open Drain Output

(LM3724)

• Guaranteed RESET Output Valid for VCC ≥ 1V

• Low Supply Current, 6μA Typical

• Power Supply Transient Immunity

• Compatible with MAX811/812 Applications

APPLICATIONS

• Microprocessor Systems

• Computers

• Controllers

• Intelligent Instruments

• Portable/Battery-Powered Equipment

DESCRIPTION

The LM3722/LM3723/LM3724 microprocessor

supervisory circuits monitor the power supplies in

microprocessor and digital systems. They provide a

reset to the microprocessor during power-up, power-

down, brown-out conditions, and manual reset.

The LM3722/LM3723/LM3724 asserts a reset signal

whenever the supply decreases below the factory190

programmed reset threshold. Reset will be asserted

for at least 100ms even after VCC rises above the

reset threshold.

The LM3722 has an active-low RESET push-pull output. The LM3723 has an active-high RESET push-

pull output. The LM3724 has an active-low open-drain

RESET output.

Three standard reset voltage options are available,

suitable for monitoring 5V, 3.3V, and 2.5V supply

voltages. Additional reset voltages are also available;

contact Texas Instruments for details.

With a low supply current of only 6μA, the

LM3722/LM3723/LM3724 are ideal for use in portable

equipment. The LM3722/LM3723/LM3724 are

available in the 5-pin SOT-23 package.