The MAX6329/MAX6349 are low-dropout, micropower linear voltage regulators with integrated microprocessor reset circuits. Each is available with preset +3.3V, +2.5V, +1.8V, or adjustable output voltages and can deliver up to 150mA load current. Employing internal P-channel MOSFET pass transistors, the devices consume only 25μA supply current, independent of the device load. The low supply current, low dropout voltage, and integrated reset functionality make these devices ideal for battery powered portable equipment. The MAX6329/MAX6349 include an internal reset circuit that indicates when the regulator output drops below standard microprocessor supply tolerances (-5% or -10%). The reset output remains asserted for 100ms (min) after the regulator output exceeds the selected reset threshold, ensuring that supply voltages and clock oscillators have stabilized before processor activity is enabled. Reset outputs are available in push-pull (active-low or -high) and open-drain (active-low) options. The internal reset circuit replaces external microprocessor supervisors or RC-based reset time delays. The MAX6329/MAX6349 are optimized for use with a 1μF (min) output capacitor. The regulator output voltage is adjustable with an external resistor-divider network at SET (reset threshold voltages track the desired output voltage). Each device includes thermal shutdown protection, output short-circuit protection, and reverse leakage protection. The MAX6329YPUT includes a shutdown feature to reduce regulator current below 1μA (max) and the MAX6349 offers a manual reset input to assert a microprocessor reset while the regulator output is within specification.
Feature
- Preset +3.3V/+2.5V/+1.8V or Adjustable Regulator Output
- ±3.0% Regulator Accuracy Over the Specifed Operating Range
- 25μA Supply Current
- Low 180mV Dropout at 100mA Load
- Small Output Capacitor (1μF min ceramic or tantalum)
- Zero Reverse Leakage Current
- Thermal and Short-Circuit Protection
- Integrated Microprocessor Reset Circuit with 100ms (min) Timeout
- Open-Drain and Push-Pull Reset Outputs
- Regulator Shutdown Input (MAX6329) or Manual Reset Input (MAX6349)
- 6-Pin SOT23 Package
Applications
- Audio Systems
- Cordless Phones
- Electronic Planners
- Global Positioning Systems (GPS)
- Handheld Instruments (PDAs, Palmtops)
- Modems
- Palmtop Computers
- PCMCIA Cards
- USB Devices