Key Specs
| Spec | Value | Condition | Source |
|---|---|---|---|
| Control Features | - | Digi-Key | |
| Current Quiescent IQ | 4 µA | Digi-Key | |
| Input Voltage (Max) | 6V | Digi-Key | |
| Mounting Type | Surface Mount | Digi-Key | |
| Number Of Regulators | 1 | Digi-Key | |
| Operating Temperature Range | -40°C ~ 125°C | Digi-Key | |
| Output Configuration | Positive | Digi-Key | |
| Output Current (Max) | 250mA | Digi-Key | |
| Output Type | Fixed | Digi-Key | |
| Output Voltage (Max) | - | Digi-Key | |
| Output Voltage (Min) | 3.5V | Digi-Key | |
| Package Case | TO-236-3, SC-59, SOT-23-3 | Digi-Key | |
| Protection Features | Over Current, Over Temperature, Short Circuit | Digi-Key | |
| Psrr | 44dB (100Hz) | Digi-Key | |
| Supplier Device Package | SOT-23-3 | Digi-Key | |
| Voltage Dropout (Max) | 0.35V @ 250mA | Digi-Key |
When To Use
Use the MCP1700T-3502E/TT in low-power, battery-operated applications requiring a fixed 3.5V output voltage and a maximum output current of 250mA. Its ultra-low quiescent current of 4 µA makes it ideal for portable devices and energy-sensitive systems. Avoid using this device in applications where the input voltage exceeds 6V or where adjustable output voltage is required; in such cases, consider a regulator with higher input voltage tolerance or adjustable output options.
When Not To Use
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Output current > 250mA: The 250mA max output current rating disqualifies this part for higher load demands. Use a high-current synchronous buck with external FETs instead to avoid thermal runaway and premature device failure.
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Input-output voltage differential under 0.35V: The dropout voltage of 0.35V at full load is too high for low-voltage headroom scenarios. Use an LDO regulator optimized for ultra-low dropout to prevent output voltage sag and loss of regulation.
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Battery-powered system requiring ultra-low quiescent current in sleep mode: The 4µA quiescent current is moderate but too high for μA-level sleep mode budgets. Use a low-IQ PFM buck to extend battery life by reducing bias current in standby states.
Application Notes
The input node is the switching node where the internal pass transistor modulates current; minimizing loop area here reduces electromagnetic interference. The output pin is noise-sensitive and should be routed away from noisy signals to maintain output voltage stability. At the maximum output current of 250mA with a dropout voltage of 0.35V, the device typically does not require a heatsink due to its low power dissipation, but thermal considerations should be evaluated based on ambient temperature and PCB layout.
Gotchas
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Engineer omits verifying input voltage limits and applies more than 6V at the input. Result: The device may suffer permanent damage or malfunction due to exceeding the maximum input voltage. Fix: Always ensure the input voltage does not exceed 6V.
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Engineer assumes external capacitors are needed and adds large output capacitors with high ESR. Result: Excessive ESR can cause instability or oscillation. Fix: Use the device without external capacitors or follow Microchip’s recommended minimal output capacitance guidelines if needed.