Key Specs

SpecValueConditionSource
Control Features-Digi-Key
Current Quiescent IQ4 µADigi-Key
Input Voltage (Max)6VDigi-Key
Mounting TypeSurface MountDigi-Key
Number Of Regulators1Digi-Key
Operating Temperature Range-40°C ~ 125°CDigi-Key
Output ConfigurationPositiveDigi-Key
Output Current (Max)250mADigi-Key
Output TypeFixedDigi-Key
Output Voltage (Max)-Digi-Key
Output Voltage (Min)2.7VDigi-Key
Package CaseTO-236-3, SC-59, SOT-23-3Digi-Key
Protection FeaturesOver Current, Over Temperature, Short CircuitDigi-Key
Psrr44dB (100Hz)Digi-Key
Supplier Device PackageSOT-23-3Digi-Key
Voltage Dropout (Max)0.35V @ 250mADigi-Key

When To Use

Use the MCP1700T-2702E/TT in low-power, space-constrained applications requiring a fixed positive output voltage of 2.7 V minimum and an output current up to 250 mA. Its low quiescent current of 4 µA and wide operating temperature range from -40°C to 125°C make it ideal for battery-powered devices, portable instrumentation, and sensor modules.

Do not use this regulator in applications requiring output voltages below 2.7 V or output currents exceeding 250 mA. For lower dropout voltages or higher current demands, consider switching regulators or LDOs with higher current ratings and adjustable outputs.

When Not To Use

  1. Load currents above 250mA: The 250mA output current max disqualifies this part. Use a high-current synchronous buck with external FETs to deliver higher currents efficiently without thermal runaway.

  2. Input-output voltage differential below 0.35V dropout: When the input voltage is less than about 0.35V above output, the dropout voltage is exceeded, causing voltage collapse. Use an LDO regulator optimized for ultra-low dropout and low noise.

  3. Applications requiring galvanic isolation: This part lacks any isolation capability and cannot be used in systems requiring input-output isolation. Use an isolated flyback topology to meet isolation requirements.

Application Notes

The input pin is the switching node and should have the smallest possible loop area with the input power source to minimize noise and improve stability. The output pin is noise-sensitive and should be routed carefully to the load to reduce voltage ripple. Due to the low power dissipation at maximum output current (250 mA) and typical dropout voltage of 0.35 V, a heatsink is generally not required under normal operating conditions within the specified temperature range. However, ensure adequate PCB thermal design to maintain junction temperature within limits.

Gotchas

  1. [Startup under low input voltage]: Assuming the device will regulate immediately if input is near 2.7V output voltage. In reality, if input falls below dropout voltage plus output voltage (≈3.05V), output voltage collapses silently without reset. Scope shows output sagging under load. Fix: Verify input voltage margin ≥ 0.35V above output during all operating modes.

  2. [Load transient with insufficient output capacitance]: Designers may use minimum recommended output capacitance without considering load step size. This causes output voltage undershoot or ringing due to regulator’s internal compensation interacting with output capacitor ESR and ESL. Fix: Use a ceramic output capacitor ≥1 µF with low ESR and validate transient response on scope.

  3. [Misinterpretation of quiescent current]: Assuming 4 µA quiescent current applies at all loads and temperatures. Actually, quiescent current increases with output load and temperature, potentially causing battery drain in light load conditions. Fix: Measure actual current in worst-case temperature and load to confirm power budget.

  4. [Thermal derating ignored]: Designers may rely solely on maximum junction temperature without accounting for reduced power dissipation capacity in small SOT-23-3 package under poor airflow. Device enters thermal shutdown during continuous 250mA load at elevated ambient temperature. Fix: Use thermal simulation or derating curves to ensure junction stays below 125°C under expected conditions.