Microchip Technology MIC5504-1.8YM5-TR

MIC5504-1.8YM5-TR Overview

MIC5504-1.8YM5-TR is a fixed-output, low-dropout linear voltage regulator manufactured by Microchip Technology. It converts an input supply between 2.5V and 5.5V into a regulated 1.8V output and can deliver up to 300mA of continuous load current under suitable thermal conditions.

The device is supplied in a 5-pin SOT-23 package and is intended for compact, battery-powered and portable electronic systems. Its combination of low quiescent current, enable control, automatic output discharge and an internal enable pull-down resistor makes it useful for powering microcontrollers, digital logic, sensors and other low-voltage loads that require a controlled 1.8V supply rail.

Unlike a basic always-on regulator, the MIC5504-1.8YM5-TR allows a processor or power-management controller to switch the output on and off through the EN pin. When disabled, its internal output-discharge circuit helps remove charge stored in the output capacitor, while the internal EN pull-down keeps the regulator off when the control signal is floating.

Technical Context

The MIC5504-1.8YM5-TR is positioned between a higher-voltage power source and a low-voltage electronic load. A typical circuit may receive power from a lithium battery, a regulated 3.3V rail or a 5V system, while the load requires a clean and stable 1.8V supply.

In this power path, the VIN pin receives the source voltage, the internal control loop regulates the output, and the VOUT pin supplies the 1.8V load. The regulator continuously adjusts its internal pass device to compensate for changes in input voltage and load current.

The part is particularly useful for circuits in which a low-voltage subsystem must remain disabled during startup. The internal pull-down resistor on EN prevents an undefined floating control signal from accidentally enabling the rail. After the host controller drives EN high, the regulator starts and establishes the 1.8V output.

When EN is driven low, the regulator turns off and the automatic discharge function connects an internal discharge path to VOUT. This feature can help bring the powered circuit to a known off state and reduce residual voltage during power sequencing, restart or fault recovery.

Design limitation: Microchip states that the MIC5501/2/3/4 family is not suitable for RF transmitter systems. Engineers designing radio transmitters should select a regulator specifically characterized for the required RF environment.

Key Specifications

MIC5504-1.8YM5-TR Pinout and Package Design

The MIC5504-1.8YM5-TR pinout uses a 5-pin SOT-23 package. The package code in the ordering number is M5, while the TR suffix identifies tape-and-reel packaging.

Enable Thresholds

• Logic-low: 0.2V maximum.
• Logic-high: 1.2V minimum.
• Internal EN pull-down: 4MΩ typical.

The controlling processor must provide voltage levels that satisfy these thresholds under all expected operating conditions. The internal pull-down is intended to establish a safe disabled state, but it should not be treated as a replacement for a properly driven control signal when deterministic power sequencing is required.

Input and Output Capacitors

A 1µF input capacitor and a 1µF output capacitor are required for normal application stability. Low-ESR ceramic capacitors are recommended. Microchip recommends X5R or X7R dielectric materials because their capacitance remains more stable over voltage and temperature than Y5V capacitors.

The capacitors should be positioned close to the VIN, VOUT and GND pins. Long traces can add impedance and reduce transient performance. The ground ends of both capacitors should return through a short path to the same low-impedance ground area used by the regulator.

Thermal and PCB Considerations

The regulator dissipates approximately the voltage difference between VIN and VOUT multiplied by the output current:

Power dissipation ≈ (VIN − 1.8V) × IOUT

For example, converting 5V to 1.8V at a 300mA load produces approximately 0.96W before accounting for the regulator's small ground current. This level of dissipation is generally too high for a small SOT-23 package without exceeding the allowable junction temperature.

Therefore, the 300mA rating does not mean that 300mA can be delivered under every input-voltage and ambient-temperature condition. The designer must calculate power dissipation, package thermal resistance, PCB copper area and ambient temperature before selecting the maximum load current.

Key Features

• Fixed 1.8V regulation for low-voltage loads: The fixed output removes the need for external feedback resistors, reducing component count in compact sensor, processor and portable-device power rails.
• 300mA output capability: The available current can support a microcontroller and several low-power peripherals when the total load and thermal conditions remain within specification.
• Low typical quiescent current: The 38µA typical ground current helps reduce standby losses in battery-powered instruments and handheld electronics.
• Automatic output discharge: When EN is low, the internal discharge path helps remove residual charge from the output capacitor, supporting predictable shutdown and power-cycle behavior.
• Internal enable pull-down: The regulator defaults to an off state when the host control signal is floating, which is useful during processor reset and boot sequences.
• Small SOT-23-5 package: The compact package allows the regulator to be placed close to the powered load, reducing trace length and saving PCB area.
• Integrated protection: Current limiting and thermal shutdown help protect the regulator during overload and excessive-temperature conditions, although normal operation must not rely on repeatedly activating these protections.
• Stable with ceramic capacitors: Operation with 1µF ceramic input and output capacitors supports a compact power-supply layout with a low external component count.

MIC5504-1.8YM5-TR Applications

Portable Microcontroller and Sensor Systems Use scenario: Battery-powered data loggers, handheld meters and compact sensing devices. IC role: Converts a higher battery or system rail into a controlled 1.8V supply for the processor, sensor or digital interface. Design value: Low quiescent current reduces standby loss, while enable control allows the host to shut down the 1.8V subsystem when it is not required.

GPS and Portable Navigation Equipment Use scenario: Portable navigation units and location-tracking devices containing low-voltage digital circuitry. IC role: Supplies a local 1.8V rail from a suitable battery-derived or system input voltage. Design value: The compact package and low external component count help fit the regulator into space-limited portable equipment.

Portable Medical Electronics Use scenario: Handheld monitoring products and portable diagnostic electronics requiring a small 1.8V digital rail. IC role: Regulates the input source and powers the low-voltage control or sensing subsystem. Design value: Enable control and automatic output discharge can support controlled startup and shutdown. Final medical-product suitability must be verified at the complete system level.

5V-to-1.8V Local Power Rails Use scenario: Industrial controllers, embedded boards and mixed-voltage systems that include a 5V source and 1.8V logic. IC role: Produces the required 1.8V supply close to the load. Design value: Provides a simple linear-regulator solution when load current and power dissipation are low enough. For higher current from a 5V input, a switching converter may provide better thermal efficiency.

MIC5504-1.8YM5-TR Equivalent and Alternatives

A MIC5504-1.8YM5-TR equivalent must be evaluated by more than output voltage and package name. The replacement should be checked for pin assignment, input range, output current, accuracy, dropout voltage, quiescent current, enable behavior, output-discharge function and thermal performance.

MIC5504-1.8YM5-TR vs MIC5501-1.8YM5-TR: Both devices provide a fixed 1.8V output in a SOT-23-5 package, but the MIC5504 is optimized for systems that benefit from automatic output discharge and a defined disabled state when EN is floating. The MIC5501 may be suitable when those functions are unnecessary and EN is always driven to a valid logic level.

Selection advice: Choose MIC5504-1.8YM5-TR when controlled shutdown, residual-voltage discharge and safe enable behavior during processor startup are important. Do not treat another 1.8V SOT-23 regulator as a direct replacement until the complete pinout, capacitor requirements, enable polarity, thermal performance and output-discharge behavior have been compared.

Quality, Handling and Traceability

The MIC5504-1.8YM5-TR is an ESD-sensitive semiconductor device. The official data sheet specifies a 3kV human-body-model ESD rating and recommends appropriate handling precautions.

During receiving, storage and assembly, the device should be managed using suitable ESD controls, including grounded workstations, conductive packaging and trained handling procedures.

For purchasing verification, confirm the following information with the supplier:

• Full ordering part number: MIC5504-1.8YM5-TR
• Manufacturer: Microchip Technology
• Output voltage: 1.8V
• Package: SOT-23-5
• Package top marking appropriate for the 1.8V MIC5504 SOT-23 version
• Date code and lot information
• Original reel or manufacturer packaging information
• Moisture, storage and soldering requirements shown on the applicable packaging documentation

Traceability, inspection reports and additional testing should only be claimed when those services have actually been completed and documented for the supplied lot.

Availability and Purchasing Support

The TR suffix identifies tape-and-reel packaging. For the SOT-23 version, the official ordering system specifies 3,000 devices per reel.

Current MIC5504-1.8YM5-TR stock, price, date code, minimum order quantity and delivery schedule should be confirmed through a current quotation. Availability can vary by production lot, authorized distribution channel and market demand.

For a production order, provide the required quantity, target delivery date, packaging requirement and acceptable date-code range. For an alternative-part request, also provide the input voltage, maximum load current, PCB footprint and required shutdown behavior so that compatibility can be reviewed correctly.

About Microchip Technology

Microchip Technology develops microcontrollers, analog devices, power-management products, connectivity devices, security products and other embedded-system components. The MIC5504 family is part of its analog power-management portfolio and is designed to provide a compact, low-component-count linear-regulation solution for portable and general-purpose electronic systems.

Designers should use the latest Microchip documentation, product-change notices and package information when approving MIC5504-1.8YM5-TR for a new or revised design.

Frequently Asked Questions

Where can I find the MIC5504-1.8YM5-TR datasheet download?

The MIC5504-1.8YM5-TR datasheet is included in the Microchip MIC5501/2/3/4 family data sheet. Use the latest revision from the manufacturer's official product documentation and confirm that the electrical characteristics, package information and ordering code match the device being purchased.

What is the output voltage of MIC5504-1.8YM5-TR?

MIC5504-1.8YM5-TR provides a fixed nominal output voltage of 1.8V. Its initial output accuracy is specified as ±2% at 25°C, with a wider specified variation across the full operating junction-temperature range.

What should be considered in the MIC5504-1.8YM5-TR pinout design?

The MIC5504-1.8YM5-TR pinout uses pin 1 for VIN, pin 2 for GND, pin 3 for EN, pin 4 as NC and pin 5 for VOUT. Place the required input and output ceramic capacitors close to the device and use short ground connections. Pin 4 must not be used as an electrical connection.

Can the EN pin of MIC5504-1.8YM5-TR be left floating?

The MIC5504 includes an internal pull-down resistor on the EN pin, so leaving EN floating keeps the regulator disabled. For reliable power sequencing, however, the host controller should normally drive EN to a defined logic level.

What happens to the output when MIC5504-1.8YM5-TR is disabled?

When EN is low, the regulator turns off and its internal automatic discharge circuit provides a path that helps discharge the output capacitor and connected output rail.

What is the main MIC5504-1.8YM5-TR application?

A typical MIC5504-1.8YM5-TR application is generating a controlled 1.8V local power rail for a microcontroller, sensor, memory device or digital interface in portable or mixed-voltage equipment.

Can MIC5504-1.8YM5-TR deliver 300mA from a 5V input?

The device is electrically rated for up to 300mA, but converting 5V to 1.8V at that current creates substantial power dissipation in the regulator. The allowable current must be calculated from the input-output voltage difference, PCB thermal performance, ambient temperature and maximum junction temperature. A switching regulator may be more appropriate for a continuous high-current 5V-to-1.8V conversion.

Is MIC5504-1.8YM5-TR suitable for RF transmitter circuits?

No. Microchip states that the MIC5501/2/3/4 family is not suitable for RF transmitter systems. A regulator specifically intended and tested for the RF transmitter environment should be selected.

Is there a direct MIC5504-1.8YM5-TR equivalent?

A possible MIC5504-1.8YM5-TR equivalent cannot be selected using voltage and package alone. Any candidate must match the pinout, 1.8V output, input range, current capacity, enable thresholds, capacitor stability requirements and thermal limits. The automatic discharge and internal EN pull-down functions must also be considered.

What should be checked before replacing MIC5504-1.8YM5-TR?

Before replacing the device, compare the pin assignment, package footprint, fixed output accuracy, maximum load current, minimum input voltage, dropout voltage, quiescent current, output capacitor requirement, enable polarity, output-discharge behavior and operating-temperature range. Prototype testing should be completed under worst-case input, load and temperature conditions.