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PKM22EPP-40 original imported piezoelectric large hole buzzer HYR-2212 fire alarm loud buzzer

SKU: FA3048-7
Model

PKM22EPP-40
Manufacturer

Murata Electronics (Original)
Buzzer Type

Piezoelectric Sounder (External Drive, No Internal Circuitry)
Resonant Frequency

4kHz
Sound Pressure Level

75dB min @ 3Vp-p, 10cm
Operating Voltage Range

Up to 25Vp-p
Capacitance

12,000pF ±30% at 1kHz
Operating Temperature

-20°C to +70°C

The PKM22EPP-40 is an original, imported piezoelectric sounder from Murata Electronics, specifically engineered for fire alarm systems, security equipment, and industrial alarm applications where high reliability and clear sound output are critical. Unlike active buzzers with built-in oscillators, the PKM22EPP-40 is an external drive type — it requires a driving signal (square wave or sine wave) from a microcontroller, timer IC, or dedicated driver circuit to produce sound.

At the heart of the buzzer is a piezoelectric ceramic element that vibrates when an alternating voltage is applied, generating sound waves without the need for a mechanical contact or coil. This contactless operation eliminates sparking, wear, and EMI noise, making the PKM22EPP-40 far more reliable and longer-lasting than electromagnetic buzzers. The large sound hole design (22mm diameter) provides a wider sound dispersion pattern, ensuring the alarm tone carries clearly across large rooms and industrial spaces.

The PKM22EPP-40 operates at a resonant frequency of 4kHz, a pitch that is highly effective for alarm and warning applications — loud enough to be noticed immediately but not so piercing as to cause discomfort. With a sound pressure level of 75dB minimum at 3Vp-p and 10cm, it meets the requirements of most fire alarm and industrial warning standards. The buzzer supports a wide operating voltage range up to 25Vp-p, giving designers flexibility in driving circuit selection.

The device features a rugged encased construction with a 22mm diameter and through-hole PC pins for secure PCB mounting. It is compatible with standard wave soldering techniques, though Murata specifies strict soldering temperature limits to prevent damage to the internal support structure — the resin case and cover must not be exposed to excessive heat.

The PKM22EPP-40 is widely used in fire alarm systems, security alarms, industrial control panels, home appliances (microwave ovens, refrigerators), communications equipment, computer peripherals, and medical devices.

Important Note: This is an external drive buzzer — it does not contain an internal oscillator and will not produce sound when connected directly to a DC voltage. You must provide an AC driving signal (typically a square wave at the resonant frequency, or a sine wave) from a microcontroller, timer, or dedicated driver IC. When driving directly from an IC or microcontroller pin, Murata recommends inserting a series resistor of approximately 1–2kΩ to protect the IC and ensure stable oscillation. Do not apply DC voltage to the terminals — doing so may cause silver migration and permanent damage. The buzzer is not waterproof and cannot be washed; avoid exposure to moisture and cleaning solvents.

Whether you are designing a fire alarm panel, a security system, or an industrial warning device, the PKM22EPP-40 provides a reliable, proven solution for high-quality audible alerting with the trusted quality of an original Murata component.

Features

  • Original Murata PKM22EPP-40 — Genuine imported piezoelectric sounder for critical alarm applications

  • External drive design — No internal oscillator; flexible tone generation via external driving circuit

  • 4kHz resonant frequency — Effective alarm pitch for fire and security warnings

  • 75dB minimum sound pressure — Loud and clear at 3Vp-p, 10cm measuring distance

  • Wide operating voltage range — Up to 25Vp-p, compatible with various driving circuits

  • Large 22mm sound hole — Wide sound dispersion for large room coverage

  • Piezoelectric technology — No contacts, no EMI, no wear; highly reliable and long-lasting

  • Rugged encased construction — Through-hole PC pins for secure PCB mounting

  • Wide application range — Fire alarms, security systems, industrial control, home appliances, medical devices

  • Proven Murata quality — Trusted original component for professional alarm designs

Technical Specifications 

# Parameter Specification
1 Model PKM22EPP-40
2 Manufacturer Murata Electronics (Original)
3 Buzzer Type Piezoelectric Sounder (External Drive, No Internal Circuitry)
4 Resonant Frequency 4kHz
5 Sound Pressure Level 75dB min @ 3Vp-p, 10cm
6 Operating Voltage Range Up to 25Vp-p
7 Capacitance 12,000pF ±30% at 1kHz
8 Operating Temperature -20°C to +70°C 

Usage

Getting Started

  1. Identify the pins — The PKM22EPP-40 has two through-hole pins. Determine polarity according to the datasheet; incorrect polarity may affect performance.

  2. Design the driving circuit — This buzzer requires an external driving signal. Common driving circuits include:

    • Transistor astable multivibrator — Simple two-transistor circuit generating a square wave

    • Inverter or NAND gate oscillator — Logic gate based oscillator for stable frequency

    • Microcontroller PWM output — Use tone() function or PWM at 4kHz

  3. Add series resistor (recommended) — When driving directly from an IC or microcontroller pin, insert a 1–2kΩ series resistor to protect the IC and ensure stable oscillation.

  4. Connect the buzzer — Wire the buzzer terminals to the driver circuit output. Observe correct polarity.

  5. Apply driving signal — Power the driver circuit. The buzzer will produce a 4kHz tone at the volume determined by the driving voltage.

  6. Adjust volume (optional) — The sound pressure level increases with driving voltage up to 25Vp-p. Use the appropriate voltage for your application.

Pin Connections

Buzzer Pin Function
Pin 1 Connect to driver circuit output
Pin 2 Connect to driver circuit output (observe polarity)

Example Arduino Code (Direct PWM Drive with Series Resistor)

cpp
#define BUZZER_PIN 8

void setup() {
  pinMode(BUZZER_PIN, OUTPUT);
}

void loop() {
  tone(BUZZER_PIN, 4000);  // 4kHz tone
  delay(500);
  noTone(BUZZER_PIN);
  delay(500);
}

Note: Use a 1–2kΩ series resistor between the Arduino pin and the buzzer terminal.

Typical Applications

  • Fire alarm systems — High-reliability audible warning for smoke and heat detectors

  • Security alarms — Intrusion detection, door/window sensors, panic buttons

  • Industrial control panels — Fault indicators, machine status alerts, process warnings

  • Home appliances — Microwave ovens, refrigerators, washing machines, dryers

  • Communications equipment — Telephone ringers, intercom systems, office equipment

  • Medical devices — Patient alerts, equipment status indication

  • Instrumentation — Measurement alerts and status indication

Notes for Business Buyers

  • Original Murata component — Genuine quality and proven reliability for critical alarm applications

  • External drive required — Designers must provide a driving circuit; not a drop-in replacement for active buzzers

  • Solder carefully — Follow Murata‘s soldering conditions strictly to avoid damaging the internal support structure

  • Suitable for bulk purchasing — Ideal for fire alarm manufacturers, security system integrators, and industrial panel builders

Q: What is the PKM22EPP-40 used for?

It is a Murata piezoelectric sounder for fire alarms, security systems, industrial control panels, home appliances, communications equipment, and medical devices.

Q: Is the PKM22EPP-40 an active or passive buzzer?

It is an external drive (passive) piezoelectric sounder. It has no internal oscillator and requires an AC driving signal to produce sound.

Q: Can I connect the PKM22EPP-40 directly to a DC voltage?

No. Applying DC voltage may cause silver migration and permanent damage to the piezoelectric element. Always use an AC driving signal (square wave or sine wave).

Q: What is the resonant frequency?

The buzzer operates at a resonant frequency of 4kHz.

Q: What is the sound pressure level?

The sound pressure level is 75dB minimum at 3Vp-p, 10cm. Some variants in the PKM22EPP series offer up to 85dB.

Q: What driving circuit should I use?

Common circuits include transistor astable multivibrators, inverter/NAND gate oscillators, or microcontroller PWM/tone output.

Q: Do I need a series resistor when driving from an IC?

Yes. Murata recommends a 1–2kΩ series resistor between the IC output and the buzzer to ensure stable oscillation and protect the IC.

Q: What is the operating voltage range?

The buzzer supports up to 25Vp-p driving voltage. Higher voltage produces louder sound.

Q: Can I wash or clean the PKM22EPP-40?

No. The buzzer is not hermetically sealed and cannot be washed. Avoid exposure to cleaning solvents and moisture.

Q: Can I purchase in bulk for a product development project?

Yes. The PKM22EPP-40 is suitable for bulk purchasing by fire alarm manufacturers, security system integrators, and industrial panel builders.

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