A sound generator is an integrated circuit or a voice chip with a standard CMOS process & fixed voice storage memory. This IC generates audio signals with analog, digital (or) mixed-mode electronics. The sound generator IC examples are; YM3812, UM66, UM3561, SN76477, SN76489, AY-3-8910, YM3812, 6581, etc. So, these ICs are utilized in different applications like toys, alarm circuits, musical instruments, computer sound cards, arcade game machines, etc. This article elaborates on one sound generator IC like UM3561 IC, pinout, specifications, and its applications.
What is UM3561 IC?
The UM3561 is a low-power and low-cost sound generator integrated circuit, that operates typically at 3V that generates sirens and alarm sounds. This is a CMOS LSI IC including a programmed mask ROM & a tone generator. So this IC can generate three alarm sounds & one sound effect based on the written data by the ROM. Here, stored data within the ROM reacts to every tone and can be chosen with the data location address. Thus, UM3561 IC is frequently used in alarm circuits and toys to reproduce siren sounds. In addition, we can connect an external speaker with a bypassing transistor.
Block Diagram:
The UM3561 IC block diagram is shown below. This IC includes an oscillator circuit that produces oscillation frequency, controlled through an external resistor. So this resistor is connected between Pin-7 (OSC1) and Pin-8 (OSC2) then this oscillation frequency can be shifted to a control circuit. This control circuit working mainly depends on the tone selection throughout Pin 6 (SEL-1) and Pin 1 (SEL-2). Thus, the control circuit moves the signal toward the address counter then it moves the signal into the ROM. At last, the tone signals will be generated through pin 3 (output pin).
UM3561 IC Block Diagram
UM3561 IC Working
The UM3561 IC works by generating different sounds like sirens for toys and alarm circuits. So this IC uses a programmed mask ROM with a tone generator, where the ROM provides the data to the tone generator, after that, it generates different tones. Here, mask ROM reproduces alarm sounds electronically and the tone generator produces different tones depending on the stored information in the ROM.
The UM3561 IC includes two selection pins SEL1 & SEL2 which generate different siren sounds. So, SEL1 and SEL2 pins are set to NC to produce a police siren. Similarly, the SEL1 pin is set to VDD & SEL2 pin is set to NC to produce a fire brigade siren. Finally, sound can be generated through an external speaker which is connected through a bypassing transistor.
Pin Configuration:
The pin configuration of UM3561 IC is shown below. So this IC includes 8 pins which are discussed below.
UM3561 IC Pin Diagram
- Pin-1 (SEL-2): It is a sound effect selection pin-2.
- Pin-2 (Vss/GND): It is a negative power input or GND pin of the IC.
- Pin-3 (Output): This output pin produces a mono-tone sound.
- Pin-4 (NC): This pin may include an internal testing function. Thus it can leave open for normal operations.
- Pin-5 (Vdd/Vcc): This is the positive power input of the IC.
- Pi-6 (SEL-1): It is a sound effect selection pin-1.
- Pin-7 (OSC-1): It is terminal-1 of an external oscillator.
- Pin-8 (OSC-2): It is terminal-2 of an external oscillator.
Features & Specifications:
The features and specifications of UM3561 IC include the following.
- UM3561 IC is a low-power & low-cost sound generator IC.
- This IC includes 8 pins.
- It is available in an 8-pin DIP package.
- DC voltage supply ranges from 3.0 to +5.0V.
- The operating current Idd is 150µA.
- Its IO voltage or Vss is 3.0V to VDD +3.0V.
- A minimum operating voltage or Vdd is 2.4V at VSS = 0V, FOSC = 106496 Hz, and TA=25°C.
- Its operating current or Idd is 150µA at VSS = 0V, FOSC = 106496 Hz and TA=25°C.
- It allows you to produce four different sounds.
- The operating current value is 150 µA & the output current is 3 mA.
- This IC has a power-on reset capability because of which it starts in a similar condition to powering the chip.
- This IC includes a magnetic speaker that can be driven by connecting an NPN transistor.
- Its operating ambient temperature ranges from -10°C to 60°C.
- Its storage temperature ranges from -55°C to 125°C.
Equivalent & Alternatives :
Equivalent to UM3561 ICs are M3561, AS10515F16MIL, SE5534JGB, VTAN1111C-TR, FMMT493, 1584C6W20, VCEW1151CCS-TR, A1425A-PL84C, T0247, SJW1151CKS-100-TR, VCEW1151CDS-3BZH3-TR, VCKW1151CA3S-TR, TN0985, STEVAL-IME008V1, HBX-2071, SG240128B, SG12832A, SH320240C, etc. So, alternatives to UM3561 ICs are; UM3561, HT1621B, Max232, HT82C36, etc.
Security Alarm Circuit with UM3561 IC
Whenever a security alarm switch is hidden below the floor mat then it triggers an alarm once any person walks above it. This mat switch can be utilized as a security measure within a controlled area. So security alarm circuit is designed with the CMOS UM3561 IC which is used mostly in alarms and toys due to its lower cost & power saving capacity.
This circuit does not utilize the battery current within standby mode thus leading to longer battery life. So this circuit can stabilize the 9V DC mains adaptor instead of the battery.
The required components to make this security alarm circuit with UM3561 IC include; a 5V supply, three switches like; S1, S2 & S3, UM3561 IC, transistors like BC548, BC558 & BS170, resistors like 1K, 10K, 2.2M, 100E & 220K, 3.3V ZD1 Zener diode and a speaker. Thus, connect this circuit as per the diagram shown below.
Security Alarm Circuit with UM3561 IC
Working
Once the connections are made, this switch must be placed under the mat. So this security alarm circuit works as; when anyone pushes the switch, then signals are given to the base terminal of the T1 transistor. So the voltage at this terminal increases as compared to the emitter voltage & T1 transistor will start conducting. The conduction mode within this transistor makes the T2 transistor start conducting then it switches on the BS170 MOSFET.
This MOSFET provides the voltage supply to Pin 5 of IC to make the pin-3 or output pin of IC1 high. So this high can be supplied to T4 & T5 Darlington pair transistors and the connected loudspeaker to generate sound. Here a Zener diode is connected at pin-5 of IC1 because the working voltage of this IC changes from 3Volts to 4.5Volts thus excess voltage may harm the chip. So the UM3561 IC in the above circuit produces a tone related to a police siren. Here, the R6 resistor is utilized to control its oscillation. Thus, the number of switches in the above circuit can be increased to increase the ability of the circuit.
Advantages & Disadvantages
The advantages of UM3561 IC include the following.
- UM3561 IC generates multi-siren tones.
- It is a low-power and low-cost IC.
- It needs a few additional components only.
- It generates monotone o/p along with quick test ability.
- This IC can be utilized to design a compact sound module with fewer additional components.
- This IC has up to 3mA output current which is sufficient to drive an 8 ohm speaker.
The disadvantages of UM3561 IC include the following.
- UM3561 ICs cannot operate at high voltages.
- These ICs are delicate.
- They have a limited power rating.
- They can generate more noise throughout their operation.
Applications
The applications of UM3561 IC include the following.
- The UM3561 IC is used to produce siren sounds for toys, doorbells, alarms, etc.
- This circuit is built around the CMOS UM3561 IC, mostly used in toys and alarms because of its power-saving and low-cost ability.
- This IC generates different sounds like sirens, fire brigade, ambulance, gun sounds & police.
- This IC is used to design different circuits like a fire engine siren, police sirens, machine gun sounds & ambulance sirens.
- A tone generator IC can be used to verify for breaks within a circuit and locate and trace wires to perform continuity & polarity tests.
- This can be used to produce auditory alarm tones including programmable frequency &timing for CPAP machines, electrocardiograms & patient monitoring.
- It is used to generate dial tones within telephones or sirens sound within VIP vehicles or ambulances.
Please refer to this link for the UM3561 IC Datasheet.
Thus, this is an overview of UM3561 IC, pin configuration, features, specifications, circuit, working, pros, cons, and its uses. So this is an 8-pin low-cost and low-power chip that generates different kinds of siren sounds like gun sounds, ambulance, police, fire brigade, etc. This IC includes a programmed mask ROM & a tone generator where the ROM provides data to the tone generator, then it generates different tones. Thus, this is the best choice to stimulate siren sounds within toys & alarm circuits. Here is a question for you, what is UM3561 IC?