Analog Multiplier vs Digital Multiplier | Difference between Analog Multiplier and Digital Multiplier

This page compares Analog Multiplier vs Digital Multiplier and mentions difference between Analog Multiplier and Digital Multiplier.

Analog Multiplier

analog multiplier

Definition: The analog multiplier is device having two inputs and one output port. The output signal is product of two input signals.

This is shown in the figure-1. As shown, output voltage Vout is equal to Vx*Vy/K.
Where K is scale factor.

The polarity of output (Vout) depends on polarity of two input types viz. positive and negative. This is shown in the table-1 below. Based on this, there are various quadrant types for the analog multiplier.

Type of analog multiplier Input-1 (Vx) Input-2 (Vy) Output (Vout)
Single Quadrant unipolar unipolar unipolar
Two Quadrant bipolar unipolar bipolar
four quadrant bipolar bipolar bipolar

Digital Multiplier

The common method of digital multiplication is "add and shift algorithm". Following are the basic types of digital multipliers.
• Serial or parallel multiplier
• Shift and Add multiplier
• Array multiplier
• Booth multiplier
• Modified Booth multiplier
• Wallace Tree multiplier
• combined booth and wallace tree multiplier

4 bit Digital Multiplier

The figure-2 depicts array multiplier based on add/shift algorithm. Each partial product is result of multiplication of multiplicand and multiplier bit. Partial product are shifted according to their respective bit orders and are added. Addition operation is using normal carry propagate method. For length N multiplier, total N-1 adders are needed.

4 bit Digital Multiplier circuit

The figure-3 depicts 4-bit digital multiplier circuit.

What is Difference between

difference between FDM and OFDM
Difference between SC-FDMA and OFDM
Difference between SISO and MIMO
Difference between TDD and FDD
Difference between 802.11 standards viz.11-a,11-b,11-g and 11-n

RF and Wireless Terminologies