Discretize input at specified interval




The Quantizer block passes its input signal through a stair-step function so that many neighboring points on the input axis are mapped to one point on the output axis. The effect is to quantize a smooth signal into a stair-step output. The output is computed using the round-to-nearest method, which produces an output that is symmetric about zero.

y = q * round(u/q)

where y is the output, u the input, and q the Quantization interval parameter.

Data Type Support

The Quantizer block accepts and outputs real or complex signals of type single or double. For more information, see Data Types Supported by Simulink in the Simulink® documentation.


Quantization interval

The interval around which the output is quantized. Permissible output values for the Quantizer block are n*q, where n is an integer and q the Quantization interval. The default is 0.5.

Treat as gain when linearizing

Simulink software by default treats the Quantizer block as unity gain when linearizing. This setting corresponds to the large-signal linearization case. If you clear this check box, the linearization routines assume the small-signal case and set the gain to zero.

Sample time


This parameter is not visible in the block dialog box unless it is explicitly set to a value other than -1. To learn more, see Blocks for Which Sample Time Is Not Recommended.


The sldemo_boiler model shows how you can use the Quantizer block.

The Quantizer block appears in the Boiler Plant model/digital thermometer/ADC subsystem.

The ADC subsystem digitizes the input analog voltage by:

  • Multiplying the analog voltage by 256/5 with the Gain block

  • Rounding the value to integer floor with the Quantizer block

  • Limiting the output to a maximum of 255 (the largest unsigned 8-bit integer value) with the Saturation block

For more information, see Explore the Fixed-Point "Bang-Bang Control" Model (Stateflow) in the Stateflow® documentation.


Data Types

Double | Single

Sample Time

Inherited from driving block

Direct Feedthrough


Multidimensional Signals


Variable-Size Signals


Zero-Crossing Detection


Code Generation


Introduced before R2006a

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