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PWM ICs

Authors:
Geoffrey Hunter
Geoffrey Hunter
Published On:
Aug 18, 2026
Last Updated:
Aug 18, 2026

PWM ICs (also called PWM generators or PWM controllers) are integrated circuits dedicated to generating a pulse width modulated signal in hardware, without the need for a microcontroller and firmware. Typically the frequency is set with an external resistor (or resistor/capacitor network) and the duty cycle is set by either an analogue control voltage or a digital interface such as I2C.

Why Use a Dedicated PWM IC?

Why use a dedicated PWM IC instead of a microcontroller? There are several reasons:

  • No firmware, and therefore no firmware to certify/maintain.
  • The duty cycle can be driven directly from an analogue signal (e.g. straight from a sensor or op-amp), with no ADC in between. This also means it can be faster to respond.
  • Guaranteed behaviour at power-up and on brown-out — smaller start-up time before the output is valid (a dedicated hardware oscillator spins up and stabilizes much faster than a MCU takes to boot).
  • Frees up an MCU timer peripheral, or removes the MCU entirely from a simple design.
  • Low part count and small board area.

Saying that, a microcontroller is often the better choice if you already need the MCU for other reasons, or need flexibility and or fine-grained control over the PWM signal.

Example ICs

LTC6992

The LTC6992 is a voltage-controlled PWM generator from Analog Devices (originally Linear Technology). It is part of their TimerBlox family of silicon timing devices (this family also contains things such as voltage-controlled oscillators, one-shots and delay ICs)1.

Typical application circuit and waveform for the LTC6992 PWM generator IC.1

The PWM frequency is controlled by a single external resistor, RSETR_{SET}. The duty cycle is controlled by an 0-1 V analogue voltage applied to the MOD pin. Four versions of the LTC6992 exist, each with a slightly different duty-cycle range:1

Device NameDuty Cycle Range
LTC6992-10% to 100%
LTC6992-25% to 95%
LTC6992-30% to 95%
LTC6992-45% to 100%

Footnotes

  1. Analog Devices. LTC6992-1/LTC6992-2/LTC6992-3/LTC6992-4 - TimerBlox: Voltage Controlled Pulse Width Modulator (PWM) [datasheet]. Retrieved 2026-08-18, from https://www.analog.com/media/en/technical-documentation/data-sheets/LTC6992-1-6992-2-6992-3-6992-4.pdf. ↩ ↩2 ↩3