MIC1555YM5-TR

Programmable Timers And Oscillators Overview

The MIC1555YM5-TR is a CMOS RC timer and oscillator from Microchip Technology's IttyBitty series, housed in a 5-lead SOT-23 package. Operating on a +2.7V to +18V supply, it functions as an astable or monostable device with separate threshold and trigger inputs. Key electrical parameters include a typical supply current of 240 μA at 5V, output rise/fall times of 15 ns, and a maximum astable frequency of 5 MHz. The device supports timing ranges from microseconds to hours with less than 0.005%/°C temperature stability.

Programmable Timers And Oscillators Feature Summary

• Supports both astable (oscillator) and monostable (one-shot) configurations
• Threshold input has precedence over the trigger input
• Produces a 50% duty cycle square wave using only one resistor and one capacitor
• Features low output on-resistance of less than 15Ω

Programmable Timers And Oscillators Applications

• Precision timers and sequential timing circuits
• Micropower oscillators operating up to 5 MHz
• LED blinkers and missing pulse detectors
• Charge-pump drivers for MOSFET gates

Programmable Timers And Oscillators Procurement Notes

Verify that the ordering suffix 'TR' corresponds to the standard 3,000-unit reel quantity specified for the SOT-23 package. Confirm the 'Y' suffix indicates the -40°C to +85°C industrial temperature range. Ensure the component matches the DS20005730B datasheet revision B specifications regarding pinout and electrical characteristics.

Programmable Timers And Oscillators Selection Notes

Select the MIC1555YM5-TR when independent control of threshold and trigger pins is required for custom monostable or astable designs. This model is suitable for applications needing rail-to-rail outputs without the need for a dedicated discharge pin found in traditional 555 timers. Consider the MIC1557 variant if a built-in shutdown feature is preferred over discrete external control.

Programmable Timers And Oscillators Part Context

This component belongs to the MIC1555/57 family of IttyBitty CMOS RC timers. It serves as a compact alternative to industry-standard 555 timers, eliminating the frequency control and open-collector discharge pins to fit into a 5-pin surface-mount footprint while maintaining similar functional logic for time delay and frequency generation.

Programmable Timers And Oscillators Replacement Considerations

MIC1555YD5-TR: Identical function but packaged in a 5-lead Thin SOT-23 (TSOT-23).

Programmable Timers And Oscillators FAQ

How does the MIC1555 handle simultaneous trigger and threshold signals?

The threshold input (THR) takes precedence over the trigger input (TRG). If the threshold voltage exceeds 2/3 VS, the output will switch low regardless of the state of the trigger input.

What is the minimum number of external components required for a 50% duty cycle oscillator?

Only one resistor and one capacitor are required to generate a 50% duty cycle square wave in the astable configuration.

Can this device be used as a Schmitt trigger?

Yes. By connecting the threshold and trigger pins together to form a T/T input, the device can act as an inverting Schmitt trigger with defined trip points at 1/3 VS and 2/3 VS.