MIC1555/57 IttyBitty RC Timer/Oscillator Features General Description +2.7V to +18V Operation The MIC1555 IttyBitty CMOS RC timer/oscillator and MIC1557 IttyBitty CMOS RC oscillator are designed to Low Current provide rail-to-rail pulses for precise time delay or - <1 A Typical Shutdown Mode (MIC1557) frequency generation. - 200 A Typical (TRG and THR Low) at 3V These devices are similar in function to the industry Supply standard 555, without a frequency control (FC) pin or Timing from Microseconds to Hours an open-collector discharge (D) pin. The threshold pin Zero Leakage Trigger and Threshold Inputs (THR) has precedence over the trigger (TRG) input, 50% Square Wave with One Resistor, One ensuring that the BiCMOS output is off when TRG is Capacitor high. Threshold Input Precedence Over Trigger Input The MIC1555 can be used as an astable (oscillator) or <15 Output On-Resistance monostable (one-shot) with separate threshold and No Output Cross-Conduction Current Spikes trigger inputs. In the one-shot mode, the output pulse width is precisely controlled by an external resistor and <0.005%/C Temperature Stability a capacitor. Time delays may be accurately controlled <0.055%/V Supply Stability from microseconds to hours. In the oscillator mode, the 10-pin Ultra-Thin DFN Package (2 mm 2 mm output is used to provide precise feedback, with a 0.4 mm) minimum of one resistor and one capacitor producing a Small SOT-23-5 Surface Mount Package 50% duty cycle square wave. Applications The MIC1557 is designed for astable (oscillator) operation only, with a chip select/reset (CS) input for Precision Timer low power shut-down. One resistor and one capacitor Pulse Generation provide a 50% duty cycle square wave. Other duty Sequential Timing cycle ratios may be produced using two diodes and two Time-Delay Generation resistors. Missing Pulse Detector The MIC1555/7 are powered from a +2.7V to +18V Micropower Oscillator to 5 MHz supply voltage and are rated for 40C to +85C Charge-Pump Driver ambient temperature range. The MIC1555/7 are available in SOT-23-5, and thin SOT23-5 5-pin LED Blinker packages. A low profile, ultra-thin UTDFN version of Voltage Converter the MIC1555 (with chip select) is also available. Linear Sweep Generator Variable Frequency and Duty Cycle Oscillator 2017-2019 Microchip Technology Inc. DS20005730B-page 1MIC1555/57 Package Types MIC1555 MIC1555 5-PIN SOT-23 (M5) 5-PIN TSOT-23 (D5) (TOP VIEW) (TOP VIEW) MIC1555 10-PIN UTDFN (MU) (TOP VIEW) MIC1557 MIC1557 5-PIN SOT-23 (M5) 5-PIN TSOT-23 (D5) (TOP VIEW) (TOP VIEW) Typical Application Circuits MIC1555 MIC1555 MONOSTABLE (ONE-SHOT) MONOSTABLE WITH ENABLE MIC1557 ASTABLE (OSCILLATOR) DS20005730B-page 2 2017-2019 Microchip Technology Inc.