HEF4541BP,652

Programmable Timers And Oscillators Overview

The HEF4541BP,652 is a programmable timer IC manufactured by Nexperia. It integrates a 16-stage binary counter, an RC oscillator, and power-on reset logic. The device operates on a supply voltage of 3 V to 15 V. External components RTC and CTC set the oscillator frequency between 1 Hz and 100 kHz. An external clock input at RS can replace the internal oscillator. The counter divides the frequency by 2^8, 2^10, 2^13, or 2^16 based on address inputs A0 and A1. It features low power CMOS technology, high noise immunity, and ESD protection exceeding 2000 V (HBM).

Programmable Timers And Oscillators Feature Summary

• Integrated 16-stage binary counter with selectable division ratios.
• Built-in RC oscillator for standalone timing applications.
• Wide operating voltage range from 3.0 V to 15.0 V.
• High ESD protection: >2000 V HBM and >1000 V CDM.

Programmable Timers And Oscillators Applications

• Programmable time delay generation.
• Frequency division circuits.
• Single-cycle pulse generation.
• Real-time clock base oscillators.

Programmable Timers And Oscillators Procurement Notes

Verify component authenticity through authorized distributors. Confirm package type SO14 (SOT108-1) matches design requirements. Check RoHS compliance status as per latest manufacturer documentation. Ensure ordering suffix 652 corresponds to the correct reel or tube packaging configuration required for assembly.

Programmable Timers And Oscillators Selection Notes

Select this component when a single-chip solution for timing and counting is needed. Verify that external resistor and capacitor values maintain the oscillator frequency within the 1 Hz to 100 kHz range. Ensure unused inputs are tied to VDD or VSS to prevent floating states. Consider thermal derating if total power dissipation exceeds 500 mW in high ambient temperatures.

Programmable Timers And Oscillators Part Context

This part belongs to the HEF4541B family of programmable timers. The 'BP' indicates a DIP package variant, while the datasheet provided details the 'BT' (SO14) version. Both share identical electrical specifications and functionality. The product is designed for general-purpose digital timing applications requiring low power consumption and static operation.

Programmable Timers And Oscillators Replacement Considerations

Direct pin-compatible replacements include other HEF4541B variants from different manufacturers adhering to JEDEC JESD 13-B standards. Verify supply voltage compatibility and output drive capabilities before substitution. Ensure the replacement supports the required temperature range of -40 °C to +125 °C.

Programmable Timers And Oscillators FAQ

How is the oscillator frequency determined?

The frequency is determined by external resistor RTC and capacitor CTC connected to pins 1 and 2. Typical values range from 10 kΩ to 1 MΩ for RTC and 100 pF upwards for CTC.

What is the function of the MODE input?

When MODE is LOW, the timer operates in single transition mode. When HIGH, it functions as a 2^n frequency divider.

Can an external clock be used instead of the internal oscillator?

Yes, an external clock signal applied to the RS input (pin 3) replaces the internal oscillator. The counter advances on the positive-going transition of this signal.