U6046B-MY

Overview

The U6046B-MY is a bipolar long-term timer designed for automotive applications to limit high-load operation time. It features an RC oscillator where external components R2 and C2 determine timing characteristics, enabling delay times from 3.7 seconds to 20 hours. The device includes debounced ON, OFF, and TOGGLE inputs, a power-on reset function, and load-dump protection. It operates with a supply voltage between 6V and 16V via VBatt or at 5V. The relay control output provides up to 300 mA with an integrated Z-diode.

Feature Summary

• RC Oscillator Timing: Delay range of 3.7s to 20h determined by external R2 and C2 components.
• Automotive Protection: Includes load-dump protection (up to ~40V), RF interference protection, and ISO/TR7637-1 compliance.
• Flexible Inputs: Features debounced ON, OFF, and TOGGLE inputs for manual control and retriggering capabilities.
• Relay Driver Output: Open-collector Darlington circuit with integrated 23-V Z-diode, supporting up to 300 mA static collector current.

Applications

• Rear window heating timers
• Long-term timers for high loads in automotive environments
• Automatic operation time limiting for current-consuming devices

Procurement Notes

Verify the ordering suffix -MY corresponds to the DIP8 package when sourcing this component. Confirm that the specific revision matches the required design specifications, as datasheet revisions may update pinning or electrical characteristics. Ensure compatibility with the intended PCB footprint for the 8-pin dual in-line package.

Selection Notes

Select external resistor R2 and capacitor C2 values based on the desired oscillator frequency using the provided dimensioning tables. For 12V systems, include the recommended R1 (510Ω) and C1 (47µF) filter circuit. For 5V supplies, connect Pin 7 to Pin 8 and omit the input filter components. Ensure the load current does not exceed the 300 mA output rating.

Part Context

The U6046B series is a family of bipolar long-term timers originally manufactured by Atmel, which was later acquired by Microchip Technology. The U6046B-MY specifically denotes the lead-free version housed in an 8-pin DIP package. This component is part of a broader line of automotive analog circuits designed for robust performance in harsh electrical environments.

Replacement Considerations

Public confirmed substitute part numbers are not available in the provided documentation. Verify pinout and electrical parameters against alternative long-term timers if cross-referencing other manufacturers' parts.

FAQ

How is the delay time calculated?

The delay time (td) depends on the oscillator frequency (f) and is calculated as td = 73728 / f. The frequency is determined by the external resistor R2 and capacitor C2 connected to Pin 6.

What is the function of the TOGGLE input?

The TOGGLE input (Pin 5) allows the relay output to be activated or deactivated by pressing a switch. Each press changes the state of the relay output after the debounce time has elapsed.

Can the U6046B operate at 5V?

Yes, it can operate at 5V. In this configuration, Pin 7 (VSTAB) must be connected to Pin 8 (VS), and the external R1C1 filter circuit should be omitted.