Reset IC

Electronics containing complex, code-based Integrated Circuits (ICs) are prone to lock-ups. This can lead to degraded user experience, damaged components, safety concerns and, ultimately, lower sales. One solution is to implement a hardware reset circuit which detects the lock-up and sends a hard reset signal to the locked-up IC.

GreenPAK™ is an ideal solution for a fully customizable system reset IC. Adding an additional layer of stability to systems is made easy with GreenPAK’s programmable digital and analog components in incredibly small packages. Since GreenPAK is entirely implemented in hardware, there is never any worry of lock-ups or missed events.

Common methods for system reset include:

Manual Reset
- Single Button
- Dual Button
Watchdog Supervisor
Voltage Monitor
- Over-voltage
- Under-voltage

GreenPAK Benefits for Any Reset Circuit

System Stability
- GreenPAK has zero code - Code can lead to errors, hang-ups, or missed reset events
- GreenPAK is 100% hardware - Implementing features in hardware ensures stability
Power Consumption
- GreenPAK is low-power - Often in sealed mobile devices with non-removable batteries - every uA counts
Fast Response Time
- GreenPAK is asynchronous and responds instantly - In some cases, a quick response to a reset condition is important for user experience
Configurable Reset Pulse Time
- GreenPAK timing is flexible - Different microcontrollers require different reset pulse widths
Size
- GreenPAK is as small as 1.2 mm² - Mobile and wearable electronics - every mm counts
Configurable GPIO
- GreenPAK signal routing is flexible – PCB layout and routing
- GreenPAK I/O are configurable - Pull-up/down resistors
- GreenPAK logic is configurable – Active-low/high

Resource Utilization

GreenPAK can often implement multiple functions in one small device. This isn’t limited to reset or supervisory applications. Just one GreenPAK device can implement glue logic, timing adjustment, reset, power sequencing, LED control and more depending on design requirements and resource configuration. Here is a rough guide of resource utilization when implementing different types of reset functions in our smallest GreenPAK devices. Larger GreenPAK devices can also implement these functions, and can bring more value to a design when additional functions are integrated.

GreenPAK	Single Voltage	Dual Voltage
SLG46108V	X	X
SLG46110V
SLG46120V

Manual Reset

Typically used in handheld devices or laptops with non-removable batteries, manual reset relies on user triggered events. This improves user experience as frequent, unexpected reset events can be frustrating.

Single Button – Holding a single button for a specified time
Dual Button – Holding two buttons simultaneously for a specified time

Key Design Considerations

Button Configuration – Configurable pull-up / pull-down resistors on GreenPAK’s GPIO make implementing any button configuration a snap.
De-glitch – Physical buttons are glitchy, but with GreenPAK digital deglitching and setup time are taken care of by a single delay.
Setup Time (t-setup) – Delays are often built in so accidental presses do not trigger a reset. Using one of GreenPAK’s integrated CNT/DLY blocks, setup time can range from milliseconds to seconds.

GreenPAK Dual Button Implementation

Watchdog Supervisor

MCUs or DSPs sometimes send a watchdog pulse which indicate normal operation. Using GreenPAK to monitor this pulse can ensure a reset signal is sent if the MCU experiences a lock-up or erratic behavior

Key Design Considerations

Watchdog Timing - Different MCUs will send a watchdog pulse at different regular intervals. GreenPAK’s fully configurable CNT/DLY blocks provide flexibility to work with a wide range of watchdog window configurations.

GreenPAK WDT Implementation

Voltage Monitor

Ideal for systems that operate on low-voltage supply rails and have narrow margin supply tolerances, GreenPAK can monitor supply or sensor voltage.

Key Design Considerations

Over-voltage/Under-voltage Threshold – Supply tolerances vary, but using GreenPAK with integrated ACMPs can trigger a reset over a wide range of user specified conditions
Time Sensitive Voltage Limits – Varying periods of voltages outside the limit may be tolerable for some systems. GreenPAK’s configurable CNT/DLY blocks can be used to reject reset
Hysteresis – Returning to nominal voltage may incorporate hysteresis. GreenPAK’s ACMPs can be configured with 25, 50, or 200 mV hysteresis