Introduction

Electronic devices face multiple demands simultaneously, including miniaturization, increased functionality, lower power consumption, shorter development cycles, and stable supply. Mobile devices, cameras, surveillance equipment, and projectors, in particular, must pack numerous functions into a limited circuit board area. At the same time, reducing bill of materials (BOM) costs to maintain product price competitiveness, implementing end-of-life (EOL) measures to prepare for component discontinuation, and minimizing environmental impact are also essential.

In such designs, peripheral functions such as inverters, AND/OR gates, flip-flops, timers, comparators, and level shifters may be implemented using individual ICs or discrete components. Although each circuit may be small on its own, when combined, the number of components, mounting area, wiring, suppliers, and evaluation items increase, leading to a burden on the designer. The need to revise the circuit and bill of materials every time the specifications change is also a challenge.

This article focuses on Renesas Electronics' GreenPAK, which integrates these peripheral functions onto a single, compact chip. We will explain the features of GreenPAK, its effects on the design process, and typical application examples, and then introduce key points to consider when reviewing existing circuits.

What is GreenPAK?

GreenPAK is a programmable mixed-signal IC that can be configured by combining digital logic and analog functions. Designers can use the free development environment "Go Configure Software Hub" to place and connect necessary function blocks on a GUI to configure circuits. A major feature is its ability to integrate multiple small circuits—such as logic, timing control, and signal monitoring—into a single device tailored to the application.

With typical custom ICs, development costs and time can be a barrier to adoption. Unlike conventional ASICs that require mask development, GreenPAK allows configuration creation using a dedicated GUI, making it easier to consider its application even to small-scale peripheral circuits. Furthermore, it is suitable for consolidating the small control circuits remaining around FPGAs and microcontrollers that handle large-scale computations, rather than replacing them.

For example, this could apply to situations such as "using multiple logic ICs," "managing the power-on sequence with an external circuit," "connecting signals with different voltages," or "combining a comparator and a timer." Instead of replacing the entire circuit at once, you can extract and consider functions that can be consolidated from the current bill of materials and circuit diagram.

Why is circuit consolidation needed now?

As electronic devices become more sophisticated, the number of auxiliary circuits supporting them, in addition to the main processor and sensors, is increasing. However, there are limitations to the dimensions of the circuit board and enclosure. Adding more components each time a function is added leads to more complex wiring and reduced layout flexibility. Furthermore, as the number of components increases, so do the requirements for procurement, acceptance, inventory, assembly, inspection, and change management.
 
End-of-Life (EOL) support is also crucial. In circuits composed of multiple general-purpose ICs, even the discontinuation of just one component can necessitate the selection of alternative parts, circuit modifications, board revisions, and re-evaluation. While it's impossible to eliminate all supply risks with a single device, reducing the number of components to manage is one way to streamline the scope of impact of design changes.

Furthermore, from the perspective of reducing environmental impact, it is necessary to consider the entire product, including the number of components, board area, mounting process, and material management, rather than simply looking at the power consumption of the IC. Circuit consolidation can contribute to miniaturization and cost rationalization, as well as a reduction in the number of materials used and mounting points. The reason GreenPAK is attracting attention is the need to improve these multiple issues across the board with a single design change.

Five benefits of GreenPAK

1. Component integration and miniaturization of circuit boards
By consolidating multiple logic ICs, timers, comparators, and other components into a single GreenPAK, the number of components and the mounting area can be reduced. The freed-up board space can be used not only to miniaturize the product, but also to allocate to other design requirements such as battery capacity, heat dissipation, antenna placement, and connector placement.
 
2. Rationalizing total BOM costs
In cost evaluation, it's crucial to compare not only the unit price of the IC being replaced, but also surrounding components such as resistors and capacitors, mounting costs, component management costs, and inspection man-hours. By consolidating multiple components into one, you can identify potential for total cost reductions that might not be apparent from purchasing component costs alone.
 
3. Simplification of design and adaptability to changes
Because functions can be configured via a GUI, the process of organizing requirements, creating circuits, simulating, and evaluating can be done visually. Changes to logic conditions and timings can be easily reflected in the circuit configuration, and specification adjustments during the prototyping stage can be easily accommodated.
 
4. Reduction of the number of components to be managed.
By consolidating components, the number of lines in the bill of materials can be reduced, narrowing down the scope of procurement, inventory, and alternative component considerations. However, since the consolidated device will be a critical component, the supply plan, programming method, and control conditions during mass production must be confirmed in advance.
 
5. Contribution to reducing environmental impact
Reducing the number of components, mounting points, and board area can lead to reductions in materials used and manufacturing processes. When explaining the effects, it is effective to quantitatively show a comparison of the number of components, mounting area, power consumption, etc., under identical conditions before and after the replacement.

Typical examples of use

Integration of small logic circuits

Control circuits, which consist of multiple gate ICs, flip-flops, and delay circuits, are a typical target for GreenPAK considerations. By integrating output control based on input conditions, signal inversion, logic synthesis, debouncing, and output switching after a certain period of time into a single device, wiring and bill of materials can be simplified.

Source: Renesas Electronics GreenPAK Introduction Brochure

Power Sequence Control

Systems with multiple power supplies require consideration of startup order, shutdown order, waiting times, and verification of Power Good signals. By combining logic, timers, and comparison functions with GreenPAK, you can configure a power sequencer tailored to your requirements. Stopping or retrying in the event of abnormal conditions can also be designed after clarifying the necessary conditions.

Source: Renesas Electronics GreenPAK Introduction Brochure

Level shift and signal connection

FPGAs, SoCs, and their peripheral devices often have a mix of multiple I/O voltages, such as 1.2V, 1.8V, 2.5V, and 3.3V. By selecting compatible devices, you can consider signal connections and peripheral logic between different voltage systems together. The advantage is that it allows you to incorporate not only simple voltage conversion but also enable conditions and logic processing simultaneously.

Source: Renesas Electronics GreenPAK Introduction Brochure

Signal monitoring and timing generation

By combining threshold determination using comparators with output control using timers or logic, circuits for voltage monitoring, simple resets, pulse generation, and anomaly retention can be constructed. Inventorying auxiliary circuits currently implemented with external components and checking their potential for consolidation by function will make it easier to identify the benefits.

Source: Renesas Electronics GreenPAK Introduction Brochure

Source: Renesas Electronics GreenPAK Introduction Brochure

How to proceed with the implementation consideration

First, we extract from the existing circuit the parts that are "small in scale but have a large number of components," "areas with frequent specification changes," and "areas where end-of-life (EOL) support is causing problems." Next, we organize the voltage, input/output conditions, logic, timing, accuracy, startup state, and operation in case of abnormalities for each signal. Then, we verify whether the GreenPAK's onboard functions, number of terminals, voltage conditions, package, and programming method for each device meet the requirements.

When comparing the effects, it becomes easier to make a decision by listing the number of components before and after replacement, the board footprint, BOM cost, power consumption, design effort, and evaluation items. It is important not to make a conclusion based solely on unit price, but to evaluate the total cost including assembly and management. In addition, considering mass production, we also consider version control of evaluation data and mass production data, procurement of pre-programmed products, and approval flows for changes.

The applicability of GreenPAK depends not only on the circuit size but also on the required accuracy and response speed. Rather than trying to integrate all circuits at once, a step-by-step evaluation starting with the logic, timer, signal monitoring, and level connections that GreenPAK excels at will lead to a more successful implementation.

Recruitment areas and consideration tips

GreenPAK has a proven track record in the market for mobile PCs, digital camera bodies and lenses, surveillance cameras, and projectors. These are areas where miniaturization is required, multiple control circuits and voltage systems are involved, and specification adjustments for each product are often necessary.

When searching for candidates within your own product line, pay attention to groups of small ICs located in the same vicinity on the circuit diagram. If related functions such as gate ICs and timers, comparators and latches, or level shifters and enable controls are separated into multiple components, this is a good starting point for consolidation considerations. This is an opportunity to review not only new designs, but also board revisions, component end-of-life (EOL) responses, and cost reduction activities.

Summary

GreenPAK is a programmable mixed-signal IC that combines analog functionality and digital logic, enabling the integration of small peripheral circuits into a single device. By rethinking circuits that are currently composed of multiple general-purpose ICs and discrete components, it is expected to contribute to component consolidation, board miniaturization, rationalization of total bill of materials (BOM) costs, simplified design, reduction of managed components, and reduced environmental impact.

The key is to clarify your current design challenges and signal requirements, rather than simply applying the product first. By comparing the pre- and post-replacement under identical conditions and evaluating step-by-step, starting with small peripheral circuits, you can concretely determine the effectiveness of GreenPAK. If you are facing challenges with miniaturizing existing circuits, consolidating components, or addressing end-of-life (EOL) issues, why not start by taking stock of your circuit diagrams and bills of materials?

Contact Us

For GreenPAK product information, development environment, and evaluation methods, please refer to Macnica 's Renesas Electronics product page and GreenPAK-related technical information. For specific circuit consolidation feasibility and device selection, please contact us with the voltage, logic conditions, timing, and required number of terminals of the target circuit.