Full-featured, power efficient systems often contain subsystems with different voltage requirements. For example, a wearable may normally operate at 1.8 V, but when charging, portions of the design will operate at the USB standard 5 V. Similarly, the display may operate at a different voltage than the sensors. Often, a number of discrete passive or fixed-function level shift devices are needed to make these voltage domains work together. With GreenPAK™, getting these different voltage domains working together, efficiently and with the flexibility of programmable mixed-signal, is a snap with any of our Dual Supply part numbers.
GreenPAK™ Benefits for Level Shift:
Dual Supply
- Dual Supply GreenPAK enables high efficiency level-shift without the need for external pull-up resistors
- Dual Supply GreenPAK can support 1.8 V to 5.0 V for VDD and 1.8 V to VDD for VDD2
System Stability
- GreenPAK is zero code – Implementing features in hardware ensures stability
- GreenPAK can integrate many components ensuring fewer points of failure
Power Consumption
- GreenPAK is low-power – Can operate continuously without ruining power budget
Size
- GreenPAK is as small as 1.2 mm²
Flexibility
- GreenPAK GPIO are configurable – Pull-up/pull-down resistors, Push-Pull, Open drain, etc.
- GreenPAK GPIO routing is flexible – Ensuring the least complexity in PCB routing
- GreenPAK integrates many common components – Generating custom timing and logic to further eliminate external components while bridging voltage domains and signal requirements
Uni-directional |
Bi-directional with Dedicated Ports |
Bi-directional with External Direction Indicator |
Bi-directional, Auto-sensing |
| The simplest form of level-shift is uni-directional. Shifting a single direction, up or down, is easy in GreenPAK since all GPIO can be configured as inputs or outputs |
Similar to uni-directional, using GreenPAK’s configurable GPIO to dedicate specific pins or groups of pins as input or output is easy. Each pin tied to a specific voltage domain can be configured independently allowing information to flow from lower to higher VDD or higher to lower VDD
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With GreenPAK it is also possible to dual-purpose certain GPIO as digital input AND output using the output enable pin to control the direction. | Using GreenPAK’s configurable digital and timing resources, it is even possible to implement an auto-sensing, bi-directional, level-shift solution such as the I2C Level-shift shown in AN-1104. |
Key Design ConsiderationsNumber of Signals – GreenPAK can support up to 9 inputs/8 outputs on a single voltage domain IO Configuration – Configurable pull-up / pull-down resistors on GreenPAK’s GPIO make communicating with any IC a snap |
Key Design ConsiderationsNumber of Signals – GreenPAK can support up to 9 inputs/8 outputs on a single voltage domain IO Configuration – Configurable pull-up / pull-down resistors on GreenPAK’s GPIO make communicating with any IC a snap |
Key Design ConsiderationsDirection Signal Polarity – Using GreenPAK’s integrated LUTs configured as an inverter can accommodate any signal polarity Direction Signal Origin – With GreenPAK, the direction signal input can be from either voltage domain |
Key Design ConsiderationsResponse Time – GreenPAK is capable of up to 400 kHz standard I2C |
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Dual Supply GreenPAK
GreenPAK can often implement multiple functions in one small device. This isn’t limited to level-shift 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.
Below is a list of our Dual Supply GreenPAK devices and the number of GPIO dedicated to each voltage domain.
| Part Number | VDD IO | VDD2 IO |
|---|---|---|
| SLG46121V | 5 | 4 |
| SLG46535V | 7 | 4 |
| SLG46538V | 9 | 8 |
| SLG46621V | 9 | 8 |