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Level Shifter

With GreenPAK™, getting different voltage domains working together, efficiently and with the flexibility of programmable mixed-signal, is a snap.

Often full-featured, power-efficient systems 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.

The best solution for this is any GreenPAK Dual Supply part number.

A gilr looking at the monitor

GreenPAK Benefits for Level Shift

GreenPAK Enhances Effectiveness with Dual Supply

  • Dual Supply enables high efficiency level-shift without the need for external pull-up resistors supporting 1.8 V to 5.0 V for VDD and 1.8 V to VDD for VDD2

GreenPAK Maximizes Flexibility

  • Configurable GPIO – Pull-up/pull-down resistors, Push-Pull, Open drain, etc.
  • Flexible GPIO routing – Ensuring the least complexity in PCB routing
  • Integration of many components – Generating custom timing and logic to further eliminate external components while bridging voltage domains and signal requirements

GreenPAK Ensures System Stability

  • Zero code as implementing features in hardware ensures stability
  • Integration of many components ensuring fewer points of failure

GreenPAK Lowers Power Consumption

  • Low power consumption allows GreenPAK continuously operate without ruining power budget

GreenPAK Reduces Board Size

  • Being as small as 1.2 mm² it is a perfect solution for mobile and wearable electronics
Level Shifter

Uni-directional

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

Key Design Considerations

Number 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

Uni-directional level-shift implemented in GreenPAK

Example 1. Uni-directional level-shift implemented in GreenPAK

Timing Diagram

Example 1. Timing Diagram

Bi-directional with Dedicated Ports

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

Key Design Considerations

Number 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

Bi-directional level-shift with dedicated ports implemented in GreenPAK

Example 2. Bi-directional level-shift with dedicated ports implemented in GreenPAK

Timing Diagram

Example 2. Timing Diagram

Bi-directional with External Direction Indicator

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.

Key Design Considerations

Direction 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

Bi-directional level-shift with external direction signal implemented in GreenPAK

Example 3. Bi-directional level-shift with external direction signal implemented in GreenPAK

Timing Diagram

Example 3. Timing Diagram

Bi-directional, Auto-sensing

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 Considerations

Response Time – GreenPAK is capable of up to 400 kHz standard I2C

Auto-sensing bi-directional I2C level-shift

Example 4. Auto-sensing bi-directional I2C level-shift

Timing Diagram

Example 4. AN-1104 - I2C Level Shift in SLG46620V

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

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Level Shifter

View the full list of the GreenPAK videos in our Training Video Library.