Overview
The PCA9535DB, produced by Texas Instruments, is a 16-bit I2C and SMBus low-power I/O expander with an interrupt output. This device is designed to expand the I/O capabilities of a microcontroller or other I2C/SMBus master device. It operates over a wide voltage range from 2.3V to 5.5V, making it versatile for various applications. The PCA9535DB features low standby current consumption, which is beneficial for power-sensitive designs.
Key Specifications
| Parameter | Value | Conditions |
|---|---|---|
| Voltage Range | 2.3V to 5.5V | |
| Standby Current | 1 μA Max | VI = GND, IO = 0, I/O = inputs, fSCL = 0 kHz |
| I/O Configuration | Two 8-bit Configuration Registers | |
| Interrupt Output | Open-drain active-low | |
| I2C Addressing | Three hardware pins (A0, A1, A2) for address programming | Allows up to eight devices on the same I2C bus or SMBus |
| Maximum I/O Current | 25 mA per I/O, 100 mA per octal, 200 mA total | |
| Package Options | 24SSOP, among others |
Key Features
- Low standby-current consumption of 1 μA Max, reducing power consumption when I/Os are held low.
- I2C to parallel port expander, allowing for the expansion of I/O capabilities of a microcontroller or other I2C/SMBus master device.
- Open-drain active-low interrupt output, which is activated when any input state differs from its corresponding Input Port register state.
- Two 8-bit Configuration, Input Port, Output Port, and Polarity Inversion registers for flexible configuration.
- Power-on reset feature to reset the device in case of improper operation.
- Three hardware pins (A0, A1, A2) for programming and varying the fixed I2C address, allowing up to eight devices to share the same I2C bus or SMBus.
Applications
- Expansion of I/O capabilities in microcontrollers and other I2C/SMBus master devices.
- Low-power designs where minimizing standby current is crucial.
- Industrial control systems requiring multiple I/O points.
- Automotive systems where reliable and low-power I/O expansion is necessary.
- Consumer electronics and appliances needing flexible I/O configurations.
Q & A
- What is the voltage range of the PCA9535DB?
The PCA9535DB operates over a voltage range from 2.3V to 5.5V.
- What is the standby current consumption of the PCA9535DB?
The standby current consumption is 1 μA Max when VI = GND, IO = 0, I/O = inputs, and fSCL = 0 kHz.
- How does the PCA9535DB handle I/O configuration?
The device has two 8-bit Configuration registers that allow the system master to configure the I/Os as either inputs or outputs.
- What is the purpose of the interrupt output on the PCA9535DB?
The open-drain active-low interrupt output is activated when any input state differs from its corresponding Input Port register state, indicating a change in input state to the system master.
- How many devices can share the same I2C bus or SMBus using the PCA9535DB?
Up to eight devices can share the same I2C bus or SMBus using the three hardware pins (A0, A1, A2) for address programming.
- What is the maximum current per I/O and total current for the PCA9535DB?
The maximum current per I/O is 25 mA, per octal is 100 mA, and the total current is 200 mA.
- What package options are available for the PCA9535DB?
The device is available in a 24SSOP package, among others.
- How does the PCA9535DB handle power-on reset?
The device has a power-on reset feature that resets the registers to their default state and initializes the I2C/SMBus state machine in case of improper operation.
- What are some common applications of the PCA9535DB?
Common applications include expansion of I/O capabilities in microcontrollers, low-power designs, industrial control systems, automotive systems, and consumer electronics.
- Is the PCA9535DB compatible with other Texas Instruments I/O expanders?
Yes, the PCA9535DB has the same fixed I2C address as other devices like PCA9555, PCF8575, PCF8575C, and PCF8574, allowing them to share the same I2C bus or SMBus.
