Overview
The LP3943ISQX/NOPB, produced by Texas Instruments, is a highly versatile integrated circuit designed to drive 16 LEDs independently. This device is particularly useful in applications requiring complex LED control, such as customized flashing LED lights, indicator lamps, and general-purpose I/O expansion. The LP3943 features an internal precision oscillator, which provides the necessary timing for driving each LED, and includes two prescaler registers and two PWM registers for flexible duty-cycle control. This allows for efficient dimming and blinking of LEDs with minimal bus traffic, making it an ideal choice for various electronic devices including cellular phones, digital cameras, and toys.
Key Specifications
| Parameter | Value | Unit |
|---|---|---|
| Number of Channels | 16 | |
| Operating Supply Voltage | 2.3 to 5.5 | V |
| Maximum Output Sink Current per Pin | 25 | mA |
| Maximum Total Output Sink Current per Package | 200 | mA |
| Package Type | WQFN (24 pins) | |
| Body Size | 4.00mm × 4.00mm | |
| Operating Temperature Range | -40 to 85 | °C |
| Power Dissipation | 400 | mW |
| Clock Frequency (I2C) | 400 | kHz |
Key Features
- Internal power-on reset and active low reset
- Internal precision oscillator for timing control
- Variable dim rates (from 6.25ms to 1.6s; 160Hz to 0.625Hz)
- 16 LED drivers with multiple programmable states: ON, OFF, input, and dimming at a specified rate
- 16 open-drain outputs capable of driving up to 25mA per LED
- Programmable internal PWM dimming with 8-bit duty cycle and frequency control
- Auto increment for I2C writes to reduce the number of I2C clock pulses
- Externally selectable I2C slave address via ADR0, ADR1, and ADR2 inputs
- General-purpose input/output expansion for unused LED pins
Applications
- Customized flashing LED lights for cellular phones
- Portable applications
- Digital cameras
- Indicator lamps
- General-purpose I/O expander
- Toys and other entertainment devices
Q & A
- What is the primary function of the LP3943ISQX/NOPB?
The LP3943ISQX/NOPB is designed to independently drive 16 LEDs with advanced control features such as dimming and blinking.
- What is the operating supply voltage range for the LP3943ISQX/NOPB?
The operating supply voltage range is from 2.3V to 5.5V.
- What is the maximum output sink current per pin and per package?
The maximum output sink current is 25mA per pin and 200mA per package.
- What type of package does the LP3943ISQX/NOPB come in?
The device comes in a WQFN package with 24 pins.
- What are the key features of the LP3943ISQX/NOPB's PWM control?
The device features programmable internal PWM dimming with 8-bit duty cycle and frequency control, allowing for variable dim rates.
- How does the LP3943ISQX/NOPB reduce bus traffic in SMBUS/I2C applications?
The device reduces bus traffic by requiring only the setup of the frequency and duty cycle for each output pin, after which only a single command is needed to control the LEDs.
- Can the LP3943ISQX/NOPB be used for general-purpose I/O expansion?
- What is the purpose of the auto increment feature in I2C writes?
The auto increment feature eliminates the need for repeated chip and register addressing when writing to or reading from registers in sequential order.
- How is the I2C slave address selected for the LP3943ISQX/NOPB?
The I2C slave address is selected via the ADR0, ADR1, and ADR2 inputs.
- What are some common applications of the LP3943ISQX/NOPB?
