Overview
The LP3943ISQ/NOPB, produced by Texas Instruments, is an integrated 16-channel RGB and white LED driver with independent SMBUS/I2C string control. This device is designed to independently drive 16 LEDs, each with multiple programmable states including ON, OFF, input, and dimming at specified rates. It features an internal precision oscillator, variable dim rates, and open-drain outputs capable of driving up to 25mA per LED. The LP3943 is particularly suited for applications requiring precise LED control and minimal bus traffic.
Key Specifications
| Parameter | Value | Unit |
|---|---|---|
| Number of LED Drivers | 16 | - |
| Maximum Output Sink Current per LED | 25 | mA |
| Total Package Current Limit | 200 | mA |
| Dimming Frequency Range | 0.625Hz to 160Hz | - |
| PWM Duty Cycle Control | 8-bit | - |
| Power Supply Voltage | 2.3V to 5V | V |
| Package Type | WQFN (24) | - |
| Body Size | 4.00mm × 4.00mm | - |
| I2C Clock Frequency | Up to 400kHz | - |
Key Features
- Internal precision oscillator for timing control
- Variable dim rates from 6.25ms to 1.6s (0.625Hz to 160Hz)
- 16 open-drain outputs capable of driving up to 25mA per LED
- Programmable internal PWM dimming with 8-bit duty cycle and frequency control
- Active low reset input and power-on reset
- Auto increment for I2C writes to reduce bus traffic
- Externally selectable I2C slave address via ADR0, ADR1, and ADR2 inputs
- General purpose parallel input/output (GPIO) 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 consumer electronics requiring LED control
Q & A
- What is the maximum current each LED driver can handle?
Each LED driver can handle up to 25mA.
- What is the total current limit for the package?
The total package current limit is 200mA.
- What is the range of dimming frequencies supported by the LP3943?
The LP3943 supports dimming frequencies from 0.625Hz to 160Hz.
- How is the PWM duty cycle controlled in the LP3943?
The PWM duty cycle is controlled using 8-bit registers.
- What is the power supply voltage range for the LP3943?
The power supply voltage range is from 2.3V to 5V.
- What type of package does the LP3943 come in?
The LP3943 comes in a WQFN (24) package.
- How does the auto increment feature work in I2C writes?
The auto increment feature allows the I2C master to write to or read from registers in sequential order without repeatedly selecting the chip and register addresses.
- Can unused LED pins be used for other purposes?
Yes, unused LED pins can be used for general purpose parallel input/output (GPIO) expansion.
- How is the I2C slave address selected for the LP3943?
The I2C slave address is selected via the ADR0, ADR1, and ADR2 inputs.
- What is the purpose of the internal precision oscillator in the LP3943?
The internal precision oscillator provides the necessary timing for driving each LED.
