Overview
The LP3943ISQX from Texas Instruments is a highly integrated 16-channel RGB and white LED driver designed for independent string control via SMBUS/I2C interface. This device is particularly suited for applications requiring precise and flexible LED control, such as in portable electronics, digital cameras, and customized LED lighting systems.
The LP3943 features an internal precision oscillator, which eliminates the need for external timing components, and supports variable dim rates from 6.25ms to 1.6s and frequencies from 0.625Hz to 160Hz. The device is packaged in a 24-pin WQFN (RTW) package, making it compact and suitable for space-constrained designs.
Key Specifications
| Parameter | Value | Unit |
|---|---|---|
| Number of Outputs | 16 | - |
| Output Current per Channel | 25 | mA |
| Total Output Current per Package | 200 | mA |
| Supply Voltage Range | 2.3 to 5.5 | V |
| Operating Temperature Range | -40 to 85 | °C |
| Package Type | WQFN (24 pins) | - |
| Dimming Interface | SMBUS/I2C | - |
| Dimming Frequency Range | 0.625Hz to 160Hz | - |
| Dimming Duty Cycle Control | 8-bit PWM (0-100%) | - |
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 and frequencies from 0.625Hz to 160Hz
- 16 LED drivers with multiple programmable states (ON, OFF, input, and dimming)
- 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
Applications
- Customized flashing LED lights for cellular phones
- Portable applications
- Digital cameras
- Indicator lamps
- General purpose I/O expander
- Toys and other consumer electronics
- Camera flash systems
Q & A
- What is the LP3943ISQX used for?
The LP3943ISQX is used for driving and controlling up to 16 LEDs independently, particularly in applications requiring precise dimming and control such as in portable electronics, digital cameras, and customized LED lighting systems.
- What is the maximum output current per LED and per package?
The maximum output current per LED is 25mA, and the total package current should not exceed 200mA.
- What is the operating temperature range of the LP3943ISQX?
The operating temperature range is from -40°C to 85°C.
- What interface does the LP3943ISQX use for dimming control?
The LP3943ISQX uses the SMBUS/I2C interface for dimming control.
- What is the range of dimming frequencies supported by the LP3943ISQX?
The device supports dimming frequencies from 0.625Hz to 160Hz.
- How many bits are used for PWM duty cycle control in the LP3943ISQX?
The PWM duty cycle control is 8 bits, allowing for precise control over the duty cycle.
- What is the purpose of the auto increment feature in I2C writes?
The auto increment feature reduces the number of I2C clock pulses by automatically incrementing the register address during sequential writes or reads.
- Can the I2C slave address of the LP3943ISQX be externally selected?
Yes, the I2C slave address can be externally selected via the ADR0, ADR1, and ADR2 inputs.
- What is the package type and pin count of the LP3943ISQX?
The LP3943ISQX is packaged in a 24-pin WQFN (RTW) package.
- Is the LP3943ISQX RoHS compliant?
Yes, the LP3943ISQX is lead-free and RoHS compliant.
