Overview
The LP8556SQE-E00/NOPB is a high-efficiency LED backlight driver designed by Texas Instruments. This device features an asynchronous boost converter and six high-precision current sinks, making it ideal for applications such as tablet backlighting. The LP8556 integrates a 0.19-Ω power MOSFET and supports three switching frequencies: 312 kHz, 625 kHz, and 1250 kHz, which can be set via an external resistor or pre-configured via EPROM. The device is controlled by a PWM signal and is recommended for systems without an I2C master.
Key Specifications
| Parameter | Minimum | Typical | Maximum | Unit |
|---|---|---|---|---|
| Input Voltage Range (VDD) | 2.7 | - | 20 | V |
| Boost Output Voltage Range | 16 | - | 34.5 | V |
| Switching Frequencies | 312 kHz | 625 kHz | 1250 kHz | kHz |
| Maximum LED Current | - | - | 23 mA | mA |
| Switch ON Resistance (RDS_ON) | - | 0.19 | - | Ω |
| Ambient Temperature Range | -30 | - | 85 | °C |
| Package Type | - | - | WQFN (24-pad) | - |
| Package Size | - | - | 4.00 mm × 4.00 mm | mm |
Key Features
- High-efficiency DC/DC boost converter with integrated 0.19-Ω power MOSFET.
- Adaptive output voltage control to minimize power consumption by adjusting the output voltage to the lowest sufficient level.
- Three switching frequency options: 312 kHz, 625 kHz, and 1250 kHz, settable via external resistor or EPROM.
- Programmable slew rate control and spread spectrum scheme to minimize switching noise and improve EMI performance.
- Six high-precision current sinks controllable by PWM signal or I2C master.
- PWM dimming resolution of up to 15 bits and proprietary adaptive dimming mode for higher system power saving.
- Phase shifted LED PWM dimming to reduce audible noise and smaller boost output capacitors.
- Full set of fault-protection features including input undervoltage lockout, thermal shutdown, overcurrent protection, and up to 6 levels of overvoltage protection.
- LED open and short detection for robust operation.
Applications
The LP8556SQE-E00/NOPB is primarily designed for backlighting in tablets and other portable devices. It is also suitable for other applications requiring high-efficiency LED driving, such as LCD displays in smartphones, e-readers, and other handheld devices.
Q & A
- What is the input voltage range for the LP8556SQE-E00/NOPB?
The input voltage range is from 2.7 V to 20 V.
- What are the available switching frequencies for this device?
The device can operate at 312 kHz, 625 kHz, and 1250 kHz.
- How many LED current sinks does the LP8556SQE-E00/NOPB have?
The device has six high-precision current sinks.
- What is the maximum LED current supported by this device?
The maximum LED current is 23 mA.
- What type of package is the LP8556SQE-E00/NOPB available in?
The device is available in a 24-pad WQFN package.
- What are the dimensions of the WQFN package?
The package dimensions are 4.00 mm × 4.00 mm.
- How does the adaptive output voltage control work?
The adaptive output voltage control adjusts the output voltage to the lowest sufficient level to minimize power consumption.
- What fault-protection features does the LP8556SQE-E00/NOPB have?
The device includes input undervoltage lockout, thermal shutdown, overcurrent protection, up to 6 levels of overvoltage protection, and LED open and short detection.
- Can the LP8556SQE-E00/NOPB be controlled by an I2C master?
No, this specific model (LP8556SQE-E00/NOPB) is recommended for systems without an I2C master and is controlled by a PWM signal.
- What is the ambient temperature range for the LP8556SQE-E00/NOPB?
The device operates over an ambient temperature range of –30°C to +85°C.
