MAX8678
White LED Charge Pump with 1.1W Audio Amplifier
Industry’s First LED Charge Pump with Integrated Audio Amplifier Saves 50% PCB Area While Providing Highest Efficiency
Part Details
- High-Efficiency White LED Charge Pump
- Individual Adaptive Supply for Each LED
- 4 Low-Dropout LED Current Regulators
- 24mA to 0.1mA Dimming Range
- Single-Wire, Serial-Pulse Dimming Interface
- 1% (typ) Accuracy
- Low 140µA Quiescent Current
- Mono Class AB Audio Amplifier
- 1.1W RMS Mono BTL Output (8Ω, VIN = 5V)
- Low 0.004% THD+N at 1kHz
- High 90dB PSRR at 1kHz
- Fully Differential Inputs
- -9dB to +18dB Gain Settings in 3dB Steps
- Integrated Click/Pop Suppression
- Low Quiescent Current
- Soft-Start Limits Inrush Current
- Thermal Shutdown, Open- and Short-Circuit Protection
- 16-Pin, 3mm x 3mm Thin QFN Package
The MAX8678 integrates a charge pump for white light-emitting diodes (LEDs) with an audio loudspeaker amplifier. The high-efficiency, adaptive charge pump drives up to four LEDs with constant current for uniform brightness. The LED current is adjustable from 0.1mA/LED to 24mA/LED in 31 pseudo-logarithmic steps through a single-wire serial-pulse interface. High accuracy and LED-to-LED current matching are maintained throughout the adjustment range. Individual adaptive mode switching for each LED provides high efficiency with a wide range of LED forward voltages.
The mono class AB audio amplifier directly drives an 8Ω loudspeaker with 1.1W RMS continuous power from a 5V supply with less than 1% THD+N. The gain is adjustable from -9dB to +18dB in ten 3dB steps through a single-wire serial-pulse interface. Clicks and pops are suppressed during on/off and all gain adjustments. Differential inputs improve common-mode noise rejection.
The MAX8678 includes soft-start, thermal shutdown, open-circuit and short-circuit protection, and is available in the 16-pin, 3mm x 3mm Thin QFN package (0.8mm max height).
Applications
- Camera Phones
- Cell Phones and Smartphones
- PDAs, Digital Cameras, Camcorders
Documentation
This is the most up-to-date revision of the Data Sheet.
Hardware Ecosystem
| Parts | Product Life Cycle | Description |
|---|---|---|
| Inductorless (Charge Pump) LED Drivers 3 | ||
| MAX1573 | PRODUCTION | White LED 1x/1.5x Charge Pump in UCSP and Thin QFN |
| MAX1574 | PRODUCTION | 180mA, 1x/2x, White LED Charge Pump in 3mm x 3mm TDFN |
| MAX1576 | PRODUCTION | 480mA White LED 1x/1.5x/2x Charge Pump for Backlighting and Camera Flash |
| Product 3 | ||
| MAX1575 | White LED 1x/1.5x Charge Pump for Main and Sub-Displays | |
| MAX1582 | High-Efficiency Step-Up Converters for White LED Main and Subdisplay Backlighting | |
| MAX1578 | Complete Bias and White LED Power Supplies for Small TFT Displays | |
| Step-Up (Boost) LED Drivers 5 | ||
| MAX1848 | PRODUCTION | White LED Step-Up Converter in SOT23 |
| MAX1599 | PRODUCTION | High-Efficiency, 26V Step-Up Converters for Two to Six White LEDs |
| MAX1561 | PRODUCTION | High-Efficiency, 26V Step-Up Converters for Two to Six White LEDs |
| MAX8595 | LAST TIME BUY | High-Efficiency, 36V Step-Up Converters with TA Derating Option for 2 to 9 White LEDs |
| MAX8596 | Obsolete | High-Efficiency, 36V Step-Up Converters with TA Derating Option for 2 to 9 White LEDs |
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