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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
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Status
Active: In Production.
Description
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).
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Data Sheet
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An evaluation kit is available: MAX8678EVKIT
Key Features
- 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
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Applications/Uses
- Camera Phones
- Cell Phones and Smartphones
- PDAs, Digital Cameras, Camcorders
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Key Specifications:
| White LED Drivers |
| Part Number |
Topology |
LEDs |
Config. |
Dimming Control |
POUT
(W) |
ILED
(mA) |
VIN
(V) |
VIN
(V) |
ICC
(mA) |
VOUT
(V) |
Oper. Freq.
(kHz) |
Package/Pins |
| max num. of |
max |
min |
max |
max |
max |
| MAX8678 |
Charge Pump |
4 |
Parallel |
Serial Pulse |
0.4 |
244 |
2.7 |
5.5 |
0.2 |
5 |
1000 |
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See All White LED Drivers (47)
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Pricing Notes:
This pricing is BUDGETARY, for comparing similar parts. Prices are in U.S. dollars and subject to change. Quantity pricing may vary substantially and international prices may differ due to local duties, taxes, fees, and exchange rates. For volume-specific prices and delivery, please see the price and availability page or contact an authorized distributor.
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Diagram
Typical Operating Circuit
Application Notes
Product Guides
Reliability Reports
| Show FIT data for: |
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| Request Reliability Report for: |
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Software/Models
Ordering Information
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Part Number
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Free
Sample |
Buy |
Status
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Package:
TYPE PINS FOOTPRINT
DRAWING CODE/VAR *
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Temp |
RoHS/Lead-Free?
Materials Analysis
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| MAX8678ETE+
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Active |
TQFN;16 pin;9.6 mm²
Outline Drawing:21-0136 (PDF)
Land Pattern: 90-0032 (PDF)
Use pkgcode/variation: T1633+5*
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-40°C to +85°C
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RoHS/Lead-Free: Lead Free
Materials Analysis |
| MAX8678ETE+T
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Active |
TQFN;16 pin;9.6 mm²
Outline Drawing:21-0136 (PDF)
Land Pattern: 90-0032 (PDF)
Use pkgcode/variation: T1633+5*
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-40°C to +85°C
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RoHS/Lead-Free: Lead Free
Materials Analysis |
Notes:
- Other options and links for purchasing parts are listed at: http://www.maxim-ic.com/sales.
- Didn't Find What You Need? Ask our applications engineers. Expert assistance in finding parts, usually within one business day.
- Part number suffixes: T or T&R = tape and reel; + = RoHS/lead-free; # = RoHS/lead-exempt; -D = drypack; -U/+U on DS parts = cut tape. More: See Full Data Sheet or Maxim Product Naming Conventions.
- * Some packages have variations, listed on the drawing. "PkgCode/Variation" tells which variation the product uses. Note that "+", "#", "-" in the part number suffix describes RoHS status. Package drawings may show a different suffix character.
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More Information
Didn't Find What You Need?
Information Index
Document Ref.: 19-0786
Rev 0;
2007-05-14
This page last modified: 2009-08-19
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