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MAX8822
Ultra-Efficient Negative Charge-Pump LED Driver with Dual LDOs in 3mm x 3mm Thin QFN
Independent Adaptive Voltage Supply for Four WLEDs with Two 200mA Low-Noise/High PSRR LDOs for Display Backlighting
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Status
Active: In Production.
Description
The MAX8822 drives up to four white light-emitting diodes (LEDs) with regulated constant current for display backlighting in cell phones, digital cameras, PDAs, and other handheld devices. By utilizing a proprietary negative 0.5x inverting charge pump and innovative independent low-dropout (LDO) adaptive current regulators, very high efficiency is achieved over the full 1-cell Li+ battery voltage range, even with large LED VF mismatch. The 1MHz fixed-frequency switching allows for tiny external components. The regulation scheme is optimized to ensure low EMI and low input ripple. Two 200mA, low-noise, high power-supply-rejection-ratio (PSRR) LDOs with programmable output voltages are included on-chip to provide power to camera modules or other devices.
The MAX8822 features a single-wire, serial-pulse control-logic interface that programs LED current and the output voltages of the LDOs. The LED dimming range is pseudo-logarithmic from 24mA to 0.1mA in 31 steps. LDO output voltages are programmable in 16 different combinations to meet various camera module requirements.
The MAX8822 includes soft-start, thermal shutdown, open- and short-circuit protection.
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Data Sheet
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An evaluation kit is available: MAX8822EVKIT
Key Features
- High-Efficiency Charge Pump for Up to Four White LEDs
- Independent Adaptive Voltage Supply for Each LED
- 24mA to 0.1mA Dimming Range
- 1% (typ) Current Accuracy and 0.3% Current Matching
- Low 65µA (typ) Quiescent Current
- Dual 200mA Low-Noise, High PSRR LDOs
- 16 Different Output Voltage Combinations Up to 3.3V
- High 60dB PSRR at 10kHz
- Flexible Single-Wire Control for Dimming and LDO Output Voltage
- Low 0.5µA (typ) Shutdown Mode
- Soft-Start Limits Inrush Current
- Thermal Shutdown and Open- and Short-Circuit Protection
- Tiny 16-Pin, 3mm x 3mm Thin QFN Package (0.8mm max Height) with Exposed Paddle
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Applications/Uses
- Cell Phones and Smartphones
- White LED Backlighting
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Key Specifications:
| White LED Drivers |
| Part Number |
Topology |
LEDs |
Config. |
Dimming Control |
VDROPOUT
(mV) |
POUT
(W) |
ILED
(mA) |
VIN
(V) |
VIN
(V) |
ICC
(mA) |
VOUT
(V) |
Oper. Freq.
(kHz) |
Package/Pins |
Budgetary Price |
| max num. of |
typ |
max |
min |
max |
max |
max |
See Notes |
| MAX8822 |
Charge Pump |
4 |
Parallel |
Digital |
60 |
0.4 |
24 |
2.7 |
5.5 |
1.4 |
5.5 |
1000 |
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$1.66 @1k |
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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
Product Guides
Reliability Reports
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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| MAX8822ETE+
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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 |
| MAX8822ETE+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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Similar Products by Application
Evaluation Kits
More Information
Didn't Find What You Need?
Information Index
Document Ref.: 19-0847
Rev 0;
2007-12-06
This page last modified: 2009-09-01
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