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MAX686
DAC-Controlled Boost Inverter LCD Bias Supply with Internal Switch
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Status
Active: In Production.
Description
The MAX686 DAC-controlled boost/inverter IC converts a positive input voltage to a positive or negative LCD bias voltage up to +27.5V or -27.5V. The device features an internal N-channel MOSFET switch, programmable current limiting, and an internal 6-bit digital-to-analog converter (DAC) for digital adjustment of the output voltage. It comes in a small 16-pin QSOP package (same size as an 8-pin SO).
The MAX686 uses a current-limited, pulse-frequency-modulation (PFM) control scheme to provide high efficiency over a wide range of load conditions. Its high switching frequency (up to 300kHz) allows the use of small external components.
An LCDON output allows the LCD bias voltage to be automatically disabled when the display logic voltage is removed, protecting the display. The MAX686 has a +2.7V to +5.5V input voltage range for the IC, and a +0.8V to +27.5V input voltage range for the inductor. Typical quiescent supply current is 65µA. Shutdown current is 1.5µA.
The MAX686 offers high-level integration to save space, reduce power consumption, and increase battery life, making it an excellent choice for battery-powered portable equipment. The MAX629 is similar to the MAX686, except that it does not contain a built-in DAC. Both devices have evaluation kits to facilitate designs.
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Data Sheet
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An evaluation kit is available: MAX686EVKIT
Key Features
- Internal 500mA, 28V N-Channel Switch (no external FET required)
- Adjustable Output Voltage to +27.5V or -27.5V
- 6-Bit DAC-Controlled Output Voltage
- Up to 90% Efficiency
- Small 16-Pin QSOP Package (Same size as 8-pin SO)
- Power-OK Indicator
- 65µA Quiescent Current
- 1.5µA Shutdown Current
- Up to 300kHz Switching Frequency
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Applications/Uses
- Notebook Computers
- Palmtop Computers
- PDAs and Other Handheld Devices
- Portable Data-Collection Terminals
- Positive or Negative LCD Bias
- Varactor Tuning Diode Bias
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Key Specifications:
| Inverting Switching Regulators |
| Part Number |
VIN
(V) |
VIN
(V) |
Max. IOUT
(A) |
Max. IOUT
(A) |
Output Adjust. Method |
DC-DC Outputs |
Alternate Topology |
Oper. Freq.
(kHz) |
Package/Pins |
Smallest Available Pckg.
(mm2) |
Budgetary Price |
| min |
max |
≥ |
≤ |
max w/pins |
See Notes |
| MAX686 |
2.7 |
5.5 |
0.1 |
0.1 |
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1 |
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300 |
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30.9 |
$3.18 @1k |
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See All Inverting Switching Regulators (25)
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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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| Step-Up Switching Regulators |
| Part Number |
VIN
(V) |
VIN
(V) |
Max. IOUT
(A) |
Max. IOUT
(A) |
Output Adjust. Method |
DC-DC Outputs |
Oper. Freq.
(kHz) |
Package/Pins |
Smallest Available Pckg.
(mm2) |
Budgetary Price |
| min |
max |
≥ |
≤ |
max w/pins |
See Notes |
| MAX686 |
2.7 |
5.5 |
0.1 |
0.1 |
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1 |
300 |
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30.9 |
$3.18 @1k |
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See All Step-Up Switching Regulators (91)
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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
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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| MAX686C/D
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Active |
DICE SALES;NA pin;DICE;
Land Pattern: Not Applicable
Use pkgcode/variation: DICE*
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See data sheet
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| MAX686EEE
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Active |
QSOP;16 pin;30.9 mm²
Outline Drawing:21-0055 (PDF)
Land Pattern: 90-0167 (PDF)
Use pkgcode/variation: E16-1*
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-40°C to +85°C
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RoHS/Lead-Free: No
Materials Analysis |
| MAX686EEE+
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Active |
QSOP;16 pin;30.9 mm²
Outline Drawing:21-0055 (PDF)
Land Pattern: 90-0167 (PDF)
Use pkgcode/variation: E16+1*
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-40°C to +85°C
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RoHS/Lead-Free: Lead Free
Materials Analysis |
| MAX686EEE+T
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Active |
QSOP;16 pin;30.9 mm²
Outline Drawing:21-0055 (PDF)
Land Pattern: 90-0167 (PDF)
Use pkgcode/variation: E16+1*
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-40°C to +85°C
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RoHS/Lead-Free: Lead Free
Materials Analysis |
| MAX686EEE-T
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Active |
QSOP;16 pin
Land Pattern: Not Available
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-40°C to +85°C
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See data sheet
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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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Notes and Comments
30V/0.5A internal switch reduces component count and saves space
Similar Products by Function
| MAX629 |
28V, Low-Power, High-Voltage, Boost or Inverting DC-DC Converter |
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Evaluation Kits
Products with Similar Part Numbers
Didn't Find What You Need?
Information Index
Document Ref.: 19-1327
Rev 1;
1998-02-01
This page last modified: 2007-06-01
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