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MAX1729
ECB and LCD Display Bias Supply with Accurate Output Voltage and Temperature Compensation
High-Accuracy Bias Supply Enables Use of Low-Cost Color ECB LCDs
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Status
Active: In Production.
Description
The MAX1729 micropower step-up/step-down DC-DC converter is
ideally suited for electrically controlled birefringence (ECB) and
liquid-crystal-display (LCD) bias-supply generation. It provides
step-up/step-down voltage conversion and reduces output ripple by using a step-up DC-DC converter followed by a linear regulator. This architecture permits a physically smaller inductor than those used in competing SEPIC and flyback topologies. This device features low quiescent current (67µA typical). A logic-controlled shutdown mode further reduces quiescent current to 0.4µA typical.
The MAX1729 features an input that dynamically adjusts the output
voltage to control display color or contrast. It offers two feedback modes:
internal and external. Internal feedback mode allows output voltages between 2.5V and 16V, and is specifically designed to hold temperature drift to ±11ppm/°C. External feedback mode allows the MAX1729 output voltage range to be tailored for various displays.
An on-chip temperature sensor with a positive temperature
coefficient provides compensation for LCD/ECB display temperature
characteristics. In internal feedback mode, the buffered temperature sensor
output is read and used to adjust the output voltage via a digital control
signal. External feedback mode features an additional compensation method in
which the temperature output is summed directly into the feedback network to
provide first-order negative temperature compensation of the output voltage. The
MAX1729 is available in the space-saving 10-pin µMAX package.
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Data Sheet
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An evaluation kit is available: MAX1729EVKIT
Key Features
- High-Accuracy Reference Voltage (±1%)
- ±11ppm/°C Output Voltage Drift
- On-Chip Temperature Sensor Output
- Accurate Voltage and Temperature Provide:
- Consistent ECB Colors
- Consistent LCD Gray-Scale Contrast
- +2.7V to +5.5V Input Voltage Range
- Output Voltage Range
- +2.5V to +16V in Internal Feedback Mode
- Programmable in External Feedback Mode
- Dynamic Control of the Output Voltage
- 67µA Supply Current
- 0.4µA Shutdown Current
- 10-Pin µMAX Package (1.09mm max height)
- Evaluation Kit Available (MAX1729EVKIT)
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Applications/Uses
- Cell Phones
- ECB Display Bias and Color Adjustment
- LCD Display Bias and Contrast Adjustment
- PDAs and Other Handheld Devices
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Key Specifications:
| Step-Up/Down Switching Regulators |
| Part Number |
VIN
(V) |
VIN
(V) |
VOUT
(V) |
VOUT
(V) |
Max. IOUT
(A) |
Max. IOUT
(A) |
Output Adjust. Method |
DC-DC Outputs |
Alternate Topology |
Oper. Freq.
(kHz) |
Package/Pins |
Smallest Available Pckg.
(mm2) |
| min |
max |
min |
max |
≥ |
≤ |
max w/pins |
| MAX1729 |
2.7 |
5.5 |
2.5 |
16 |
0.0025 |
0.0025 |
Resistor |
1 |
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300 |
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15.4 |
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See All Step-Up/Down Switching Regulators (9)
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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
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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| MAX1729EUB
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Active |
µMAX;10 pin;15.4 mm²
Outline Drawing:21-0061 (PDF)
Land Pattern: 90-0330 (PDF)
Use pkgcode/variation: U10-2*
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-40°C to +85°C
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RoHS/Lead-Free: No
Materials Analysis |
| MAX1729EUB-T
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Active |
µMAX;10 pin;15.4 mm²
Outline Drawing:21-0061 (PDF)
Land Pattern: 90-0330 (PDF)
Use pkgcode/variation: U10-2*
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-40°C to +85°C
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RoHS/Lead-Free: No
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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Notes and Comments
Output-voltage temperature compensation, transformerless design with smaller inductor than SEPIC/flyback, low output ripple
Similar Products by Function
| MAX863 |
Dual, High-Efficiency, PFM, Step-Up DC-DC Controller |
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Evaluation Kits
Products with Similar Part Numbers
Didn't Find What You Need?
Information Index
Document Ref.: 19-1406
Rev 1;
1999-01-01
This page last modified: 2007-07-20
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