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MAX1765
800mA, Low-Noise, Step-Up DC-DC Converter with 500mA Linear Regulator
Highly Efficient Boost Converter with Integrated LDO for Battery Powered Devices
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Status
Active: In Production.
Description
The MAX1765 is a high-efficiency, low-noise, step-up DC-DC converter intended for use in battery-powered wireless applications. This device operates at a high 1MHz fixed frequency while maintaining an exceptionally low quiescent supply current (200µA). Its small external components and tiny package make this device an excellent choice for small hand-held applications that require the longest possible battery life.
The MAX1765 uses a synchronous-rectified pulse-width-modulation (PWM) boost topology to generate 2.5V to 5.5V outputs from a wide range of input sources, such as one to three alkaline or NiCd/NiMH cells or a single lithium-ion (Li+) cell. Maxim's proprietary architecture significantly improves efficiency at low load currents while automatically transitioning to fixed-frequency PWM operation at medium to high load currents to maintain excellent full-load efficiency. Forced-PWM mode is available for applications that require constant-frequency operation at all load currents, and the MAX1765 may also be synchronized to an external clock to protect sensitive frequency bands in communications equipment.
The MAX1765's low-dropout (LDO) linear regulator and DC-DC converter have separate shutdown control. The linear regulator's 250mΩ pass device maintains excellent dropout voltage at currents up to 500mA. The MAX1765 also features analog soft-start and current-limit functions to permit optimization of efficiency, external component size, and output voltage ripple.
The MAX1765 comes in a 16-pin QSOP package and a thermally enhanced 16-pin TSSOP-EP.
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Data Sheet
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An evaluation kit is available: MAX1765EVKIT
Key Features
- High-Efficiency Step-Up Converter
- Up to 93% Efficiency
- Adjustable Output from +2.5V to +5.5V
- Up to 800mA Output
- PWM Synchronous-Rectified Topology
- 1MHz Operating Frequency (or Sync)
- LDO Linear Regulator
- 500mA LDO Linear Regulator
- 2.85V Linear Regulator Output or Adjustable (1.25V to 5V)
- Low 125mV Dropout at 500mA
- +0.7V to +5.5V Input Range
- 0.1µA Logic-Controlled Shutdown
- Adjustable Inductor Current Limit and Soft-Start
- Thermal Shutdown
- 1.5W, 16-Pin TSSOP-EP Package Available
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Applications/Uses
- Handheld Instruments (PDAs, Palmtops)
- Palmtop Computers
- PCS Phones
- Personal Communicators
- Portable Audio Players
- Wireless Handsets
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Key Specifications:
| Step-Up Switching Regulators |
| Part Number |
VIN (V) |
VIN (V) |
VOUT (V) |
VOUT (V) |
Preset VOUT (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 |
min |
max |
≥ |
≤ |
max w/pins |
See Notes |
| MAX1765 |
1 |
5.5 |
1.25 |
5 |
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0.8 |
0.8 |
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1 |
1000 |
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30.9 |
$2.88 @1k |
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See All Step-Up Switching Regulators (95)
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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/Down Switching Regulators |
| Part Number |
VIN (V) |
VIN (V) |
VOUT (V) |
VOUT (V) |
Preset 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) |
Budgetary Price |
| min |
max |
min |
max |
≥ |
≤ |
max w/pins |
See Notes |
| MAX1765 |
1 |
5.5 |
1.25 |
5 |
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0.8 |
0.8 |
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1 |
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1000 |
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30.9 |
$2.88 @1k |
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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
Didn't Find What You Need?
Information Index
Document Ref.: 19-1805
Rev 1;
2011-05-04
This page last modified: 2011-05-04
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