Product Details
Key Features
Applications/Uses
VIN (V) (min) | 3 |
VIN (V) (max) | 28 |
VOUT1 (V) (min) | 0 |
VOUT1 (V) (max) | -185 |
IOUT1 (A) (max) | 0.3 |
Switch Type | External |
Output Adjust. Method | Resistor |
# DC-DC Outputs | 1 |
Switching Frequency (kHz) | 500 |
Package/Pins | UMAX/10 |
Budgetary Price (See Notes) | 2.43 |
Simplified Block Diagram
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Parameters
VIN (V) (min) | 3 |
VIN (V) (max) | 28 |
VOUT1 (V) (min) | 0 |
VOUT1 (V) (max) | -185 |
IOUT1 (A) (max) | 0.3 |
Switch Type | External |
Output Adjust. Method | Resistor |
# DC-DC Outputs | 1 |
Switching Frequency (kHz) | 500 |
Package/Pins | UMAX/10 |
Budgetary Price (See Notes) | 2.43 |
Key Features
- Low-Cost, Off-the-Shelf Transformer
- 3V to 28V Input Range
- Low Audio-Band Noise on Talk Battery
- Effectively Handles Ring Trip Transients
- Powers 2-, 4-, or 12-Line Equipment
- High Efficiency Extends Battery Life During Life-Line Support Conditions
- Adjustable 100kHz to 500kHz Switching Frequency
- Clock Synchronization
- Internal Soft-Start
- Current-Mode PWM and Idle Mode Control Scheme
- Logic-Level Shutdown
- 10-Pin µMAX Package
Applications/Uses
- Cable and DSL Modems
- CO DSL Line Driver Supplies
- FTTH
- Industrial Power Supplies
- LMDS/MMDS
- MEMS Bias Supplies
- Routers/Switches
- Set-Top Boxes
- VoIP Ringer and Off-Hook Voltage Generators
- Wireless Local Loop (WLL)
Description
Due to its wide operating voltage range, the MAX1856 operates from a low-cost, unregulated DC power supply for cost-sensitive applications like xDSL, cable modems, set-top boxes, LMDS, MMDS, WLL, and FTTH CPE. The MAX1856 provides low audio-band noise for talk battery and a sturdy output capable of handling the ring trip conditions for ring battery.
The operating frequency can be set between 100kHz and 500kHz with an external resistor in free-running mode. For noise-sensitive applications, the MAX1856's operating frequency can be synchronized to an external clock over its operating frequency range.
The flyback topology allows operation close to 50% duty cycle, offering high transformer utilization, low ripple current, and less stress on input and output capacitors. Internal soft-start minimizes startup stress on the input capacitor, without any external components.
The MAX1856's current-mode control scheme does not require external loop compensation. The low-side current-sense resistor provides accurate current-mode control and overcurrent protection.
Technical Docs
Support & Training
Search our knowledge base for answers to your technical questions.
Filtered SearchOur dedicated team of Applications Engineers are also available to answer your technical questions. Visit our support portal .