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MAX845
Isolated Transformer Driver for PCMCIA Applications
Internal Power MOSFETs Save Space and Deliver 750mW
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Key Features
Applications/Uses
Parametric specs for Transformer Drivers
| VIN (V) (min) | 2.5 |
| VIN (V) (max) | 6 |
| Driver Output Resistance (Ω) (max) | 4 |
| Max. IOUT (A) | 0.2 |
| Topology | Push-Pull |
| Switching Frequency (kHz) | 860 |
| IQ (mA) (max) | 1.1 |
| Package/Pins | SOIC (N)/8 UMAX/8 |
| Oper. Temp. (°C) | -40 to +85 |
| Budgetary Price (See Notes) | 2.48 |
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Parameters
Parametric specs for Transformer Drivers
| VIN (V) (min) | 2.5 |
| VIN (V) (max) | 6 |
| Driver Output Resistance (Ω) (max) | 4 |
| Max. IOUT (A) | 0.2 |
| Topology | Push-Pull |
| Switching Frequency (kHz) | 860 |
| IQ (mA) (max) | 1.1 |
| Package/Pins | SOIC (N)/8 UMAX/8 |
| Oper. Temp. (°C) | -40 to +85 |
| Budgetary Price (See Notes) | 2.48 |
Key Features
- Transformer Driver for Ultra-Thin 5V-µs Transformers
- Isolated DC-to-DC Power Supply for PCMCIA Applications
- 450kHz Minimum Switching Frequency
- Ultra-Low Input Supply Current Ripple
- Single +5V or +3.3V Supply
- 5µW Low-Power Shutdown Mode
- 8-Pin SO and µMAX Packages
- Low Output Ripple Permits Miniature Output Capacitors
Applications/Uses
- Bridge Ground Differentials
- Isolated Data Acquisition
- Isolated Interface Power Supply
- Low-Power LAN Networks
- Medical Equipment
- Noise-Immunity Communications Interface
- PCMCIA Modem Cards
- Process Control
Description
The MAX845 provides an isolated power supply small enough to fit in thin PCMCIA cards and space-sensitive applications. It drives a low-profile center-tapped transformer primary from a 5V or 3.3V DC power supply. The secondary can be wound to provide any isolated positive or negative voltage at powers up to 750mW.
The MAX845 consists of an oscillator followed by a toggle flip-flop. The flip-flop generates two 50% duty-cycle square waves, which are complementary at half the oscillator frequency (450kHz, min). These two signals drive the ground-referenced N-channel power switches. Internal circuitry ensures break-before-make action between the two switches.
A low-power shutdown disables both the switches and the oscillator, reducing power consumption. An evaluation kit (MAX845EVKIT-MM) is available to evaluate low-profile 5V 40mA and 5V 100mA applications.
The MAX845 consists of an oscillator followed by a toggle flip-flop. The flip-flop generates two 50% duty-cycle square waves, which are complementary at half the oscillator frequency (450kHz, min). These two signals drive the ground-referenced N-channel power switches. Internal circuitry ensures break-before-make action between the two switches.
A low-power shutdown disables both the switches and the oscillator, reducing power consumption. An evaluation kit (MAX845EVKIT-MM) is available to evaluate low-profile 5V 40mA and 5V 100mA applications.
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 .
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