MAX5974AETE+T

The MAX5974AETE+T is an advanced Active-Clamped, Spread-Spectrum, Current-Mode PWM (Pulse Width Modulation) Controller manufactured by Maxim Integrated. This controller is specifically designed for wide-input-voltage, forward converters in Power-over-Ethernet (PoE) powered device (PD) applications.

Key Features:

1. Active-Clamped Forward PWM Controller:
   • The MAX5974AETE+T employs an active-clamped forward PWM control architecture, which enhances supply efficiency by recycling magnetizing current instead of wasting it in a dissipative clamp circuit.
2. Spread-Spectrum Operation:
   • The device features programmable frequency dithering, which provides low-EMI (Electromagnetic Interference) spread-spectrum operation. This helps to minimize interference with other electronic devices in the vicinity.
3. Current-Mode Control:
   • The MAX5974AETE+T operates in current-mode control, offering precise control over the output current. This makes it suitable for applications requiring tight regulation of the output power.
4. Programmable Switching Frequency:
   • The switching frequency of the MAX5974AETE+T is programmable from 100kHz to 600kHz, with a synchronization capability up to 1.2MHz. This allows for flexibility in design and optimization of the power conversion efficiency.
5. Output Regulation Without Optocoupler:
   • The MAX5974AETE+T (along with MAX5974A/B) features unique circuitry to achieve output regulation without the need for an optocoupler. This simplifies the circuit design and reduces the component count.
6. Enhanced Efficiency Under Light-Load Conditions:
   • Under light-load conditions, the device reduces the switching frequency (frequency foldback) to minimize switching losses and improve overall efficiency.
7. Protection Features:
   • The MAX5974AETE+T includes various protection features such as output short-circuit protection with hiccup mode, reverse current limit to prevent transformer saturation, and an internal 18V Zener clamp on the supply input.
8. Compact Packaging:
   • The device is packaged in a lead-free, 16-pin TQFN-EP package, making it suitable for space-constrained applications.
9. Operating Temperature Range:
   • The MAX5974AETE+T is rated for operation over a wide temperature range of -40°C to +85°C.

Applications:

• Active-Clamped Forward DC-DC Converters
• High-Power PDs Beyond the 802.3af/at Standard
• IP Phones, PoE IEEE 802.3af/at Powered Devices
• Security Cameras, Wireless Access Nodes

In summary, the MAX5974AETE+T is a versatile and high-performance PWM controller that offers enhanced supply efficiency, low-EMI spread-spectrum operation, and a range of protection features. Its compact packaging and wide operating temperature range make it suitable for a variety of PoE powered device applications.