MAX5974BETE+T

The MAX5974BETE+T is an active clamped, spread spectrum, current mode PWM controller in 16 pin TQFN package. It provides control for wide input voltage, active clamped, current mode PWM, forward converters in power over Ethernet (PoE) powered device (PD) applications. It accommodates low input voltage down to 10.5V. The device includes several features to enhance supply efficiency. The AUX driver recycles magnetizing current instead of wasting it in dissipative clamp circuit. Programmable dead time between AUX and main driver allows for zero voltage switching (ZVS). Under light load conditions, the device reduces switching frequency to reduce switching losses. It has unique circuitry to achieve output regulation without using an optocoupler and output short circuit protection with hicc-up mode. The device is used in PoE IEEE 802.3af/at powered devices, high power PD (beyond 802.3af/at standard), active clamped forward DC to DC converters, IP phones & wireless access nodes.

• IN clamp voltage from 17V to 20V and maximum duty cycle of 80% at fSW = 250KHz
• Operating temperature range from -40°C to 85°C
• Sample/hold feedback mode, UVLO threshold of 8.4V & internal 1% error amplifier
• Reverse current limit to prevent transformer saturation due to reverse current
• 100KHz to 600KHz programmable ±8% switching frequency, synchronization up to 1.2MHz
• Programmable frequency dithering for low EMI, spread spectrum operation
• Programmable dead time, PWM soft start, current slope compensation
• Programmable feed forward maximum duty cycle clamp, 80% maximum limit
• Frequency foldback for high efficiency light load operation, internal 18V zener clamp on supply I/P
• Internal bootstrap UVLO with large hysteresis, 100µA (typ) start-up supply current

Aplicaţii

Power Management, Consumer Electronics, Portable Devices

Note

ADI products are only authorized (and sold) for use by the customer and are not to be resold or otherwise passed on to any third party