TPS23770

www.ti.com TPS23750 TPS23770 SLVS590B – JULY 2005 – REVISED FEBRUARY 2008 INTEGRATED 100-V IEEE 802.3af PD AND DC/DC CONTROLLER FEATURES 1 2 Complete 802.3af PoE Interface – Features derived from the TPS2375 – 100 V, 0.6 Ω Internal Pass MOSFET – Standard and Legacy UVLO Choices – Fixed 140 mA Inrush Limit Primary Side DC/DC Converter Control – Minimum External Component Count – Current Mode Control – Isolated and Non-Isolated Topologies – Programmable Operating Frequency – Current Sense Leading-edge Blanking – 50% Duty Cycle Limiting – Voltage Output Error Amplifier Internal PoE and Converter Sequencing Industry-Standard 20 Lead Package Industrial Temperature Range: –40°C to 85°C APPLICATIONS All PoE PD Devices Including: – Wireless Access Points – VoIP Phones – Security Cameras VDD DESCRIPTION The TPS23750 integrates the functionality of the TPS2375 with a primary-side dc/dc PWM controller. The designer can create a front-end solution for PoE-PD applications with minimum external components. The TPS23770 is identical to the TPS23750 with the exception of the undervoltage lockout turn-on voltage, which is compatible with legacy systems. The PoE front end has all the necessary IEEE 802.3af functions including detection, classification, undervoltage lockout and inrush control. The PoE input switch is integrated within the TPS23750. The dc/dc controller section is designed to support flyback, forward, and nonsynchronous low-side switch buck topologies. The externa...