BCM59122

The Broadcom BCM59122 is a highly integrated, flexible IEEE 802.3bt-compliant power sourcing equipment (PSE) controller. It features eight low-RDS (0.2) high-voltage pass-FETs, each with a precise, lossless proprietary current sense and an onboard microcontroller, designed to simplify Power over Ethernet (PoE), PoE+, and UPoE designs and ease PCB layout. The BCM59122 offers superior protection against all possible fault conditions and overloads, supporting two-event Classification for Type 2 (30W) applications and multi-event Classification for 802.3bt Standard Type3/Type4 applications.

• Compliant with IEEE 802.3bt, supports IEEE 802.3at and IEEE 802.3af
• Supports multi-event classification for Type 2, Type 3, and Type 4
• Supports four-pair applications: 60W bt Type3 and 90W bt Type 4
• Detects legacy power devices (PDs)
• Supports cascading of multiple devices, up to 64 ports
• Programmable ICUT and ILIM for Type 1 to Type 4
• Uses Broadcom Serial Control (BSC), an NXP I2C-compatible bus
• Operates in manual/semi-autonomous mode
• Provides real-time current, voltage, and temperature measurements per port
• Offers overtemperature protection with warning and shutdown
• Operates on a 48V nominal supply and external 3.3V supply
• Enables firmware download via BSC communication bus from host
• Packaged in an 8 mm 8 mm 0.9 mm QFN-56 package with exposed pad