Overview
The Broadcom BCM59121B0KMLG is a highly integrated IEEE 802.3bt-compliant power sourcing equipment (PSE) controller, part of the BCM5912X family. This device is designed to significantly reduce the complexity of Power over Ethernet (PoE), Power over Ethernet Plus (PoE+), and UPoE designs. It features eight low-RDS (0.2 Ω) high-voltage FETs, each with a very accurate, lossless, proprietary internal current sense and an onboard microcontroller. This integration simplifies PCB layout and provides excellent protection under all possible fault conditions and overloads.
Key Specifications
| Specification | Value |
|---|---|
| Compliance | IEEE 802.3bt, IEEE 802.3at, IEEE 802.3af |
| Number of Ports | 8 |
| FETs | Low-RDS (0.2 Ω) high-voltage FETs |
| Current Sense | Proprietary internal current sense |
| Microcontroller | Onboard MCU for firmware download, custom features, and bug fixes |
| Classification Support | Type 2 (30W), Type 3, Type 4 multi-event classification |
| Power Support | Up to 60W for Type 3, up to 90W for Type 4 |
| Interface | Broadcom Serial Control (BSC) bus, up to 2.4 Mb/s |
| Certification | Underwriters Laboratory (UL) certified |
| Operating Mode | Manual and semiautonomous operating mode |
| Measurements | Real-time current, voltage, and temperature measurements per port |
| Protection | Overtemperature protection (warning and shutdown) |
Key Features
- Integrated Field Effect Transistors (FETs) eliminate the need for external FETs.
- Integrated current-sense mechanism eliminates the need for external sense resistors and fuses.
- Supports detection of legacy power devices (PDs).
- Cascading of multiple devices up to 64 ports supported (Type 4 only supported by BCM59122).
- Broadcom Serial Control (BSC) bus architecture, compatible with I2C.
- Manual and semiautonomous operating modes.
- Real-time current, voltage, and temperature measurements available per port.
- Overtemperature protection (warning and shutdown).
Applications
- Routers
- Enterprise switches
- Security camera switch hubs
- POE lighting
Q & A
- What is the BCM59121B0KMLG used for? The BCM59121B0KMLG is used as a power sourcing equipment (PSE) controller for Power over Ethernet (PoE) applications.
- What standards does the BCM59121B0KMLG comply with? It complies with IEEE 802.3bt, IEEE 802.3at, and IEEE 802.3af standards.
- How many ports does the BCM59121B0KMLG support? It supports up to 8 ports.
- What type of FETs are integrated into the BCM59121B0KMLG? It features low-RDS (0.2 Ω) high-voltage FETs.
- Does the BCM59121B0KMLG have an onboard microcontroller? Yes, it has an onboard MCU for firmware download, custom features, and bug fixes.
- What types of classification does the BCM59121B0KMLG support? It supports Type 2, Type 3, and Type 4 multi-event classification.
- What is the maximum power supported by the BCM59121B0KMLG? It supports up to 60W for Type 3 and up to 90W for Type 4.
- What interface does the BCM59121B0KMLG use? It uses the Broadcom Serial Control (BSC) bus, compatible with I2C, up to 2.4 Mb/s.
- Is the BCM59121B0KMLG UL certified? Yes, it is Underwriters Laboratory (UL) certified.
- What kind of protection does the BCM59121B0KMLG offer? It offers overtemperature protection (warning and shutdown).
