Overview
The PM8800A, produced by STMicroelectronics, is an integrated power management IC that combines a standard IEEE 802.3af compliant Power over Ethernet (PoE) interface with a current mode PWM controller. This device simplifies the design of power supply sections in all powered devices, particularly those requiring extended power beyond the limits of the IEEE 802.3af standard. The PM8800A supports power input from either Ethernet LAN cables or external auxiliary sources such as AC adapters. It features a programmable oscillator frequency, soft-start, slope compensation, and a voltage output error amplifier, making it versatile for both isolated and non-isolated configurations.
Key Specifications
| Parameter | Value | Unit |
|---|---|---|
| Max Input Current | 800 | mA |
| Max Operating Temperature | 85 | °C |
| Max Power Dissipation | 12.95 | W |
| Min Operating Temperature | -40 | °C |
| Hot-Swap MOSFET Resistance | 0.5 | Ω |
| Hot-Swap MOSFET Current | 800 | mA |
| Signature Resistance | 24.5 | kΩ |
| Programmable DC Current Limit | Up to 800 | mA |
| Maximum Duty Cycle | 80% | |
| Thermal Shutdown Temperature | 130°C (1st level), 160°C (2nd level) | °C |
Key Features
- IEEE 802.3af compliant PoE-PD interface
- Current mode pulse width modulator
- Thermal shutdown protection
- Programmable soft-start and oscillator frequency
- 80% maximum duty cycle with internal slope compensation
- Power good indication
- Supports both isolated and non-isolated applications
- Programmable DC current limit up to 800 mA
- Programmable classification current
- Integrated 100V, 0.5Ω, 800mA Hot-Swap MOSFET
- Works with power supplied from Ethernet LAN cables or from local auxiliary sources
- Programmable in-rush current limit
- High voltage start-up bias regulator
- Integrated signature resistor
Applications
- VoIP phones
- WLAN access points
- Security cameras
- PoE powered device appliances
- High power (>12.95 W) powered devices
Q & A
- What is the PM8800A and what does it integrate?
The PM8800A integrates a standard IEEE 802.3af compliant Power over Ethernet (PoE) interface and a current mode PWM controller.
- What are the key features of the PM8800A?
The PM8800A features include IEEE 802.3af compliance, current mode PWM, thermal shutdown protection, programmable soft-start and oscillator frequency, and more.
- What is the maximum input current of the PM8800A?
The maximum input current is 800 mA.
- What is the operating temperature range of the PM8800A?
The operating temperature range is from -40°C to 85°C.
- Can the PM8800A work with both isolated and non-isolated configurations?
- What is the purpose of the integrated hot-swap MOSFET?
The integrated hot-swap MOSFET is capable of sustaining twice the current of the IEEE 802.3af standard with a programmable DC current limit.
- How does the PM8800A handle in-rush current limitation?
The PM8800A has a three-step in-rush current limit that is programmable using an external resistor.
- What are some common applications of the PM8800A?
Common applications include VoIP phones, WLAN access points, security cameras, and high power powered devices.
- Does the PM8800A support power from external auxiliary sources?
- What is the thermal shutdown temperature of the PM8800A?
The thermal shutdown temperatures are 130°C (1st level) and 160°C (2nd level).
