Power over Ethernet has advanced from the 13W era of IEEE 802.3af to PoE+ (IEEE 802.3at), enabling up to 25.5W available at the powered device (PD) to support higher-performance endpoints such as PTZ cameras, wireless access points, security and access control, and intelligent sensors. Within this landscape, the PEM3200 series from Powered Ethernet stands out as an ultra‑compact, Class 4 PD module that brings full IEEE 802.3at capability with strong EMI performance, high efficiency, and simple integration for OEMs targeting 12V and 24V outputs.
What is the PEM3200?
PEM3200 is a compact, IEEE 802.3at-compliant Powered Device (PD) extraction module designed to pull power from CAT5 or better Ethernet cabling when paired with 802.3at (PoE+) or 802.3af PSEs, delivering up to 30W peak with 24–27W continuous depending on input voltage and current limits. The module delivers fixed Class 4 operation with two‑event layer‑1 classification and supports layer‑2 “AT Detect” signaling, aligning with IEEE 802.3at mechanisms used by many PSEs for high‑power negotiation. Sized among the smallest 30W PD modules on the market, it emphasizes low EMI via in‑built frequency dithering and offers a dedicated pin to fine‑tune switching frequency for targeted EMI filter design.
Key outputs include 12V and 24V variants, with a 1500V isolation DC‑DC stage, low output ripple, and integrated protections (UVLO/OVLO, inrush, overload, and short‑circuit). The design requires minimal external components; an external bridge rectifier is needed in line with the product’s streamlined footprint.
Compact, 30W PoE+ PD module for 12V/24V outputs.
IEEE 802.3at Class 4 (Type 2), two‑event classification; supports layer‑2 “AT Detect”.
High‑efficiency, 1500V‑isolated DC‑DC converter with low ripple and low EMI via frequency dithering and adjustable frequency pin.
Auxiliary power and Remote Shutdown pins for systems with local supply or standby control.
Minimal BOM; external bridge rectifier required.
Why Class 4 (PoE+) matters
IEEE 802.3at introduced Type 2/Class 4, raising PD power to 25.5W while keeping the PSE budget to 30W due to cable and interface losses. Class 4 PDs must support two‑event physical classification and may also use LLDP for power negotiation, enabling PSEs to allocate power more precisely across ports in dense deployments. For OEMs, this means more headroom for motors, radios, heaters, and processing—without resorting to external power bricks or 4‑pair 802.3bt systems.
Class 4 PD power at the device: up to 25.5W; PSE budget: 30W.
Two‑event classification and optional LLDP facilitate reliable high‑power negotiation.
Integration benefits for OEMs
The PEM3200 series is engineered to shorten time‑to‑market:
Minimal external parts with a simple external bridge rectifier supports compact layouts.
Frequency tuning pin plus built‑in dithering streamline EMI compliance work, often cutting filter size/cost.
Auxiliary power and Remote Shutdown simplify hybrid designs (e.g., keep PoE connected but idle on local power).
Output ripple kept within IEEE specs to reduce downstream regulator stress and noise coupling.
Common applications include PTZ and IP cameras, access control, A/V interfaces, routers, APs, sensors, and environmental controllers—typical PoE+ use cases needing clean 12V or 24V rails.
Electrical highlights
According to Powered Ethernet’s product page, typical operating conditions include a 36–57V input range (51V+ recommended to maximize power), with continuous output power up to 27W and peak to 30W when input current and voltage permits; IEEE 802.3at generally limits PD input current to 0.6A, and exceeding that to around 0.75A may be necessary to reach 30W, so designs should target compliant operating points for continuous loads. The module supports extracting power from data pairs, spare pairs, or both, and provides fixed Class 4 detection and classification.
Input: 36–57V; 51V+ recommended for higher power margins.
Output options: 12V and 24V models (series options list standard voltages; product matrix highlights 12V/24V for PEM3200).
Isolation: 1500V, with protections for inrush, overload, short‑circuit, UVLO/OVLO.
EMI/ripple: Low output ripple; frequency dithering and adjustable frequency pin for EMI optimization.
How PEM3200 reduces EMI and noise
High‑density Ethernet products often struggle with switching noise and radiated emissions in compact enclosures. PEM3200 addresses this at the source:
Frequency dithering spreads energy to reduce narrowband peaks that trigger EMI failures.
A dedicated frequency adjust pin helps “move” the switching node away from sensitive bands or filter resonances.
Low ripple design reduces downstream filtering burden, improving overall signal integrity.
These features can materially reduce the number and size of EMI components and PCB layers used solely for mitigation, especially in cost‑ and space‑sensitive designs.
System architecture notes
Classification: The module implements two‑event layer‑1 classification, the IEEE‑standard way for a PD to signal high‑power needs to a PoE+ PSE, and offers an “AT Detect” pin for layer‑2 coordination where systems use LLDP or similar methods.
Backward compatibility: As a Type 2 PD, PEM3200 interoperates with 802.3af PSEs at reduced power while supporting full 802.3at when available.
Standards context: Type 2/Class 4 defines 25.5W at the PD using 2‑pair power; higher powers and 4‑pair delivery are defined by 802.3bt Types 3/4, beyond PoE+ scope.
Form factor and external components
Distributors describe PEM3200’s footprint among the smallest for 30W PD modules, with a slim in‑line (SIL‑style) format around mid‑50mm length, reducing PCB real estate in compact products. The design keeps the external BOM light; notably, the bridge rectifier is external on PEM3200, a tradeoff that preserves module size while offering flexibility on rectifier selection and placement for thermal management.
Ultra‑compact 30W PD module; minimal external parts; external bridge rectifier required.
Selector guides list PEM3212/PEM3224 options and highlight EMI features and auxiliary/shutdown pins.
Typical use cases
Security and surveillance: PTZ and IP cameras needing 12V with motorized movement and heaters.
Wireless: Access points and CPE with higher‑power radios at 12V/24V.
Access control and automation: Door controllers, badge readers, and environmental systems.
Edge compute/IoT: Routers, A/V gateways, and sensors with higher thermal or RF loads.
How it compares within PoE standards
Versus 802.3af: PoE+ roughly doubles usable PD power (to 25.5W) and adds two‑event classification, enabling devices that exceed the 12.95W ceiling of 802.3af.
Versus 802.3bt: If designs require >25.5W at the PD or 4‑pair power (e.g., 45–71.3W at the PD), Type 3/4 solutions are appropriate; PEM3200 targets the sweet spot where 12V/24V and 25.5W suffice without bt complexity.
Takeaways
PEM3200 offers a compact, Class 4, IEEE 802.3at PD module with 12V/24V outputs, strong EMI controls, high efficiency, and minimal external components, ideal for space‑constrained PoE+ products.
It implements two‑event classification and supports layer‑2 signaling via AT Detect, aligning with modern PSE power negotiation practices.
For OEMs, it accelerates PoE+ designs across surveillance, wireless, control, A/V, and IoT sectors while easing compliance and BOM pressures.
FAQs
Q: What maximum power can PEM3200 deliver? A: It supports up to about 27W continuous and 30W peak depending on input voltage/current limits, aligning with IEEE 802.3at’s 25.5W at the PD and 30W at the PSE budget.
Q: Which output voltages are available? A: The series focuses on 12V and 24V variants for PoE+ applications, with product pages and selectors emphasizing these models for PEM3200.
Q: Does PEM3200 meet Class 4 and two‑event classification requirements? A: Yes, it provides fixed Class 4 with two‑event physical classification and supports layer‑2 signaling via an “AT Detect” pin, matching IEEE 802.3at PD expectations.
Q: Is LLDP required to reach PoE+ power? A: Not strictly—two‑event classification is the hardware mechanism; LLDP can also be used by some systems to refine power negotiation at layer‑2, and the module supports this via signaling.
Q: What about EMI performance? A: The module integrates frequency dithering to reduce EMI peaks and adds a frequency adjust pin so designers can tune switching frequency relative to filters and sensitive bands, helping pass emissions more easily.
Q: Do I need an external bridge rectifier? A: Yes, PEM3200 requires an external bridge rectifier, a choice that keeps the module exceptionally compact while allowing flexibility in rectifier selection and placement.
Q: What isolation rating and protections are included? A: The DC‑DC stage provides 1500V isolation and includes inrush, overload, short‑circuit, and under/over‑voltage protections for robust operation.
Q: Is it backward compatible with 802.3af PSEs? A: As a Type 2 PD, it interoperates with 802.3af PSEs but will operate at reduced power in line with the lower power budget, while fully leveraging 802.3at PSEs for Class 4 power.
Q: What applications are best suited? A: IP/PTZ cameras, wireless APs, routers, A/V interfaces, access control, sensors, and building/environmental controllers that need 12V/24V and up to 25.5W at the PD are prime candidates.
Q: How does PoE+ differ from 802.3bt? A: PoE+ (802.3at) provides up to 25.5W at the PD over 2 pairs (Class 4), while 802.3bt uses 4 pairs for higher power classes (e.g., 40–71.3W at the PD depending on class), suited to heavier loads.
Q: Does PEM3200 help reduce BOM and design time? A: Yes—its compact form, minimal external component count, built‑in EMI aids, and integrated protections reduce design iterations and external filtering, speeding time‑to‑market.Q: Where can I find a quick selection overview?
