TOLL Microelectronic13W 802.3af PoE Powered Device
Interface with Flyback/Buck DC/DC Converter
Features
Compatible with 802.3af Specifications
Support 13W PoE Power Application
100V, 0.6Ω Integrated Pass Switch
150mA DC Input Current Limit
450mA PD Operation Current Limit
Intelligent Maintain Power Signature (MPS)
Integrated 160V Switching Power MOSFET
Supports Primary-Side Regulated Flyback
without Opto-Coupler Feedback
Supports Low-side Switch Buck Converter
3A Programmable Switching Current Limit
OLP, OVP, OTP and Open-Circuit Protection
Minimal External Components
QFN4x5-28 Package
Application
IEEE 802.3af-Compliant Devices
Security Camera
VoIP Phones
WLAN Access Points
IoT Devices
Description
The TMI7321 is an integrated IEEE 802.3af PoE
compliant Powered Device (PD) power supply
solution. It includes a PD interface and an
isolated/non-isolated fly-back or Buck converter.
The PD interface includes detection and all the
functions of IEEE 802.3af, classification, 150mA
inrush current, 450mA operation current limit as
well as 100V Hot-swap MOSFET.
The DC/DC converter uses fixed peak current and
variable frequency discontinuous conduction mode
(DCM) to regulate constant output voltage. The
primary-side regulation without opto-coupler
feedback in fly-back mode simplifies the design
while buck mode continues minimizes the solution
size for non-isolated applications. A 160V
integrated power MOSFET optimizes the device for
various wide voltage applications
It incorporates over current, open-circuit, and over-
voltage protection and thermal shutdown.
The TMI7321 supports a front-end solution for
PoE-PD application with minimal external
components and is available in QFN4x5-28
package.