TPS23756 High Power/High Efficiency PoE Interface and DC/DC Controller | TI.com

TPS23756 (ACTIVE)

High Power/High Efficiency PoE Interface and DC/DC Controller

High Power/High Efficiency PoE Interface and DC/DC Controller - TPS23756
 

Description

The TPS23754 and TPS23756 devices have a combined power-over-ethernet (PoE), powered-device (PD) interface, and current-mode DC-DC controller optimized specifically for isolated converters. The PoE interface supports the IEEE 802.3at standard.

The TPS23754 and TPS23756 support a number of input voltage ORing options including highest voltage, external adapter preference, and PoE preference. These features allow the designer to determine which power source will carry the load under all conditions.

The PoE interface features the new extended hardware classification necessary for compatibility with high-power midspan power sourcing equipment (PSE) per IEEE 802.3at. The detection signature pin can also be used to force power from the PoE source off. Classification can be programmed to any of the defined types with a single resistor.

The DC-DC controller features two complementary gate drivers with programmable dead time. This simplifies the design of active-clamp forward converters or optimized gate drive for highly-efficient flyback topologies. The second gate driver may be disabled if desired for single MOSFET topologies. The controller also features internal soft start, bootstrap start-up source, current-mode compensation, and a 78% maximum duty cycle. A programmable and synchronizable oscillator allows design optimization for efficiency and eases use of the controller to upgrade existing power supply designs. Accurate programmable blanking, with a default period, simplifies the usual current-sense filter design trade-offs.

The TPS23754 device has a 15-V converter start-up while the TPS23756 device has a 9-V converter start-up. The TPS23754-1 replaces the PPD pin with a no-connect for increased pin spacing.

Features

  • Powers up to 30-W (Input) PDs
  • DC-DC Control Optimized for Isolated Converters
  • Supports High-Efficiency Topologies
  • Complete PoE Interface
  • Enhanced Classification per IEEE 802.3at With Status Flag
  • Adapter ORing Support
  • Programmable Frequency With Synchronization
  • Robust 100-V, 0.5-Ω Hotswap MOSFET
  • –40°C to 125°C Junction Temperature Range
  • Industry Standard PowerPAD™ HTSSOP-20

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Parametrics Compare all products in Powered Device

 
Vin (Min) (V)
Vin (Max) (V)
PoE Current Limit (Min) (mA)
PoE Inrush Limit (Typ) (mA)
rDS(on) per FET (Typ) (mOhms)
PoE Standards Supported
PD Power Level
DC/DC Control
Fault Response
Features
Package Group
Package Size: mm2:W x L (PKG)
Switching Frequency
Pin/Package
TPS23756 TPS23751 TPS23752 TPS23754 TPS23754-1
9.3     9.2     9.2     15.7     15.7    
57     57     57     57     57    
850     850     850     850     850    
140     140     140     140     140    
430     450     450     430     430    
802.3at Type 1 (802.3af)
802.3at Type 2    
802.3at Type 1 (802.3af)
802.3at Type 2    
802.3at Type 1 (802.3af)
802.3at Type 2    
802.3at Type 1 (802.3af)
802.3at Type 2    
802.3at Type 1 (802.3af)
802.3at Type 2    
13W
25W    
13W
25W    
13W
25W    
13W
25W    
13W
25W    
PD and DC/DC     PD and DC/DC     PD and DC/DC     PD and DC/DC     PD and DC/DC    
Auto Retry     Auto Retry     Auto Retry     Auto Retry     Auto Retry    
Thermal Shutdown
Second Gate Drive    
Thermal Shutdown
VFO    
Sleep Mode
Thermal Shutdown
VFO    
Thermal Shutdown
Second Gate Drive    
Thermal Shutdown
Second Gate Drive    
HTSSOP     HTSSOP     HTSSOP     HTSSOP     HTSSOP    
20HTSSOP: 42 mm2: 6.4 x 6.5(HTSSOP)     16HTSSOP: 32 mm2: 6.4 x 5(HTSSOP)     20HTSSOP: 42 mm2: 6.4 x 6.5(HTSSOP)     20HTSSOP: 42 mm2: 6.4 x 6.5(HTSSOP)     20HTSSOP: 42 mm2: 6.4 x 6.5(HTSSOP)    
Programmable
Synchronizable    
Programmable     Programmable     Programmable
Synchronizable    
Programmable
Synchronizable    
20HTSSOP     16HTSSOP     20HTSSOP     20HTSSOP     20HTSSOP