TPS2373 Datasheet, PDF (1/42 Pages) Texas Instruments – High-Power PoE PD Interface with Advanced Startup

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TPS2373
SLUSCD1 – APRIL 2017
TPS2373 High-Power PoE PD Interface with Advanced Startup
1 Features
•1 IEEE 802.3bt (Draft) PD Solution for Type 3 or
Type 4 PoE
• Supports Power Levels for Type-4 ( TPS2373-4)
90-W and Type-3 ( TPS2373-3) 60-W Operation
• Robust 100 V Hotswap MOSFET
– TPS2373-4 (typ.): 0.1-Ω, 2.2-A Current Limit
– TPS2373-3 (typ.): 0.3-Ω, 1.8-A Current Limit
• Allocated Power Indicator Outputs
• Advanced Startup for DC-DC
– Simplifies Downstream DC-DC Design
– Compliant to PSE Inrush
• Automatic Maintain Power Signature (MPS)
– Auto-adjust MPS for Type 1-2 or 3-4 PSE
– Supports Ultra-Low Power Standby Modes
• Primary Adapter Priority Input
• Supports PoE++ PSE
• -40°C to 125°C Junction Temperature Range
• 20-lead VQFN Package
2 Applications
• IEEE 802.3bt (Draft) Compliant Devices
• 4PPOE
• Pass-through System
• Security Cameras
• Multiband access points
• Pico-base Stations
• Video and VoIP Telephones
• Systems using Redundant Power Feeds
3 Description
The TPS2373 contains all of the features needed to
implement an IEEE802.3at or IEEE802.3bt (draft)
(Type 1-4) powered device (PD). The low internal
switch resistance allows the TPS2373-4 and
TPS2373-3 to support high power applications up to
90 W and 60 W respectively. Assuming 100-meter
CAT5 cable, this translates into 71.3 W and 51 W at
PD input.
The TPS2373 operates with enhanced features.
The Advanced Startup function for DC-DC results in a
simple, flexible, and minimal system cost solution,
while ensuring that IEEE802.3bt (draft) startup
requirements are met. It helps to reduce the size of
the low voltage bias capacitor considerably. It also
allows long DC-DC converter soft-start period and
enables the use of a low-voltage PWM controller.
The Automatic MPS function enables applications
requiring very low power standby modes. The
TPS2373 automatically generates the necessary
pulsed current to maintain the PSE power. An
external resistor is used to enable this functionality
and to program the MPS pulsed current amplitude.
Device Information⁽¹⁾
PART NUMBER
PACKAGE
BODY SIZE (NOM)
TPS2373
VQFN (20)
5.00 mm × 5.00 mm
(1) For all available packages, see the orderable addendum at
the end of the data sheet.
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Simplified Schematic
VC
TPS2373
V_in
RDET
58V
I_in
MPS
Control
RMPS
RREF
RMPS_DUTY
VDD
DEN
TPH
TPL
CLSA
CLSB
BT
VC_IN
VC_OUT
VSS
AMPS_CTL
PG
APD
REF
RTN
MPS_DUTY
Xfrmer Aux
Bias Supply
+
CBULK
Vc
SS
Low Voltage
DCDC
Controller
GAT2
Small
Vc Cap
CVC_OUT
MPS pulses
I_in
GATE
MPS pulses automatically generated if I_in is too low
1
DC/DC Converter
T1
CVC_IN
DVC
DVC2
V_in
(50 V/div)
Inrush Wait
time
I_in
(1 A/div)
VC_OUT
(5 V/div)
VC_IN
(5 V/div)
20 ms/div
Copyright © 2017, Texas Instruments Incorporated
An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications,
intellectual property matters and other important disclaimers. ADVANCE INFORMATION for pre-production products; subject to
change without notice.