Datasheet
TPS23757
SLVS948D –JULY 2009–REVISED NOVEMBER 2013
www.ti.com
REVISION HISTORY
Changes from Revision Original (August 2009) to Revision A Page
• Changed the ESDS statement. ............................................................................................................................................. 2
Changes from Revision A (September 2009) to Revision B Page
• Changed From: IEEE 802.3at (draft) To: IEEE 802.3at throughout the data sheet ............................................................. 1
• Changed the Thermal resistance note in the DISSIPATION RATINGS table to include additional information .................. 3
• Changed Table 1 - Notes for the Class 4 row. ..................................................................................................................... 8
• Changed the section - Using DEN to disable PoE ............................................................................................................. 22
Changes from Revision B (December 2009) to Revision C Page
• Changed the application report From: SLAU303 To: SLAU535 ......................................................................................... 23
Changes from Revision C (June 2012) to Revision D Page
• Changed Table 1, Class 0 and Class 3 Max From: 12.95 To: 13; Class 4 Min From: 12.95 To: 13 ................................... 8
• Changrd Equation 5, From: – I
PPD
To: + I
PPD
........................................................................................................................ 9
• Changed Table 2, PD INPUT POWER (max) From: 12.92(13) W To 13 W; POWER ≤ 12.95 W To: ≤ 13 W, and
POWER > 12.95 W To: > 13 W .......................................................................................................................................... 16
• Changed text in the Detection section From: :( ΔV / ΔI ) between 23.75 kΩ and 26.25 kΩ at the PI." To: " ( ΔV / ΔI )
between 23.7 kΩ and 26.3 kΩ at the PI." ........................................................................................................................... 17
• Changed text in the Maintain Power Signature section From: "75 ms every 225 ms) and an ac impedance lower
than 26.25 kΩ in parallel with 0.05 μF" To: "75 ms every 325 ms) and an ac impedance lower than 26.3 kΩ in
parallel with 0.05 μF" .......................................................................................................................................................... 18
• Added text to the Startup and Converter Operation: "Additional loading applied between V
VDD
and V
RTN
during the
inrush state may prevent successful PD and subsequent converter start up." .................................................................. 18
• Changrd text in the Detection Resistor, R
DEN
From: "between 23.75 kΩ and 26.25 kΩ, or 25 kΩ ± 5%: To: ".between
23.7 kΩ and 26.3 kΩ, or 25 kΩ ± 5%" ................................................................................................................................ 24
• Changed the equation for Calculate R
PPD1
. From: –I
PPD
to: + I
PPD
, From: – 5 µA to + 5 µA, and From: = 32.26 To: =
31.64 ................................................................................................................................................................................... 25
• Changed the equation for Check PPD turn on and PPD turn off voltages (a), From: –I
PPD
to: + I
PPD
, and From: =
18.07 To: = 18.4 ................................................................................................................................................................. 25
• Changed the equation for Check PPD turn on and PPD turn off voltages (b), From: –I
PPD
to: + I
PPD
, and From: =
14.54 To: = 14.75 ............................................................................................................................................................... 25
• Added text to the end of the PPD Pin Divider Network, R
PPD1
, R
PPD2
section .................................................................... 25
32 Submit Documentation Feedback Copyright © 2009–2013, Texas Instruments Incorporated