Electronic Components Datasheet Search
  English  ▼

Delete All
ON OFF
ALLDATASHEET.COM

X  

Preview PDF Download HTML

TPS254900A-Q1 Datasheet(PDF) 28 Page - Texas Instruments

Click here to check the latest version.
Part No. TPS254900A-Q1
Description  Automotive USB Host Charger With Short-to-VBATT Protection
Download  39 Pages
Scroll/Zoom Zoom In 100% Zoom Out
Maker  TI1 [Texas Instruments]
Homepage  http://www.ti.com
Logo 

TPS254900A-Q1 Datasheet(HTML) 28 Page - Texas Instruments

Zoom Inzoom in Zoom Outzoom out
 28 / 39 page
background image
28
TPS254900A-Q1
SLUSCU5A – NOVEMBER 2017 – REVISED JANUARY 2018
www.ti.com
Product Folder Links: TPS254900A-Q1
Submit Documentation Feedback
Copyright © 2017–2018, Texas Instruments Incorporated
For USB port applications, because the VBUS pin is exposed to IEC61000-4-2 level-4 ESD, use a low-ESR
capacitance to protect OUT.
The TPS254900A-Q1 device is capable of handling up to 18-V battery voltage. When VBUS is shorted to the
battery, the LCR tank circuit formed can induce ringing. The peak voltage seen on the OUT pin depends on the
short-circuit cable length. The parasitic inductance and resistance varies with length, causing the damping factor
and peak voltage to differ. Longer cables with larger resistance reduce the peak current and peak voltage.
Consider high-voltage derating for the ceramic capacitor, because the peak voltage can be higher than twice the
battery voltage.
Based on the three situations described, a 10-µF, 35-V, X7R, 1210 low-ESR ceramic capacitor placed close to
OUT is recommended. If the battery voltage is 16 V and a 16-V transient voltage suppressor (TVS) is used, then
the capacitor voltage can be reduced to 25 V. Considering temperature variation, placing an additional 35-V
aluminum electrolytic capacitor can lower the peak voltage and make the system more robust.
9.2.2.3 BIAS Capacitance
The capacitance on the BIAS pin helps the IEC ESD performance on the DM_IN and DP_IN pins.
When a short to battery on DP_IN, DM_IN and/or OUT occurs, high voltage can be seen on the BIAS pin. Place
a 2.2-µF, 50-V, X7R, 0805, low-ESR ceramic capacitor close to the BIAS pin. The whole current path from BIAS
to GND should be as short as possible. Additionally, use a 5.1-k
Ω discharge resistor from BIAS to OUT.
9.2.2.4 Output and BIAS TVS
The TPS254900A-Q1 device can withstand high transient voltages due to LCR tank ringing, but in order to make
OUT, DP_IN, and DM_IN robust, place one TVS close to the OUT pin, and another TVS close to the BIAS pin.
When choosing the TVS, the reverse standoff voltage VR depends on the battery voltage (16 V or 18 V).
Considering the peak pulse power capability, a 400-W device is recommended such as an SMAJ16 for a 16-V
battery or an SMAJ18 for an 18-V battery.
9.2.3 Application Curves
VBAT = 14 V
t = 10 µs/div
Figure 44. Disabled, 25-V, 1206, X7R COUT Capacitor
Without SMAJ18
VBAT = 18 V
t = 10 µs/div
Figure 45. Disabled, 35-V, 1210, X7R COUT Capacitor
Without SMAJ18


Html Pages

1  2  3  4  5  6  7  8  9  10  11  12  13  14  15  16  17  18  19  20  21  22  23  24  25  26  27  28  29  30  31  32  33  34  35  36  37  38  39 


Datasheet Download




Link URL




Privacy Policy
ALLDATASHEET.COM
Does ALLDATASHEET help your business so far?  [ DONATE ]  

About Alldatasheet   |   Advertisement   |   Datasheet Upload   |   Contact us   |   Privacy Policy   |   Alldatasheet API   |   Link Exchange   |   Manufacturer List
All Rights Reserved© Alldatasheet.com


Mirror Sites
English : Alldatasheet.com  |   English : Alldatasheet.net  |   Chinese : Alldatasheetcn.com  |   German : Alldatasheetde.com  |   Japanese : Alldatasheet.jp
Russian : Alldatasheetru.com  |   Korean : Alldatasheet.co.kr  |   Spanish : Alldatasheet.es  |   French : Alldatasheet.fr  |   Italian : Alldatasheetit.com
Portuguese : Alldatasheetpt.com  |   Polish : Alldatasheet.pl  |   Vietnamese : Alldatasheet.vn