Electronic Components Datasheet Search
  English  ▼
ALLDATASHEET.NET

X  

AN3275 Datasheet(PDF) 11 Page - STMicroelectronics

Part # AN3275
Description  Improving the performance of smartcard interfaces
Download  32 Pages
Scroll/Zoom Zoom In 100%  Zoom Out
Manufacturer  STMICROELECTRONICS [STMicroelectronics]
Direct Link  http://www.st.com
Logo STMICROELECTRONICS - STMicroelectronics

AN3275 Datasheet(HTML) 11 Page - STMicroelectronics

Back Button AN3275 Datasheet HTML 7Page - STMicroelectronics AN3275 Datasheet HTML 8Page - STMicroelectronics AN3275 Datasheet HTML 9Page - STMicroelectronics AN3275 Datasheet HTML 10Page - STMicroelectronics AN3275 Datasheet HTML 11Page - STMicroelectronics AN3275 Datasheet HTML 12Page - STMicroelectronics AN3275 Datasheet HTML 13Page - STMicroelectronics AN3275 Datasheet HTML 14Page - STMicroelectronics AN3275 Datasheet HTML 15Page - STMicroelectronics Next Button
Zoom Inzoom in Zoom Outzoom out
 11 / 32 page
background image
AN3275
Emergency deactivation/fault detection
Doc ID 17962 Rev 1
11/32
3.2
PORADJ VDD undervoltage with external divider
In this case, a resistor bridge is applied to the PORADJ pin (see Figure 7). VTH(ext) rise and
VTH(ext) fall are the external rising threshold voltage and the external falling threshold voltage
on VDD, respectively. They are the voltages on pin PORADJ that switch the device on and
off. By knowing these values and using the formula:
VPORADJ =(R2/R1 + R2) x VDD
it is possible to set R1 and R2 such that the device powers on and off at the values of VDD
desired by the user (R1 + R2 = 100 kΩ typ).
In particular, R1 and R2 have to be set so that, when VDD is getting low, before turning the
microcontroller off, the smartcard has to be switched off properly as well. The same is true
for the microcontroller startup in that the smartcard has to be turned on after the
microcontroller. Figure 8 and Figure 9 on page 13 show the VTH(ext) rise and VTH(ext) fall on
the PORADJ pin (1.196 V and 1.155 V, respectively).
The VTH(ext)fall threshold of the ST8024L is slightly lower (80 mV typ.) than the ST8024
device. If for example, the microcontroller is shut down at 2.5 V, appropriate resistor values
must be chosen to ensure proper deactivation of the ST8024L device.
Table 2 shows an example of the resistor values between the ST8024 and ST8024L devices
if the microcontroller is shut down at 2.5 V.
Table 2.
Resistor values for VTH(ext)fall trip point
ST8024
ST8024L
R1
50 k
Ω
55.5 k
Ω
R2
50 k
Ω
44.5 k
Ω
VTH(ext)fall
1.25 V
1.14 V
Table 3.
VPORADJ trip point
VDD
VPORADJ
ST8024
ST8024L
5.0
2.500
2.275
4.5
2.250
2.048
4.0
2.000
1.820
3.5
1.750
1.593
3.0
1.500
1.365
2.5
1.250
1.138
2.0
1.000
0.910


Similar Part No. - AN3275

ManufacturerPart #DatasheetDescription
logo
Panasonic Semiconductor
AN3275SB PANASONIC-AN3275SB Datasheet
124Kb / 15P
   CM detection IC for VCRs in the North American market
More results

Similar Description - AN3275

ManufacturerPart #DatasheetDescription
logo
Maxim Integrated Produc...
AN1943 MAXIM-AN1943 Datasheet
211Kb / 4P
   Improving the Performance of the MAX4455 by Reducing On-Screen Display Artifacts
Mar 21, 2003
logo
STMicroelectronics
ST8034HN STMICROELECTRONICS-ST8034HN Datasheet
967Kb / 31P
   24-pin smartcard interfaces
ST8034T STMICROELECTRONICS-ST8034T Datasheet
1Mb / 39P
   16-pin smartcard interfaces
AN1015 STMICROELECTRONICS-AN1015 Datasheet
347Kb / 19P
   Software techniques for improving microcontrollers EMC performance
logo
National Semiconductor ...
DS92LV3241 NSC-DS92LV3241_10 Datasheet
171Kb / 6P
   Improving the Robustness of Channel Link Designs with Channel Link II Ser/Des
logo
STMicroelectronics
AN2269 STMICROELECTRONICS-AN2269 Datasheet
818Kb / 25P
   Using the ST8024 Smartcard Interface
AN2646 STMICROELECTRONICS-AN2646 Datasheet
446Kb / 43P
   Smartcard interface with the STM8S microcontroller
logo
Linear Dimensions Semic...
DC2399 LINEAR_DIMENSIONS-DC2399 Datasheet
3Mb / 22P
   the starter kit for demonstrating the performance and ease of use of the LTC짰2984
logo
National Semiconductor ...
AN-2026 NSC-AN-2026 Datasheet
450Kb / 8P
   The Effect of PCB Design on the Thermal Performance of SIMPLE SWITCHER
logo
STMicroelectronics
AN4566 STMICROELECTRONICS-AN4566 Datasheet
369Kb / 19P
   Extending the DAC performance of STM32 microcontrollers
More results


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


Datasheet Download

Go To PDF Page


Link URL




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

About Alldatasheet   |   Advertisement   |   Contact us   |   Privacy Policy   |   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
Indian : Alldatasheet.in  |   Mexican : Alldatasheet.com.mx  |   British : Alldatasheet.co.uk  |   New Zealand : Alldatasheet.co.nz
Family Site : ic2ic.com  |   icmetro.com