Motore di ricerca datesheet componenti elettronici
  Italian  ▼
ALLDATASHEETIT.COM

X  

SA2531 Scheda tecnica(PDF) 2 Page - Sames

Il numero della parte SA2531
Spiegazioni elettronici  SINGLE CHIP TELEPHONE POWER EXTRACTION FOR EXTERNAL LOADS
Download  4 Pages
Scroll/Zoom Zoom In 100%  Zoom Out
Produttore elettronici  SAMES [Sames]
Homepage  http://www.sames.co.za
Logo SAMES - Sames

SA2531 Scheda tecnica(HTML) 2 Page - Sames

  SA2531 Datasheet HTML 1Page - Sames SA2531 Datasheet HTML 2Page - Sames SA2531 Datasheet HTML 3Page - Sames SA2531 Datasheet HTML 4Page - Sames  
Zoom Inzoom in Zoom Outzoom out
 2 / 4 page
background image
SAN3020
sames
sames
sames
sames
2/4
When driving external loads by extracting power from the available line current, care must be taken not to affect
both DC and AC impedance. The extracted voltage should be independent from line current (assuming a line
current >20mA).
The application shown will shut off the external load when going on-hook and power-up the load when going off-
hook.
The current driving capability depends on the available line current, higher line currents allow higher driving
currents. At minimum line current (20mA), the maximum load current is
≈15mA (see pt.6 for further details).
Only 4 external components , shown in the dotted area (1 general purpose PNP transistor:Bmin=250, 1 general
purpose diode , 1 resistor and 1 pol. capacitor) must be added to the standard SA253x application to get a high
efficiency power extraction for external loads with the features described in pt.5 above.
When updating an existing circuit, the connection from pin #25 (= CS, SA253x) to the shunt transistor’s base (in
most applications = Q3) must be opened and a diode (D5) installed. All further components are simply added to the
circuit.
The shunt transistor (Q3) is regulating the voltage at LI ( #27) to
≈ 4.5V. Consequently, the voltage at CS ( #25) is
VLI - VBE. When adding D5, the voltage drop between LI and CS is Vconst = 2x VBE. This constant voltage provides
the base current of the power extraction transistor Q5 via R22.
The maximum load current also depends on the gain (B= IC / IB) of the transistor used. The transistor used should
have a B of
≥250 . Transistors with lower gain may also be used, but the maximum load current may be lower.
7.1 Minimum output voltage with high signals on line:
As shown in the diagram (pt. 9), the output voltage at high load currents will drop with high transmit or receive
signals on line, since the load is not supplied during the negative half-wave of the line signal. The diagram shows
the Vout/ILoad curves with no AC signal at line and with a constant AC line signal of 1Vpeak.
In practical use, an AC signal of 2Vpp is not present continuously, so the effective output voltage will be higher. It is
also possible to buffer the voltage drop during line signal bursts by increasing the value of capacitor C19.
However, the voltage decrease with high signal bursts on line should be taken into consideration when the load
voltage must not drop below a certain value.
Small loads can also be connected at VDD directly, as long as the following rules are observed:
1. When on-hook, the load must only draw <1µA , because it is connected in parallel to the VDD -cap, which
maintains memory data retention in on-hook state, charged by a 5M
Ω resistor . A higher load current would
discharge this capacitor and erase the memory contents.
2. The load will also be supplied in ringing mode.
3. When off-hook, the load current can be <5mA, provided it does not exceed this current at any time.
6 Hardware configuration
7 Circuit description
8 Connecting loads at VDD


Codice articolo simile - SA2531

Produttore elettroniciIl numero della parteScheda tecnicaSpiegazioni elettronici
logo
Sames
SA2531 SAMES-SA2531 Datasheet
392Kb / 24P
   VERSATILE SINGLE CHIP TELEPHONE WITH 14 NUMBER REPERTORY DIALLER
SA2531 SAMES-SA2531 Datasheet
71Kb / 13P
   SINGLE CHIP TELEPHONE INTERFACE FOR KEYBOARD ENTRY VIA uC
SA2531A SAMES-SA2531A Datasheet
392Kb / 24P
   VERSATILE SINGLE CHIP TELEPHONE WITH 14 NUMBER REPERTORY DIALLER
SA2531B SAMES-SA2531B Datasheet
392Kb / 24P
   VERSATILE SINGLE CHIP TELEPHONE WITH 14 NUMBER REPERTORY DIALLER
SA2531C SAMES-SA2531C Datasheet
392Kb / 24P
   VERSATILE SINGLE CHIP TELEPHONE WITH 14 NUMBER REPERTORY DIALLER
More results

Descrizione simile - SA2531

Produttore elettroniciIl numero della parteScheda tecnicaSpiegazioni elettronici
logo
Sames
SA2532KA SAMES-SA2532KA Datasheet
187Kb / 21P
   SINGLE CHIP TELEPHONE FOR INDIA
SA2532 SAMES-SA2532 Datasheet
583Kb / 22P
   VERSATILE SINGLE CHIP TELEPHONE
logo
ATMEL Corporation
U3600BM ATMEL-U3600BM Datasheet
709Kb / 43P
   SINGLE CHIP CORDLESS TELEPHONE IC
logo
ams AG
AS2540 AMSCO-AS2540_04 Datasheet
934Kb / 19P
   Remote Controlled Single-Chip-Telephone
logo
ATMEL Corporation
U3600BM ATMEL-U3600BM_05 Datasheet
738Kb / 44P
   Single-chip Cordless Telephone IC
logo
IC MICROSYSTEMS
ICM9102M ICMIC-ICM9102M Datasheet
339Kb / 3P
   SINGLE CHIP TELEPHONE BOARD MODULE
logo
ams AG
AS2540 AMSCO-AS2540 Datasheet
248Kb / 18P
   Remote Controlled Single-Chip-Telephone
logo
Sames
SA2532P SAMES-SA2532P Datasheet
149Kb / 21P
   ONE MEMORY SINGLE CHIP TELEPHONE
AN1500A SAMES-AN1500A Datasheet
623Kb / 27P
   SINGLE CHIP TELEPHONE DEMO BOARD
logo
OKI electronic componet...
MSM7557 OKI-MSM7557 Datasheet
153Kb / 25P
   Single Chip MSK Modem with Compandor for Cordless Telephone
More results


Html Pages

1 2 3 4


Scheda tecnica Scarica

Go To PDF Page


Link URL




Privacy Policy
ALLDATASHEETIT.COM
Lei ha avuto il aiuto da alldatasheet?  [ DONATE ] 

Di alldatasheet   |   Richest di pubblicita   |   contatti   |   Privacy Policy   |   scambio Link   |   Ricerca produttore
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