数据搜索系统,热门电子元器件搜索 |
|
ST3917BD 数据表(PDF) 8 Page - STMicroelectronics |
|
ST3917BD 数据表(HTML) 8 Page - STMicroelectronics |
8 / 16 page DEVICE OPERATION During on-hook all keypad inputs are high imped- ance internally and it requires very low current for memory retention. At anytime,row inputs are initial- ized at logic level 1 and column inputs are initialized at logic level 0 at off-hook. The circuit verifies that a valid key has been entered by alternately scan- ning the Row and Column inputs. If the input is still valid following 32ms of debounce,the digit is stored into memory, and dialing begins after a pre-signal delay of approximately 40ms measured from the initial key closure. Output tone duration is shown in Table 1. The device allows manual dialing of an indefinite number of digits, but if more than 32 digits are dialed, LND will be inhibited. Table 4 : DTMF Output Frequencies (Hz) Key Input Std Frequency Output Frequency %in Deviation Row 1 Row 2 Row 3 Row 4 Column 1 Column 2 Column 3 697 770 852 941 1209 1336 1477 699.1 766.2 847.4 948 1215.9 1331.7 1471.9 +0.31 -0.49 -0.54 +0.74 +0.57 -0.32 -0.35 Normal Dialing D D D ... Normal dialing is straight forward, all keyboard entries will be stored in the buffer and signalled in succession. Hook Flash D Flash D ... Hook flash may be entered into the dialed sequence at any point by keying in the function key, FLASH. When a FLASH key is pressed, no further key inputs will be accepteduntil the hookflashfunctionhasbeen dialed. The key input following aFLASH will be stored as the initial digit of the new number (overwriting the numberdialed beforethe FLASH) unless it is another FLASH. FLASH key pressed immediately afterhook- switch or LND will not clear the LND buffer unless digits are entered following the FLASH key. Flash LND not cleared LND Flash LND not cleared LND Flash D1 D2 LND buffer will contain D1, D2 Last Number Dialed Off-Hook LND Last number redialing is accomplished by entering the LND key at off-hook or after the FLASH key, the subsequent LND keys pressed will be ignored. Sequence Digit Emitted OFF-HO OK, D1, D2, ON-HOOK D1, D2 OFF-HOO K, LND, LND, ON-HOOK D1, D2 OFF-HOO K, D3, D4, LND, ON-HOOK D3, D4 OFF-HO OK, LND, ON-HOOK D3, D4 Last Number Dialed Inhibition Last number redialing by LND key is inhibited if there are more than 32 digits stored. Last Number Dialed Cascading Digits dial after the LND will cascade into the LND buffer for the next redialing. In cascade operation, the keyboard is inhibited upon pressing the LND key, the LND output must be completed before acceptance of any key entry. Sequence Digit Emitted OFF-HO OK, D1, D2, ON-HOOK D1, D2 OFF-HOO K, LND, D3, D4, ON-HOOK D1, D2, D3, D4 OFF-HO OK, LND, ON-HOOK D1, D2, D3, D4 Pause Off-Hook D Pause D ... A pause may be entered into the dialed sequence at any point by keying in the special function key, PAUSE. Pause inserts a 3.1 seconds (Tone mode) or 3.4 seconds (Pulse mode) delay into the dialing sequence. The total delay, including predigit and post digit pauses as shown in Table 5. Table 5 : Special Function Delays Function First / Auto Delay (second) Pulse Tone SOFT- SWITCH First Auto 0.2 1 PAUSE First Auto 2.6 3.4 3.0 3.1 Each delay shown in Table 5 represents the time required from the time the special function key is depressed until a new digit is dialed. The time is considered ”FIRST” key if all previous inputs have been completely dialed. The time is considered ”AUTO” if in redial, or if previous digits dialing is still in progress. ST3917A - ST3917B 8/16 |
类似零件编号 - ST3917BD |
|
类似说明 - ST3917BD |
|
|
链接网址 |
隐私政策 |
ALLDATASHEETCN.COM |
ALLDATASHEET是否为您带来帮助? [ DONATE ] |
关于 Alldatasheet | 广告服务 | 联系我们 | 隐私政策 | 链接交换 | 制造商名单 All Rights Reserved©Alldatasheet.com |
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 |