công cụ tìm kiếm bảng dữ liệu linh kiện điện tử |
|
ADM706RAN bảng dữ liệu(PDF) 10 Page - Analog Devices |
|
ADM706RAN bảng dữ liệu(HTML) 10 Page - Analog Devices |
10 / 16 page ADM706P/ADM706R/ADM706S/ADM706T, ADM708R/ADM708S/ADM708T CIRCUIT INFORMATION WATCHDOG TRANSITION DETECTOR WATCHDOG INPUT (WDI) POWER-FAIL INPUT (PFI) POWER-FAIL WATCHDOG OUTPUT (WDO) RESET, (P = RESET) Rev. C | Page 10 of 16 OUTPUT (PFO) *VOLTAGE REFERENCE = 2.63V (P/R), 2.93V (S), 3.08V (T) RESET AND WATCHDOG TIMEBASE RESET GENERATOR MR VCC 70μA VCC WATCHDOG TIMER VREF* 1.25V ADM706P/ADM706R/ ADM706S/ADM706T Figure 13. ADM706 Functional Block Diagram 1.25V POWER-FAIL INPUT (PFI) RESET * VOLTAGE REFERENCE = 2.63V (R), 2.93V (S), 3.08V (T) RESET GENERATOR MR VCC 70μA VCC RESET VREF* POWER-FAIL OUTPUT (PFO) ADM708R/ADM708S/ ADM708T Figure 14. ADM708 Functional Block Diagram POWER-FAIL RESET The reset output provides a reset (RESET or RESET) output signal to the microprocessor whenever the VCC input is below the reset threshold. The actual reset threshold voltage is dependent on whether a P, R, S, or T suffix device is used. An internal timer holds the reset output active for 200 ms after the voltage on VCC rises above the threshold. This is intended as a power-on reset signal for the microprocessor. It allows time for both the power supply and the microprocessor to stabilize after power-up. If a power supply brownout or interruption occurs, the reset line is similarly activated and remains active for 200 ms after the supply recovers. If another interruption occurs during an active reset period, the reset timeout period continues for an additional 200 ms. The reset output is guaranteed to remain valid with VCC as low as 1 V. This ensures that the microprocessor is held in a stable shutdown condition as the power supply starts up. The ADM706P provides an active high RESET signal; the ADM706R/ADM706S/ADM706T provide an active low RESET signal; and the ADM708R/ADM706S/ADM706T provide both RESET and RESET. MANUAL RESET The MR input allows other reset sources, such as a manual reset switch, to generate a processor reset. The input is effectively debounced by the timeout period (200 ms typical). The MR input is TTL-/CMOS-compatible; it can also be driven by any logic reset output. If unused, the MR input can be tied high or left floating. VRT MR EXTERNALLY DRIVEN LOW VCC RESET MR WDO VRT tRS tRS NOTES RESET = COMPLEMENT OF RESET Figure 15. RESET, MR, and WDO Timing WATCHDOG TIMER (ADM706x) The watchdog timer circuit is used to monitor the activity of the microprocessor to check that it is not stalled in an indefinite loop. An output line on the processor is used to toggle the watchdog input (WDI) line. If this line is not toggled within the timeout period (1.6 seconds), the watchdog output (WDO) is driven low. The WDO output is connected to a nonmaskable interrupt (NMI) on the processor. Therefore, if the watchdog timer times out, an interrupt is generated. The interrupt service routine is used to rectify the problem. The watchdog timer is cleared either by a high-to-low or by a low-to-high transition on WDI. Pulses as narrow as 50 ns are detected. The timer is also cleared by RESET/RESET going active. Therefore, the watchdog timeout period begins after reset goes inactive. When VCC falls below the reset threshold, WDO is forced low whether or not the watchdog timer has timed out. Normally, this generates an interrupt, but it is overridden by RESET/RESET going active. tWP WDI WDO RESET tRS RESET EXTERNALLY TRIGGERED BY MR tWD tWD tWD Figure 16. Watchdog Timing |
Số phần tương tự - ADM706RAN |
|
Mô tả tương tự - ADM706RAN |
|
|
Link URL |
Chính sách bảo mật |
ALLDATASHEET.VN |
Cho đến nay ALLDATASHEET có giúp ích cho doanh nghiệp của bạn hay không? [ DONATE ] |
Alldatasheet là | Quảng cáo | Liên lạc với chúng tôi | Chính sách bảo mật | Trao đổi link | Tìm kiếm theo nhà sản xuất 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 |