Electronic Components Datasheet Search |
|
MAX6724A Datasheet(PDF) 10 Page - Maxim Integrated Products |
|
MAX6724A Datasheet(HTML) 10 Page - Maxim Integrated Products |
10 / 18 page Detailed Description Supply Voltages The MAX6715A–MAX6729A/MAX6797A µP supervisory circuits maintain system integrity by alerting the µP to fault conditions. These ICs are optimized for systems that monitor two or three supply voltages. The output- reset state is guaranteed to remain valid while either VCC1 or VCC2 is above 0.8V. Threshold Levels Input-voltage threshold level combinations are indicat- ed by a two-letter code in the Reset Voltage Threshold Suffix Guide (Table 1). Contact factory for availability of other voltage threshold combinations. Reset Outputs The MAX6715A–MAX6729A/MAX6797A provide an active-low reset output (RST) and the MAX6725A/ MAX6726A also provide an active-high (RST) output. RST, RST, RST1, and RST2 are asserted when the volt- age at either VCC1 or VCC2 falls below the voltage threshold level, RSTIN drops below threshold, or MR is pulled low. Once reset is asserted, it stays low for the reset timeout period (see Table 2). If VCC1, VCC2, or RSTIN goes below the reset threshold before the reset timeout period is completed, the internal timer restarts. The MAX6715A/MAX6717A/MAX6719A/MAX6721A/ MAX6723A/MAX6725A/MAX6727A/MAX6728A contain open-drain reset outputs, while the MAX6716A/ MAX6718A/MAX6720A/MAX6722A/MAX6724A/ MAX6726A/MAX6729A/MAX6797A contain push-pull reset outputs. The MAX6727A provides two separate open-drain RST outputs driven by the same internal logic. Manual-Reset Input Many µP-based products require manual-reset capabil- ity, allowing the operator, a test technician, or external logic circuitry to initiate a reset. A logic-low on MR asserts the reset output. Reset remains asserted while MR is low for the reset timeout period (tRP) after MR returns high. This input has an internal 50k Ω pullup resistor to VCC1 and can be left unconnected if not used. MR can be driven with CMOS logic levels, or with open-drain/collector outputs. Connect a normally open momentary switch from MR to GND to create a manual- reset function; external debounce circuitry is not required. If MR is driven from long cables or if the device is used in a noisy environment, connect a 0.1µF capacitor from MR to GND to provide additional noise immunity. Adjustable Input Voltage The MAX6719A/MAX6720A and MAX6723A–MAX6727A provide an additional input to monitor a third system volt- age. The threshold voltage at RSTIN is typically 626mV. Connect a resistor-divider network to the circuit as shown in Figure 1 to establish an externally controlled threshold voltage, VEXT_TH. VEXT_TH = 626mV((R1 + R2)/R2) Low-leakage current at RSTIN allows the use of large- valued resistors resulting in reduced power consump- tion of the system. Watchdog Input The watchdog monitors µP activity through the watch- dog input (WDI). To use the watchdog function, con- nect WDI to a bus line or µP I/O line. When WDI remains high or low for longer than the watchdog time- out period, the reset output asserts. The MAX6721A–MAX6729A/MAX6797A include a dual- mode watchdog timer to monitor µP activity. The flexi- ble timeout architecture provides a long period initial watchdog mode, allowing complicated systems to complete lengthy boots, and a short period normal watchdog mode, allowing the supervisor to provide quick alerts when processor activity fails. After each reset event (VCC power-up/brownout, manual reset, or watchdog reset), there is a long initial watchdog period of 35s minimum. The long watchdog period mode pro- vides an extended time for the system to power-up and fully initialize all µP and system components before assuming responsibility for routine watchdog updates. Dual/Triple, Ultra-Low-Voltage, SOT23 µP Supervisory Circuits 10 ______________________________________________________________________________________ MAX6719A/ MAX6720A/ MAX6723A– MAX6727A VEXT_TH R1 R2 RSTIN GND Figure 1. Monitoring a Third Voltage |
Similar Part No. - MAX6724A |
|
Similar Description - MAX6724A |
|
|
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 |
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 |