Electronic Components Datasheet Search |
|
PT7M6834FD0TA3E Datasheet(PDF) 7 Page - Pericom Semiconductor Corporation |
|
PT7M6834FD0TA3E Datasheet(HTML) 7 Page - Pericom Semiconductor Corporation |
7 / 12 page ||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||| 2013-11-0003 PT0236-6 11/18/13 7 PT7M6832-6840 Ultra Low Voltage Detectors Application Information Negative-Going VCC Transients In addition to issuing a reset to the µP during power-up, power-down, and brownout conditions, the PT7M6832– PT7M6840 are relatively immune to short-duration negative- going Vcc transients. A 0.1µF bypass capacitor mounted as close as possible to the Vcc pin provides additional transient immunity. Valid Reset Output Down to Vcc = 0 When Vcc falls below 0.9V, the PT7M6832/6835/6838 push- pull RESET output no longer sinks current for it becomes an open circuit. Therefore, high-impedance CMOS logic inputs connected to RESET can drift to undetermined voltages. This presents no problem in most applications since most µP and other circuitry are inoperative with Vcc lower than 0.9V. However, in applications where RESET must be valid down to 0, adding a pull-down resistor to RESET causes any stray leakage currents to flow to ground, holding RESET low(Fig.4). R3’s value is not critical; 100kΩ is large enough not to load RESET and small enough to pull RESET to ground. A 100kΩ pull-up resistor to Vcc is also recommended for the PT7M6833/PT7M6836/PT7M6839 if RESET is required to remain valid for Vcc < 0.85V. Interfacing to µPs with Bidirectional Reset Pins Since the RESET output on the PT7M6834/6837/6840 is open-drain, these devices interface easily with µPs that have bidirectional reset pins. Connecting the µP supervisor’s RESET output directly to the µP’s RESET pin with a single pull-up resistor allows either device to assert a reset (Fig.5). Open-Drain RESET Output with Multiple Supplies In some systems the open-drain output is used to level-shift from the monitored supply to reset circuitry powered by some other supply (Fig.6). Note: As the PT7M6834/6837/6840’s Vcc decreases, so does the IC’s ability to sink current at RESET. Also, with any pull- up, RESET will be pulled high as Vcc declines toward 0. The voltage where this occurs depends on the pull-up resistor value and the voltage to which it is connected. RESET VCC PT7M6832 /6835 /6838 R3 100k Ω RESET VCC PT7M6834 /6837 /6840 VCC RESET INPUT Bidirectional µP VCC Fig.4 Reset output valid to VCC=0 circuit Fig.5 Interfacing to µPs with Bidirectional Reset I/O RESET VCC PT7M6834 /6837 /6840 VCC RESET INPUT 5V System +1.2V +5.0V Fig.6 Open-drain Reset output with multiple supplies |
Similar Part No. - PT7M6834FD0TA3E |
|
Similar Description - PT7M6834FD0TA3E |
|
|
Link URL |
Privacy Policy |
ALLDATASHEET.COM |
Does ALLDATASHEET help your business so far? [ DONATE ] |
About Alldatasheet | Advertisement | Datasheet Upload | 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 |