 |
Electronic Components Datasheet Search |
|
|
Electronic Components Datasheet Search |
|
G684 Datasheet(PDF) 6 Page - Global Mixed-mode Technology Inc |
|
|
|||||||||||||||||||||||||||||
G684 Datasheet(HTML) 6 Page - Global Mixed-mode Technology Inc |
|
|
6 / 7 page  Ver: 1.2 Jun 03, 2004 TEL: 886-3-5788833 http://www.gmt.com.tw 6 G684/G685 Global Mixed-mode Technology Inc. Interfacing to µPs with Bidirectional Reset Pins Since the RESET output on the G685L is open drain, this device interfaces easily with µPs that have bidirec- tional reset pins, such as the Motorola 68HC11. Connect- ing the µP supervisor’s RESET output directly to the microcontroller’s (µC’s) RESET pin with a single pull-up resistor allows either device to assert reset (Figure 3). Figure 3. Interfacing to µPs with Bidirectional Reset I/O G685L Open-Drain RESET Output Allows Use with Multiple Supplies Generally, the pull-up connected to the G685L will connect to the supply voltage that is being monitored at the IC’s VCC pin. However, some systems may use the open-drain output to level-shift from the monitored sup- ply to reset circuitry powered by some other supply (Figure 4). Note that as the G685L’s VCC decreases below 1V, so does the IC’s ability to sink current at RESET . Also, with any pull-up, RESET will be pulled high as VCC decays toward 0. The voltage where this occurs depends on the pull-up resistor value and the voltage to which it is connected. Figure 4. G685L Open-Drain RESET Output Allows Use with Multiple Supplies Benefits of Highly Accurate Reset Threshold Most µP supervisor ICs have reset threshold voltages between 5% and 10% below the value of nominal sup- ply voltages. This ensures a reset will not occur within 5% of the nominal supply, but will occur when the sup- ply is 10% below nominal. When using ICs rated at only the nominal supply ±5%, this leaves a zone of uncertainty where the supply is between 5% and 10% low, and where the reset may or may not be asserted. The G68_ _463/G68_ _308 use highly accurate circuitry to ensure that reset is asserted close to the 5% limit, and long before the supply has declined to 10% below nominal. RESET INPUT GND µP V CC RESET GND G685 V CC V CC MOTOROLA 68HCXX RPULL-UP RESET INPUT GND µP V CC RESET GND G685 V CC V CC MOTOROLA 68HCXX RPULL-UP RESET INPUT GND 5V SYSTEM V CC RESET GND G685 V CC RPULL-UP +3.3V +5.0 RESET INPUT GND 5V SYSTEM V CC V CC RPULL-UP +3.3V +5.0V RESET INPUT GND 5V SYSTEM V CC RESET GND G685 V CC RPULL-UP +3.3V +5.0 RESET INPUT GND 5V SYSTEM V CC V CC RPULL-UP +3.3V +5.0V |
|
|
Link URL |
| Does ALLDATASHEET help your business so far? [ DONATE ] |
About Alldatasheet | Advertisement | Contact us | Privacy Policy | Link to Datasheet | 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 |
English ▼
English
Chinese
German
Japanese
Russian
Korean
Spanish
French
Italian
Portuguese
Polish
Vietnamese
Indian
Mexican
British
New Zealand
