Electronic Components Datasheet Search |
|
SPT9691SCN Datasheet(PDF) 7 Page - Cadeka Microcircuits LLC. |
|
SPT9691SCN Datasheet(HTML) 7 Page - Cadeka Microcircuits LLC. |
7 / 10 page SPT9691 TYPICAL INTERFACE CIRCUIT The typical interface circuit using the comparator is shown in figure 3. Although it needs few external components and is easy to apply, there are several conditions that should be noted to achieve optimal performance. The very high operat- ing speeds of the comparator require careful layout, decou- pling of supplies, and proper design of transmission lines. Since the SPT9691 comparator is a very high frequency and high gain device, certain layout rules must be followed to avoid oscillations. The comparator should be soldered to the board with component lead lengths kept as short as possible. A ground plane should be used, while the input impedance to the part is kept as low as possible, to decrease parasitic feedback. If the output board traces are longer than approxi- mately half an inch, microstripline techniques must be em- ployed to prevent ringing on the output waveform. Also, the microstriplines must be terminated at the far end with the characteristic impedance of the line to prevent reflections. All supply voltage pins should be decoupled with high frequency capacitors as close to the device as possible. All ground pins should be connected to the same ground plane to further improve noise immunity and shielding. If using the SPT9691 as a single comparator, the outputs of the inactive compara- tor can be grounded, left open or terminated with 50 Ohms to -2 V. All outputs on the active comparator, whether used or unused, should have identical terminations to minimize ground current switching transients. Diode D1 connected between AVCC and GND is recom- mended to prevent possible damage to the device in case the AVCC supply is disconnected. The diode should be a 1N914 or equivalent. If AVCC is disconnected with this diode in place, there will be approximately a 6 mA current draw from both AVEE and DVEE. Diode D2 connected between AVEE and DVEE is necessary to avoid power supply se- quence latch-up. This diode keeps AVEE (also the substrate) less than a silicon diode drop away from the most negative circuit potential if DVEE is powered up first. This diode should be a 1N5817 (Schottky) or equivalent. Note: At no time should both inputs be allowed to float with power applied to the device. At least one of the inputs should be tied to a voltage within the common mode range (-4.0 to +8.0 V) to prevent possible damage to the device. To prevent possible latch-up during initial power up, the input voltages should not exceed ±1 V. Additional protection diodes D3-D6 should be used on the inputs if there is the possibility of exceeding the absolute maximum ratings of the inputs with respect to AVCC and DVEE (1N914 or equivalent). NOTE: For ease of implementation, all diodes (D1 - D6) can be 1N5817 (Schottky) or equivalent. Figure 3 - SPT9691 Typical Interface Circuit Figure 4 - SPT9691 Typical Interface Circuit With Hysteresis RL 50 Ω -2 V .1 µF Q Output Q Output AVEE DVEE AVCC GND VREF VIN .1 µF .1 µF .1 µF D1 D2 Inverting Input D3 D4 D5 D6 + - Noninverting Input LE LE = Represents line termination. ECL RL 50 Ω RL 50 Ω -2 V .1 µF Q Output Q Output AVEE DVEE AVCC GND VREF VIN .1 µF .1 µF .1 µF D1 D2 Inverting Input D3 D5 D6 D4 + - Noninverting Input LE LE -1.3 V -2 V 100 Ω = Represents line termination. RL 50 Ω .1 µF 7 10/6/97 |
Similar Part No. - SPT9691SCN |
|
Similar Description - SPT9691SCN |
|
|
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 |