Datasheet MAX912, MAX913 (Analog Devices) - 8
| Manufacturer | Analog Devices |
| Description | Single/Dual, Ultra-Fast, Low-Power, Precision TTL Comparators |
| Pages / Page | 11 / 8 — Single/Dual, Ultra-Fast, Low-Power Precision TTL Comparators. … |
| File Format / Size | PDF / 1.1 Mb |
| Document Language | English |
Single/Dual, Ultra-Fast, Low-Power Precision TTL Comparators. Applications Information. Power Supplies and Bypassing
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Single/Dual, Ultra-Fast, Low-Power Precision TTL Comparators Applications Information
1) Use a printed circuit board with an unbroken ground plane.
Power Supplies and Bypassing
2) Pay close attention to the bandwidth of bypass com- The MAX912/MAX913 are tested with ±5V power sup- ponents and keep leads short. plies that provide an input common-mode range (VCM) of 8.7V (-5.2V to +3.5V). Operation from a single +5V 3) Avoid sockets; solder the comparator and other supply provides a common-mode input range of 3.7V components directly to the board to minimize (-0.2V to +3.5). Connect V- to GND for single-supply unwanted parasitic inductance and capacitance. operation. The MAX912/MAX913 will operate from a
Input Slew Rate
minimum single-supply voltage of +4.5V. The MAX912/MAX913 design eliminates the input slew- The V+ supply provides power to both the analog input rate requirement imposed on many standard compara- stage and digital output circuits, whereas the V- supply tors. As long as LE is high after the maximum propaga- only powers the analog section. Bypass V+ and V- to tion delay and the input is greater than the ground with 0.1µF to 1.0µF ceramic capacitors in parallel comparator’s total DC error, the output will be valid with 10µF or greater tantalum capacitors. Connect the without oscillations.
MAX912/MAX913
ceramic capacitors very close to the MAX912/MAX913’s supply pins, keeping leads short to minimize lead induc-
Maximum Clock (LE) and Signal Rate
tance. For particularly noisy applications, use ferrite The maximum clock and signal rate is 70MHz, based beads on the power-supply lines. on the comparator’s rise and fall time with a 5mV over- drive at +25°C (Figure 1). With a 20mV overdrive, the
Board Layout
maximum propagation delay is 12ns and the clock sig- As with all high-speed components, careful attention to nal rate is 85MHz. layout is essential for best performance. IN+ IN- HYSTERESIS BAND* Q WITH HYSTERESIS IDEAL (WITHOUT HYSTERESIS) *WHEN HYSTERESIS IS ADDED, A COMPARATOR CANNOT RESOLVE ANY INPUT SIGNAL WITHIN THE HYSTERESIS BAND. Figure 2. Effect of Hysteresis on Input Resolution
Chip Information
MAX912 TRANSISTOR COUNT: 285 MAX913 TRANSISTOR COUNT: 154 PROCESS: Bipolar
8 _______________________________________________________________________________________
1) Use a printed circuit board with an unbroken ground plane.
Power Supplies and Bypassing
2) Pay close attention to the bandwidth of bypass com- The MAX912/MAX913 are tested with ±5V power sup- ponents and keep leads short. plies that provide an input common-mode range (VCM) of 8.7V (-5.2V to +3.5V). Operation from a single +5V 3) Avoid sockets; solder the comparator and other supply provides a common-mode input range of 3.7V components directly to the board to minimize (-0.2V to +3.5). Connect V- to GND for single-supply unwanted parasitic inductance and capacitance. operation. The MAX912/MAX913 will operate from a
Input Slew Rate
minimum single-supply voltage of +4.5V. The MAX912/MAX913 design eliminates the input slew- The V+ supply provides power to both the analog input rate requirement imposed on many standard compara- stage and digital output circuits, whereas the V- supply tors. As long as LE is high after the maximum propaga- only powers the analog section. Bypass V+ and V- to tion delay and the input is greater than the ground with 0.1µF to 1.0µF ceramic capacitors in parallel comparator’s total DC error, the output will be valid with 10µF or greater tantalum capacitors. Connect the without oscillations.
MAX912/MAX913
ceramic capacitors very close to the MAX912/MAX913’s supply pins, keeping leads short to minimize lead induc-
Maximum Clock (LE) and Signal Rate
tance. For particularly noisy applications, use ferrite The maximum clock and signal rate is 70MHz, based beads on the power-supply lines. on the comparator’s rise and fall time with a 5mV over- drive at +25°C (Figure 1). With a 20mV overdrive, the
Board Layout
maximum propagation delay is 12ns and the clock sig- As with all high-speed components, careful attention to nal rate is 85MHz. layout is essential for best performance. IN+ IN- HYSTERESIS BAND* Q WITH HYSTERESIS IDEAL (WITHOUT HYSTERESIS) *WHEN HYSTERESIS IS ADDED, A COMPARATOR CANNOT RESOLVE ANY INPUT SIGNAL WITHIN THE HYSTERESIS BAND. Figure 2. Effect of Hysteresis on Input Resolution
Chip Information
MAX912 TRANSISTOR COUNT: 285 MAX913 TRANSISTOR COUNT: 154 PROCESS: Bipolar
8 _______________________________________________________________________________________
