for additional information regarding custom microelectronic products and services, please contact micro networks at: models md3802/3805/3810 are high- performance, precision 2/5/10mhz full- scale voltage-to-frequency converters, intended for those applications that require maximum performance at the most economical cost. these converters feature >126/134/142-db dynamic range, 0.01/0.02/0.05% linearity, and 5% overrange capability. all models accept a -100 m v to -10v full- scale analog input signal that is converted to an output signal whose frequency is proportional to the full-scale frequency within 0.01/0.02/0.05% linearity, using the long-proven charge-balance tech- nique. the devices offer buffered compli- mentary ttl-compatible frequency outputs that will drive capacitive loads as high as 50 pf. models md3802/3805/3810, in addition to functioning as v/f converters, can also be used as f/v converters. in this configu- ration, the converters will accept frequen- cies from dc to 2/5/10mhz and will produce proportional single-ended output voltages from 0v to -10v. in applications where overall system throughput must be maintained at a specific rate, or where fixed offset or different scale voltages would be more convenient, custom frequencies and/or custom trimming can be easily accommo- dated. by increasing the full-scale output frequency by 10 to 20%, for example, additional time would be available for the system microprocessor to access the results of each conversion. please contact the factory to discuss your specific timing requirements. all models are packaged in a 1.31" x 0.80" x 0.15" 24-pin ceramic dil package. power dissipation is lower than 0.75/0.85/1.0 watts, and operation to specified accuracy is guaranteed over the 0 c to +70 c temperature range. n guaranteed minimum/ maximum specifications n wide dynamic range >2,000,000/5,000,000/ 10,000,000:1 >126/134/142 db n excellent linearity 0.01/0.02/0.05% fsr 0.01/0.02/0.05% of input n excellent stability 10 m v/ c offset 75 ppm/ c gain n voltage or current inputs n offset and gain error trimmable to zero n complementary frequency outputs-ttl/cmos compatible n small 24-pin dip n low power <0.75/0.85/1.0w features: 324 clark st., worcester, ma 01606 tel. (508) 852-5400 ? fax (508) 853-8296 e-mail C sales@mnc.com web site C http://www.mnc.com n precision integration n digital data transmission n frequency synthesis n analytical instrumentation n medical instrumentation n telemetry n data recording n weighing systems n tachometers n accelerometers n flow meters n robotics applications: md3802/3805/3810 2/5/10mhz v/f, f/v converters
md3802/3805/3810 2/5/10mhz v/f, f/v converters absolute maximum ratings operating temperature range 0 c to +70 c storage temperature range -65 c to +150 c +15v supply (pin 1) +15.45 volts -15v supply (pin 5) -15.45 volts +5v supply (pin 20) +5.25 volts analog input (pin 11) -15 volts to +15 volts specifications @ t a = +25 c, supplies = 15v and +5v, unless otherwise indicated specifications 324 clark st., worcester, ma 01606 tel. (508) 852-5400 ? fax (508) 853-8296 e-mail C sales@mnc.com web site C http://www.mnc.com ordering information part number md3802 MD3805 md3810 2mhz full-scale 5mhz full-scale 10mhz full-scale 15 10 5 7 analog inputs input voltage range nonsaturating overrange configuration input impedance md3802 MD3805 md3810 offset voltage (trimmable to zero) transfer characteristics full-scale output md3802 MD3805 md3810 transfer function md3802 MD3805 md3810 gain error (trimmable to zero) nonlinearity (max.) md3802 (not specified under MD3805 overrange conditions) md3810 full-scale step response md3802 (maximum; to 0.01%) MD3805 md3810 overload recovery md3802 MD3805 md3810 stability gain temperature coefficient md3802 MD3805, md3810 offset temperature coefficient power supply rejection gain offset warm-up time (to specified accuracy) output pulse width md3802 MD3805 md3810 logic levels: logic 1 logic 0 (3 ma sink) power supply requirements 15v supplies +5v supply +15v current drain md3802 MD3805 md3810 -15v current drain +5v current drain md3802 MD3805 md3810 power dissipation md3802 MD3805 md3810 min. typ. max. units 5 2 5 10 200 80 40 +3.5 14.55 +4.75 volts % k w k w k w mv mhz mhz mhz % ppm of fsr/ c ppm of fsr/ c ppm of fsr/ c ppm of fsr/%vs m v/%vs minutes nsec nsec nsec volts volts volts volts ma ma ma ma ma ma ma mw mw mw specifications subject to change without notification as micro networks reserves the right to make improvements and changes in its products. 50 75 10 250 100 50 +4.0 0.01%fs 0.01%v in 0.02%fs 0.02%v in 0.05%fs 0.05%v in 2 cycles of new f out + 20 m sec 2 cycles of new f out + 10 m sec 2 cycles of new f out + 5 m sec 8 cycles of new f out 10 cycles of new f out 12 cycles of new f out 0 to -10 2mhz?(v in / 10v) 5mhz?(v in / 10v) 10mhz?(v in / 10v) single-ended 10 1 75 100 30 200 10 2 300 120 60 +4.5 0.4 15.45 5.25 20 25 35 10 45 50 60 750 850 1000
324 clark st., worcester, ma 01606 tel. (508) 852-5400 ? fax (508) 853-8296 e-mail C sales@mnc.com web site C http://www.mnc.com using the md38xx general considerations C a typical circuit configuration for the md38xx models used as v/f converters is depicted in figure 2. the layout should be clean, with output pulses routed as far away from the input analog signals as possible. to obtain maximum performance, bypass capacitors, as shown in both figures, should be mounted right at the appropriate pins of the converters. figure 2. v/f converter configuration. offset adjust i in v in integrator (8) (10) (11) (1) +15v (2,3,4) agnd (5) -15v (20) +5v (22) dgnd (9) (19) f out (18) f in (23,24) output (21) output schmidt trigger charge pump output output 24 23 21 19 18 2, 3, 4 5 20 22 1 11 10 8 200 10-turn 100ppm 20k 10-turn gain adjust offset adjust v in i in +15v -15v +15v agnd -15v +5v dgnd 6.8 f 6.8 f 6.8 f block diagram md3802/3805/3810 2/5/10mhz v/f, f/v converters
md3802/3805/3810 2/5/10mhz v/f, f/v converters 324 clark st., worcester, ma 01606 tel. (508) 852-5400 ? fax (508) 853-8296 e-mail C sales@mnc.com web site C http://www.mnc.com offset and gain trimming C the offset adjustment potentiometer should be a 20 k w , 10-turn unit. with this pot in the circuit, initial offsets of up to 10mv may be trimmed to zero. the gain adjustment potentiometer should be a 200 w , 10-turn unit. to ensure that the temperature coefficient of the potentiometer does not become significant relative to the overall gain tempco specification, a 100 ppm or better potentiometer is recommended. with this pot in the circuit, initial gain errors of up to 2% may be trimmed to zero. grounding C the analog and digital grounds are internally separated in the md38xx models. the use of ground plane is not necessary for proper operation of the md38xx. however, a ground plane is recommended with any analog signal condi- tioning circuitry that may be used in a v/f application, especially if this circuitry involves high gains. any amplifiers used ahead of the md38xx should have decoupling capacitors on their power supply pins to help eliminate potential problems with the high-frequency output of the v/f. offset and gain calibra tion offset calibration C offset calibra- tion should be performed prior to gain calibration. with a -1mv analog input signal at pin 11 of the md38xx, adjust the offset potentiometer until a frequency of 200/500/ 1000hz is observed on output pins 21, 23 or 24. gain calibration C with a full scale analog input voltage of -10.00v on pin 11 (md38xx), adjust the gain potentiometer until a full scale frequency of 2.000/5.000/ 10.000mhz is observed on output pin 21, 23 or 24. n/c pins C pins marked as n/c (no connect) have no electric connection to the internal circuitry of the md38xx. output pins C pins 23 and 24 are tied together internally. either or both may be used as the source of the frequency output of the md38xx, as long as the load specifications are not exceeded. pin 21 provides a complementary signal relative to pins 23 and 24 with similar loading limits. v/f mode analog inputs C single-ended analog inputs from 0 to -10v are applied to pin 11 of the v/f converter through the gain adjustment potentiometer. f/v mode figure 3 depicts the typical circuit configuration for the md38xx used in the f/v mode. in this mode, the md38xx will accept a 0 to 2/5/ 10mhz input pulse train, with negative-going pulses, (250 50) (100 20) (50 10)nsec in width, and will produce a voltage output propor- tional to the input frequency. riding on the output voltage will be a ripple voltage. addi-
324 clark st., worcester, ma 01606 tel. (508) 852-5400 ? fax (508) 853-8296 e-mail C sales@mnc.com web site C http://www.mnc.com md3802/3805/3810 2/5/10mhz v/f, f/v converters +15v agnd -15v +5v dgnd 6.8 f 6.8 f 6.8 f 8 9 11 18 200 10-turn 100ppm gain adjust v out f in 2, 3, 4 5 20 22 1 20k 10-turn offset adjust +15v -15v c 1 c 2 r 1 r 2 r 1 + r 2 f/v md38xx v out f in + - v out f ? = 1 2 r 1 r 2 c 1 c 2 f cutoff c 1(pf) c 2(pf) r 1(k ) r 2(k ) 20 khz 25 khz 30 khz 50 khz 100 khz 180 150 150 68 33 470 330 330 180 100 16.2 21.0 17.4 16.9 14.3 46.2 39.2 27.4 48.7 53.6 output ripple (mv) md3802 MD3805 md3810 70 60 60 50 80 35 20 40 20 20 5 5 5 5 5 tional filtering of the output voltage by the use of a 2-pole active filter will reduce the output ripple as shown in table 1. a representative 2-pole active filter circuit is shown in figure 4. suitable compo- nent values are listed in table 1. it is recom- mended that a high input impedance, low noise op amp be used, and that offset nulling be done in order to obtain accurate dc performance. figure 3. f/v converter configuration. table 1. ripple reduction by active filter. figure 4. typical 2-pole active filter v/f/v analog data ink C figure 5 depicts the md38xx used as both the v/f and f/v in an analog data link. low-level analog data may be transmitted over considerable distances with no degradation due to noise using this system, and with total system linearity of 0.02/0.04/0.10%.
324 clark st., worcester, ma 01606 tel. (508) 852-5400 ? fax (508) 853-8296 e-mail C sales@mnc.com web site C http://www.mnc.com revision 1 4/98 - 5m ? copyright 1998 1 +15v supply 2 analog ground 3 analog ground 4 analog ground 5 -15v supply 6 no connect 7 no connect 8 offset trim 9 v out 10 i in 11 v in 12 no connect 24 output 23 output 22 digital ground 21 output 20 +5v supply 19 f out 18 f in 17 no connect 16 no connect 15 no connect 14 no connect 13 no connect 13 24 12 pin 1 pin designations md3802/3805/3810 2/5/10mhz v/f, f/v converters 24 23 21 19 18 2, 3, 4 5 20 22 1 11 10 8 200 10-turn 100ppm 20k 10-turn gain adjust 1-shot offset adjust v in i in +15v -15v +15v agnd -15v +5v dgnd 6.8 f 6.8 f 6.8 f +15v agnd -15v +5v dgnd 6.8 f 6.8 f 6.8 f 8 9 11 18 200 10-turn 100ppm gain adjust v out 2, 3, 4 5 20 22 1 20k 10-turn offset adjust +15v -15v figure 5. analog data link.
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