ANALOG DEVICES + 10 Volt Precision Reference Series AD2700/AD2701/AD2702 FEATURES Very High Accuracy: 10.000 Volts +2.5mV (L and U) Low Temperature Coefficient: 3ppm/C Performance Guaranteed -55C to +125 C 10mA Output Current Capability Low Noise Short Circuit Protected Available as /883B PRODUCT DESCRIPTION The AD2700 family of precision 10 volt references offer the user excellent accuracy and stability at a moderate price by combining the recognized advantages of thin film technology and active laser trimming. The low temperature drift (3ppm/C) achieved with these technologies can be matched only by the use of ovens, chip heaters for temperature regu- lation, or with hand selected components and manual trim- ming. In addition, temperature-regulated devices are guaran- teed only up to +85C operation, whereas the U- and S-grade devices in the AD2700 family are guaranteed to +125C. The AD2700 is a +10 volt reference which is designed to interface with high accuracy bipolar D/A converters of 10 and 12 bit resolution. The 10mA output drive capability also makes the AD2700 ideal for use as a general positive system reference. The AD2701 is a negative 10 volt reference especially de- signed to interface with CMOS D/A and A/D converters, as shown in the applications. For systems requiring a dual tracking reference, the AD2702 offers both positive and negative preci- sion 10 volt outputs in a single package. Both are often used with 5$2XX Series 12-bit A/D converters which require -10V external references for high accuracy over wide temperature ranges. All three devices are offered i in J and L grades for opera- tion from -25C to +85C and S and U grades for the -55C to +125C temperature range. Screening to MIL-STD- 883 is available for S and U grades of the AD2700 family. Information furnished by Anelog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog Devices for its use; nor for any infringements of patents or other rights of third parties which may result from its use. No license Is granted by implica- tion or otherwise under eny petent or patent rights of Analog Devices. REV. B FUNCTIONAL BLOCK DIAGRAMS FINE ADJUST +16.0V 10,0000V OUTPUT AD2700 COMMON FINE -15.0V -FINE ADJUST ADJUST PRODUCT HIGHLIGHTS 1, Active laser trimming of both initial accuracy and temper- ature performance results in very high accuracy over the temperature range without external components. The AD2700/01/02 LD grades have a maximum output voltage error at 25C of +2.5mV with no external adjustments. 2. The performance of the AD2700 series is achieved by a well-characterized design and precise control over the manufacturing process. 3. The AD2700 series is well suited for a broad range of applications requiring an accurate, stable reference source such as high resolution data converters (12 or 14 bits), test and measurement systems and calibration standards. Model Output AD2700 +10.000V AD2701 -10,000V AD2702 +10.000V P.O. Box 280; Norwood, Massachusetts 02062 U.S.A. Tel: 617/329-4700 Twx: 710/394-6577 Telex: 924491 Cables: ANALOG NORWOODMASSAD2700/AD2701/AD2702 SPECIFICATIONS f= 211 vies sternse nova) MODEL JD LD sD UD ABSOLUTE MAX RATINGS . Input Voltage (for applicable supply) +20V : . Power Dissipation @ +25C AD2700,01 300mW . AD2702 450mW . * o Operating Temperature Range -25C to +85C . -55 Cto +125 C oe Storage Temperature Range -65 Cto +150 C . . . Lead Temperature (soldering, 10s) +300C . . Short Circuit Protection (to GND) Continuous * * * OUTPUT VOLTAGE ERROR @ +25C AD2700 10,000V +0,005V 0.0025V . =" AD2701 = -10,000V +0.005V 0.0025V : bod AD2702 +10.000V 40.005V +0.0025V . ** OUTPUT CURRENT! @+25C +10mA * . * (Vin = 13 to 18V) over op. temp. range +5mA +5mA, -2mA af ae OUTPUT VOLTAGE ERROR AD2700,01 10ppm/C 3ppm/C ae a (Tents 0 Tras) t11.0mV 4,.3mV +8mV +5.5mV AD2702. 10ppm/C Sppm/C = 3ppm/C +11.0mV +5.5mV +10.0mV +5.5mV LINE REGULATION . * * VIN = $13.5 to 16.5V 300uV/V LOAD REGULATION Oto t10mA 50uV/mA * * * OUTPUT RESISTANCE 0,052 . ; INPUT VOLTAGE, OPERATING +13V to +18V * " QUIESCENT CURRENT AD2700, 01 +14mA . . AD2702 +17mA, -4mA . . NOISE (0.1 to 10Hz) 50zV p-p typ . * LONG TERM STABILITY (@ +55C) 100ppm/1000 Hrs. (typ) * . OFFSET ADJUST RANGE (See Diagrams) +20mV (min) . . = OFFSET ADJUST TEMP DRIFT EFFECT +4uV/C per mV of Adjust (typ) . * * PACKAGE OPTION*** DH-14C DH-14C DH-14C DH-14C NOTES *Same as JD grade performance. **Same as LD grade performance. ***Same as SD" grade performance. ' Specified with resistive load to common, Device not intended for use in driving a dynamic load. ? Output voltage error as a function of temperature is determined using the box method. Each unit is tested at Trin. Tmax and +25C. At each temperature Vout must fall within the rectangular area bounded by the minimum and maximum temperature and whose maximum Voy value is equal to Vou nominal plus or minus the maximum +25C error plus the maximum drift error from +25C. The box limits are noted below the drift values used to calculate the box. * Analog Devices reserves the right to ship side-brazed ceramic pac (outline DH-14D) in lieu of the standard ceramic packages for J L grade parts." *See Section 14 for package outline information. Specifications subject to change without notice. REV. BAD2700/AD2701/AD2702 FINE V, FINE TEST +0 ADJUST +16 POINT NAC A/C OOOGOOO AD2700: +10,000 VOLT REFERENCE OOO000D. we UNC UNC ONC FINE Vouy FINE TEST Si ADJUST -15 POINT NIC OOOOOOO AD2701. -10.000 VOLT REFERENCE OO00000 nic UNC UNC ONC anne Ve FINE +10 ADJUST +15 POINT n/c OOOOOOD ADZ702: 210.000 VOLT REFERENCE SO50000, FINE -10 FINE -15 n/c 8 6N/C OC ADJUST Voy ADJUST Pin Designations USING AD2700 REFERENCE WITH THE AD7520 AND AN IC AMPLIFIER TO BUILD A DAC The AD2700 series is ideal for use with the AD7520 series of CMOS D/A converters. A CMOS converter in a unipolar appli- cation as shown below performs an inversion of the voltage reference input. Thus, use of the +10 volt AD2700 reference will result in a 0 to -10 volt output range. Alternatively, using +96V (OR -15 FOR AD2701) +15V SIT 1 (MSB) <44 nD DIGITAL INPUT > iu BIT 10 (LSB) Unipolar Binary Operation DIGITAL INPUT ANALOG OUTPUT Vour * 10.000V -16v "-4 10k v5 + O- 1104 3 1 Vgyy = -10.000V 2 aozz 43 y 12 14 | Your * *10.000v : * P" OKEXTERNAL 10k POTENTIOMETER PROVIDES 30mv OUTPUT OFF. 10% = SET ADJUST. TEMPERATURE EFFECT IS 24uV/" PER mV OF LL OFFSET CORRECTION (EXTER- = NAL ADJUSTMENT OPTIONAL). Fine Trim Connections the -10 volt AD2701 will result in a 0 to +10 volt range. Two operational amplifiers are used to give a bipolar output range of -10 volt to +10 volt, as shown in the lower figure. Either the AD2700 or AD2701 can be used, depending on the trans- fer code characteristic desired, For more detailed applications information, refer to the AD7520 Data Sheet. +15V Vner . R33 10 MEGOHM (mse 1% 14 4 ott se) ie 16 Freepmack lout? __T TI 5 1 Vout OIGITAL 3 OIGIT: AD7520 ste 2G + pene | 13 2 fourz = BIT 10 (L$8) a Bipolar Operation '(4-Quadrant Multiplication} 1111111111 1000000001 -Vacr a- 2710) Vag (1/2 + 2719) ~VREF 1000000000 3 0111111111 Var (1/2 - 279) 0000000001 -Veer (2710) 0000000000 0 NOTE: 1 LSB = 2'* Vier Table |. Code Table Unipolar Binary Operation REV. B DIGITAL INPUT TLiliviiiti ANALOG OUTPUT Veer (1 - 29) 1000000001 -Veer (2) 1000000000 0 0111111111 Veer (2%) 0000000001 Vrer (1 - 277) 0000000000 VreF NOTE: 1 LSB = 2 VREF Table li. Code Tabie Bipolar (Offset Binary) OperationAD2700/AD2701/AD2702 USING THE AD2700 VOLTAGE REFERENCE WITH D/A CONVERTER An AD2700 Voltage Reference can be used with an inverting operational amplifier and an R-2R ladder network. If all bits but the MSB are off (i.e., grounded), the output voltage is (-R/2R)Eger. If all bits but Bit 2 are off, it can be shown that the output voltage is 4(-R/2R)Egep = 4Egpp: The lumped resistance of all the less-significant-bit circuitry (to the left of Bit 2) is 2R; the Thevenin equivalent looking back from the MSB towards Bit 2 is the generator, Epgr/2, and the series resistance 2R; since the grounded MSB series DIGITAL INPUT CODE Lse BITS wire une ! ' TERMINATION a. Basic Circuit resistance, 2R, has virtually no influence because the amplifier summing point is at virtual ground the output voltage is therefore -Egpp/4. The same line of thinking can be employed to show that the nth bit produces an increment of output equal to 2" Expr. BIT 2 SWITCH CLOSED 1 1 AD2700 | : | ] L Whe We LUMPED RESISTANCE OF LESS-SIGNIFICANT BITS 6. Example: Contribution of Bit 2: All Other Bits 0 Sout ~ -2.5V = -KEper ! I ! ' ! c. Simplified Equivalent of Circuit (b.) PACKAGE DIMENSIONS Dimensions shown in inches and (mm). 2.506 (12.8 0.498 (12.8) 0.428 (10.9) 0.416 (10.6) GLASS BEAD STAND-OFFS 0.2 (6.08) 0.175 (4.45) | 2.255 (6.48) 0.206 (6.21) LU af fe al PIN 1 IDENTIFIER SQOUARED-OFF Hermetically sealed 14-Pin Dual-in-Line (Gross leak tested per MIL-STD-883, Method 1014) Pin 7 is electrically connected to the case. Case has metal bottom surface. 14-Pin Dual-In-Line Metal Package OER a Sea am ae ~ BJ StH papasage i rane SANE t, pape AS t ie tA he eee Z T w / soi sat \ aha | [a eee 1 Raa eee aE 14-Pin Dual-in-Line Ceramic Package -4- REV. B C350a88/83 PRINTED IN U.S.A.