7872 MAXWELL | Alldatasheet
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All data sheets are subject to change without notice (858) 503-3300 - Fax: (858) 503-3301 - www.maxwell.com 14-Bit A/D Converter 7872 ©2001 Maxwell Technologies All rights reserved.
5.21.02 Rev 4
FEATURES:
- 14-bit resolution and accuracy Total dose hardness: - > 100 krad (Si), depending upon space mission Single event effects: - SEL > 104 MeV/mg/cm2 - SEUTH = 1.4 MeV/mg/cm2 - SEUSat = 1E-3 cm2/Device Package: - 16 pin RAD-PAK® flat package - 16 pin RAD-PAK® dual-in-line package Fast Conversion Times: 10 µ s Low 50 mW typical power consumption High speed LC 2MOS technology - Analog input range of ±3V - 83 KSPS throughput rate - Operates with +5V/-5V power supplies - 80 dB SNR at 10 kHz input frequency - 2 s complement coding - Serial output DESCRIPTION: Maxwell Technologies’ 7872 high-speed 14-bit ADC microcir- cuit features a greater than 100 krad (Si) total dose tolerance; depending upon orbit. The 7872 consists of a track/hold ampli- fier, successive-approximation ADC, 3V buried Zener refer- ence and versatile interface logic. It features a self-contained, laser- trimmed internal clock, so no external clock timing com- ponents are required. For mini mum noise possible, the on- chip clock may be overridden to synchronize the device oper- ation to the digital system. The 7872 is a serial output device. It is capable of interfacing to all modern microprocessors and digital signal processors. The 7872 operates from ±5V power supplies, accepts bipolar input signals of ±3V and is able to convert full power signals up to 41.5 kHz. It is also fully speci- fied for dynamic performance parameters including distortion and signal-to-noise ratio. Maxwell Technologies' patented R AD-PAK® packaging technol- ogy incorporates radiation shielding in the microcircuit pack- age. It eliminates the need for box shielding while providing the required radiation shielding for a lifetime in orbit or space mission. In a GEO orbit, R AD-PAK provides greater than 100 krad (Si) radiation dose tolerance. This product is available with screening up to Class S. REFERENCE CLOCK CONTROL LOGIC 14-BIT DAC SERIAL INTERFACE 12 11 13 14 9 16 4 5 6 SAR + COUNTER 8 15 R R TRACK/HOLD COMP AGND C REF REF OUT V IN VDD VDD CLK CONTROL CONVST SSTRB SCLK SDATA DGND V SS Logic Diagram
TABLE 1. 7872 PIN DESCRIPTION
1 CONTROL Control Function
3 CLK Clock Input
5 SCLK Serial Clock
6 SDATA Serial Data
7 NC Non Connect
8 DGND Digital Ground
10 NC No Connect
11 C REF Reference Capacitor
12 AGND Analog Ground
13 REF
14 V IN Analog Input
15 V SS Negative Supply
16 V DD Positive Supply
TABLE 2. 7872 ABSOLUTE MAXIMUM RATINGS
TABLE 3. 7872 DC ELECTRICAL CHARACTERISTICS FOR DYNAMIC PERFORMANCE 1
- V IN = ± 3 V. Guaranteed by design.
- SNR calculation includes distortion and noise components.
TABLE 4. 7872 DC ELECTRICAL CHARACTERISTICS FOR ACCURACY
- Measured with respect to internal reference.
TABLE 5. 7872 DC ELECTRICAL CHARACTERISTICS FOR ANALOG INPUT
TABLE 6. 7872 DC ELECTRICAL CHARACTERISTICS FOR REFERENCE OUTPUT TABLE 7. 7872 DC ELECTRICAL CHARACTERISTICS FOR LOGIC INPUTS TABLE 8. 7872 DC ELECTRICAL CHARACTERISTICS FOR LOGIC OUTPUTS TABLE 9. 7872 DC ELECTRICAL CHARACTERISTICS FOR CONVERSION TIME
TABLE 10. 7872 DC ELECTRICAL CHARACTERISTICS FOR POWER REQUIREMENTS TABLE 11. 7872 TIMING CHARACTERISTICS 1,2
- All input signals are specified with tr = tr = 5 ns (10% to 90% of 5 V) and timed from a voltage level of 1.6 V.
- Serial timing is measured with a 4.7 k Ω pull-up resistor on SDATA and SSTRB and a 2 kΩ pull-up resistor on SCLK. The
capacitance on all three outputs is 35 pF.
- SCLK mark/space ration (measured from a voltage level of 1.6 V) is 40/60 to 60/40.
- SDATA will drive higher capacitive loads, but this will add to t 12 since it increases the external RC time constant (4.7kΩ /CL) and
hence, the time to reach 2.4 V.
FIGURE 1. MODE 1 TIMING DIAGRAM SERIAL
- External 4.7 k Ω pull-up resistor.
- External 2 k Ω pull-up resistor continuos SCLK (DASHED LINE) when 14/8/CLK (CONTROL) = -5 V; noncontinuous when 14/
FIGURE 2. MODE 2 TIMING DIAGRAM, SERIAL READ
- Times t15, t18, t19 and t20 are the same for a high byte read as for a low byte read.
- External 4.7 k Ω pull-up resistor.
- Continuos SCLK (DASHED LINE) when 14/8/CLK (CONTROL ) = -5 V; noncontinuous when 14/8/CLK (CONTROL) = 0 V.
External 2 kΩ pull-up resistor.
FIGURE 3. LOAD CIRCUIT FOR ACCESS TIME FIGURE 4. LOAD CIRCUIT FOR OUTPUT FLOAT DELAY
8All data sheets are subject to change without notice ©2001 Maxwell Technologies All rights reserved. 14-Bit A/D Converter 7872 Note: All dimensions in inches
16 PIN RAD-PAK® FLAT PACKAGE
A 0.116 0.130 0.143 b 0.015 0.017 0.022 c 0.004 0.005 0.009 D -- 0.415 0.440 E 0.245 0.280 0.285 E1 -- -- 0.315 E2 0.130 0.156 -- E3 0.030 0.062 -- e 0.050 BSC L 0.325 0.335 0.345 Q 0.020 0.033 0.045 S1 0.005 0.024 -- N1 6
9All data sheets are subject to change without notice ©2001 Maxwell Technologies All rights reserved. 14-Bit A/D Converter 7872 Note: All dimensions in inches
16 PIN RAD-PAK® DUAL IN LINE PACKAGE
A -- 0.157 0.200 b 0.014 0.018 0.026 b2 0.045 0.047 0.065 c 0.008 0.010 0.018 D -- 0.800 0.840 E 0.220 0.295 0.310 eA 0.300 BSC eA/2 0.150 BSC e 0.100 BSC L 0.135 0.145 0.155 Q 0.000 0.002 0.060 S1 0.005 0.027 -- S2 0.005 -- -- N1 6 eA/2 E D A Q c L eAe b N/2
10All data sheets are subject to change without notice ©2001 Maxwell Technologies All rights reserved. 14-Bit A/D Converter 7872 Important Notice: These data sheets are created using the chip manufacturer’s published specifications. Maxwell Technologies verifies functionality by testing key parameters either by 100% testing, sample testing or characterization. The specifications presented within these data sheets represent the latest and most accurate information available to date. However, these specifications are subject to change without notice and Maxwell Technologies assumes no responsibility for the use of this information. Maxwell Technologies’ products are not authorized for use as critical components in life support devices or systems without express written approval from Maxwell Technologies. Any claim against Maxwell Technologies must be made within 90 days from the date of shipment from Maxwell Tech- nologies. Maxwell Technologies’ liability shall be limited to replacement of defective parts.
11All data sheets are subject to change without notice ©2001 Maxwell Technologies All rights reserved. 14-Bit A/D Converter 7872 Feature Option Details7872 RP X X Screening Flow Package Radiation Feature Base Product Nomenclature Monolithic S = Maxwell Class S B = Maxwell Class B I = Industrial (testing @ -55°C, +25°C, +125°C) E = Engineering (testing @ +25° D = Dual In-line Package (DIP) F = Flat Pack RP = R AD-PAK® package 14-Bit A/D Converter