HI-574A, HI-674A, HI-774 S E M I C O N D U C T O R Complete, 12-Bit A/D Converters with Microprocessor Interface August 1997 Features Description * Complete 12-Bit A/D Converter with Reference and Clock The HI-X74(A) is a complete 12-bit, Analog-to-Digital Converter, including a +10V reference clock, three-state outputs and a digital interface for microprocessor control. Successive approximation conversion is performed by two monolithic dice housed in a 28 lead package. The bipolar analog die features the Harris Dielectric Isolation process, which provides enhanced AC performance and freedom from latch-up. * Full 8-Bit, 12-Bit or 16-Bit Microprocessor Bus Interface * Bus Access Time . . . . . . . . . . . . . . . . . . . . . . . . . . 150ns * No Missing Codes Over Temperature * Minimal Setup Time for Control Signals * Fast Conversion Times - HI-574A (Max) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25s - HI-674A (Max) . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15s - HI-774 (Max) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9s * Digital Error Correction (HI-774) * Low Noise, via Current-Mode Signal Transmission Between Chips * Byte Enable/Short Cycle (AO Input) - Guaranteed Break-Before-Make Action, Eliminating Bus Contention During Read Operation. Latched by Start Convert Input (To Set the Conversion Length) * Supply Voltage . . . . . . . . . . . . . . . . . . . . . 12V to 15V Applications * Military and Industrial Data Acquisition Systems * Electronic Test and Scientific Instrumentation * Process Control Systems Custom design of each IC (bipolar analog and CMOS digital) has yielded improved performance over existing versions of this converter. The voltage comparator features high PSRR plus a high speed current-mode latch, and provides precise decisions down to 0.1 LSB of input overdrive. More than 2X reduction in noise has been achieved by using current instead of voltage for transmission of all signals between the analog and digital ICs. Also, the clock oscillator is current controlled for excellent stability over temperature. The HI-X74(A) offers standard unipolar and bipolar input ranges, laser trimmed for specified linearity, gain and offset accuracy. The low noise buried zener reference circuit is trimmed for minimum temperature coefficient. Power requirements are +5V and 12V to 15V, with typical dissipation of 385mW (HI-574A/674A) and 390mW (HI-774) at 12V. All models are available in sidebrazed DIP, PDIP, and CLCC. For additional HI-Rel screening including 160 hour burnin, specify "-8" suffix. For MIL-STD-883 compliant parts, request HI-574A/883, HI-674A/883, and HI-774/883 data sheets. Pinouts 22 DB6 8 21 DB5 REFERENCE INPUT 10 19 DB3 -12V/-15V SUPPLY, VEE 11 18 DB2 BIPOLAR OFFSET 12 BIP OFF 17 DB1 10V INPUT 13 16 DB0 20V INPUT 14 15 DIG COMMON, DC 37 DB9 CHIP ENABLE, CE 10 36 DB8 11 35 DB7 12 34 DB6 13 33 DB5 14 32 DB4 15 31 DB3 NC 16 LSB BIPOLAR OFFSET, 17 BIP OFF 30 NC 29 DB2 18 19 20 21 22 23 24 25 26 27 28 10V (c) Harris Corporation 1997 NC 38 NC READ CONVERT, R/C 9 CAUTION: These devices are sensitive to electrostatic discharge. Users should follow proper IC Handling Procedures. Copyright DB10 39 NC NC 8 +15V SUPPLY, VCC +10V REFERENCE, REF OUT ANALOG COMMON, AC REFERENCE INPUT, REF IN -15V SUPPLY, VEE 20 DB4 1 44 43 42 41 40 6-7 DB1 +12V/+15V SUPPLY, VCC 7 DIGITAL DATA OUTPUTS 2 NC 23 DB7 3 NC 6 4 NC 7 (LSB) DB0 CHIP ENABLE, CE 9 5 STATUS, STS 24 DB8 DB11, MSB 25 DB9 5 NC 4 READ/CONVERT, R/C NC DIG COMMON, DC BYTE ADDR/SHORT CYCLE, AO MSB NC 26 DB10 NC 27 DB11 3 ANALOG COMMON, AC NC BYTE ADDRESS/ SHORT CYCLE, AO CHIP SELECT, CS DATA MODE SELECT, 12/8 +5V SUPPLY, VLOGIC 2 CHIP SEL, CS NC DATA MODE SEL, 12/8 +10V REF, REF OUT 6 28 STATUS, STS 20V +5V SUPPLY, VLOGIC 1 (CLCC) TOP VIEW NC (PDIP, SBDIP) TOP VIEW File Number 3096.4 HI-574A, HI-674A, HI-774 Ordering Information INL TEMPERATURE RANGE (oC) HI3-574AJN-5 1.0 LSB 0 to 75 28 Ld PDIP E28.6 HI3-574AKN-5 0.5 LSB 0 to 75 28 Ld PDIP E28.6 HI3-574ALN-5 0.5 LSB 0 to 70 28 Ld PDIP E28.6 HI1-574AJD-5 1.0 LSB 0 to 75 28 Ld SBDIP D28.6 HI1-574AKD-5 0.5 LSB 0 to 75 28 Ld SBDIP D28.6 HI1-574ALD-5 0.5 LSB 0 to 75 28 Ld SBDIP D28.6 HI1-574ASD-2 1.0 LSB -55 to 125 28 Ld SBDIP D28.6 HI1-574ATD-2 0.5 LSB -55 to 125 28 Ld SBDIP D28.6 HI1-574AUD-2 0.5 LSB -55 to 125 28 Ld SBDIP D28.6 HI1-574ASD/883 1.0 LSB -55 to 125 28 Ld SBDIP D28.6 HI1-574ATD/883 0.5 LSB -55 to 125 28 Ld SBDIP D28.6 HI1-574AUD/883 0.5 LSB -55 to 125 28 Ld SBDIP D28.6 HI4-574ASE/883 1.0 LSB -55 to 125 44 Ld CLCC J44.A HI4-574ATE/883 0.5 LSB -55 to 125 44 Ld CLCC J44.A HI4-574AUE/883 0.5 LSB -55 to 125 44 Ld CLCC J44.A HI3-674AJN-5 1.0 LSB 0 to 75 28 Ld PDIP E28.6 HI3-674AKN-5 0.5 LSB 0 to 75 28 Ld PDIP E28.6 HI3-674ALN-5 0.5 LSB 0 to 75 28 Ld PDIP E28.6 HI1-674AJD-5 1.0 LSB 0 to 75 28 Ld SBDIP D28.6 HI1-674AKD-5 0.5 LSB 0 to 75 28 Ld SBDIP D28.6 HI1-674ALD-5 0.5 LSB 0 to 75 28 Ld SBDIP D28.6 HI1-674ASD-2 1.0 LSB -55 to 125 28 Ld SBDIP D28.6 HI1-674ATD-2 0.5 LSB -55 to 125 28 Ld SBDIP D28.6 HI1-674AUD-2 0.5 LSB -55 to 125 28 Ld SBDIP D28.6 HI1-674ASD/883 1.0 LSB -55 to 125 28 Ld SBDIP D28.6 HI1-674ATD/883 0.5 LSB -55 to 125 28 Ld SBDIP D28.6 HI1-674AUD/883 0.5 LSB -55 to 125 28 Ld SBDIP D28.6 HI4-674ASE/883 1.0 LSB -55 to 125 44 Ld CLCC J44.A HI4-674ATE/883 0.5 LSB -55 to 125 44 Ld CLCC J44.A HI4-674AUE/883 0.5 LSB -55 to 125 44 Ld CLCC J44.A HI3-774J-5 1.0 LSB 0 to 75 28 Ld PDIP E28.6 HI3-774K-5 0.5 LSB 0 to 75 28 Ld PDIP E28.6 HI1-774J-5 1.0 LSB 0 to 75 28 Ld SBDIP D28.6 HI1-774K-5 0.5 LSB 0 to 75 28 Ld SBDIP D28.6 HI1-774U-2 0.5 LSB -55 to 125 28 Ld SBDIP D28.6 HI1-774T/883 0.5 LSB -55 to 125 28 Ld SBDIP D28.6 HI4-774S/883 1.0 LSB -55 to 125 44 Ld CLCC J44.A HI4-774T/883 0.5 LSB -55 to 125 44 Ld CLCC J44.A HI4-774U/883 0.5 LSB -55 to 125 44 Ld CLCC J44.A PART NUMBER 6-8 PACKAGE PKG. NO. HI-574A, HI-674A, HI-774 Functional Block Diagram BIT OUTPUTS MSB 12/8 CS AO LSB NIBBLE A (NOTE) CONTROL LOGIC NIBBLE B (NOTE) NIBBLE C (NOTE) THREE-STATE BUFFERS AND CONTROL R/C CE VLOGIC POWER-UP RESET DIGITAL COMMON 12 BITS CLK STS SAR OSCILLATOR STROBE DIGITAL CHIP ANALOG CHIP 12 BITS VCC VEE COMP DAC - + VREF IN 10K VREF OUT 5K + +10V REF 5K - 2.5K 10K 5K ANALOG COMMON BIP OFF NOTE: "Nibble" is a 4-bit digital word. 6-9 20V 10V INPUT INPUT HI-574A, HI-674A, HI-774 Absolute Maximum Ratings Thermal Information Supply Voltage VCC to Digital Common . . . . . . . . . . . . . . . . . . . . . . 0V to +16.5V VEE to Digital Common. . . . . . . . . . . . . . . . . . . . . . . 0V to -16.5V VLOGIC to Digital Common . . . . . . . . . . . . . . . . . . . . . . 0V to +7V Analog Common to Digital Common1V Control Inputs (CE, CS, AO, 12/8, R/C) to Digital Common . . -0.5V to VLOGIC +0.5V Analog Inputs (REFIN, BIPOFF, 10VIN) to Analog Common. . . . . . . . . . 16.5V 20VIN to Analog Common . . . . . . . . . . . . . . . . . . . . . . . . . . 24V REFOUT . . . . Indefinite Short To Common, Momentary Short To VCC Thermal Resistance (Typical, Note 1) JA (oC/W) JC (oC/W) CLCC Package . . . . . . . . . . . . . . . . . . 65 14 SBDIP Package . . . . . . . . . . . . . . . . . . 60 18 HI3-574AxN-5, HI3-674AxN-5, HI3-774xN-5 65 N/A Maximum Junction Temperature HI3-574AxN-5, HI3-674AxN-5, HI3-774xN-5. . . . . . . . . . . . 150oC HI1-574AxD-2, HI1-574AxD-5 . . . . . . . . . . . . . . . . . . . . . . . 175oC HI1-674AxD-2, HI1-674AxD-5 . . . . . . . . . . . . . . . . . . . . . . . 175oC HI1-774xD-2, HI1-774xD-5 . . . . . . . . . . . . . . . . . . . . . . . . . 175oC Maximum Storage Temperature Range HI3-574AxN-5, HI3-674AxN-5, HI3-774xN-5. . . . . .-40oC to 85oC HI1-574AxD-2, HI1-574AxD-5 . . . . . . . . . . . . . . . .-65oC to 150oC HI1-674AxD-2, HI1-674AxD-5 . . . . . . . . . . . . . . . .-65oC to 150oC HI1-774xD-2, HI1-774xD-5 . . . . . . . . . . . . . . . . . .-65oC to 150oC Maximum Lead Temperature (Soldering, 10s) . . . . . . . . . . . . 300oC Operating Conditions Temperature Range HI3-574AxN-5, HI1-574AxD-5 . . . . . . . . . . . . . . . . . .0oC to 75oC HI3-674AxN-5, HI1-674AxD-5 . . . . . . . . . . . . . . . . . .0oC to 75oC HI3-774xN-5, HI1-774xD-5 . . . . . . . . . . . . . . . . . . . . .0oC to 75oC HI1-574AxD-2, HI1-674AxD-2, HI1-774xD-2 . . . . -55oC to 125oC DC and Transfer Accuracy Specifications Die Characteristics Transistor Count HI-574A, HI-674A . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1117 HI-774 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2117 Typical at 25oC with VCC = +15V or +12V, VLOGIC = +5V, VEE = -15V or -12V, Unless Otherwise Specified TEMPERATURE RANGE -5 (0oC to 75oC) PARAMETER J SUFFIX K SUFFIX L SUFFIX UNITS 12 12 12 Bits 1 1/2 1/2 LSB 1 1/ 1/ LSB HI-574A, HI-674A 12 12 12 Bits HI-774 11 12 12 Bits HI-574A, HI-674A 11 12 12 Bits HI-774 11 12 12 Bits 2 1.5 1 LSB 4 4 3 LSB 0.15 0.1 0.1 % of FS 25oC (Max), With Fixed 50 Resistor From REF OUT To REF IN (Adjustable to Zero) 0.25 0.25 0.15 % of FS TMIN to TMAX (No Adjustment At 25oC) 0.475 0.375 0.20 % of FS TMIN to TMAX (With Adjustment To Zero 25oC) 0.22 0.12 0.05 % of FS DYNAMIC CHARACTERISTICS Resolution (Max) Linearity Error 25oC (Max) 0oC to 75oC (Max) 2 2 Max Resolution For Which No Missing Codes Is Guaranteed 25oC TMIN to TMAX Unipolar Offset (Max) Adjustable to Zero Bipolar Offset (Max) VIN = 0V (Adjustable to Zero) VIN = -10V Full Scale Calibration Error 6-10 HI-574A, HI-674A, HI-774 DC and Transfer Accuracy Specifications Typical at 25oC with VCC = +15V or +12V, VLOGIC = +5V, VEE = -15V or -12V, Unless Otherwise Specified (Continued) TEMPERATURE RANGE -5 (0oC to 75oC) PARAMETER J SUFFIX K SUFFIX L SUFFIX UNITS HI-574A, HI-674A 2 1 1 LSB HI-774 2 1 1 LSB HI-574A, HI-674A 2 1 1 LSB HI-774 2 2 1 LSB HI-574A, HI-674A 9 2 2 LSB HI-774 9 5 2 LSB 2 1 1 LSB 1/ 1/ 1/ LSB Temperature Coefficients Guaranteed Max Change, TMIN to TMAX (Using Internal Reference) Unipolar Offset Bipolar Offset Full Scale Calibration Power Supply Rejection Max Change In Full Scale Calibration +13.5V < VCC < +16.5V or +11.4V < VCC < +12.6V +4.5V < VLOGIC < +5.5V 2 2 -16.5V < VEE < -13.5V or -12.6V < VEE < -11.4V 2 1 2 1 LSB ANALOG INPUTS Input Ranges Bipolar -5 to +5 V -10 to +10 V 0 to +10 V 0 to +20 V 10V Span 5K, 25% 20V Span 10K, 25% +4.5 to +5.5 V VCC +11.4 to +16.5 V VEE -11.4 to -16.5 V ILOGIC 7 Typ, 15 Max mA ICC +15V Supply 11 Typ, 15 Max mA IEE -15V Supply 21 Typ, 28 Max mA 15V, +15V 515 Typ, 720 Max mW 12V, +5V 385 Typ mW +10.00 0.05 Max V 2.0 Max mA Unipolar Input Impedance POWER SUPPLIES Operating Voltage Range VLOGIC Operating Current Power Dissipation Internal Reference Voltage TMIN to TMAX Output Current, Available For External Loads (External Load Should Not Change During Conversion). 6-11 HI-574A, HI-674A, HI-774 DC and Transfer Accuracy Specifications Typical at 25oC with VCC = +15V or +12V, VLOGIC = +5V, VEE = -15V or -12V, Unless Otherwise Specified TEMPERATURE RANGE -2 (-55oC to 125oC) S SUFFIX T SUFFIX U SUFFIX UNITS 12 12 12 Bits 25oC 1 1/2 1/2 LSB -55oC to 125oC (Max) 1 1 1 LSB HI-574A, HI-674A 12 12 12 Bits HI-774 11 12 12 Bits HI-574A, HI-674A 11 12 12 Bits HI-774 11 12 12 Bits HI-574A, HI-674A 2 1.5 1 LSB HI-774 2 2 1 LSB 4 4 3 LSB 0.15 0.1 0.1 % of FS 25oC (Max), With Fixed 50 Resistor From REF OUT To REF IN (Adjustable To Zero) 0.25 0.25 0.15 % of FS TMIN to TMAX (No Adjustment At 25oC) 0.75 0.50 0.275 % of FS TMIN to TMAX (With Adjustment To Zero At 25oC) 0.50 0.25 0.125 % of FS Unipolar Offset 2 1 1 LSB Bipolar Offset 2 2 1 LSB Full Scale Calibration 20 10 5 LSB 2 1 1 LSB 1/ 1/ 1/ LSB PARAMETER DYNAMIC CHARACTERISTICS Resolution (Max) Linearity Error Max Resolution For Which No Missing Codes Is Guaranteed 25oC TMIN to TMAX Unipolar Offset (Max) Adjustable to Zero Bipolar Offset (Max) VIN = 0V (Adjustable to Zero) VIN = -10V Full Scale Calibration Error Temperature Coefficients Guaranteed Max Change, TMIN to TMAX (Using Internal Reference) Power Supply Rejection Max Change In Full Scale Calibration +13.5V < VCC < +16.5V or +11.4V < VCC < +12.6V +4.5V < VLOGIC < +5.5V 2 2 -16.5V < VEE < -13.5V or -12.6V < VEE < -11.4V 2 1 2 1 LSB ANALOG INPUTS Input Ranges Bipolar Unipolar 6-12 -5 to +5 V -10 to +10 V 0 to +10 V 0 to +20 V HI-574A, HI-674A, HI-774 DC and Transfer Accuracy Specifications Typical at 25oC with VCC = +15V or +12V, VLOGIC = +5V, VEE = -15V or -12V, Unless Otherwise Specified (Continued) TEMPERATURE RANGE -2 (-55oC to 125oC) S SUFFIX PARAMETER T SUFFIX U SUFFIX UNITS Input Impedance 10V Span 5K, 25% 20V Span 10K, 25% +4.5 to +5.5 V VCC +11.4 to +16.5 V VEE -11.4 to -16.5 V ILOGIC 7 Typ, 15 Max mA ICC +15V Supply 11 Typ, 15 Max mA IEE -15V Supply 21 Typ, 28 Max mA 15V, +15V 515 Typ, 720 Max mW 12V, +5V 385 Typ mW +10.00 0.05 Max V 2.0 Max mA POWER SUPPLIES Operating Voltage Range VLOGIC Operating Current Power Dissipation Internal Reference Voltage TMIN to TMAX Output current, available for external loads (External load should not change during conversion). Digital Specifications All Models, Over Full Temperature Range PARAMETER MIN TYP MAX Logic "1" +2.4V - +5.5V Logic "0" -0.5V - +0.8V Current - 0.1A 5A Capacitance - 5pF - - - +0.4V Logic "1" (ISOURCE - 500A) +2.4V - - Logic "1" (ISOURCE - 10A) +4.5V - - Leakage (High-Z State, DB11-DB0 Only) - 0.1A 5A Capacitance - 5pF - Logic Inputs (CE, CS, R/C, AO, 412/8) Logic Outputs (DB11-DB0, STS) Logic "0" (ISINK - 1.6mA) Timing Specifications (HI-574A) 25oC, Note 2, Unless Otherwise Specified SYMBOL PARAMETER MIN TYP MAX UNITS - - 200 ns CONVERT MODE tDSC STS Delay from CE 6-13 HI-574A, HI-674A, HI-774 Timing Specifications (HI-574A) 25oC, Note 2, Unless Otherwise Specified (Continued) SYMBOL PARAMETER MIN TYP MAX UNITS tHEC CE Pulse Width 50 - - ns tSSC CS to CE Setup 50 - - ns tHSC CS Low During CE High 50 - - ns tSRC R/C to CE Setup 50 - - ns tHRC R/C Low During CE High 50 - - ns tSAC AO to CE Setup 0 - - ns tHAC AO Valid During CE High 50 - - ns 12-Bit Cycle TMIN to TMAX 15 20 25 s 8-Bit Cycle TMIN to TMAX 10 13 17 s - 75 150 ns 25 - - ns - 100 150 ns tC Conversion Time READ MODE tDD Access Time from CE tHD Data Valid After CE Low tHL Output Float Delay tSSR CS to CE Setup 50 - - ns tSRR R/C to CE Setup 0 - - ns tSAR AO to CE Setup 50 - - ns tHSR CS Valid After CE Low 0 - - ns tHRR R/C High After CE Low 0 - - ns tHAR AO Valid After CE Low 50 - - ns STS Delay After Data Valid 300 - 1200 ns MIN TYP MAX UNITS - - 200 ns tHS Timing Specifications (HI-674A) 25oC, Note 2, Unless Otherwise Specified SYMBOL PARAMETER CONVERT MODE tDSC STS Delay from CE tHEC CE Pulse Width 50 - - ns tSSC CS to CE Setup 50 - - ns tHSC CS Low During CE High 50 - - ns tSRC R/C to CE Setup 50 - - ns tHRC R/C Low During CE High 50 - - ns tSAC AO to CE Setup 0 - - ns tHAC AO Valid During CE High 50 - - ns 12-Bit Cycle TMIN to TMAX 9 12 15 s 8-Bit Cycle TMIN to TMAX 6 8 10 s - 75 150 ns 25 - - ns - 100 150 ns tC Conversion Time READ MODE tDD Access Time from CE tHD Data Valid After CE Low tHL Output Float Delay 6-14 HI-574A, HI-674A, HI-774 Timing Specifications (HI-674A) 25oC, Note 2, Unless Otherwise Specified (Continued) SYMBOL PARAMETER MIN TYP MAX UNITS tSSR CS to CE Setup 50 - - ns tSRR R/C to CE Setup 0 - - ns tSAR AO to CE Setup 50 - - ns tHSR CS Valid After CE Low 0 - - ns tHRR R/C High After CE Low 0 - - ns tHAR AO Valid After CE Low 50 - - ns STS Delay After Data Valid 25 - 850 ns tHS Timing Specifications (HI-774) 25oC, Into a load with RL = 3k and CL = 50pF, Note 2, Unless Otherwise Specified SYMBOL PARAMETER MIN TYP MAX UNITS - 100 200 ns CONVERT MODE tDSC STS Delay from CE tHEC CE Pulse Width 50 30 - ns tSSC CS to CE Setup 50 20 - ns tHSC CS Low During CE High 50 20 - ns tSRC R/C to CE Setup 50 0 - ns tHRC R/C Low During CE High 50 20 - ns tSAC AO to CE Setup 0 0 - ns tHAC AO Valid During CE High 50 30 - ns 12-Bit Cycle TMIN to TMAX (-5) - 8.0 9 s 8-Bit Cycle TMIN to TMAX (-5) - 6.4 6.8 s 12-Bit Cycle TMIN to TMAX (-2) - 9 11 s 8-Bit Cycle TMIN to TMAX (-2) - 6.8 8.3 s - 75 150 ns 25 35 - ns - 70 150 ns tC Conversion Time READ MODE tDD Access Time from CE tHD Data Valid After CE Low tHL Output Float Delay tSSR CS to CE Setup 50 0 - ns tSRR R/C to CE Setup 0 0 - ns tSAR AO to CE Setup 50 25 - ns tHSR CS Valid After CE Low 0 0 - ns tHRR R/C High After CE Low 0 0 - ns tHAR AO Valid After CE Low 50 25 - ns - 90 300 ns tHS STS Delay After Data Valid NOTES: 1. Dissipation rating assumes device is mounted with all leads soldered to printed circuit board. 2. Time is measured from 50% level of digital transitions. Tested with a 50pF and 3k load. 6-15 HI-574A, HI-674A, HI-774 Definitions of Specifications Pin Descriptions DESCRIPTION Linearity Error PIN SYMBOL 1 VLOGIC 2 12/8 Data Mode Select - Selects between 12-bit and 8-bit output modes. 3 CS Chip Select - Chip Select high disables the device. 4 AO Byte Address/Short Cycle - See Table 1 for operation. 5 R/C Read/Convert - See Table 1 for operation. 6 CE Chip Enable - Chip Enable low disables the device. 7 VCC Positive Supply (+12V/+15V) 8 REF OUT +10V Reference Differential Linearity Error (No Missing Codes) 9 AC Analog Common 10 REF IN Reference Input 11 VEE 12 BIP OFF Bipolar Offset 13 10V Input 10V Input - Used for 0V to 10V and -5V to +5V input ranges. A specification which guarantees no missing codes requires that every code combination appear in a monotonic increasing sequence as the analog input level is increased. Thus every code must have a finite width. For the HI-X74(A)K and L grades, which guarantee no missing codes to 12-bit resolution, all 4096 codes must be present over the entire operating temperature ranges. The HI-X74(A)J grade guarantees no missing codes to 11-bit resolution over temperature; this means that all code combinations of the upper 11 bits must be present; in practice very few of the 12-bit codes are missing. 14 20V Input 20V Input - Used for 0V to 20V and -10V to +10V input ranges. Logic supply pin (+5V) Negative Supply (-12V/-15V). Linearity error refers to the deviation of each individual code from a line drawn from "zero" through "full scale". The point used as "zero" occurs 1/2 LSB (1.22mV for 10V span) before the first code transition (all zeros to only the LSB "on"). "Full scale" is defined as a level 11/2 LSB beyond the last code transition (to all ones). The deviation of a code from the true straight line is measured from the middle of each particular code. The HI-X74(A)K and L grades are guaranteed for maximum nonlinearity of 1/2 LSB. For these grades, this means that an analog value which falls exactly in the center of a given code width will result in the correct digital output code. Values nearer the upper or lower transition of the code width may produce the next upper or lower digital output code. The HI-X74(A)J is guaranteed to 1 LSB max error. For this grade, an analog value which falls within a given code width will result in either the correct code for that region or either adjacent one. Note that the linearity error is not user-adjustable. Unipolar Offset The first transition should occur at a level 1/2 LSB above analog common. Unipolar offset is defined as the deviation of the actual transition from that point. This offset can be adjusted as discussed on the following pages. The unipolar offset temperature coefficient specifies the maximum change of the transition point over temperature, with or without external adjustment. 15 DC Digital Common 16 DB0 Data Bit 0 (LSB) 17 DB1 Data Bit 1 18 DB2 Data Bit 2 Bipolar Offset 19 DB3 Data Bit 3 20 DB4 Data Bit 4 21 DB5 Data Bit 5 22 DB6 Data Bit 6 Similarly, in the bipolar mode, the major carry transition (0111 1111 1111 to 1000 0000 0000) should occur for an analog value 1/2 LSB below analog common. The bipolar offset error and temperature coefficient specify the initial deviation and maximum change in the error over temperature. 23 DB7 Data Bit 7 24 DB8 Data Bit 8 25 DB9 Data Bit 9 26 DB10 Data Bit 10 27 DB11 Data Bit 11 (MSB) 28 STS Status Bit - Status high implies a conversion is in progress. Full Scale Calibration Error The last transition (from 1111 1111 1110 to 1111 1111 1111) should occur for an analog value 11/2 LSB below the nominal full scale (9.9963V for 10.000V full scale). The full scale calibration error is the deviation of the actual level at the last transition from the ideal level. This error, which is typically 0.05 to 0.1% of full scale, can be trimmed out as shown in Figures 2 and 3. The full scale calibration error over temperature is given with and without the initial error trimmed out. The temperature coefficients for each grade indicate the maximum change in the full scale gain from the initial value using the internal 10V reference. 6-16 HI-574A, HI-674A, HI-774 Temperature Coefficients Power Supplies The temperature coefficients for full-scale calibration, unipolar offset, and bipolar offset specify the maximum change from the initial (25oC) value to the value at TMIN or TMAX . Supply voltages to the HI-X74(A) (+15V, -15V and +5V) must be "quiet" and well regulated. Voltage spikes on these lines can affect the converter's accuracy, causing several LSBs to flicker when a constant input is applied. Digital noise and spikes from a switching power supply are especially troublesome. If switching supplies must be used, outputs should be carefully filtered to assure "quiet" DC voltage at the converter terminals. Power Supply Rejection The standard specifications for the HI-X74A assume use of +5.00V and 15.00V or 12.00V supplies. The only effect of power supply error on the performance of the device will be a small change in the full scale calibration. This will result in a linear change in all lower order codes. The specifications show the maximum change in calibration from the initial value with the supplies at the various limits. Code Width A fundamental quantity for A/D converter specifications is the code width. This is defined as the range of analog input values for which a given digital output code will occur. The nominal value of a code width is equivalent to 1 least significant bit (LSB) of the full scale range or 2.44mV out of 10V for a 12-bit ADC. Quantization Uncertainty Analog-to-digital converters exhibit an inherent quantization uncertainty of 1/2 LSB. This uncertainty is a fundamental characteristic of the quantization process and cannot be reduced for a converter of given resolution. Left-justified Data The data format used in the HI-X74(A) is left-justified. This means that the data represents the analog input as a fraction of full-scale, ranging from 0 to 4095 . This implies a 4096 binary point to the left of the MSB. Applying the HI-X74(A) For each application of this converter, the ground connections, power supply bypassing, analog signal source, digital timing and signal routing on the circuit board must be optimized to assure maximum performance. These areas are reviewed in the following sections, along with basic operating modes and calibration requirements. Physical Mounting and Layout Considerations Layout Unwanted, parasitic circuit components, (L, R, and C) can make 12-bit accuracy impossible, even with a perfect A/D converter. The best policy is to eliminate or minimize these parasitics through proper circuit layout, rather than try to quantify their effects. The recommended construction is a double-sided printed circuit board with a ground plane on the component side. Other techniques, such as wire-wrapping or point-to-point wiring on vector board, will have an unpredictable effect on accuracy. In general, sensitive analog signals should be routed between ground traces and kept well away from digital lines. If analog and digital lines must cross, they should do so at right angles. Further, a bypass capacitor pair on each supply voltage terminal is necessary to counter the effect of variations in supply current. Connect one pair from pin 1 to 15 (VLOGIC supply), one from pin 7 to 9 (VCC to Analog Common) and one from pin 11 to 9 (VEE to Analog Common). For each capacitor pair, a 10F tantalum type in parallel with a 0.1F ceramic type is recommended. Ground Connections Pins 9 and 15 should be tied together at the package to guarantee specified performance for the converter. In addition, a wide PC trace should run directly from pin 9 to (usually) +15V common, and from pin 15 to (usually) the +5V Logic Common. If the converter is located some distance from the system's "single point" ground, make only these connections to pins 9 and 15: Tie them together at the package, and back to the system ground with a single path. This path should have low resistance. (Code dependent currents flow in the VCC , VEE and VLOGIC terminals, but not through the HI-X74(A)'s Analog Common or Digital Common). Analog Signal Source HI-574A and HI-674A The device chosen to drive the HI-X74A analog input will see a nominal load of 5k (10V range) or 10k (20V range). However, the other end of these input resistors may change 400mV with each bit decision, creating abrupt changes in current at the analog input. Thus, the signal source must maintain its output voltage while furnishing these step changes in load current, which occur at 1.6s and 950ns intervals for the HI-574A and HI-674A, respectively. This requires low output impedance and fast settling by the signal source. The output impedance of an op amp, for example, has an open loop value which, in a closed loop, is divided by the loop gain available at a frequency of interest. The amplifier should have acceptable loop gain at 600KHz for use with the HI-X74A. To check whether the output properties of a signal source are suitable, monitor the HI-X74A's input (pin 13 or 14) with an oscilloscope while a conversion is in progress. Each of the twelve disturbances should subside in 1s or less for the HI-574A and 500ns or less for the HI-674A. (The comparator decision is made about 1.5s and 850ns after each code change from the SAR for the HI-574A and HI-674A, respectively.) If the application calls for a Sample/Hold to precede the converter, it should be noted that not all Sample/Holds are compatible with the HI-574A in the manner described above. These will require an additional wideband buffer amplifier to lower their output impedance. A simpler solution is to use the Harris HA-5320 Sample/Hold, which was designed for use with the HI-574A. 6-17 HI-574A, HI-674A, HI-774 The device driving the HI-774 analog input will see a nominal load of 5k (10V range) or 10k (20V range). However, the other end of these input resistors may change as much as 400mV with each bit decision. These input disturbances are caused by the internal DAC changing codes which causes a glitch on the summing junction. This creates abrupt changes in current at the analog input causing a "kick back" glitch from the input. Because the algorithm starts with the MSB, the first glitches will be the largest and get smaller as the conversion proceeds. These glitches can occur at 350ns intervals so an op amp with a low output impedance and fast settling is desirable. Ultimately the input must settle to within the window of Figure 1 at the bit decision points in order to achieve 12-bit accuracy. The HI-774 differs from the most high-speed successive approximation type ADC's in that it does not require a high performance buffer or sample and hold. With error correction the input can settle while the conversion is underway, but only during the first 4.8s. The input must be within 10.76% of the final value when the MSB decision is made. This occurs approximately 650ns after the conversion has been initiated. Digital error correction also loosens the bandwidth requirements of the buffer or sample and hold. As long as the input "kick back" disturbances settle within the window of Figure 1 the device will remain accurate. The combined effect of settling and the "kick back" disturbances must remain in the Figure 1 window. direction by up to 15 LSBs. This results in a total correction range of +31 to -32 LSBs. When an 8-bit conversion is performed, the input must settle to within 1/2 LSB at 8-bit resolution (which equals 8 LSBs at 12-bit resolution). With the HI-774 a conversion can be initiated before the input has completely settled, as long as it meets the constraints of the Figure 1 window. This allows the user to start conversion up to 4.8s earlier than with a typical analog to digital converter. A typical successive approximation type ADC must have a constant input during a conversion because once a bit decision is made it is locked in and cannot change. 32 ALLOWABLE INPUT CHANGE (LSBs AT 12-BIT RESOLUTION) HI-774 8-BIT CONVERSION BIT DECISION POINTS 8 0 ~ 4.8s -8 LAST BIT DECISION (12-BIT) -16 MSB BIT DECISION ~ 650ns 12-BIT CONVERSION -31 1 CONVERSION INITIATED If the design is being optimized for speed, the input device should have closed loop bandwidth to 3MHz, and a low output impedance (calculated by dividing the open loop output resistance by the open loop gain). If the application requires a high speed sample and hold the Harris HA-5330 or HA-5320 are recommended. 2 3 4 5 TIME (s) 6 7 8 FIGURE 1. HI-774 ERROR CORRECTION WINDOW vs TIME In any design the input (pin 13 or 14) should be checked during a conversion to make sure that the input stays within the correctable window of Figure 1. Digital Error Correction OFFSET R1 100K HI-774 The HI-774 features the smart successive approximation register (SSAR) which includes digital error correction. This has the advantage of allowing the initial input to vary within a +31 to -32 LSB window about the final value. The input can move during the first 4.8s, after which it must remain stable within 1/2 LSB. With this feature a conversion can start before the input has settled completely; however, it must be within the window as described in Figure 1. 2 12/8 STS 28 3 CS HIGH BITS 24-27 4 AO MIDDLE BITS 5 R/C 6 CE 20-23 LOW BITS +15V -15V The conversion cycle starts by making the first 8-bit decisions very quickly, allowing the internal DAC to settle only to 8-bit accuracy. Then the converter goes through two error correction cycles. At this point the input must be stable within 1/2 LSB. These cycles correct the 8-bit word to 12-bit accuracy for any errors made (up to +16 or -32 LSBs). This is up one count or down two counts at 8-bit resolution. The converter then continues to make the 4 LSB decisions, settling out to 12-bit accuracy. The last four bits can adjust the code in the positive END OF CONVERSION (12 BIT) 1/2 LSB 16 16-19 GAIN R2 10 REF IN 100K 100 8 REF OUT 100 +5V 1 13 10VIN +15V 7 14 20VIN -15V 11 12 BIP OFF 0V TO +10V ANALOG INPUTS 0V TO +20V 9 ANA COM DIG COM 15 When driving the 20V (pin 14) input, minimize capacitance on pin 13. 6-18 FIGURE 2. UNIPOLAR CONNECTIONS HI-574A, HI-674A, HI-774 2 12/8 STS 28 3 CS HIGH BITS 24-27 4 AO MIDDLE BITS 5 R/C 6 CE adjustment is complete. Therefore, calibration is performed in terms of the observable code changes instead of the midpoint between code changes. For example, midpoint of the first LSB increment should be positioned at the origin, with an output code of all 0's. To do this, apply an input of +1/2 LSB (+1.22mV for the 10V range; +2.44mV for the 20V range). Adjust the Offset potentiometer R1 until the first code transition flickers between 0000 0000 0000 and 0000 0000 0001. 20-23 LOW BITS GAIN 16-19 R2 Next, perform a Gain Adjust at positive full scale. Again, the ideal input corresponding to the last code change is applied. This is 11/2 LSBs below the nominal full scale (+9.9963V for 10V range; +19.9927V for 20V range). Adjust the Gain potentiometer R2 for flicker between codes 1111 1111 1110 and 1111 1111 1111. 10 REF IN 100 8 REF OUT 100 5V ANALOG INPUTS 10V 12 BIP OFF R1 OFFSET +5V 1 +15V 7 13 10VIN 14 20VIN 9 ANA COM Bipolar Connections and Calibration -15V 11 Refer to Figure 3. The gain and offset errors listed under Specifications may be adjusted to zero using potentiometers R1 and R2 (see Note). If this isn't required, either or both pots may be replaced by a 50, 1% metal film resistor. DIG COM 15 When driving the 20V (pin 14) input, minimize capacitance on pin 13. FIGURE 3. BIPOLAR CONNECTIONS Range Connections and Calibration Procedures The HI-X74(A) is a "complete" A/D converter, meaning it is fully operational with addition of the power supply voltages, a Start Convert signal, and a few external components as shown in Figure 2 and Figure 3. Nothing more is required for most applications. Connect the Analog signal to pin 13 for a 5V range, or to pin 14 for a 10V range. Calibration of offset and gain is similar to that for the unipolar ranges as discussed above. First apply a DC input voltage 1/2 LSB above negative full scale (i.e., -4.9988V for the 5V range, or -9.9976V for the 10V range). Adjust the offset potentiometer R1 for flicker between output codes 0000 0000 0000 and 0000 0000 0001. Next, apply a DC input voltage 11/2 LSBs below positive full scale (+4.9963V for 5V range; +9.9927V for 10V range). Adjust the Gain potentiometer R2 for flicker between codes 1111 1111 1110 and 1111 1111 1111. Whether controlled by a processor or operating in the standalone mode, the HI-X74(A) offers four standard input ranges: 0V to +10V, 0V to +20V, 5V and 10V. The maximum errors for gain and offset are listed under Specifications. If required, however, these errors may be adjusted to zero as explained below. Power supply and ground connections have been discussed in an earlier section. NOTE: The 100 potentiometer R2 provides Gain Adjust for the 10V and 20V ranges. In some applications, a full scale of 10.24V (LSB equals 2.5mV) or 20.48V (LSB equals 5.0mV) is more convenient. For these, replace R2 by a 50, 1% metal film resistor. Then, to provide Gain Adjust for the 10.24V range, add a 200 potentiometer in series with pin 13. For the 20.48V range, add a 500 potentiometer in series with pin 14. Unipolar Connections and Calibration Controlling the HI-X74(A) Refer to Figure 2. The resistors shown (see Note) are for calibration of offset and gain. If this is not required, replace R2 with a 50, 1% metal film resistor and remove the network on pin 12. Connect pin 12 to pin 9. Then, connect the analog signal to pin 13 for the 0V to 10V range, or to pin 14 for the 0V to 20V range. Inputs to +20V (5V over the power supply) are no problem - the converter operates normally. The HI-X74(A) includes logic for direct interface to most microprocessor systems. The processor may take full control of each conversion, or the converter may operate in the "stand-alone" mode, controlled only by the R/C input. Full control consists of selecting an 8-bit or 12-bit conversion cycle, initiating the conversion, and reading the output data when ready-choosing either 12 bits at once or 8 followed by 4, in a left-justified format. The five control inputs are all TTL/CMOS-compatible: (12/8, CS, AO , R/C and CE). Table 1 illustrates the use of these inputs in controlling the converter's operations. Also, a simplified schematic of the internal control logic is shown in Figure 7. Calibration consists of adjusting the converter's most negative output to its ideal value (offset adjustment), then, adjusting the most positive output to its ideal value (gain adjustment). To understand the procedure, note that in principle, one is setting the output with respect to the midpoint of an increment of analog input, as denoted by two adjacent code changes. Nominal value of an increment is one LSB. However, this approach is impractical because nothing "happens" at a midpoint to indicate that an 6-19 HI-574A, HI-674A, HI-774 "Stand-Alone Operation" Conversion Length The simplest control interface calls for a singe control line connected to R/C. Also, CE and 12/8 are wired high, CS and AO are wired low, and the output data appears in words of 12 bits each. A Convert Start transition (see Table 1) latches the state of AO , which determines whether the conversion continues for 12 bits (AO low) or stops with 8 bits (AO high). If all 12 bits are read following an 8-bit conversion, the last three LSBs will read ZERO and DB3 will read ONE. AO is latched because it is also involved in enabling the output buffers (see "Reading the Output Data"). No other control inputs are latched. The R/C signal may have any duty cycle within (and including) the extremes shown in Figures 8 and 9. In general, data may be read when R/C is high unless STS is also high, indicating a conversion is in progress. Timing parameters particular to this mode of operation are listed below under "Stand-Alone Mode Timing". TABLE 1. TRUTH TABLE FOR HI-X74(A) CONTROL INPUTS HI-574A STAND-ALONE MODE TIMING SYMBOL PARAMETER MIN TYP MAX UNITS tHRL Low R/C Pulse Width 50 - - ns tDS STS Delay from R/C - - 200 ns Data Valid after R/C Low 25 - - ns STS Delay after Data Valid 300 - 1200 ns tHRH High R/C Pulse Width 150 - - ns tDDR Data Access Time - - 150 ns tHDR tHS Time is measured from 50% level of digital transitions. Tested with a 50pF and 3k load. CE CS R/C 12/8 AO 0 X X X X None X 1 X X X None 0 0 X 0 Initiate 12-bit conversion 0 0 X 1 Initiate 8-bit conversion 1 0 X 0 Initiate 12-bit conversion 1 0 X 1 Initiate 8-bit conversion 1 0 X 0 Initiate 12-bit conversion 1 0 X 1 Initiate 8-bit conversion 1 0 1 1 X Enable 12-bit Output 1 0 1 0 0 Enable 8 MSBs Only 1 0 1 0 1 Enable 4 LSBs Plus 4 Trailing Zeroes HI-674A STAND-ALONE MODE TIMING SYMBOL PARAMETER MIN TYP MAX UNITS tHRL Low R/C Pulse Width 50 - - ns tDS STS Delay from R/C - - 200 ns Data Valid after R/C Low 25 - - ns STS Delay after Data Valid 25 - 850 ns tHRH High R/C Pulse Width 150 - - ns tDDR Data Access Time - - 150 ns tHDR tHS OPERATION Conversion Start A conversion may be initiated as shown in Table 1 by a logic transition on any of three inputs: CE, CS or R/C. The last of the three to reach the correct state starts the conversion, so one, two or all three may be dynamically controlled. The nominal delay from each is the same, and if necessary, all three may change state simultaneously. However, to ensure that a particular input controls the start of conversion, the other two should be set up at least 50ns earlier. See the HI-774 Timing Specifications, Convert Mode. Time is measured from 50% level of digital transitions. Tested with a 50pF and 3k load. This variety of HI-X74(A) control modes allows a simple interface in most system applications. The Convert Start timing relationships are illustrated in Figure 4. HI-774 STAND-ALONE MODE TIMING tHRL Low R/C Pulse Width 50 - - ns tDS STS Delay from R/C - - 200 ns The output signal STS indicates status of the converter by going high only while a conversion is in progress. While STS is high, the output buffers remain in a high impedance state and data cannot be read. Also, an additional Start Convert will not reset the converter or reinitiate a conversion while STS is high. 20 - - ns Reading the Output Data - - 850 ns 150 - - ns - - 150 ns The output data buffers remain in a high impedance state until four conditions are met: R/C high, STS low, CE high and CS low. At that time, data lines become active according to the state of inputs 12/8 and AO . Timing constraints are illustrated in Figure 5. SYMBOL tHDR tHS PARAMETER Data Valid after R/C Low STS Delay after Data Valid tHRH High R/C Pulse Width tDDR Data Access Time MIN TYP MAX UNITS 6-20 HI-574A, HI-674A, HI-774 The 12/8 input will be tied high or low in most applications, though it is fully TTL/CMOS-compatible. With 12/8 high, all 12 output lines become active simultaneously, for interface to a 12-bit or 16-bit data bus. The AO input is ignored. CE With 12/8 low, the output is organized in two 8-bit bytes, selected one at a time by AO . This allows an 8-bit data bus to be connected as shown in Figure 6. AO is usually tied to the least significant bit of the address bus, for storing the HI-X74(A) output in two consecutive memory locations. (With AO low, the 8 MSBs only are enabled. With AO high, 4 MSBs are disabled, bits 4 through 7 are forced low, and the 4 LSBs are enabled). This two byte format is considered "left justified data," for which a decimal (or binary!) point is assumed to the left of byte 1: BYTE 1 * X X X X tHRR R/C tSRR AO tSAR STS X X X X X X MSB X 0 tHAR tHS BYTE 2 X tHSR tSSR CS 0 0 0 DB11-DB0 HIGH IMPEDANCE tDD LSB Further, AO may be toggled at any time without damage to the converter. Break-before-make action is guaranteed between the two data bytes, which assures that the outputs strapped together in Figure 6 will never be enabled at the same time. tHD DATA VALID tHL See HI-774 Timing Specifications for more information. FIGURE 5. READ CYCLE TIMING A read operation usually begins after the conversion is complete and STS is low. For earliest access to the data, however, the read should begin no later than (tDD + tHS) before STS goes low. See Figure 5. AO 2 12/8 tSSC CS R/C tHSC tSRC STS 28 1 tHEC CE ADDRESS BUS tHRC DB11 (MSB) 27 3 26 4 AO 25 5 24 6 23 22 7 AO 8 tSAC tHAC STS tC tDSC HIGH IMPEDANCE DB11-DB0 HI-774 21 9 20 10 19 11 18 12 17 13 DB0 (LSB) 16 DIG. 15 COM. 14 See HI-774 Timing Specifications for more information. FIGURE 4. CONVERT START TIMING FIGURE 6. INTERFACE TO AN 8-BIT DATA BUS 6-21 DATA BUS HI-574A, HI-674A, HI-774 NIBBLE B ZERO OVERRIDE NIBBLE A, B INPUT BUFFERS 12/8 NIBBLE C READ CONTROL CS AO STATUS R/C CE CONVERT CONTROL EOC9 CURRENT CONTROLLED OSCILLATOR STROBE CLOCK CK D POWER UP RESET Q Q RESET AO LATCH EOC13 FIGURE 7. HI-774 CONTROL LOGIC tHRL R/C tDS STS tC tHDR DB11-DB0 tHS DATA VALID DATA VALID FIGURE 8. LOW PULSE FOR R/C - OUTPUTS ENABLED AFTER CONVERSION R/C tHRH tDS STS tDDR DB11-DB0 HIGH-Z tC tHDR HIGH-Z DATA VALID FIGURE 9. HIGH PULSE FOR R/C - OUTPUTS ENABLED WHILE R/C HIGH, OTHERWISE HIGH-Z 6-22 HI-574A, HI-674A, HI-774 Die Characteristics DIE DIMENSIONS: PASSIVATION: Analog: 3070mm x 4610mm Digital: 1900mm x 4510mm Type: Nitride Over Silox Nitride Thickness: 3.5kA 0.5kA Silox Thickness: 12kA 1.5kA METALLIZATION: WORST CASE CURRENT DENSITY: Digital Type: Nitrox Thickness: 10kA 2kA 1.3 x 105 A/cm2 Metal 1: AlSiCu Thickness: 8kA 1kA Metal 2: AlSiCu Thickness: 16kA 2kA Analog Type: Al Thickness: 16kA 2kA Metallization Mask Layout DB11 STS VLOGIC VLOGIC 12/8 CS AO HI-574A, HI-674A, HI-774 R/C DB10 CE VCC DB9 VREFOUT ANALOG COMMON DB8 ANALOG COMMON DB7 ANALOG COMMON DB6 VREFIN DB5 DB4 DB3 DB2 6-23 DB1 DB0 DIGITAL COMMON 10V IN 20V IN BIPOLAR OFFSET VEE