HI-565A S E M I C O N D U C T O R High Speed, Monolithic D/A Converter with Reference August 1997 Features Description * 12-Bit DAC and Reference on a Single Chip The HI-565A is a fast, 12-bit, current output, digital-to-analog converter. The monolithic chip includes a precision voltage reference, thin-film R2R ladder, reference control amplifier and twelve high speed bipolar current switches. * Pin Compatible With AD565A * Very High Speed: Settles to 0.5 LSB in 250ns (Max) Full Scale Switching Time 30ns (Typ) * Guaranteed For Operation With 12V Supplies * Monotonicity Guaranteed Over Temperature * Nonlinearity Guaranteed Over Temp (Max) . . 0.5 LSB * Low Gain Drift (Max, DAC Plus Ref) . . . . . . 25ppm/oC * Low Power Dissipation . . . . . . . . . . . . . . . . . . . .250mW Applications * CRT Displays The Harris dielectric isolation process provides latch free operation while minimizing stray capacitance and leakage currents, to produce an excellent combination of speed and accuracy. Also, ground currents are minimized to produce a low and constant current through the ground terminal, which reduces error due to code dependent ground currents. HI-565A dice are laser trimmed for a maximum integral non-linearity error of 0.5 LSB at 25oC. In addition, the low noise buried zener reference is trimmed both for absolute value and temperature coefficient. Power dissipation is typically 250mW, with 15V supplies. The HI-565A is offered in both commercial and military grades. See Ordering Information. * High Speed A/D Converters * Signal Reconstruction * Waveform Synthesis Ordering Information LINEARITY (INL) LINEARITY (DNL) TEMP. RANGE (oC) HI1-565AJD-5 0.50 LSB 0.75 LSB 0 to 75 24 Ld SBDIP D24.6 HI1-565AKD-5 0.25 LSB 0.50 LSB 0 to 75 24 Ld SBDIP D24.6 HI1-565ASD-2 0.50 LSB 0.75 LSB -55 to 125 24 Ld SBDIP D24.6 HI1-565ATD-2 0.25 LSB 0.50 LSB -55 to 125 24 Ld SBDIP D24.6 HI1-565ASD/883 0.50 LSB 0.50 LSB -55 to 125 24 Ld SBDIP D24.6 HI1-565ATD/883 0.25 LSB 0.50 LSB -55 to 125 24 Ld SBDIP D24.6 PART NUMBER Pinout PACKAGE Functional Diagram HI-565A (SBDIP) TOP VIEW REF OUT VCC 3 NC 1 24 BIT 1 (MSB) IN 4 NC 2 23 BIT 2 IN + VCC 3 22 BIT 3 IN REF OUT (+10V) 4 21 BIT 4 IN REF GND 5 20 BIT 5 IN REF IN 6 19 BIT 6 IN -VEE 7 18 BIT 7 IN BIPOLAR R IN 8 17 BIT 8 IN IDAC OUT 9 16 BIT 9 IN 10V SPAN R 10 15 BIT 10 IN 20V SPAN R 11 14 BIT 11 IN POWER GND 12 8 HI-565A 5K REF IN 6 19.95K REF GND (c) Harris Corporation 1997 10 10V SPAN 9.95K IREF 0.5mA - 5 11 20V SPAN BIP. OFF 5K DAC 9 IO 3.5K + (4X IREF X CODE) - OUT 2.5K 3K 7 12 24 . . . -VEE PWR MSB GND . . .13 LSB 13 BIT 12 (LSB) IN CAUTION: These devices are sensitive to electrostatic discharge. Users should follow proper IC Handling Procedures. Copyright PKG. NO. 10-12 File Number 3109.1 HI-565A Absolute Maximum Ratings Thermal Information VCC to Power GND. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0V to +18V VEE to Power GND . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0V to -18V Voltage on DAC Output (Pin 9) . . . . . . . . . . . . . . . . . . . . -3V to +12V Digital Inputs (Pins 13-24) to Power GND . . . . . . . . . . -1V to +7.0V REF In to REF GND . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12V Bipolar Offset to REF GND. . . . . . . . . . . . . . . . . . . . . . . . . . . . 12V 10V Span R to REF GND . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12V 20V Span R to REF GND . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24V REF Out . . . . . . . . . . . . . . . . . . . . . . Indefinite Short to Power GND Momentary Short to VCC Thermal Resistance (Typical, Note 1) JA (oC/W) JC (oC/W) SBDIP Package . . . . . . . . . . . . . . . . . . 75 30 Maximum Package Power Dissipation SBDIP Package . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 500mW Maximum Junction Temperature . . . . . . . . . . . . . . . . . . . . . . . 175oC Maximum Storage Temperature Range . . . . . . . . . .-65oC to 150oC Maximum Lead Temperature (Soldering 10s) . . . . . . . . . . . . . 300oC Operating Conditions Die Characteristics Transistor Count . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 200 Process . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Bipolar-DI Temperature Ranges HI-565AS,T-2. . . . . . . . . . . . . . . . . . . . . . . . . . . . . -55oC to 125oC H1-565AJ, K-5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .0oC to 75oC CAUTION: Stresses above those listed in "Absolute Maximum Ratings" may cause permanent damage to the device. This is a stress only rating and operation of the device at these or any other conditions above those indicated in the operational sections of this specification is not implied. NOTE: 1. JA is measured with the component mounted on an evaluation PC board in free air. Electrical Specifications TA = 25oC, VCC = +15V, VEE = -15V, Unless Otherwise Specified HI-565AJ, HI565AS PARAMETER HI-565AK, HI-565AT TEST CONDITIONS MIN TYP MAX MIN TYP MAX UNITS Input Voltage Bit ON Logic "1" (TMlN to TMAX) +2.0 - +5.5 +2.0 - +5.5 V Input Voltage Bit OFF Logic "0" (TMlN to TMAX) - - +0.8 - - +0.8 V Logic Current Bit ON Logic "1" (TMlN to TMAX) - 0.01 +1.0 - 0.01 +1.0 A Logic Current Bit OFF Logic "0" (TMlN to TMAX) - -2.0 -20 - -2.0 -20 A 12 - - 12 - - Bits DATA INPUTS (Pins 13 to 24) (Note 1) Resolution OUTPUT Unipolar Current (All Bits ON) -1.6 -2.0 -2.4 -1.6 -2.0 -2.4 mA Bipolar Current (All Bits ON or OFF) 0.8 1.0 1.2 0.8 1.0 1.2 mA Resistance (Exclusive of Span Resistors) 1.8K 2.5K 3.2K 1.8K 2.5K 3.2K - 0.01 0.05 - 0.01 0.05 % of FS - 0.05 0.15 - 0.05 0.1 % of FS - 20 - - 20 - pF -1.5 - +10 -1.5 - +10 V Unipolar Offset at 25oC 0.07oC Over Temperature Bipolar Offset at 0.2 (T), 0.25 (S) Over Temperature (Figure 2, R3 = 50 Fixed) Capacitance Compliance Voltage (TMIN to TMAX) ACCURACY (Error Relative to Full Scale) Integral Non-Linearity (25oC) End Point Method - 0.25 (0.006) 0.50 (0.012) - 0.12 (0.003) 0.12 (0.006) LSB % of FS Integral Non-Linearity (TMIN to TMAX) End Point Method - 0.50 (0.012) 0.75 (0.018) - 0.25 (0.006) 0.50 (0.012) LSB % of FS Differential Non-Linearity 25oC - 0.50 0.75 - 0.25 0.50 LSB Differential Non-Linearity TMIN to TMAX 2 ppm/ oC MONOTONICITY GUARANTEED TEMPERATURE COEFFIClENTS With Internal Reference Unipolar Zero - 10-13 1 2 - 1 HI-565A Electrical Specifications TA = 25oC, VCC = +15V, VEE = -15V, Unless Otherwise Specified (Continued) HI-565AJ, HI565AS PARAMETER TEST CONDITIONS HI-565AK, HI-565AT MIN TYP MAX MIN TYP MAX UNITS With Internal Reference Bipolar Zero - 5 10 - 5 10 ppm/ oC With Internal Reference Gain (Full Scale) - 15 40 - 10 25 ppm/ oC With Internal Reference Differential Nonlinearity - 2 - - 2 - ppm/ oC - 350 500 - 350 500 ns - 150 250 - 150 250 ns SETTLING TIME T0 0.5 LSB With High, Z External Load (Note 2) With 75 External Load FULL SCALE TRANSITION From 50% of Logic Input to 90% of Analog Output Rise Time - 15 30 - 15 30 ns Fall Time - 30 50 - 30 50 ns POWER REQUIREMENTS VCC (+11.4 to +16.5VDC) - 9.0 11.8 - 9.0 11.8 mA VEE (+11.4 to -16.5VDC) - -9.5 -14.5 - -9.5 -14.5 mA POWER SUPPLY GAIN SENSITIVITY (Note 3) VCC (+11.4 to +16.5VDC) - 3 10 - 3 10 ppm of FS/% VEE (+11.4 to -16.5VDC) - 15 25 - 15 25 ppm of FS/% PROGRAMMABLE OUTPUT RANGES (See Table 2) Unipolar 5 (Note 1) 0 to +5 0 to +5 V Bipolar 5 (Note 1) -2.5 to +2.5 -2.5 to +2.5 V Unipolar 10 (Note 1) 0 to +10 0 to +10 V Bipolar 10 (Note 1) -5 to +5 -5 to +5 V Bipolar 20 (Note 1) -10 to +10 -10 to +10 V EXTERNAL ADJUSTMENTS 0.25 - 0.1 0.25 % of FS 0.05 0.15 - 0.05 0.1 % of FS 0.25 - - 0.25 - - % of FS 0.15 - - 0.15 - - % of FS 15K 20K 25K 15K 20K 25K - Voltage 9.90 10.00 10.10 9.90 10.00 10.10 V Current (Available for External Loads) 1.5 2.5 - 1.5 2.5 - mA Gain Error with Fixed 50 Resister for R2 (Figure 1) - Bipolar Zero Error with Fixed 50 Resister for R3 (Figure 2) - Gain Adjustment Range (Figure 1) Bipolar Zero Adjustment Range 0.1 REFERENCE INPUT Input Impedance REFERENCE OUTPUT NOTES: 1. Guaranteed by characterization or design but not tested over the operating temperature range. 2. See settling time discussion and Figure 3. 3. The Power Supply Gain Sensitivity is tested in reference to a VCC , VEE of 15V. 10-14 HI-565A Definitions of Specifications Digital Inputs The HI-565A accepts digital input codes in binary format and may be user connected for any one of three binary codes. Straight Binary, Two's Complement (Note 1), or Offset Binary, (See Operating Instructions). TABLE 1. ANALOG OUTPUT DIGITAL INPUT (NOTE 1) TWO'S COMPLEMENT STRAIGHT BINARY OFFSET BINARY 000...000 Zero -FS (Full Scale) Zero 100...000 1/ FS 2 Zero -FS 111...111 +FS - 1 LSB +FS - 1 LSB Zero - 1 LSB 011...111 1/2FS - 1 LSB Zero - 1 LSB +FS - 1 LSB Compliance Voltage is the maximum output voltage range that can be tolerated and still maintain its specified accuracy. Compliance Limit implies functional operation only, and makes no claims to accuracy. Glitch a glitch on the output of a D/A converter is a transient spike resulting from unequal internal ON-OFF switching times. Worst case glitches usually occur at half-scale or the major carry code transition from 011...1 to 100...0 or vice versa. For example, if turn ON is greater than turn OFF for 011...1 to 100...0, an intermediate state of 000...0 exists, such that, the output momentarily glitches toward zero output. Matched switching times and fast switching will reduce glitches considerably. MSB...LSB Detailed Description Op Amp Selection The Hl-565As current output may be converted to voltage using the standard connections shown in Figures 1 and 2. The choice of operational amplifier should be reviewed for each application, since a significant trade-off may be made between speed and accuracy. NOTE: 1. Invert MSB with external inverter to obtain Two's Complement Coding. Nonlinearity of a D/A converter is an important measure of its accuracy. It describes the deviation from an ideal straight line transfer curve drawn between zero (all bits OFF) and full scale (all bits ON) (End Point Method). Differential Nonllnearlty for a D/A converter, it is the difference between the actual output voltage change and the ideal (1 LSB) voltage change for a one bit change in code. A Differential Nonlinearity of 1 LSB or less guarantees monotonicity; i.e., the output always increases for an increasing input. Settling Time is the time required for the output to settle to within the specified error band for any input code transition. It is usually specified for a full scale or major carry transition, settling to within 0.5 LSB of final value. Gain Drift is the change in full scale analog output over the specified temperature range, expressed in parts per million of full scale range per oC (ppm of FSR/ oC). Gain error is measured with respect to 25oC at high (TH) and low (TL) temperatures. Gain drift is calculated for both high (TH -25oC) and low ranges (25oC -TL) by dividing the gain error by the respective change in temperature. The specification is the larger of the two representing worst-case drift. Offset Drift is the change in analog output with all bits OFF over the specified temperature range expressed in parts per million of full scale range per oC (ppm of FSR/ oC). Offset error is measured with respect to 25oC at high (TH) and low (TL) temperatures. Offset Drift is calculated for both high (TH -25oC) and low (25oC -TL) ranges by dividing the offset error by the respective change in temperature. The specification given is the larger of the two, representing worst-case drift. Power Supply Sensitivity is a measure of the change in gain and offset of the D/A converter resulting from a change in -15V or +15V supplies. It is specified under DC conditions and expressed as parts per million of full scale range per percent of change in power supply (ppm of FSR/%). For highest precision, use an HA-5130. This amplifier contributes negligible error, but requires about 11s to settle within 0.1% following a 10V step. The Harris Semiconductor HA-2600 is the best all-around choice for this application, and it settles in 1.5s (also to 0.1% following a 10V step). Remember, settling time for the DAC amplifier combination is the square root of tD2 plus tA2, where tD , tA are settling times for the DAC and amplifier. No-Trim Operation The Hl-565A will perform as specified without calibration adjustments. To operate without calibration, substitute 50 resistors for the 100 trimming potentiometers: In Figure 1 replace R2 with 50 also remove the network on pin 8 and connect 50 to ground. For bipolar operation in Figure 2, replace R3 and R4 with 50 resistors. With these changes, performance is guaranteed as shown under Specifications, "External Adjustments". Typical unipolar zero will be 0.5 LSB plus the op amp offset. The feedback capacitor, C, must be selected to minimize settling time. Calibration Calibration provides the maximum accuracy from a converter by adjusting its gain and offset errors to zero. For the Hl-565A, these adjustments are similar whether the current output is used, or whether an external op amp is added to convert this current to a voltage. Refer to Table 2 for the voltage output case, along with Figure 1 or Figure 2. Calibration is a two step process for each of the five output ranges shown in Table 2. First adjust the negative full scale (zero for unipolar ranges). This is an offset adjust which translates the output characteristic, i.e., affects each code by the same amount. Next adjust positive FS. This is a gain error adjustment, which rotates the output characteristic about the negative FS value. 10-15 HI-565A For the bipolar ranges, this approach leaves an error at the zero code, whose maximum value is the same as for integral nonlinearity error. In general, only two values of output may be calibrated exactly; all others must tolerate some error. Choosing the extreme end points (plus and minus full scale) minimizes this distributed error for all other codes. TABLE 2. OPERATING MODES AND CALIBRATION CIRCUIT CONNECTIONS MODE Unipolar (See Figure 1) OUTPUT PRANGE PIN 10 TO PIN 11 TO RESlSTOR (R) 0 to +10V VO Pin 10 0 to +5V VO 10V Bipolar (See Figure 2) APPLY INPUT CODE ADJUST TO SET VO 1.43K All 0's All 1's R1 R2 0V +9.99756V Pin 9 1.1K All 0's All 1's R1 R2 0V +4.99878V NC VO 1.69K All 0's All 1's R3 R4 -10V +9.99512V 5V VO Pin 10 1.43K All 0's All 1's R3 R4 -5V +4.99756V 2.5V VO Pin 9 1.1K All 0's All 1's R3 R4 -2.5V +2.49878V VCC REF OUT 4 BIP. OFF. 3 8 11 R4 100 + HI-565A 10V REF IN CALIBRATION 6 9.95K DAC 0.5mA 19.95K REF 5 GND - 10 5K 10V SPAN C 9 IO (4 x I REF x CODE) + 3.5K 100 5K I REF 100k 20V SPAN + - DAC OUT 2.5K VO R (SEE TABLE 2) 3K CODE INPUT 7 -VEE 12 24 MSB 13 LSB PWR GND FIGURE 1. UNIPOLAR VOLTAGE OUTPUT R3 4 BIP. OFF. 3 8 11 R4 100 + 10V REF IN 100 VCC REF OUT 6 REF 5 GND HI-565A 5K I REF 9.95K DAC 0.5mA 19.95K 5K 3.5K (4 x I REF x CODE) - 10V SPAN C 9 IO + 10 20V SPAN 2.5K DAC OUT VO + - R (SEE TABLE 2) 3K CODE INPUT 7 -VEE 12 24 MSB 13 LSB PWR GND FIGURE 2. BIPOLAR VOLTAGE OUTPUT 10-16 +15V R1 50k -15V HI-565A Settling Time This is a challenging measurement, in which the result depends on the method chosen, the precision and quality of test equipment and the operating configuration of the DAC (test conditions). As a result, the different techniques in use by converter manufacturers can lead to consistently different results. An engineer should understand the advantage and limitations of a given test method before using the specified settling time as a basis for design. The approach used for several years at Harris Analog Products Division calls for a strobed comparator to sense final perturbations of the DAC output waveform. This gives the LSB a reasonable magnitude (814V for the HI-565A), which provides the comparator with enough overdrive to establish an accurate 0.5 LSB window about the final settled value. Also, the required test conditions simulate the DACs environment for a common application - use in a successive approximation A/D converter. Considerable experience has shown this to be a reliable and repeatable way to measure settling time. The usual specification is based on a 10V step, produced by simultaneously switching all bits from off-to-on (tON) or onto-off (tOFF). The slower of the two cases is specified, as measured from 50% of the digital input transition to the final entry within a window of 0.5 LSB about the settled value. Four measurements characterize a given type of DAC: (a) tON , to final value +0.5 LSB (b) tON , to final value -0.5 LSB (c) tOFF , to final value +0.5 LSB (d) tOFF , to final value -0.5 LSB OUT SYNC IN PULSE GENERATOR NO. 1 TRIG OUT Procedure As shown in Figure 3B, settling time equals tX plus the comparator delay (tD = 15ns). To measure tX : * Adjust the delay on generator No. 2 for a tX of several microseconds. This assures that the DAC output has settled to its final value. * Switch on the LSB (+5V). * Adjust the VLSB supply for 50% triggering at COMPARATOR OUT. This is indicated by traces of equal brightness on the oscilloscope display as shown in Figure 3B. Note DVM reading. * Switch the LSB to Pulse (P). * Readjust the VLSB supply for 50% triggering as before, and note DVM reading. One LSB equals one tenth the difference in the DVM readings noted above. * Adjust the VLSB supply to reduce the DVM reading by 5 LSBs (DVM reads 10X, so this sets the comparator to sense the final settled value minus 0.5 LSB). Comparator output disappears. * Reduce generator No. 2 delay until comparator output reappears, and adjust for "equal brightness". * Measure tX from scope as shown in Figure 3B. Settling time equals tX + tD , i.e., tX + 15ns. PULSE GENERATOR NO. 2 OUT +3V 20V 20% BIAS (A) (Cases (b) and (c) may be eliminated unless the overshoot exceeds 0.5 LSB). For example, refer to Figure 3 for the measurement of case (d). 0V HI-565A 24 8 TURN ON 23 11 TURN OFF 9.95K 5K P 13 10 NC (B) 2.5K LSB STROBE IN (D) COMP OUT 2V 12 10 90 0.1F tX COMP. STROBE 0.8V EQUAL BRIGHTNESS 4V COMP. OUT (D) 200K DVM SETTLING TIME tD = COMPARATOR DELAY 50% (C) SCHOTTKY DIODES 5 2mA DAC OUTPUT (B) (TURN -400mV OFF) 9 +5V -0.5 LSB 0V 5K 14 DIGITAL INPUT 50% (A) (C) 0V VLSB SUPPLY ~100kHz FIGURE 3A. FIGURE 3B. 10-17 HI-565A Other Considerations Grounds Bypass Capacitors The Hl-565A has two ground terminals, pin 5 (REF GND) and pin 12 (PWR GND). These should not be tied together near the package unless that point is also the system signal ground to which all returns are connected. (If such a point exists, then separate paths are required to pins 5 and 12). Power supply bypass capacitors on the op amp will serve the HI-565A also. If no op amp is used, a 0.01F ceramic capacitor from each supply terminal to pin 12 is sufficient, since supply current variations are small. The current through pin 5 is near-zero DC (Note 1); but pin 12 carries up to 1.75mA of code - ependent current from bits 1, 2, and 3. The general rule is to connect pin 5 directly to the system "quiet" point, usually called signal or analog ground. Connect pin 12 to the local digital or power ground. Then, of course, a single path must connect the analog/signal and digital/power grounds. Layout Connections to pin 9 (IOUT) on the Hl-565A are most critical for high speed performance. Output capacitance of the DAC is only 20pF, so a small change or additional capacitance may alter the op amp's stability and affect settling time. Connections to pin 9 should be short and few. Component leads should be short on the side connecting to pin 9 (as for feedback capacitor C). See the Settling Time section. Current Cancellation Current cancellation is a two step process within the HI-565A in which code dependent variations are eliminated, then the resulting DC current is supplied internally. First an auxiliary 9-bit R-2R ladder is driven by the complement of the DACs input code. Together, the main and auxiliary ladders draw a continuous 2.25mA from the internal ground node, regardless of input code. Part of this DC current is supplied by the zener voltage reference, and the remainder is sourced from the positive supply via a current mirror which is laser trimmed for zero current through the external terminal (pin 5). 10-18 HI-565A Die Characteristics DIE DIMENSIONS: WORST CASE CURRENT DENSITY: 0.75 x 105 A/cm2 179 mils x 107 mils x 19 mils 1 mil METALLIZATION: TRANSISTOR COUNT: Type: Al Thickness: 16kA 2kA 200 PASSIVATION: Type: Nitride Over Silox Nitride Thickness: 3.5kA 0.5kA Silox Thickness: 12kA 1.5kA Metallization Mask Layout HI-565A (MSB) BIT 1 V+ BIT 2 VREF OUT BIT 3 VREF GND BIT 4 BIT 5 VREF IN -VS BIT 6 BIPOLAR 12 BIT 7 IDAC OUT BIT 8 BIT 9 10V SPAN BIT 10 20V POWER BIT 12 SPAN GND (LSB) 10-19 BIT 11