SPT5420 13-BIT, OCTAL D/A CONVERTER TECHNICAL DATA JUNE 26, 2001 FEATURES APPLICATIONS • 13-bit resolution • Pin compatible with AD7839 • Eight DACs in one package • Buffered voltage outputs • Wide output voltage swing V DD–2.5 V to VSS+2.5 V • 15 µs settling time to ±0.5 LSB • Double-buffered digital inputs • Microprocessor and TTL/CMOS compatible • Automatic test equipment • Instrumentation • Process control GENERAL DESCRIPTION DAC’s full-scale output voltage and output voltage offset are adjustable with analog inputs (RGND, VREFB, VREFT). The SPT5420 contains eight 13-bit digital-to-analog CMOS converters designed primarily for automatic test equipment applications. It uses novel circuit topology to convert the 13-bit digital inputs into output voltages which are proportionate to the applied reference voltages. Each The SPT5420 operates over an industrial temperature range of –40 °C to +85 °C and is available in a 10 x 10 mm, 44-lead metric quad flat pack (MQFP) plastic package. BLOCK DIAGRAM VREFT01 VREFB01 13 D 0A LEA0 13 D 1A LEA1 13 D 2A LEA2 13 D0D12 13 LDAC D 4A LEA4 WR CS 3A LEA3 13 A0A2 D Control 8 Logic LEA0LEA7 13 LDAC D 5A LEA5 13 D 6A LEA6 13 D 7A LEA7 Q LE D 0B Q LE 1B Q LE 2B Q LE 3B Q LE 4B Q LE 5B Q LE 6B Q LE 7B Q LE 13 RGND23 RGND01 - + DAC0 LDAC Q LE D 13 - + DAC1 VOUT0 VOUT1 LDAC Q LE D 13 - + DAC2 LDAC Q LE D - 13 DAC3 + DAC4 + VOUT2 VOUT3 LDAC Q LE D 13 - VOUT4 LDAC Q LE D 13 + DAC5 - VOUT5 LDAC Q LE D 13 + DAC6 - VOUT6 LDAC Q LE D 13 + DAC7 - LDAC VREFT2345 VREFB2345 VREFT67 VREFB67 CLR RGND45 RGND67 VOUT7 ABSOLUTE MAXIMUM RATINGS (Beyond which damage may occur)1 25 °C Supply Voltages VCC ........................................................................ +6 V VDD ...................................................................... +15 V VSS ...................................................................... –15 V Temperature Operating Temperature .......................... –40 to +85 °C Storage ................................................ –65 to +150 °C Input Voltages VREFT .................................... VSS –0.3 V to VDD +0.3 V VREFB ................................... VDD +0.3 V to VSS –0.3 V Digital inputs ....................................–0.3 V to VCC +0.3 V Note: 1. Operation at any Absolute Maximum Rating is not implied. See Electrical Specifications for proper nominal applied conditions in typical applications. ELECTRICAL SPECIFICATIONS TA = TMIN to TMAX, VCC = +5.0 V, VDD = +11.5 V, VSS = –8.0 V, VREFT=3.5 V, VREFB = –1.5 V, RL = +10 kΩ, CL = 50 pF, unless otherwise specified. TEST LEVEL MIN Accuracy Resolution Integral Linearity Error (ILE) Differential Linearity Error (DLE) Zero-Scale Error Full Scale Error Gain Error VI VI VI VI VI VI 13 –2.0 –1.0 –25 –25 –25 Reference Inputs Input Current VREFT1 VREFB2 IV VI VI 0 –5.0 RGND Inputs DC Input Impedance Input Range V IV –2.0 Output Characteristics Output Swing3,4 Short Circuit Current Resistive Load DC Output Impedance VI IV VI IV Digital Inputs Logic 1 Voltage Logic 0 Voltage Maximum Input Current Input Capacitance VI VI VI V PARAMETERS TEST CONDITIONS SPT5420 TYP ±0.5 ±0.3 +3.5 –1.5 MAX UNITS +2.0 +1.0 +25 +25 +25 Bits LSB LSB mV mV mV ±100 +5.0 0 nA V V 2.0 kΩ V 60 +7/–3 15 5 1.0 2.4 0.8 10 –10 10 V mA kΩ Ω V V µA/pin pF Notes: 1. VREFT < 8 V + (VSS x 0.5); e.g., if VSS = –8 V, then VREFT < 4 V 2. VREFB > (VDD x 0.5) – 9.5 V; e.g., if VDD = 11 V, then VREFB > –4 V 3. VSS + 2.5 V ≤ VOUT ≤ VSS + 16.0 V for 18.5 V ≤ VDD – VSS ≤ 20.0 V VSS + 2.5 V ≤ VOUT ≤ VDD – 2.5 V for VDD – VSS ≤ 18.5 V 4. VOUT = 2 X (VREFB +[VREFT – VREFB] X INPUT CODE 8192 ) – VRGND SPT5420 2 6/26/01 ELECTRICAL SPECIFICATIONS TA = TMIN to TMAX, VCC = +5.0 V, VDD = +11.5 V, VSS = –8.0 V, VREFT=3.5 V, VREFB=–1.5 V, RL = +10 kΩ, CL = 50 pF, unless otherwise specified. PARAMETERS Power Requirements VCC Supply Voltage (Digital) VDD Supply Voltage (Analog)1,2 VSS Supply Voltage (Analog)1,2 ICC Supply Current IDD Supply Current ISS Supply Current Power Supply Rejection Ratio TEST CONDITIONS TEST LEVEL IV VI VI VI VI VI IV IV Outputs Unloaded Outputs Unloaded ∆VDD / ∆Full Scale ∆VSS / ∆Full Scale Dynamic Performance Output Settling Time3 (Full Scale Change to ±0.5 LSB) CL ≤ 220 pF Slew Rate Glitch Impulse Channel to Channel Isolation DAC to DAC Crosstalk Digital Crosstalk Digital Feedthrough IV V V V V V V Timing Characteristics (See page 4) IV MIN SPT5420 TYP 4.75 5 –12.5 5 11.5 –8 5 5 80 80 MAX UNITS 5.25 12.5 –5 0.5 10 10 V V V mA mA mA dB dB 15 2.0 35 100 40 1 1 µs V/µs nV-s dB nV-s nV-s nV-s 1. Supplies should provide 2.5 V headroom above and below max output swing. 2. VDD – VSS ≤ 20 V 3. Output can drive 10,000 pF without oscillation, but with settling time degradation. DEFINITION OF SELECTED TERMINOLOGY Channel-to-Channel Isolation Channel-to-Channel isolation refers to the proportion of input signal from one DAC’s reference input that appears at the output of the other DAC. It is expressed in dBs. DAC-to-DAC Crosstalk DAC-to-DAC crosstalk is defined as the glitch impulse that appears at one DAC’s output due to both the digital change and subsequent analog output change at any other DAC. It is specified in nV-s. Digital Crosstalk The glitch impulse transferred to one DAC’s output due to a change in digital input code of any other DAC. It is specified in nV-s. Digital Feedthrough Digital feedthrough is the noise at a DAC’s output caused by changes to D0–D12 while WR is high. TEST LEVEL CODES All electrical characteristics are subject to the following conditions: All parameters having min/max specifications are guaranteed. The Test Level column indicates the specific device testing actually performed during production and Quality Assurance inspection. Any blank section in the data column indicates that the specification is not tested at the specified condition. LEVEL I II III IV V VI TEST PROCEDURE 100% production tested at the specified temperature. 100% production tested at TA = +25 °C, and sample tested at the specified temperatures. QA sample tested only at the specified temperatures. Parameter is guaranteed (but not tested) by design and characterization data. Parameter is a typical value for information purposes only. 100% production tested at TA = +25 °C. Parameter is guaranteed over specified temperature range. SPT5420 3 6/26/01 TIMING CHARACTERISTICS Figure 1a – Timing Diagram: Latched Mode (LDAC Strobed) t1 Figure 1b – Timing Diagram: Transparent Mode (LDAC Held Low) t2 A0A2 A0A2 t3 CS t3 CS t5 WR t2 t1 t5 t6 t4 t6 t4 WR t7 t7 t8 t8 D0D12 D0D12 t9 t9 VOUT VOUT t10 t11 LDAC CLR t9 VOUT PARAMETER SYMBOL MIN TYP Address Valid to WR Setup t1 20 Address Valid to WR Hold t2 0 CS Pulse Width Low t3 50 WR Pulse Width Low t4 50 CS to WR Setup t5 0 WR to CS Hold t6 0 Data Setup t7 25 Data Hold t8 0 Settling Time1 t9 LDAC Pulse Width Low t10 50 CLR Pulse Activation t11 NOTES: All digital input rise and fall times are measured from 10% tr = tf = 5 ns. 1. RL = 10 kΩ CL ≤ 220 pF MAX 15 300 UNIT ns ns ns ns ns ns ns ns us ns ns to 90% of +5 V. SPT5420 4 6/26/01 VOLTAGE REFERENCES AND ANALOG GROUND INPUTS ANALOG OUTPUTS VS DIGITAL INPUT CODE Three VREFTXX and three VREFBXX inputs set the output range of the three corresponding groups of DACs (0 and 1; 2 through 5; 6 and 7). Four RGNDXX inputs set the output offset voltage of the four corresponding groups of DACs (0 and 1; 2 and 3; 4 and 5; 6 and 7). The formula for output swing and offset is presented in the “Analog Outputs” section below. The output voltage range is equal to twice the difference between VREFTXX and VREFBXX. The output voltage is given by: VOUT = 2 X (VREFB +[VREFT – VREFB] X INPUT CODE 8192 ) – VRGND CODE = 0 – 8191 DAC ADDRESSING AND LATCHING Table I – DAC Addressing Each DAC has an input latch which receives data from the data bus, and a DAC latch which receives data from the input latch. The analog output of each DAC corresponds to the data in its DAC latch. One of the eight input latches is addressed by the address lines A(2:0) according to Table I. While CS and WR are low, the addressed input latch is transparent and the seven other input latches are latched. Bringing CS or WR high latches data into the addressed input latch. While LDAC is low, all eight DAC latches are transparent. Bringing LDAC high latches data into the DAC latches. While CS, WR and LDAC are low, both latches are transparent and input data is transferred directly to the selected DAC. While CLR is low, all DAC outputs are set to their corresponding RGNDXX. Bringing CLR high returns each DAC’s output to the voltage corresponding to the data in each DAC latch. A2 0 0 0 0 1 1 1 1 A1 0 0 1 1 0 0 1 1 Addressed Input Latch DAC# 0 1 2 3 4 5 6 7 A0 0 1 0 1 0 1 0 1 Table II – Control Logic Table Table II summarizes this information, and figures 1a and 1b should be referenced for timing limitations. POWER SUPPLY SEQUENCING WR CS LDAC CLR 0 1 x x x x 0 x 1 x x x x x x 0 1 x 1 1 1 1 1 0 Input Latch DAC Latch transparent1 x latched x latched x x transparent x latched DAC outputs at RGNDXX Note: 1. Only the input latch addressed by A(2:0) is transparent. The other input latches are latched. The sequence in which VDD, VSS and VCC come up is not critical. The reference inputs, VREFTXX and VREFBXX, must come on only after VDD and VSS have been established. However, they may be turned on prior to VCC. The digital inputs must be driven only after VDD, VSS and VCC have been established. Reverse the power-on sequence for power-down. SPT5420 5 6/26/01 TYPICAL PERFORMANCE CHARACTERISTICS Integral Linearity Error vs Code Differential Linearity Error vs Code 0.20 1.00 0.80 0.00 0.60 0.20 DLE (LSBs) ILE (LSBs) 0.40 0.20 0.00 0.20 0.40 0.60 0.40 0.80 0.60 0.80 1.00 1.00 0 1440 2880 4320 Code 5760 0 IDD ISS 6 5760 7200 Load Capacitance vs Settling Time Capacitance (pF) Supply Current (mA) 7 4320 10000 VREFT=+5 V VREFB=5 V VDD=12 V VSS=8 V 2880 Code IDD/ISS vs Temperature 8 1440 7200 5 VSWING=10 V 1000 100 10 1 11.20 11.70 12.20 13.90 17.90 26.50 52.00 70.00 Settling Time to ±0.5 LSB (µS) 4 40 0 25 70 85 Temperature °C Digital-to-Analog Glitch Impulse DAC to DAC Crosstalk code 0FFFH to 1000H code 0FFFH to 1000H 2 mV/div DAC to DAC glitch output glitch 2 V/div 2 mV/div WR 2 µS 2 µS SPT5420 6 6/26/01 TYPICAL PERFORMANCE CHARACTERISTICS Slew and Settling Time Digital Feedthrough CL=50 pF RL=10 kW output 20 mV/div code 0FFFH to 1000H 2 mV/div digital feedthrough output 2 V/div code 0000H to 1FFFH 2 µS 1 µS PACKAGE OUTLINE 44-Lead MQFP A B SYMBOL A B C D E F G H I J K Pin 1 Index C E D INCHES MIN MAX 0.5098 0.5295 0.3917 0.3957 0.3917 0.3957 0.5098 0.5295 0.0311 0.0319 0.0118 0.0177 0.0768 0.0827 0.0039 0.0098 0.0287 0.0406 0.0630 REF 0° 7° MILLIMETERS MIN MAX 12.95 13.45 9.95 10.05 9.95 10.05 12.95 13.45 0.79 0.81 0.30 0.45 1.95 2.10 0.10 0.25 0.73 1.03 1.60 REF 0° 7° F G K I H J SPT5420 7 6/26/01 CLR (Active Low) Analog Clear. Sets the output voltages to RGND. (Each RGND is common to a DAC pair.) CLR does not reset the digital latches. When CLR is brought back high, the DAC outputs revert back to their original outputs as determined by the data in their DAC latches. LDAC When this logic input is taken low, the contents of the input latches are transferred to their respective DAC latches. (Active Low) Data is latched on rising edge. VREFT67 VSS A0 – A2 Addresses DAC0 to DAC7 for loading the eight input latches. CLR D12 (MSB) D11 D10 D9 D8 D0 – D12 Digital Inputs (D0 = LSB) VDD VOUT4 RGND45 VOUT5 VOUT6 VREFT2345 VOUT1 VOUT2 RGND23 VOUT3 VREFB2345 PIN ASSIGNMENTS 44 RGND01 VOUT0 VREFB01 1 RGND67 VOUT7 VREFB67 VREFT01 VDD VSS Top View LDAC A2 A1 A0 CS ANALOG PINS VREFT01 Top Reference Voltage for DACs 0 and 1 VREFT2345 Top Reference Voltage for DACs 2, 3, 4 and 5 VREFT67 Top Reference Voltage for DACs 6 and 7 VREFB01 Bottom Reference Voltage for DACs 0 and 1 D5 D6 D7 WR VCC GND D0 (LSB) D1 D2 D3 D4 VREFB2345 Bottom Reference Voltage for DACs 2, 3, 4 and 5 PIN FUNCTIONS Name Function DIGITAL CONTROL PINS VREFB67 Bottom Reference Voltage for DACs 6 and 7 RGND01 Reference Ground for Output Amplifiers 0 and 1 RGND23 Reference Ground for Output Amplifiers 2 and 3 RGND45 Reference Ground for Output Amplifiers 4 and 5 RGND67 Reference Ground for Output Amplifiers 6 and 7 VOUT0–7 Output Voltage Pins for DAC0 – DAC7 POWER SUPPLY PINS CS Chip Select (Active Low) VCC Digital +5 V Supply WR Level Triggered Write Input (Active Low). Used in conjunction with CS to write data to the SPT5420 input data latches. Data is latched into selected input data latch on the rising edge of WR. VDD Analog +11.5 V Supply (Nominal) VSS Analog –8 V Supply (Nominal) GND Ground ORDERING INFORMATION PART NUMBER SPT5420SIM TEMPERATURE RANGE PACKAGE –40 to +85 °C 44L MQFP SPT5420 8 6/26/01