TLC0820AC, TLC0820AI Advanced LinCMOS HIGH-SPEED 8-BIT ANALOG-TO-DIGITAL CONVERTERS USING MODIFIED FLASH TECHNIQUES SLAS064A – SEPTEMBER 1986 – REVISED JUNE 1994 D D D D D D D D Advanced LinCMOS Silicon-Gate Technology 8-Bit Resolution Differential Reference Inputs Parallel Microprocessor Interface Conversion and Access Time Over Temperature Range Read Mode . . . 2.5 µs Max No External Clock or Oscillator Components Required On-Chip Track and Hold Single 5-V Supply TLC0820A Is Direct Replacement for National Semiconductor ADC0820C/CC and Analog Devices AD7820K/B/T DB, DW, OR N PACKAGE (TOP VIEW) ANLG IN (LSB) D0 D1 D2 D3 WR/RDY MODE RD INT GND 1 20 2 19 3 18 4 17 5 16 6 15 7 14 8 13 9 12 10 11 VCC NC OFLW D7 (MSB) D6 D5 D4 CS REF + REF – FN PACKAGE (TOP VIEW) D1 D0 (LSB) ANLG IN VCC NC D description INT GND REF – REF+ CS The TLC0820AC and the TLC0820AI are Advanced LinCMOS 8-bit analog-to-digital converters each consisting of two 4-bit flash 3 2 1 20 19 D2 18 OFLW 4 converters, a 4-bit digital-to-analog converter, a D3 17 D7 (MSB) 5 summing (error) amplifier, control logic, and a WR/RDY 16 D6 6 result latch circuit. The modified flash technique MODE 15 D5 7 allows low-power integrated circuitry to complete RD 14 D4 8 an 8-bit conversion in 1.18 µs over temperature. 9 10 11 12 13 The on-chip track-and-hold circuit has a 100-ns sample window and allows these devices to convert continuous analog signals having slew rates of up to 100 mV/µs without external NC – No internal connection sampling components. TTL-compatible 3-state output drivers and two modes of operation allow interfacing to a variety of microprocessors. Detailed information on interfacing to most popular microprocessors is readily available from the factory. AVAILABLE OPTIONS PACKAGE TA TOTAL UNADJUSTED ERROR SSOP (DB) 0°C to 70°C ± 1 LSB TLC0820ACDB – 40°C to 85°C ± 1 LSB — PLASTIC SMALL OUTLINE (DW) PLASTIC CHIP CARRIER (FN) PLASTIC DIP (N) TLC0820ACDW TLC0820ACFN TLC0820ACN TLC0820AIDW TLC0820AIFN TLC0820AIN Advanced LinCMOS is a trademark of Texas Instruments Incorporated. Copyright 1994, Texas Instruments Incorporated PRODUCTION DATA information is current as of publication date. Products conform to specifications per the terms of Texas Instruments standard warranty. Production processing does not necessarily include testing of all parameters. POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 2–1 TLC0820AC, TLC0820AI Advanced LinCMOS HIGH-SPEED 8-BIT ANALOG-TO-DIGITAL CONVERTERS USING MODIFIED FLASH TECHNIQUES SLAS064A – SEPTEMBER 1986 – REVISED JUNE 1994 functional block diagram REF+ REF – 12 4-Bit Flash Analog-to-Digital Converter (4 MSBs) 11 4 4 18 2 4 3 4 Output Latch and 3-State Buffers 4-Bit Digital-to-Analog Converter Summing Amplifier –1 ANLG IN MODE WR/RDY CS RD 2–2 1 4-Bit Flash Analog-to-Digital Converter (4 LSBs) 5 14 15 16 4 17 OFLW D0 (LSB) D1 D2 D3 D4 D5 D6 D7 (MSB) +1 7 6 Timing and Control 13 8 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 9 INT Digital Outputs TLC0820AC, TLC0820AI Advanced LinCMOS HIGH-SPEED 8-BIT ANALOG-TO-DIGITAL CONVERTERS USING MODIFIED FLASH TECHNIQUES SLAS064A – SEPTEMBER 1986 – REVISED JUNE 1994 Terminal Functions TERMINAL NAME ANLG IN NO. I/O DESCRIPTION 1 I Analog input CS 13 I Chip select. CS must be low in order for RD or WR to be recognized by the ADC. D0 2 O Digital, 3-state output data, bit 1 (LSB) D1 3 O Digital, 3-state output data, bit 2 D2 4 O Digital, 3-state output data, bit 3 D3 5 O Digital, 3-state output data, bit 4 D4 14 O Digital, 3-state output data, bit 5 D5 15 O Digital, 3-state output data, bit 6 D6 16 O Digital, 3-state output data, bit 7 D7 17 O Digital, 3-state output data, bit 8 (MSB) GND 10 Ground INT 9 O Interrupt. In the write-read mode, the interrupt output (INT) going low indicates that the internal count-down delay time, td(int), is complete and the data result is in the output latch. The delay time td(int) is typically 800 ns starting after the rising edge of WR (see operating characteristics and Figure 3). If RD goes low prior to the end of td(int), INT goes low at the end of td(RIL) and the conversion results are available sooner (see Figure 2). INT is reset by the rising edge of either RD or CS. MODE 7 I Mode select. MODE is internally tied to GND through a 50-µA current source, which acts like a pulldown resistor. When MODE is low, the read mode is selected. When MODE is high, the write-read mode is selected. NC 19 OFLW 18 O Overflow. Normally OFLW is a logical high. However, if the analog input is higher than Vref+, OFLW will be low at the end of conversion. It can be used to cascade two or more devices to improve resolution (9 or 10 bits). 8 I Read. In the write-read mode with CS low, the 3-state data outputs D0 through D7 are activated when RD goes low. RD can also be used to increase the conversion speed by reading data prior to the end of the internal count-down delay time. As a result, the data transferred to the output latch is latched after the falling edge of RD. In the read mode with CS low, the conversion starts with RD going low. RD also enables the 3-state data outputs on completion of the conversion. RDY going into the high-impedance state and INT going low indicate completion of the conversion. REF – 11 I Reference voltage. REF – is placed on the bottom of the resistor ladder. REF + 12 I Reference voltage. REF + is placed on the top of the resistor ladder. VCC WR/RDY 20 RD 6 No internal connection Power supply voltage I/O Write ready. In the write-read mode with CS low, the conversion is started on the falling edge of the WR input signal. The result of the conversion is strobed into the output latch after the internal count-down delay time, td(int), provided that the RD input does not go low prior to this time. The delay time td(int) is approximately 800 ns. In the read mode, RDY (an open-drain output) goes low after the falling edge of CS and goes into the high-impedance state when the conversion is strobed into the output latch. It is used to simplify the interface to a microprocessor system. POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 2–3 TLC0820AC, TLC0820AI Advanced LinCMOS HIGH-SPEED 8-BIT ANALOG-TO-DIGITAL CONVERTERS USING MODIFIED FLASH TECHNIQUES SLAS064A – SEPTEMBER 1986 – REVISED JUNE 1994 absolute maximum ratings over operating free-air temperature range (unless otherwise noted)† Supply voltage, VCC (see Note 1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 V Input voltage range, all inputs (see Note 1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . – 0.2 V to VCC + 0.2 V Output voltage range, all outputs (see Note 1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . – 0.2 V to VCC + 0.2 V Operating free-air temperature range: TLC0820AC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0°C to 70°C TLC0820AI . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . – 40°C to 85°C Storage temperature range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . – 65°C to 150°C Case temperature for 10 seconds: FN package . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 260°C Lead temperature 1,6 mm (1/16 inch) from case for 10 seconds: DB, DW or N package . . . . . . . . . . . 260°C † Stresses beyond those listed under “absolute maximum ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated under “recommended operating conditions” is not implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability. NOTE 1: All voltages are with respect to network GND. recommended operating conditions MIN NOM MAX Supply voltage, VCC 4.5 5 8 Analog input voltage – 0.1 Positive reference voltage, Vref + Vref – GND Negative reference voltage, Vref – High level input voltage, High-level voltage VIH VCC = 4.75 4 75 V to 5.25 5 25 V Low level input voltage, Low-level voltage VIL VCC = 4.75 4 75 V to 5.25 5 25 V CS, WR/RDY, RD MODE Operating free-air free air temperature, temperature TA 2–4 Vref+ V 2 1.5 • DALLAS, TEXAS 75265 V V 3.5 MODE TLC0820AI POST OFFICE BOX 655303 V 0.8 TLC0820AC V VCC + 0.1 VCC CS, WR/RDY, RD Pulse duration, write in write-read mode, tw(W) (see Figures 2, 3, and 4) UNIT 0.5 50 0 70 – 40 85 V µs °C TLC0820AC, TLC0820AI Advanced LinCMOS HIGH-SPEED 8-BIT ANALOG-TO-DIGITAL CONVERTERS USING MODIFIED FLASH TECHNIQUES SLAS064A – SEPTEMBER 1986 – REVISED JUNE 1994 electrical characteristics at specified operating free-air temperature, VCC = 5 V (unless otherwise noted) PARAMETER VOH VOL Hi h l High-level l output t t voltage lt Low level output voltage Low-level TA† MIN Full range 2.4 VCC = 4.75 V,, IOH = – 10 µA Full range 4.5 25°C 4.6 VCC = 5.25 V,, IOL = 1.6 mA Full range 0.4 25°C 0.34 TEST CONDITIONS D0 – D7, INT, or OFLW D0 – D7, OFLW, INT, or WR/RDY VCC = 4.75 V, IOH = – 360 µA CS or RD IIH High-level input current WR/RDY Full range VIH = 5 V IIL IOZ Low-level input current Off-state ((high-impedance-state) g ) output current Full range IOS VI = 5 V CS at 5 V V, VI = 0 VO = 5 V D0 – D7 or OFLW INT Reference resistance ICC Supply current Ci Input capacitance CS, WR/RDY, and RD at 0 V D0 – D7 170 – 0.005 –1 Co Output capacitance D0 – D7 † Full range is as specified in recommended operating conditions. – 0.1 Full range –3 25°C – 0.3 25°C 8.4 –6 – 7.2 Full range – 4.5 25°C – 5.3 Full range 1.25 25°C 1.4 14 mA – 12 –9 6 2.3 Full range 25°C µA 7 Full range 25°C µA 3 0.3 Full range µA – 0.3 25°C Full range • DALLAS, TEXAS 75265 0.3 –3 Full range Full range ANLG IN POST OFFICE BOX 655303 50 0.1 25°C CS at 5 V V, µA 3 25°C VO = 0 Rreff 0.3 Full range Analog input current Short circuit output current Short-circuit 0.1 Full range D0 – D7 or WR/RDY D0 – D7, OFLW, INT, or WR/RDY 1 V 200 25°C VO = 0 II 0.005 Full range VO = 5 V UNIT 3 25°C VIL = 0 MAX V Full range MODE CS, WR/RDY, RD, or MODE TYP 5.3 15 7.5 13 5 kΩ mA pF 45 5 pF 2–5 TLC0820AC, TLC0820AI Advanced LinCMOS HIGH-SPEED 8-BIT ANALOG-TO-DIGITAL CONVERTERS USING MODIFIED FLASH TECHNIQUES SLAS064A – SEPTEMBER 1986 – REVISED JUNE 1994 operating characteristics, VCC = 5 V, Vref+ = 5 V, Vref– = 0, tr = tf = 20 ns, TA = 25°C (unless otherwise noted) PARAMETER TEST CONDITIONS† TYP MAX UNIT ± 1/16 ± 1/4 LSB 1 LSB See Figure 1 1.6 2.5 µs tconv(R) + 20 tconv(R) + 50 ns kSVS Supply-voltage sensitivity Total unadjusted error‡ VCC = 5 V ± 5%, MODE at 0 V, TA = MIN to MAX TA = MIN to MAX tconv(R) Conversion time, read mode MODE at 0 V, MIN ta(R) Access time, RD↓ to data valid MODE at 0 V, See Figure 1 CL = 15 pF 280 Access time time, RD↓ to data valid MODE at 5 V, td(WR) < td(i d(int)), See Figure 2 190 ta(R1) (R1) CL = 100 pF 210 320 CL = 15 pF 120 Access time time, RD↓ to data valid MODE at 5 V, td(WR) > td(i d(int)), See Figure 3 70 ta(R2) (R2) CL = 100 pF 90 150 ta(INT) Access time, INT↓ to data valid MODE at 5 V, See Figure 4 20 50 ns tdis Disable time, time RD↑ to data valid RL = 1 kΩ, CL = 10 pF, See Figures 1, 2, 3, and 5 70 95 ns td(int) Delay time time, WR/RDY↑ to INT↓ MODE at 5 V, CL = 50 pF, See Figures 2, 3, and 4 800 1300 ns td(NC) Delay time, to next conversion See Figures 1, 2, 3, and 4 500 ns td(WR) Delay time, WR/RDY↑ to RD↓ in write-read mode See Figure 2 0.4 µs td(RDY) time CS↓ to WR/RDY↓ Delay time, MODE at 0 V, See Figure 1 CL = 50 pF, td(RIH) Delay time, RD↑ to INT↑ CL = 50 pF, td(RIL) Delay time, time RD↓ to INT↓ MODE at 5 V, See Figure 2 td(WIH) Delay time time, WR/RDY↑ to INT↑ MODE at 5 V, See Figure 4 ns ns 50 100 ns See Figures 1, 2, and 3 125 225 ns td(WR) < td(int), 200 290 ns CL = 50 pF, 175 270 ns Slew-rate tracking 0.1 † For conditions shown as MIN or MAX, use the appropriate value specified under recommended operating conditions. ‡ Total unadjusted error includes offset, full-scale, and linearity errors. 2–6 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 V/µs TLC0820AC, TLC0820AI Advanced LinCMOS HIGH-SPEED 8-BIT ANALOG-TO-DIGITAL CONVERTERS USING MODIFIED FLASH TECHNIQUES SLAS064A – SEPTEMBER 1986 – REVISED JUNE 1994 PARAMETER MEASUREMENT INFORMATION CS 50% RD 50% 50% 50% td(NC) WR/RDY 50% With External Pullup td(RDY) td(RIH) INT 50% 50% tconv(R) 90% 10% D0–D7 90% 10% ta(R) tdis Figure 1. Read-Mode Waveforms (MODE Low) CS CS tw(W) tw(W) WR/RDY 50% 50% WR/RDY 50% 50% td(WR) 50% td(NC) td(NC) 50% RD 50% RD 50% 50% 50% 50% INT 90% 10% 90% 50% td(int) td(RIH) td(int) D0 – D7 td(RIH td(WR) td(RIL) INT 50% 90% 10% D0 – D7 10% ta(R2) ta(R1) tdis Figure 2. Write-Read-Mode Waveforms [MODE High and td(WR) < td(int)] POST OFFICE BOX 655303 90% 10% tdis Figure 3. Write-Read-Mode Waveforms [MODE High and td(WR) > td(int)] • DALLAS, TEXAS 75265 2–7 TLC0820AC, TLC0820AI Advanced LinCMOS HIGH-SPEED 8-BIT ANALOG-TO-DIGITAL CONVERTERS USING MODIFIED FLASH TECHNIQUES SLAS064A – SEPTEMBER 1986 – REVISED JUNE 1994 PARAMETER MEASUREMENT INFORMATION CS Low RD Low tw(W) WR/RDY 50% 50% 50% td(WIH) 50% INT td(NC) 50% td(int) ta(INT) 90% D0 – D7 Data Valid 10% Figure 4. Write-Read-Mode Waveforms (Stand-Alone Operation, MODE High, and RD Low) VCC CL = 10 pF TLC0820 Input tr RD Data Output Dn CS RD GND CL VCC 90% 50% 10% GND tdis 1 kΩ 90% Data Outputs VOH GND tr = 20 ns TEST CIRCUIT VOLTAGE WAVEFORMS VCC CL = 10 pF tr TLC0820 90% 50% 10% 1 kΩ Input RD RD Data Output Dn CS GND GND tdis VCC CL Data Outputs 10% tr = 20 ns VOLTAGE WAVEFORMS Dn = D0 . . . D7 TEST CIRCUIT Figure 5. Test Circuit and Voltage Waveforms 2–8 VCC POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 VOL TLC0820AC, TLC0820AI Advanced LinCMOS HIGH-SPEED 8-BIT ANALOG-TO-DIGITAL CONVERTERS USING MODIFIED FLASH TECHNIQUES SLAS064A – SEPTEMBER 1986 – REVISED JUNE 1994 PRINCIPLES OF OPERATION The TLC0820AC and TLC0820AI each employ a combination of sampled-data comparator techniques and flash techniques common to many high-speed converters. Two 4-bit flash analog-to-digital conversions are used to give a full 8-bit output. The recommended analog input voltage range for conversion is – 0.1 V to VCC + 0.1 V. Analog input signals that are less than Vref – + 1/2 LSB or greater than Vref+ – 1/2 LSB convert to 00000000 or 11111111, respectively. The reference inputs are fully differential with common-mode limits defined by the supply rails. The reference input values define the full-scale range of the analog input. This allows the gain of the ADC to be varied for ratiometric conversion by changing the Vref+ and Vref – voltages. The device operates in two modes, read (only) and write-read, that are selected by MODE. The converter is set to the read (only) mode when MODE is low. In the read mode, WR/RDY is used as an output and is referred to as the ready terminal. In this mode, a low on WR/RDY while CS is low indicates that the device is busy. Conversion starts on the falling edge of RD and is completed no more than 2.5 µs later when INT falls and WR/RDY returns to the high-impedance state. Data outputs also change from high-impedance to active states at this time. After the data is read, RD is taken high, INT returns high, and the data outputs return to their high-impedance states. When MODE is high, the converter is set to the write-read mode and WR/RDY is referred to as the write terminal. Taking CS and WR/RDY low selects the converter and initiates measurement of the input signal. Approximately 600 ns after WR/RDY returns high, the conversion is completed. Conversion starts on the rising edge of WR/RDY in the write-read mode. The high-order 4-bit flash ADC measures the input by means of 16 comparators operating simultaneously. A high-precision 4-bit DAC then generates a discrete analog voltage from the result of that conversion. After a time delay, a second bank of comparators does a low-order conversion on the analog difference between the input level and the high-order DAC output. The results from each of these conversions enter an 8-bit latch and are output to the 3-state output buffers on the falling edge of RD. POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 2–9 TLC0820AC, TLC0820AI Advanced LinCMOS HIGH-SPEED 8-BIT ANALOG-TO-DIGITAL CONVERTERS USING MODIFIED FLASH TECHNIQUES SLAS064A – SEPTEMBER 1986 – REVISED JUNE 1994 APPLICATION INFORMATION CS 13 WR 6 RD 8 VCC WR/RDY ANLG IN CS 20 5V 1 ANLG IN RD TLC0820 µP Bus D0 2 D1 3 D2 4 D3 5 D4 14 D5 15 D6 16 D7 17 MODE D0 D1 REF+ 7 5V 12 5V D2 0.1 µF D3 D4 D5 REF – 11 D6 0.1 µF D7 D8 18 OFL 13 6 8 OFLW GND VCC WR/RDY ANLG IN CS 10 20 5V 1 RD TLC0820 2 3 4 5 14 15 16 17 18 D0 D1 MODE REF+ POST OFFICE BOX 655303 5V 12 D2 0.1 µF D3 D4 D5 REF – 11 D6 D7 OFLW GND Figure 6. Configuration for 9-Bit Resolution 2–10 7 • DALLAS, TEXAS 75265 10 0.1 µF IMPORTANT NOTICE Texas Instruments and its subsidiaries (TI) reserve the right to make changes to their products or to discontinue any product or service without notice, and advise customers to obtain the latest version of relevant information to verify, before placing orders, that information being relied on is current and complete. All products are sold subject to the terms and conditions of sale supplied at the time of order acknowledgement, including those pertaining to warranty, patent infringement, and limitation of liability. TI warrants performance of its semiconductor products to the specifications applicable at the time of sale in accordance with TI’s standard warranty. Testing and other quality control techniques are utilized to the extent TI deems necessary to support this warranty. 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