TLV0831C, TLV0831I TLV0832C, TLV0832I 3-VOLT 8-BIT ANALOG-TO-DIGITAL CONVERTERS WITH SERIAL CONTROL SLAS148 – SEPTEMBER 1996 D D D D D D D D D D 8-Bit Resolution 2.7 V to 3.6 V VCC Easy Microprocessor Interface or Standalone Operation Operates Ratiometrically or With VCC Reference Single Channel or Multiplexed Twin Channels With Single-Ended or Differential Input Options Input Range 0 V to VCC With VCC Reference Inputs and Outputs Are Compatible With TTL and MOS Conversion Time of 32 µs at f(CLK) = 250 kHz Designed to Be Functionally Equivalent to the National Semiconductor ADC0831 and ADC0832 at 3 V Supply Total Unadjusted Error . . . ± 1 LSB TLV0831 . . . D OR P PACKAGE (TOP VIEW) CS IN+ IN– GND 1 8 2 7 3 6 4 5 VCC CLK DO REF TLV0832 . . . D OR P PACKAGE (TOP VIEW) CS CH0 CH1 GND 1 8 2 7 3 6 4 5 VCC /REF CLK DO DI description These devices are 8-bit successive-approximation analog-to-digital converters. The TLV0831 has single input channels; the TLV0832 has multiplexed twin input channels. The serial output is configured to interface with standard shift registers or microprocessors. The TLV0832 multiplexer is software configured for single-ended or differential inputs. The differential analog voltage input allows for common-mode rejection or offset of the analog zero input voltage value. In addition, the voltage reference input can be adjusted to allow encoding any smaller analog voltage span to the full 8 bits of resolution. The operation of the TLV0831 and TLV0832 devices is very similar to the more complex TLV0834 and TLV0838 devices. Ratiometric conversion can be attained by setting the REF input equal to the maximum analog input signal value, which gives the highest possible conversion resolution. Typically, REF is set equal to VCC (done internally on the TLV0832). The TLV0831C and TLV0832C are characterized for operation from 0°C to 70°C. The TLV0831I and TLV0832I are characterized for operation from – 40°C to 85°C. AVAILABLE OPTIONS PACKAGE TA SMALL OUTLINE (D) PLASTIC DIP (P) 0°C to 70°C TLV0831CD TLV0832CD TLV0831CP TLV0832CP – 40°C to 85°C TLV0831ID TLV0832ID TLV0831IP TLV0832IP Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet. Copyright 1996, 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 1 TLV0831C, TLV0831I TLV0832C, TLV0832I 3-VOLT 8-BIT ANALOG-TO-DIGITAL CONVERTERS WITH SERIAL CONTROL SLAS148 – SEPTEMBER 1996 functional block diagram Start Flip-Flop CLK CS CLK Shift Register ODD/EVEN D DI (TLV0832 only) S R Start CLK To Internal Circuits CLK SGL/DIF CH0/IN+ CH1/IN – Analog MUX S Comparator R Time Delay EN CS CS CS CS CS EN REF (TLV0831 only) Ladder and Decoder Bits 0–7 R EN SAR Logic and Latch CLK Bits 0–7 Bit 1 MSB First 9-Bit Shift Register LSB First One Shot 2 POST OFFICE BOX 655303 R • DALLAS, TEXAS 75265 EOC R CLK D DO TLV0831C, TLV0831I TLV0832C, TLV0832I 3-VOLT 8-BIT ANALOG-TO-DIGITAL CONVERTERS WITH SERIAL CONTROL SLAS148 – SEPTEMBER 1996 functional description The TLV0831 and TLV0832 use a sample-data-comparator structure that converts differential analog inputs by a successive-approximation routine. The input voltage to be converted is applied to an input terminal and is compared to ground (single ended), or to an adjacent input (differential). The TLV0832 input terminals can be assigned a positive (+) or negative (–) polarity. The TLV0831 contains only one differential input channel with fixed polarity assignment; therefore it does not require addressing. The signal can be applied differentially, between IN+ and IN–, to the TLV0831 or can be applied to IN+ with IN– grounded as a single ended input. When the signal input applied to the assigned positive terminal is less than the signal on the negative terminal, the converter output is all zeros. Channel selection and input configuration are under software control using a serial-data link from the controlling processor. A serial-communication format allows more functions to be included in a converter package with no increase in size. In addition, it eliminates the transmission of low-level analog signals by locating the converter at the analog sensor and communicating serially with the controlling processor. This process returns noise-free digital data to the processor. A conversion is initiated by setting CS low, which enables all logic circuits. CS must be held low for the complete conversion process. A clock input is then received from the processor. An interval of one clock period is automatically inserted to allow the selected multiplexed channel to settle. DO comes out of the high-impedance state and provides a leading low for one clock period of multiplexer settling time. The SAR comparator compares successive outputs from the resistive ladder with the incoming analog signal. The comparator output indicates whether the analog input is greater than or less than the resistive-ladder output. As the conversion proceeds, conversion data is simultaneously output from DO, with the most significant bit (MSB) first. After eight clock periods, the conversion is complete. When CS goes high, all internal registers are cleared. At this time, the output circuits go to the high-impedance state. If another conversion is desired, CS must make a high-to-low transition followed by address information. A TLV0832 input configuration is assigned during the multiplexer-addressing sequence. The multiplexer address shifts into the converter through the data input (DI) line. The multiplexer address selects the analog inputs to be enabled and determines whether the input is single ended or differential. When the input is differential, the polarity of the channel input is assigned. In addition to selecting the differential mode, the polarity may also be selected. Either channel of the channel pair may be designated as the negative or positive input. On each low-to-high transition of the clock input, the data on DI is clocked into the multiplexer-address shift register. The first logic high on the input is the start bit. A 2-bit assignment word follows the start bit on the TLV0832. On each successive low-to-high transition of the clock input, the start bit and assignment word are shifted through the shift register. When the start bit is shifted into the start location of the multiplexer register, the input channel is selected and conversion starts. The TLV0832 DI terminal to the multiplexer shift register is disabled for the duration of the conversion. The TLV0832 outputs the least-significant-bit (LSB) first data after the MSB-first data stream. The DI and DO terminals can be tied together and controlled by a bidirectional processor I/O bit received on a single wire. This is possible because DI is only examined during the multiplexer-addressing interval and DO is still in the high-impedance state. POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 3 TLV0831C, TLV0831I TLV0832C, TLV0832I 3-VOLT 8-BIT ANALOG-TO-DIGITAL CONVERTERS WITH SERIAL CONTROL SLAS148 – SEPTEMBER 1996 sequence of operation TLV0831 1 2 3 4 5 6 7 8 9 10 CLK tsu tconv CS MSB-First Data MUX Settling Time Hi-Z DO MSB 7 Hi-Z LSB 6 5 4 3 2 1 0 TLV0832 1 2 3 4 5 6 10 11 12 13 14 18 19 20 21 CLK tconv tsu CS +Sign Bit Start ODD SGL Bit DI (TLV0832 only) Don’t Care DIF EVEN MSB-First Data LSB-First Data MUX Settling Time DO Hi-Z MSB 7 LSB 6 2 1 MSB 0 1 2 6 TLV0832 MUX-ADDRESS CONTROL LOGIC TABLE MUX ADDRESS SGL/DIF L L H H CHANNEL NUMBER ODD/EVEN L H L H CH0 CH1 + – + – + + H = high level, L = low level, – or + = terminal polarity for the selected input channel 4 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 7 TLV0831C, TLV0831I TLV0832C, TLV0832I 3-VOLT 8-BIT ANALOG-TO-DIGITAL CONVERTERS WITH SERIAL CONTROL SLAS148 – SEPTEMBER 1996 absolute maximum ratings over recommended operating free-air temperature range (unless otherwise noted)† Supply voltage, VCC (see Note 1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6.5 V Input voltage range, VI: Logic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . – 0.3 V to VCC + 0.3 V Analog . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . – 0.3 V to VCC + 0.3 V Input current, II . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ± 5 mA Total input current . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ± 20 mA Operating free-air temperature range, TA: C suffix . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0°C to 70°C I suffix . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . – 40°C to 85°C Storage temperature range, Tstg . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . – 65°C to 150°C Lead temperature 1,6 mm (1/16 inch) from case for 10 seconds: P 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 voltage values, except differential voltages, are with respect to the network ground terminal. recommended operating conditions Supply voltage, VCC (see clock operating conditions) High-level input voltage, VIH MIN NOM MAX 2.7 3.3 3.6 2 Low-level input voltage, VIL frequency f(CLK) Clock frequency, VCC = 2.7 V VCC = 3.3 V Clock duty cycle (see Note 2) UNIT V V 0.8 V 250 kHz 10 600 kHz 40% 60% Pulse duration, CS high, twH(CS) 220 ns Setup time, CS low or TLV0832 data valid before CLK↑, tsu 350 ns Hold time, TLV0832 data valid after CLK↑, th Operating free-air free air temperature, temperature TA 90 C suffix I suffix ns 0 70 – 40 85 °C NOTE 2: The clock-duty-cycle range ensures proper operation at all clock frequencies. When a clock frequency is used outside the recommended duty-cycle range, the minimum pulse duration (high or low) is 1 µs. POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 5 TLV0831C, TLV0831I TLV0832C, TLV0832I 3-VOLT 8-BIT ANALOG-TO-DIGITAL CONVERTERS WITH SERIAL CONTROL SLAS148 – SEPTEMBER 1996 electrical characteristics over recommended range of operating free-air temperature, VCC = 3.3 V, f(CLK) = 250 kHz (unless otherwise noted) digital section C SUFFIX MIN TYP‡ MAX TEST CONDITIONS† PARAMETER I SUFFIX MIN TYP‡ MAX VCC = 3 V, VCC = 3 V, IOH = – 360 µA 2.8 2.4 IOH = – 10 µA 2.9 2.8 VCC = 3 V, VIH = 3.6 V IOL = 1.6 mA High-level input current IIL Low-level input current VIL = 0 IOH High-level output (source) current At VOH, DO= 0 V, TA = 25°C – 6.5 IOL Low-level output (sink) current At VOL, DO= 0 V, IOZ High-impedance-state output g current (DO) TA = 25°C TA = 25°C 8 VO = 3.3 V, VO = 0, Ci Input capacitance VOH High level output voltage High-level VOL IIH Low-level output voltage TA = 25°C UNIT V 0.4 V 0.005 0.34 1 0.005 1 µA – 0.005 –1 – 0.005 –1 µA – 15 – 6.5 –16 8 – 15 mA –16 mA 0.01 3 0.01 3 – 0.01 –3 – 0.01 –3 5 Co Output capacitance 5 † All parameters are measured under open-loop conditions with zero common-mode input voltage. ‡ All typical values are at VCC = 3.3 V, TA = 25°C. µA 5 pF 5 pF analog and converter section PARAMETER VIC Common-mode input voltage On channel II( I(stdby) tdb ) Off channel Standby input current (see Note 4) On channel Off channel TEST CONDITIONS† MIN See Note 3 – 0.05 to VCC+ 0.05 TYP‡ MAX UNIT V VI = 3.3 V VI = 0 1 –1 VI = 0 VI = 3.3 V –1 µA 1 ri(REF) Input resistance to REF 1.3 2.4 5.9 kΩ † All parameters are measured under open-loop conditions with zero common-mode input voltage. ‡ All typical values are at VCC = 3.3 V, TA = 25°C. NOTES: 3. When channel IN– is more positive than channel IN+, the digital output code is 0000 0000. Connected to each analog input are two on-chip diodes that conduct forward current for analog input voltages one diode drop above VCC. Care must be taken during testing at low VCC levels (3 V) because high-level analog input voltage (3.6 V) can, especially at high temperatures, cause the input diode to conduct and cause errors for analog inputs that are near full scale. As long as the analog voltage does not exceed the supply voltage by more than 50 mV, the output code is correct. To achieve an absolute 0- to 3.3-V input range requires a minimum VCC of 3.25 V for all variations of temperature and load. 4. Standby input currents go in or out of the on or off channels when the A/D converter is not performing conversion and the clock is in a high or low steady-state conditions. total device TYP‡ MAX TLV0831 0.2 0.75 TLV0832 1.5 2.5 PARAMETER ICC MIN Supply current ‡ All typical values are at VCC = 3.3 V, TA = 25°C. 6 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 UNIT mA TLV0831C, TLV0831I TLV0832C, TLV0832I 3-VOLT 8-BIT ANALOG-TO-DIGITAL CONVERTERS WITH SERIAL CONTROL SLAS148 – SEPTEMBER 1996 operating characteristics VCC = Vref = 3.3 V, f(CLK) = 250 kHz, tr = tf = 20 ns, TA = 25°C (unless otherwise noted) TEST CONDITIONS† PARAMETER Supply-voltage variation error Total unadjusted error (see Note 5) Common-mode error tpd d Propagation delay time, output data after CLK↑ (see Note 6) tdi dis time DO after CS↑ Output disable time, tconv Conversion time (multiplexer-addressing time not included) TYP MAX UNIT VCC = 3 V to 3.6 V Vref = 3.3 V, TA = MIN to MAX ± 1/16 ± 1/4 LSB ±1 LSB Differential mode ± 1/16 ± 1/4 LSB 200 500 80 200 80 125 MSB-first data LSB-first data CL = 100 pF CL = 10 pF, CL = 100 pF, MIN ns RL = 10 kΩ RL = 2 kΩ 250 8 ns clock periods † All parameters are measured under open-loop conditions with zero common-mode input voltage. For conditions shown as MIN or MAX, use the appropriate value specified under recommended operating conditions. NOTES: 5. Total unadjusted error includes offset, full-scale, linearity, and multiplexer errors. 6. The MSB-first data is output directly from the comparator and, therefore, requires additional delay to allow for comparator response time. LSB-first data applies only to TLV0832. POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 7 TLV0831C, TLV0831I TLV0832C, TLV0832I 3-VOLT 8-BIT ANALOG-TO-DIGITAL CONVERTERS WITH SERIAL CONTROL SLAS148 – SEPTEMBER 1996 PARAMETER MEASUREMENT INFORMATION VCC CLK 50% 50% GND VCC tsu tsu CLK VCC 50% GND CS tpd 0.4 V GND th 2V VOH th DO 50% VOL VCC 2V DI 0.4 V 0.4 V Figure 2. Data-Output Timing GND Figure 1. TLV0832 Data-Input Timing VCC Test Point S1 RL From Output Under Test CL (see Note A) S2 LOAD CIRCUIT tr CS 50% tr VCC 90% 10% CS 10% GND DO Output 90% VCC GND DO Output S1 closed S2 open VCC 10% VOLTAGE WAVEFORMS VOLTAGE WAVEFORMS NOTE A: CL includes probe and jig capacitance. Figure 3. Output Disable Time Test Circuit and Voltage Waveforms 8 GND tdis tdis S1 open S2 closed VCC 90% 50% POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 GND TLV0831C, TLV0831I TLV0832C, TLV0832I 3-VOLT 8-BIT ANALOG-TO-DIGITAL CONVERTERS WITH SERIAL CONTROL SLAS148 – SEPTEMBER 1996 TYPICAL CHARACTERISTICS UNADJUSTED OFFSET ERROR vs REFERENCE VOLTAGE LINEARITY ERROR vs REFERENCE VOLTAGE 1.5 VCC = 3.3 V f(CLK) = 250 kHz TA = 25°C VI+ = VI – = 0 V 14 1.25 12 E L – Linearity Error – LSB EO(unadj) – Unadjusted Offset Error – LSB 16 10 8 6 4 1.0 0.75 0.5 0.25 2 0 0.01 0.1 1.0 0 10 1 0 Vref – Reference Voltage – V 4 Figure 5 LINEARITY ERROR vs FREE-AIR TEMPERATURE LINEARITY ERROR vs CLOCK FREQUENCY 0.5 2.0 Vref = 3.3 V VCC = 3.3 V 1.8 Vref = 3.3 V f(CLK) = 250 kHz 1.6 E L – Linearity Error – LSB E L – Linearity Error – LSB 3 Vref – Reference Voltage – V Figure 4 0.45 2 0.4 0.35 0.3 1.4 85°C 1.2 1 0.8 25°C 0.6 0.4 – 40°C 0.2 0.25 – 50 – 25 0 25 50 75 100 0 0 100 TA – Free-Air Tempertature – °C 200 300 400 500 600 700 800 f(CLK) – Clock Frequency – kHz Figure 6 Figure 7 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 9 TLV0831C, TLV0831I TLV0832C, TLV0832I 3-VOLT 8-BIT ANALOG-TO-DIGITAL CONVERTERS WITH SERIAL CONTROL SLAS148 – SEPTEMBER 1996 TYPICAL CHARACTERISTICS TLV0831 TLV0831 SUPPLY CURRENT vs FREE-AIR TEMPERATURE SUPPLY CURRENT vs CLOCK FREQUENCY 0.3 0.5 f(CLK) = 250 kHz CS = High VCC = 3.3 V TA = 25°C 0.4 I CC – Supply Current – mA I CC – Supply Current – mA VCC = 3.6 V VCC = 3.3 V 0.2 VCC = 3 V 0.3 0.2 0.1 0.1 – 50 – 25 0 25 50 75 0 100 0 100 TA – Free-Air Temperature — °C 200 Figure 9 OUTPUT CURRENT vs FREE-AIR TEMPERATURE 16.5 VCC = 3.3 V I O – Output Current – mA 16 IOL (DO = 3.3 V) 15.5 – IOH (DO = 0 V) 15 – IOH (DO = 2.4 V) 14.5 IOL (DO = 0.4 V) – 25 0 25 50 TA – Free-Air Temperature – °C Figure 10 10 400 f(CLK) – Clock Frequency – kHz Figure 8 14 – 50 300 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 75 100 500 TLV0831C, TLV0831I TLV0832C, TLV0832I 3-VOLT 8-BIT ANALOG-TO-DIGITAL CONVERTERS WITH SERIAL CONTROL SLAS148 – SEPTEMBER 1996 Differential Nonlinearity – LSB TYPICAL CHARACTERISTICS 1 0.5 0 Vref = 3.3 V TA = 25°C F(CLK) = 250 kHz VDD = 3.3 V –0.5 –1 0 32 64 96 128 160 192 224 256 224 256 Output Code Figure 11. Differential Nonlinearity With Output Code Integral Nonlinearity – LSB 1 Vref = 3.3 V TA = 25°C F(CLK) = 250 kHz VDD = 3.3 V 0.5 0 –0.5 –1 0 32 64 96 128 160 192 Output Code Figure 12. Integral Nonlinearity With Output Code Total Unadjusted Error – LSB 1 Vref = 3.3 V TA = 25°C F(CLK) = 250 kHz VDD = 3.3 V 0.5 0 –0.5 –1 0 32 64 96 128 160 192 224 256 Output Code Figure 13. Total Unadjusted Error With Output Code POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 11 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. 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