TLV571IDW

TLV571 2.7 V TO 5.5 V, 1-CHANNEL, 8-BIT, PARALLEL ANALOG-TO-DIGITAL CONVERTER SLAS239A – SEPTEMBER 1999 – REVISED FEBRUARY 2000 features applications D D D D D D D D D D D D D D D D D D D D Fast Throughput Rate: 1.25 MSPS at 5 V, 625 KSPS at 3 V Wide Analog Input: 0 V to AVDD Differential Nonlinearity Error: < ± 0.5 LSB Integral Nonlinearity Error: < ± 0.5 LSB Single 2.7-V to 5.5-V Supply Operation Low Power: 12 mW at 3 V and 35 mW at 5 V Auto Power Down of 1 mA Max Software Power Down: 10 µA Max Internal OSC Hardware Configurable DSP and Microcontroller Compatible Parallel Interface Binary/Twos Complement Output Hardware Controlled Extended Sampling Hardware or Software Start of Conversion Mass Storage and HDD Automotive Digital Servos Process Control General-Purpose DSP Image Sensor Processing DW OR PW PACKAGE (TOP VIEW) CS WR RD CLK DGND DVDD INT/EOC DGND DGND D0 D1 D2 description 1 2 3 4 5 6 7 8 9 10 11 12 24 23 22 21 20 19 18 17 16 15 14 13 NC AIN AVDD AGND REFM REFP CSTART A1/D7 A0/D6 D5 D4 D3 The TLV571 is an 8-bit data acquisition system NC – No internal connection that combines a high-speed 8-bit ADC and a parallel interface. The device contains two on-chip control registers allowing control of software conversion start and power down via the bidirectional parallel port. The control registers can be set to a default mode using a dummy RD while WR is tied low allowing the registers to be hardware configurable. The TLV571 operates from a single 2.7-V to 5.5-V power supply. It accepts an analog input range from 0 V to AVDD and digitizes the input at a maximum 1.25 MSPS throughput rate at 5 V. The power dissipations are only 12 mW with a 3-V supply or 35 mW with a 5-V supply. The device features an auto power-down mode that automatically powers down to 1 mA 50 ns after conversion is performed. In software power-down mode, the ADC is further powered down to only 10 µA. Very high throughput rate, simple parallel interface, and low power consumption make the TLV571 an ideal choice for high-speed digital signal processing. AVAILABLE OPTIONS PACKAGE TA 24 TSSOP (PW) 24 SOIC (DW) – 40°C to 85°C TLV571IPW TLV571IDW 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  2000, 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 TLV571 2.7 V TO 5.5 V, 1-CHANNEL, 8-BIT, PARALLEL ANALOG-TO-DIGITAL CONVERTER SLAS239A – SEPTEMBER 1999 – REVISED FEBRUARY 2000 functional block diagram REFP AVDD AIN REFM 8-BIT SAR ADC Internal Clock DVDD Three State Latch D0 – D5 D6/A0 D7/A1 MUX CLK CS RD WR CSTART Input Registers and Control Logic AGND INT/EOC DGND Terminal Functions TERMINAL NAME NO. I/O DESCRIPTION AGND 21 AIN 23 AVDD 22 A0/D6 16 I/O Bidirectional 3-state data bus. D6/A0 along with D7/A1 is used as address lines to access CR0 and CR1 for initialization. A1/D7 17 I/O Bidirectional 3-state data bus. D7/A1 along with D6/A0 is used as address lines to access CR0 and CR1 for initialization. CLK 4 I External clock input CS 1 I Chip select. A logic low on CS enables the TLV571. CSTART 18 I Hardware sample and conversion start input. The falling edge of CSTART starts sampling and the rising edge of CSTART starts conversion. DGND 5, 8, 9 DVDD 6 Analog ground I ADC analog input Analog supply voltage, 2.7 V to 5.5 V Digital ground Digital supply voltage, 2.7 V to 5.5 V D0 – D5 10 –15 I/O Bidirectional 3-state data bus INT/EOC 7 O End-of-conversion/interrupt NC 24 RD 3 I Read data. A falling edge on RD enables a read operation on the data bus when CS is low. REFM 20 I Lower reference voltage (nominally ground). REFM must be supplied or REFM pin must be grounded. REFP 19 I Upper reference voltage (nominally AVDD). The maximum input voltage range is determined by the difference between the voltage applied to REFP and REFM. WR 2 I Write data. A rising edge on the WR latches in configuration data when CS is low. When using software conversion start, a rising edge on WR also initiates an internal sampling start pulse. When WR is tied to ground, the ADC in nonprogrammable (hardware configuration mode). 2 Not connected POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 TLV571 2.7 V TO 5.5 V, 1-CHANNEL, 8-BIT, PARALLEL ANALOG-TO-DIGITAL CONVERTER SLAS239A – SEPTEMBER 1999 – REVISED FEBRUARY 2000 detailed description analog-to-digital SAR converter Ain Charge Redistribution DAC _ SAR Register + REFM ADC Code Control Logic Figure 1 The TLV571 is a successive-approximation ADC utilizing a charge redistribution DAC. Figure 1 shows a simplified version of the ADC. The sampling capacitor acquires the signal on Ain during the sampling period. When the conversion process starts, the SAR control logic and charge redistribution DAC are used to add and subtract fixed amounts of charge from the sampling capacitor to bring the comparator into a balanced condition. When the comparator is balanced, the conversion is complete and the ADC output code is generated. sampling frequency, fs The TLV571 requires 16 CLKs for each conversion, therefore the equivalent maximum sampling frequency achievable with a given CLK frequency is: fs(max) = (1/16) fCLK The TLV571 is software configurable. The first two MSB bits, D(7,6) are used to address which register to set. The remaining six bits are used as control data bits. There are two control registers, CR0 and CR1, that are user configurable. All of the register bits are written to the control register during write cycles. A description of the control registers is shown in Figure 2. POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 3 TLV571 2.7 V TO 5.5 V, 1-CHANNEL, 8-BIT, PARALLEL ANALOG-TO-DIGITAL CONVERTER SLAS239A – SEPTEMBER 1999 – REVISED FEBRUARY 2000 detailed description (continued) control registers A1 A0 A(1:0)=00 D5 D4 D2 D1 D0 D2 SWPWDN D1 Don’t Care D0 Don’t Care Don’t Care Don’t Care Control Register One (CR1) D5 D4 D1 D3 D2 Reserved OSCSPD 0 Reserved 0 Reserved OUTCODE D0 Reserved Control Register Zero (CR0) D5 D4 D3 STARTSEL PROGEOC CLKSEL 0: 0: HARDWARE INT START (CSTART) 1: EOC 1: SOFTWARE START A(1:0)=01 D3 0: Reserved Bit Always Write 0 0: INT. OSC. SLOW 1: INT. OSC. FAST 0: Internal Clock 0: NORMAL 1: Powerdown 1: External Clock 0: Reserved Bit Always Write 0 0: Reserved Bit, Always Write 0 0: Binary 1: 2’s Complement 0: Reserved Bit, Always Write 0 Figure 2. Input Data Format hardware configuration option The TLV571 can configure itself. This option is enabled when the WR pin is tied to ground and a dummy RD signal is applied. The ADC is now fully configured. Zeros or default values are applied to both control registers. The ADC is configured ideally for 3-V operation, which means the internal OSC is set at 10 MHz and hardware start of conversion using CSTART. ADC conversion modes The TLV571 provides two start of conversion modes. Table 1 explains these modes in more detail. 4 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 TLV571 2.7 V TO 5.5 V, 1-CHANNEL, 8-BIT, PARALLEL ANALOG-TO-DIGITAL CONVERTER SLAS239A – SEPTEMBER 1999 – REVISED FEBRUARY 2000 detailed description (continued) Table 1. Conversion Modes START OF CONVERSION OPERATION COMMENTS – FOR INPUT Hardware start (CSTART) CR0.D5 = 0 • • • • • Software start CR0.D5 = 1 • Repeated conversions from AIN With external clock, WR and RD rising • WR rising edge to start sampling initially. Thereafter, sampling occurs at the edge must be a minimum 5 ns before or after CLK rising edge. rising edge of RD. • Conversion begins after 6 clocks after sampling has begun. Thereafter, if in INT mode, one INT pulse generated after each conversion • If in EOC mode, EOC will go high to low at start of conversion and return high at end of conversion. Repeated conversions from AIN CSTART rising edge must be applied CSTART falling edge to start sampling a minimum of 5 ns before or after CLK rising edge. CSTART rising edge to start conversion If in INT mode, one INT pulse generated after each conversion If in EOC mode, EOC will go high to low at start of conversion, and return high at end of conversion. configure the device The device can be configured by writing to control registers CR0 and CR1. Table 2. TLV571 Programming Examples REGISTER INDEX D5 D4 D3 D2 D1 D0 COMMENT 0 0 0 0 0 0 0 Normal, INT OSC 1 0 0 0 0 0 0 Binary 0 0 0 1 1 1 0 0 Power down, EXT OSC 0 1 0 0 0 0 1 0 2’s complement output D7 D6 CR0 0 CR1 0 CR0 CR1 EXAMPLE1 EXAMPLE2 power down The TLV571 offers two power down modes, auto power down and software power down. This device will automatically proceed to auto power down mode if RD is not present one clock after conversion. Software power down is controlled directly by the user by pulling CS to DVDD. Table 3. Power Down Modes AUTO POWER DOWN SOFTWARE POWER DOWN (CS = DVDD) 1 mA 10 µA Comparator Power down Power down Clock buffer Power down Power down Control registers Saved Saved Minimum power down time 1 CLK 2 CLK Minimum resume time 1 CLK 2 CLK PARAMETERS/MODES Maximum power down dissipation current POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 5 TLV571 2.7 V TO 5.5 V, 1-CHANNEL, 8-BIT, PARALLEL ANALOG-TO-DIGITAL CONVERTER SLAS239A – SEPTEMBER 1999 – REVISED FEBRUARY 2000 detailed description (continued) reference voltage input The TLV571 has two reference input pins: REFP and REFM. The voltage levels applied to these pins establish the upper and lower limits of the analog inputs to produce a full-scale and zero-scale reading respectively. The values of REFP, REFM, and the analog input should not exceed the positive supply or be less than GND consistent with the specified absolute maximum ratings. The digital output is at full scale when the input signal is equal to or higher than REFP and is at zero when the input signal is equal to or lower than REFM. sampling/conversion All sampling, conversion, and data output in the device are started by a trigger. This could be the RD, WR, or CSTART signal depending on the mode of conversion and configuration. The rising edge of RD, WR, and CSTART signal are extremely important, since they are used to start the conversion. These edges need to stay close to the rising edge of the external clock (if it is used as CLK). The minimum setup and hold time with respect to the rising edge of the external clock should be 5 ns minimum. When the internal clock is used, this is not an issue since these two edges will start the internal clock automatically. Therefore, the setup time is always met. Software controlled sampling lasts 6 clock cycles. This is done via the CLK input or the internal oscillator if enabled. The input clock frequency can be 1 MHz to 20 MHz, translating into a sampling time from 0.6 µs to 0.3 µs. The internal oscillator frequency is 9 MHz minimum (ocillator frequency is between 9 MHz to 22 MHz), translating into a sampling time from 0.6 µs to 0.3 µs. Conversion begins immediately after sampling and lasts 10 clock cycles. This is again done using the external clock input (1 MHz–20 MHz) or the internal oscillator (9 MHz minimum) if enabled. Hardware controlled sampling, via CSTART, begins on falling CSTART lasts the length of the active CSTART signal. This allows more control over the sampling time, which is useful when sampling sources with large output impedances. On rising CSTART, conversion begins. Conversion in hardware controlled mode also lasts 10 clock cycles. This is done using the external clock input (1 MHz–20 MHz) or the internal oscillator (9 MHz minimum) as is the case in software controlled mode. ExtClk th(WRL_EXTCLKH) ≥5 ns tsu(WRH_EXTCLKH) ≥5 ns WR OR th(RDL_EXTCLKH) ≥5 ns tsu(RDH_EXTCLKH) ≥5 ns RD OR th(CSTARTL_EXTCLKH) ≥5 ns tsu(CSTARTH_EXTCLKH) ≥5 ns td(EXTCLK_CSTARTL) ≥5 ns CSTART NOTE: tsu = setup time, th = hold time Figure 3. Trigger Timing – Software Start Mode Using External Clock 6 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 TLV571 2.7 V TO 5.5 V, 1-CHANNEL, 8-BIT, PARALLEL ANALOG-TO-DIGITAL CONVERTER SLAS239A – SEPTEMBER 1999 – REVISED FEBRUARY 2000 start of conversion mechanism There are two ways to convert data: hardware and software. In the hardware conversion mode the ADC begins sampling at the falling edge of CSTART and begins conversion at the rising edge of CSTART. Software start mode ADC samples for 6 clocks, then conversion occurs for ten clocks. The total sampling and conversion process lasts only 16 clocks in this case. If RD is not detected during the next clock cycle, the ADC automatically proceeds to a power-down state. Data is valid on the rising edge of INT in both conversion modes. hardware CSTART conversion external clock With CS low and WR low, data is written into the ADC. The sampling begins at the falling edge of CSTART and conversion begins at the rising edge of CSTART. At the end of conversion, EOC goes from low to high, telling the host that conversion is ready to be read out. The external clock is active and is used as the reference at all times. With this mode, it is required that CSTART is not applied at the rising edge of the clock (see Figure 4). POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 7 t su(CSL_WRL) t h(WRH_CSH) t su(CSL_RDL) t su(CSL_RDL) CS WR t d(CSH_CSTARTL) t h(RDH_CSH) tc (10 CLKs) tc POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 t (sample) t(sample) CSTART RD t su(DAV_WRH) t h(WRH_DAV) D[0:7] Config Data t dis(RDH_DAV) ADC ADC t en(RDL_DAV) t en(RDL_DAV) INT OR EOC Auto Powerdown Figure 4. Input Conversion – Hardware CSTART, External Clock TLV571 2.7 V to 5.5 V, 1-CHANNEL, 8-BIT RARALLEL ANALOG-TO-DIGITAL CONVERTER CLK SLAS239A – SEPTEMBER 1999 – REVISED FEBRUARY 2000 8 start of conversion mechanism (continued) internal clock With CS low and WR low, data is written into the ADC. The sampling begins at the falling edge of CSTART, and conversion begins at the rising edge of CSTART. The internal clock turns on at the rising edge of CSTART. The internal clock is disabled after each conversion. t su(CSL_WRL) t h(WRH_CSH) t su(CSL_RDL) t su(CSL_RDL) CS t d(CSH_CSTARTL) WR t t h(RDH_CSH) POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 t(sample) (STARTOSC) tc CSTART 0 1 9 10 INTCLK RD t su(DAV_WRH) D[0:7] t dis(RDH_DAV) h(WRH_DAV) Config Data ADC Data t en(RDL_DAV) ADC Data t en(RDL_DAV) INT tc OR EOC Auto Powerdown Figure 5. Input Conversion – Hardware CSTART, Internal Clock Auto Powerdown 9 SLAS239A – SEPTEMBER 1999 – REVISED FEBRUARY 2000 t TLV571 2.7 V TO 5.5 V, 1-CHANNEL, 8-BIT PARALLEL ANALOG-TO-DIGITAL CONVERTER t (STARTOSC) With CS low and WR low, data is written into the ADC. Sampling begins at the rising edge of WR. The conversion process begins 6 clocks after sampling begins. At the end of conversion, the INT goes low telling the host that conversion is ready to be read out. EOC B low during the conversion. The external clock is active and used as the reference at all times. With this mode, WR and RD should not be applied at the rising edge of the clock (see Figure 3). 0 1 5 6 7 15 16 0 4 5 15 CLK t su(CSL_WRL) t su(CSL_RDL) POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 t h(WRH_CSH) t t su(CSL_RDL) h(RDH_CSH) CS WR RD tc t(sample) t su(DAV_WRH) t(sample) t h(WRH_DAV) D[0:7] Config Data tc t dis(RDH_DAV) ADC Data ADC Data t en(RDL_DAV) t en(RDL_DAV) INT OR EOC Auto Powerdown Figure 6. Input Conversion – Software Start, External Clock TLV571 2.7 V to 5.5 V, 1-CHANNEL, 8-BIT RARALLEL ANALOG-TO-DIGITAL CONVERTER external clock SLAS239A – SEPTEMBER 1999 – REVISED FEBRUARY 2000 10 software START conversion software START conversion (continued) internal clock With CS low and WR low, data is written into the ADC. Sampling begins at the rising edge of WR. Conversion begins 6 clocks after sampling begins. The internal clock begins at the rising edge of WR. The internal clock is disabled after each conversion. Subsequent sampling begins at the rising edge of RD. t su(CSL_RDL) t su(CSL_WRL) t h(RDH_CSH) CS t h(WRH_CSH) WR POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 RD t t (STARTOSC) (STARTOSC) 0 4 5 6 15 0 4 5 15 t(sample) t(sample) t su(DAV_WRH) D[0:7] Config Data h(WRH_DAV) t tc dis(RDH_DAV) tc ADC Data ADC t en(RDL_DAV) INT OR EOC Auto Powerdown Figure 7. Input Conversion – Software Start, Internal Clock Auto Powerdown 11 SLAS239A – SEPTEMBER 1999 – REVISED FEBRUARY 2000 t TLV571 2.7 V TO 5.5 V, 1-CHANNEL, 8-BIT PARALLEL ANALOG-TO-DIGITAL CONVERTER INTCLK TLV571 2.7 V TO 5.5 V, 1-CHANNEL, 8-BIT, PARALLEL ANALOG-TO-DIGITAL CONVERTER SLAS239A – SEPTEMBER 1999 – REVISED FEBRUARY 2000 software START conversion (continued) system clock source The TLV571 internally derives multiple clocks from the SYSCLK for different tasks. SYSCLK is used for most conversion subtasks. The source of SYSCLK is programmable via control register zero, bit 3. The source of SYSCLK is changed at the rising edge of WR of the cycle when CR0.D3 is programmed. internal clock (CR0.D3 = 0, SYSCLK = internal OSC) The TLV571 has a built-in 10 MHz OSC. When the internal OSC is selected as the source of SYSCLK, the internal clock starts with a delay (one half of the OSC period max) after the falling edge of the conversion trigger (either WR, RD, or CSTART). The OSC speed can be set to 10 ± 1 MHz or 20 ± 2 MHz by setting register bit CR1.D4. external clock (CR0.D3 = 1, SYSCLK = external clock) The TLV571 is designed to accept an external clock input (CMOS/TTL logic) with frequencies from 1 MHz to 20 MHz. host processor interface The TLV571 provides a generic high-speed parallel interface that is compatible with high-performance DSPs and general-purpose microprocessors. The interface includes D(0–7), INT/EOC, RD, and WR. output format The data output format is unipolar (code 0 to 255). The output code format can be either binary or twos complement by setting register bit CR1.D1. power up and initialization After power up, CS must be low to begin an I/O cycle. INT/EOC is initially high. The TLV571 requires two write cycles to configure the two control registers. The first conversion after the device has returned from the power down state may be invalid and should be disregarded. definitions of specifications and terminology integral nonlinearity Integral nonlinearity 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 before the first code transition. The full-scale point is defined as level 1/2 LSB beyond the last code transition. The deviation is measured from the center of each particular code to the true straight line between these two points. differential nonlinearity An ideal ADC exhibits code transitions that are exactly 1 LSB apart. DNL is the deviation from this ideal value. A differential nonlinearity error of less than ±1 LSB ensures no missing codes. zero offset The major carry transition should occur when the analog input is at zero volts. Zero error is defined as the deviation of the actual transition from that point. gain error The first code transition should occur at an analog value 1/2 LSB above negative full scale. The last transition should occur at an analog value 1 1/2 LSB below the nominal full scale. Gain error is the deviation of the actual difference between first and last code transitions and the ideal difference between first and last code transitions. 12 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 TLV571 2.7 V TO 5.5 V, 1-CHANNEL, 8-BIT, PARALLEL ANALOG-TO-DIGITAL CONVERTER SLAS239A – SEPTEMBER 1999 – REVISED FEBRUARY 2000 software START conversion (continued) signal-to-noise ratio + distortion (SINAD) Signal-to-noise ratio + disortion is the ratio of the rms value of the measured input signal to the rms sum of all other spectral components below the Nyquist frequency, including harmonics but excluding dc. The value for SINAD is expressed in decibels. effective number of bits (ENOB) For a sine wave, SINAD can be expressed in terms of the number of bits. Using the following formula, N = (SINAD – 1.76)/6.02 it is possible to get a measure of performance expressed as N, the effective number of bits. Thus, the effective number of bits for a device for sine wave inputs at a given input frequency can be calculated directly from its measured SINAD. total harmonic distortion (THD) Total harmonic distortion is the ratio of the rms sum of the first six harmonic components to the rms value of the measured input signal and is expressed as a percentage or in decibels. spurious free dynamic range (SFDR) Spurious free dynamic range is the difference in dB between the rms amplitude of the input signal and the peak spurious signal. DSP interface The TLV571 is a 8-bit single input channel analog-to-digital converter with throughput up to 1.25 MSPS at 5 V and up to 625 KSPS at 3 V. To achieve 1.25 MSPS throughput, the ADC must be clocked at 20 MHz. Likewise to achieve 625 KSPS throughout, the ADC must be clocked at 10 MHz. The TLV571 can be easily interfaced to microcontrollers, ASICs, and DSPs. Figure 8 shows the pin connections to interface the TLV571 to the TMS320C6x DSP. TMS320C6X A0–A15 TLV571 EN Address Decoder AIN CS REF HW WR HR RD EOC INTx REFP REFM D0– D7 D0– D15 Figure 8. TMS320C6x DSP Interface POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 13 TLV571 2.7 V TO 5.5 V, 1-CHANNEL, 8-BIT, PARALLEL ANALOG-TO-DIGITAL CONVERTER SLAS239A – SEPTEMBER 1999 – REVISED FEBRUARY 2000 grounding and decoupling considerations General practices should apply to the PCB design to limit high frequency transients and noise that are fed back into the supply and reference lines. This requires that the supply and reference pins be sufficiently bypassed. In most cases 0.1-µF ceramic chip capacitors are adequate to keep the impedance low over a wide frequency range. Since their effectiveness depends largely on the proximity to the individual supply pin, they should be placed as close to the supply pins as possible. To reduce high frequency and noise coupling, it is highly recommended that digital and analog grounds be shorted immediately outside the package. This can be accomplished by running a low impedance line between DGND and AGND under the package. DVDD AVDD TLV571 AVDD 100 nF DVDD 100 nF DGND AGND VREFP REFP 100 nF VREFM REFM Figure 9. Placement for Decoupling Capacitors power supply ground layout Printed-circuit boards that use separate analog and digital ground planes offer the best system performance. Wire-wrap boards do not perform well and should not be used. The two ground planes should be connected together at the low-impedance power-supply source. The best ground connection may be achieved by connecting the ADC AGND terminal to the system analog ground plane making sure that analog ground currents are well managed. Driving Source† TLV571 Rs VS VI AIN Ri(ADC) VC Ci 15 pF VI = Input Voltage at AIN VS = External Driving Source Voltage Rs = Source Resistance Ri(ADC)= Input Resistance of ADC Ci = Input Capacitance VC = Capacitance Charging Voltage † Driving source requirements: • Noise and distortion for the source must be equivalent to the resolution of the converter. • Rs must be real at the input frequency. Figure 10. Equivalent Input Circuit Including the Driving Source 14 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 TLV571 2.7 V TO 5.5 V, 1-CHANNEL, 8-BIT, PARALLEL ANALOG-TO-DIGITAL CONVERTER SLAS239A – SEPTEMBER 1999 – REVISED FEBRUARY 2000 simplified analog input analysis Using the equivalent circuit in Figure 10, the time required to charge the analog input capacitance from 0 to VS within 1/2 LSB, tch(1/2 LSB), can be derived as follows. ǒ Ǔ The capacitance charging voltage is given by: V C(t) + VS 1–e–tchńRtCi Where (1) Rt = Rs + Ri Ri = Ri(ADC) tch = Charge time The input impedance Ri is 718 Ω at 5 V, and is higher (~ 1.25 kΩ) at 2.7 V. The final voltage to 1/2 LSB is given by: (2) VC (1/2 LSB) = VS – (VS /512) ǒ Ǔ Equating equation 1 to equation 2 and solving for cycle time tc gives: V S ǒ Ǔ * VSń512 + VS 1–e–tchńRtCi and time to change to 1/2 LSB (minimum sampling time) is: (3) tch (1/2 LSB) = Rt × Ci × ln(512) Where ln(512) = 6.238 Therefore, with the values given, the time for the analog input signal to settle is: tch (1/2 LSB) = (Rs + 718 Ω) × 15 pF × ln(512) (4) This time must be less than the converter sample time shown in the timing diagrams. Which is 6x SCLK. tch (1/2 LSB) ≤ 6x 1/f(SCLK) (5) Therefore the maximum SCLK frequency is: Max(f(SCLK) ) = 6 / tch (1/2 LSB) = 6/(ln(512) × Rt × Ci ) POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 (6) 15 TLV571 2.7 V TO 5.5 V, 1-CHANNEL, 8-BIT, PARALLEL ANALOG-TO-DIGITAL CONVERTER SLAS239A – SEPTEMBER 1999 – REVISED FEBRUARY 2000 absolute maximum ratings over operating free-air temperature range (unless otherwise noted)† Supply voltage, GND to VCC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . – 0.3 V to 6.5 V Analog input voltage range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . – 0.3 V to AVDD + 0.3 V Reference input voltage range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . AVDD + 0.3 V Digital input voltage range . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . – 0.3 V to DVDD + 0.3 V Operating virtual junction temperature range, TJ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . – 40°C to 150°C Operating free-air temperature range, TA, . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . – 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 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 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. recommended operating conditions power supplies MIN MAX UNIT Analog supply voltage, AVDD 2.7 5.5 V Digital supply voltage, DVDD 2.7 5.5 V NOTE 1: Abs (AVDD – DVDD) < 0.5 V analog inputs Analog input voltage, AIN MIN MAX UNIT AGND VREFP V digital inputs MIN NOM 2.1 2.4 MAX UNIT High-level input voltage, VIH DVDD = 2.7 V to 5.5 V Low level input voltage, VIL DVDD = 2.7 V to 5.5 V 0.8 V DVDD = 4.5 V to 5.5 V 20 MHz DVDD = 2.7 V to 3.3 V 10 MHz Input CLK frequency Pulse duration duration, CLK high high, tw(CLKH) (CLKH) Pulse duration duration, CLK low low, tw(CLKL) V DVDD = 4.5 V to 5.5 V, fCLK = 20 MHz 23 ns DVDD = 2.7 V to 3.3 V, fCLK = 10 MHz 46 ns DVDD = 4.5 V to 5.5 V, fCLK = 20 MHz 23 ns DVDD = 2.7 V to 3.3 V, fCLK = 10 MHz 46 ns Rise time, I/O and control, CLK, CS 50 pF output load 4 Fall time, I/O and control, CLK, CS 50 pF output load 4 ns reference specifications MIN External reference voltage VREFP AVDD = 3 V AVDD = 5 V VREFM AVDD = 3 V AVDD = 5 V VREFP – VREFM 16 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 MAX UNIT AVDD AVDD V 2.5 AGND 1 V AGND 2 V 2 AVDD–AGND V 2 NOM V TLV571 2.7 V TO 5.5 V, 1-CHANNEL, 8-BIT, PARALLEL ANALOG-TO-DIGITAL CONVERTER SLAS239A – SEPTEMBER 1999 – REVISED FEBRUARY 2000 electrical characteristics over recommended operating free-air temperature range, supply voltages, and reference voltages (unless otherwise noted) digital specifications PARAMETER TEST CONDITIONS MIN TYP MAX UNIT Logic inputs IIH IIL High-level input current DVDD = 5 V, DVDD = 3 V, Input = DVDD –1 1 µA Low-level input current DVDD = 5 V, DVDD = 3 V, Input = 0 V –1 1 µA Ci Input capacitance 15 pF 10 Logic outputs VOH VOL High-level output voltage Low-level output voltage IOH = 50 µA to 0.5 mA IOL = 50 µA to 0.5 mA IOZ IOL High-impedance-state output current DVDD = 5 V, DVDD = 3 V, Input = DVDD Low-impedance-state output current DVDD = 5 V, DVDD = 3 V, Input = 0 V Co Output capacitance DVDD– 0.4 V 0.4 V 1 µA –1 µA 5 Internal clock pF 3 V, AVDD = DVDD 9 10 11 5 V, AVDD = DVDD 18 20 22 MHz dc specifications PARAMETER TEST CONDITIONS MIN Resolution TYP MAX 8 UNIT Bits Accuracy Integral nonlinearity, INL Best fit Differential nonlinearity, DNL ± 0.3 ±0.5 LSB ± 0.3 ±0.5 LSB Missing codes EO EG 0 Offset error ± 0.15% ± 0.3% FSR Gain error ± 0.2% ± 0.4% FSR Analog input Ci Input capacitance Ilkg Input leakage current Voltage reference input ri Input resistance Ci Input capacitance AIN, AVDD = 3 V, AVDD = 5 V 15 pF MUX input, AVDD = 3 V, AVDD = 5 V 25 pF ±1 VAIN = 0 to AVDD 2 µA kΩ 300 pF Power supply PD IPD Operating supply current, current IDD + IREF AVDD = DVDD = 3 V, fCLK = 10 MHz AVDD = DVDD = 5 V, fCLK = 20 MHz Power dissipation AVDD+DVDD = 3 V AVDD+DVDD = 5 V Software IDD + IREF AVDD = 3 V AVDD = 5 V Auto IDD + IREF AVDD = 3 V AVDD = 5 V Supply current in power-down power down mode POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 4 5.5 mA 7 8.5 mA 12 17 mW 35 43 mW 1 8 µA 2 10 µA 0.5 1 mA 0.5 1 mA 17 TLV571 2.7 V TO 5.5 V, 1-CHANNEL, 8-BIT, PARALLEL ANALOG-TO-DIGITAL CONVERTER SLAS239A – SEPTEMBER 1999 – REVISED FEBRUARY 2000 electrical characteristics over recommended operating free-air temperature range, supply voltages, and reference voltages (unless otherwise noted) (continued) ac specifications, AVDD = DVDD = 5 V (unless otherwise noted) PARAMETER TEST CONDITIONS MIN TYP MAX UNIT fI = 100 kHz,, 80% of FS fs = 1.25 MSPS, AVDD = 5 V fs = 625 KSPS, AVDD = 3 V 47 49 dB 47 49 dB fI = 100 kHz,, 80% of FS fs = 1.25 MSPS, AVDD = 5 V fs = 625 KSPS, AVDD = 3 V 47 49 dB distortion THD Total harmonic distortion, fI = 100 kHz,, 80% of FS fs = 1.25 MSPS, AVDD = 5 V fs = 625 KSPS, AVDD = 3 V Effective number of bits, bits ENOB fI = 100 kHz,, 80% of FS fs = 1.25 MSPS, AVDD = 5 V fs = 625 KSPS, AVDD = 3 V range SFDR Spurious free dynamic range, fI = 100 kHz,, 80% of FS fs = 1.25 MSPS, AVDD = 5 V fs = 625 KSPS, AVDD = 3 V Signal to noise ratio, Signal-to-noise ratio SNR Signal to noise ratio + distortion, Signal-to-noise distortion SINAD 47 49 dB –64 –52 dB –62 –52 dB 7.5 7.9 Bits 7.5 7.9 Bits –65 –51 dB –64 –51 dB Analog input Full power bandwidth Full-power Small-signal bandwidth Sampling Sam ling rate rate, fs 18 –1 dB Full-scale 0 dB input sine wave –3 dB Full-scale 0 dB input sine wave –1 dB –20 dB input sine wave –3 dB –20 dB input sine wave 12 15 18 MHz 30 MHz 20 MHz 35 MHz AVDD = 4.5 V to 5.5 V 0.0625 1.25 MSPS AVDD = 2.7 V to 3.3 V 0.0625 0.625 MSPS POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 TLV571 2.7 V TO 5.5 V, 1-CHANNEL, 8-BIT, PARALLEL ANALOG-TO-DIGITAL CONVERTER SLAS239A – SEPTEMBER 1999 – REVISED FEBRUARY 2000 timing requirements, AVDD = DVDD = 5 V (unless otherwise noted) PARAMETER tc(CLK) Input In ut clock Cycle time t(sample) Reset and sampling time tc TEST CONDITIONS MIN DVDD = 4.5 V to 5.5 V 50 TYP MAX UNIT ns DVDD = 2.7 V to 3.3 V 100 ns 6 SYSCLK Cycles Total conversion time 10 SYSCLK Cycles twL(EOC) Pulse width, end of conversion, EOC 10 SYSCLK Cycles twL(INT) Pulse width, interrupt 1 SYSCLK Cycles t(STARTOSC) Start-up time, internal oscillator td(CSH_ CSTARTL) Delay time, CS high to CSTART low 100 ns 10 ns DVDD = 5 V at 50 pF 20 ns DVDD = 3 V at 50 pF 40 ns DVDD = 5 V at 50 pF 5 ns DVDD = 3 V at 50 pF 10 ns ten(RDL_DAV) en(RDL DAV) Enable time, time data out tdis(RDH_DAV) dis(RDH DAV) Disable time time, data out tsu(CSL_WRL) Setup time, CS to WR 5 th(WRH_CSH) Hold time, CS to WR 5 ns ns tw(WR) Pulse width, write 1 Clock Period tw(RD) Pulse width, read 1 Clock Period tsu(DAV_WRH) Setup time, data valid to WR 10 ns th(WRH_DAV) Hold time, data valid to WR 5 tsu(CSL_RDL) Setup time, CS to RD 5 ns th(RDH_CSH) Hold time, CS to RD 5 ns th(WRL_EXTXLKH) Hold time WR to clock high 5 ns th(RDL_EXTCLKH) Hold time RD to clock high 5 ns th(CSTARTL_EXTCLKH) Hold time CSTART to clock high 5 ns tsu(WRH_EXTCLKH) Setup time WR high to clock high 5 ns tsu(RDH_EXTCLKH) Setup time RD high to clock high 5 ns tsu(CSTARTH_EXTCLKH) Setup time CSTART high to clock high 5 ns 5 ns td(EXTCLK_CSTARTL) Delay time clock low to CSTART low NOTE: Specifications subject to change without notice. Data valid is denoted as DAV. POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 ns 19 TLV571 2.7 V TO 5.5 V, 1-CHANNEL, 8-BIT, PARALLEL ANALOG-TO-DIGITAL CONVERTER SLAS239A – SEPTEMBER 1999 – REVISED FEBRUARY 2000 TYPICAL CHARACTERISTICS I CC – Supply Current – mA SUPPLY CURRENT vs FREE AIR TEMPERATURE 8.0 7.5 AVDD = DVDD = 5 V, 20 MHz 7.0 6.5 6.0 5.5 5.0 4.5 4.0 AVDD = DVDD = 3 V, 10 MHz 3.5 3.0 2.5 2.0 1.5 1.0 0.5 0.0 –40 –30 –20 –10 0 10 20 30 40 50 60 70 80 TA – Free Air Temperature – °C Figure 11 ANALOG INPUT BANDWIDTH vs FREQUENCY SUPPLY CURRENT vs CLOCK FREQUENCY 1 7 0 AVDD = DVDD = 5 V Analog Input Bandwidth – dB I CC – Supply Current – mA 6 5 4 3 AVDD = DVDD = 3 V 2 –1 –2 –3 –4 AVDD = DVDD = 5 V, AIN = 90% of FS, REF = 5 V, 1 –5 0 0 2 4 6 8 10 12 14 16 18 20 TA = 25°C –6 0.1 Figure 12 Figure 13 POST OFFICE BOX 655303 10 f – Frequency – MHz fclock – Clock Frequency – MHz 20 1 • DALLAS, TEXAS 75265 100 TLV571 2.7 V TO 5.5 V, 1-CHANNEL, 8-BIT, PARALLEL ANALOG-TO-DIGITAL CONVERTER SLAS239A – SEPTEMBER 1999 – REVISED FEBRUARY 2000 TYPICAL CHARACTERISTICS DNL – Differential Nonlinearity – LSB DIFFERENTIAL NONLINEARITY vs DIGITAL OUTPUT CODE 0.15 AVDD = DVDD = 3 V, External Ref = 3 V, CLK = 10 MHz, TA = 25°C 0.10 0.05 –0.00 –0.05 –0.10 –0.15 0 64 128 192 256 Digital Output Code Figure 14 INL – Integral Nonlinearity – LSB INTEGRAL NONLINEARITY vs DIGITAL OUTPUT CODE 0.14 0.12 0.10 0.08 0.06 0.04 0.02 0.00 AVDD = DVDD = 3 V, External Ref = 3 V, CLK = 10 MHz, TA = 25°C –0.02 –0.04 –0.06 0 64 128 192 256 Digital Output Code Figure 15 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 21 TLV571 2.7 V TO 5.5 V, 1-CHANNEL, 8-BIT, PARALLEL ANALOG-TO-DIGITAL CONVERTER SLAS239A – SEPTEMBER 1999 – REVISED FEBRUARY 2000 DNL – Differential Nonlinearity – LSB TYPICAL CHARACTERISTICS DIFFERENTIAL NONLINEARITY vs DIGITAL OUTPUT CODE 0.12 AVDD = DVDD = 5 V, External Ref = 5 V, CLK = 20 MHz, TA = 25°C 0.10 0.08 0.06 0.04 0.02 0.00 –0.02 –0.04 –0.06 –0.08 0 64 128 192 256 192 256 Digital Output Code Figure 16 INL – Integral Nonlinearity – LSB INTEGRAL NONLINEARITY vs DIGITAL OUTPUT CODE 0.14 0.12 0.10 0.08 0.06 0.04 0.02 0.00 –0.02 –0.04 –0.06 –0.08 AVDD = DVDD = 5 V, External Ref = 5 V, CLK = 20 MHz, TA = 25°C 0 64 128 Digital Output Code Figure 17 22 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 TLV571 2.7 V TO 5.5 V, 1-CHANNEL, 8-BIT, PARALLEL ANALOG-TO-DIGITAL CONVERTER SLAS239A – SEPTEMBER 1999 – REVISED FEBRUARY 2000 TYPICAL CHARACTERISTICS EFFECTIVE NUMBER OF BITS vs FREQUENCY ENOB – Effective Number of Bits – BITS 10 AVDD = DVDD = 3 V, External Ref = 3 V 9 8 7 6 5 0 100 200 f – Frequency – kHz 300 Figure 18 EFFECTIVE NUMBER OF BITS vs FREQUENCY ENOB – Effective Number of Bits – BITS 10 AVDD = DVDD = 5 V, External Ref = 5 V 9 8 7 6 5 0 200 400 600 f – Frequency – kHz Figure 19 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 23 TLV571 2.7 V TO 5.5 V, 1-CHANNEL, 8-BIT, PARALLEL ANALOG-TO-DIGITAL CONVERTER SLAS239A – SEPTEMBER 1999 – REVISED FEBRUARY 2000 TYPICAL CHARACTERISTICS FAST FOURIER TRANSFORM vs FREQUENCY 20 AIN = 200 KHz Magnitude – dB 0 –20 CLK = 10 MHz –40 AVDD = DVDD = 3 V External Ref = 3 V –60 –80 –100 –120 –140 0 100000 200000 300000 f – Frequency – Hz Figure 20 FAST FOURIER TRANSFORM vs FREQUENCY 20 AIN = 200 KHz Magnitude – dB 0 –20 CLK = 20 MHz –40 AVDD = DVDD = 5 V External Ref = 5 V –60 –80 –100 –120 –140 0 200000 400000 f – Frequency – Hz Figure 21 24 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 600000 PACKAGE OPTION ADDENDUM www.ti.com 10-Dec-2020 PACKAGING INFORMATION Orderable Device Status (1) Package Type Package Pins Package Drawing Qty Eco Plan (2) Lead finish/ Ball material MSL Peak Temp Op Temp (°C) Device Marking (3) (4/5) (6) TLV571IDW ACTIVE SOIC DW 24 25 RoHS & Green NIPDAU Level-1-260C-UNLIM -40 to 85 TLV571I TLV571IPW ACTIVE TSSOP PW 24 60 RoHS & Green NIPDAU Level-2-260C-1 YEAR -40 to 85 TY571 (1) The marketing status values are defined as follows: ACTIVE: Product device recommended for new designs. LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect. NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in a new design. PREVIEW: Device has been announced but is not in production. Samples may or may not be available. OBSOLETE: TI has discontinued the production of the device. (2) RoHS: TI defines "RoHS" to mean semiconductor products that are compliant with the current EU RoHS requirements for all 10 RoHS substances, including the requirement that RoHS substance do not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, "RoHS" products are suitable for use in specified lead-free processes. TI may reference these types of products as "Pb-Free". RoHS Exempt: TI defines "RoHS Exempt" to mean products that contain lead but are compliant with EU RoHS pursuant to a specific EU RoHS exemption. Green: TI defines "Green" to mean the content of Chlorine (Cl) and Bromine (Br) based flame retardants meet JS709B low halogen requirements of