TLV2553-Q1 www.ti.com ..................................................................................................................................................................................................... SLAS579 – APRIL 2009 12-BIT 200-KSPS 11-CHANNEL LOW-POWER SERIAL ADC FEATURES APPLICATIONS • • • • • • 1 • • • • • • • • • • • Qualified for Automotive Applications 12-Bit-Resolution Analog-to-Digital Converter (ADC) Up to 200-KSPS (150-KSPS for 3 V) Throughput Over Operating Temperature Range With 12-Bit Output Mode 11 Analog Input Channels Three Built-In Self-Test Modes Inherent Sample and Hold Function Linearity Error of +1 LSB (Max) On-Chip Conversion Clock Unipolar or Bipolar Output Operation Programmable Most Significant Bit (MSB) or Least Significant Bit (LSB) First Programmable Power Down Programmable Output Data Length SPI Compatible Serial Interface With I/O Clock Frequencies up to 15 MHz (CPOL=0, CPHA=0) Process Control Portable Data Logging Battery-Powered Instruments Automotive DW PACKAGE (TOP VIEW) AIN0 AIN1 AIN2 AIN3 AIN4 AIN5 AIN6 AIN7 AIN8 GND VCC EOC 18 I/O CLOCK 17 DATA IN 16 DATA OUT 15 CS 14 REF+ 13 REF– 12 AIN10 11 AIN9 1 20 2 19 3 4 5 6 7 8 9 10 DESCRIPTION\ORDERING INFORMATION The TLV2553 is a 12-bit switched-capacitor successive-approximation analog-to-digital converter (ADC). The ADC has three control inputs [chip select (CS), the input-output clock, and the address/control input (DATAIN)] designed for communication with the serial port of a host processor or peripheral through a serial 3-state output. In addition to the high-speed converter and versatile control capability, the device has an on-chip 14-channel multiplexer that can select any one of 11 inputs or any one of three internal self-test voltages using configuration register 1. The sample-and-hold function is automatic. At the end of conversion, when programmed as EOC, the pin 19 output goes high to indicate that conversion is complete. The converter incorporated in the device features differential high-impedance reference inputs that facilitate ratiometric conversion, scaling, and isolation of analog circuitry from logic and supply noise. A switched-capacitor design allows low-error conversion over the full operating temperature range. The TLV2553I is characterized for operation from TA = –40°C to 85°C. ORDERING INFORMATION (1) PACKAGE (2) TA –40°C to 85°C (1) (2) SOP – DW Reel of 2000 ORDERABLE PART NUMBER TLV2553IDWRQ1 TOP-SIDE MARKING TLV2553IQ1 For the most current package and ordering information, see the Package Option Addendum at the end of this document, or see the TI web site at www.ti.com. Package drawings, thermal data, and symbolization are available at www.ti.com/packaging. 1 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. PRODUCTION DATA information is current as of publication date. Products conform to specifications per the terms of the Texas Instruments standard warranty. Production processing does not necessarily include testing of all parameters. Copyright © 2009, Texas Instruments Incorporated TLV2553-Q1 SLAS579 – APRIL 2009 ..................................................................................................................................................................................................... www.ti.com FUNCTIONAL BLOCK DIAGRAM VCC 20 REF + 14 REF − 13 3 AIN0 1 AIN1 2 AIN2 3 AIN3 4 AIN4 5 AIN5 6 AIN6 7 AIN7 8 AIN8 9 AIN9 11 AIN10 12 DATA IN CS I/O CLOCK Self Test 14-Channel Analog Multiplexer Low Power 12-Bit SAR ADC Sample and Hold 4 Input Address Register 18 19 Control Logic and I/O Counters EOC 12 12 Output Data Register 12-to-1 Data Selector and Driver 17 15 Reference CTRL 16 DATA OUT 4 Internal OSC 10 GND 2 Submit Documentation Feedback Copyright © 2009, Texas Instruments Incorporated Product Folder Link(s): TLV2553-Q1 TLV2553-Q1 www.ti.com ..................................................................................................................................................................................................... SLAS579 – APRIL 2009 TERMINAL FUNCTIONS TERMINAL NAME AIN0–AIN10 CS DATA IN NO. I/O DESCRIPTION 1–9, 11, 12 I Analog input. These 11 analog-signal inputs are internally multiplexed. 15 I Chip select. A high-to-low transition on CS resets the internal counters and controls and enables DATA OUT, DATA IN, and I/O CLOCK. A low-to-high transition disables DATA IN and I/O CLOCK within a setup time. I Serial data input. The 4-bit serial data can be used as address selects the desired analog input channel or test voltage to be converted next, or a command to activate other other features. The input data is presented with the MSB (D7) first and is shifted in on the first four rising edges of the I/O CLOCK. After the four address/command bits are read into the command register CMR, I/O CLOCK clocks the remaining four bits of configuration in. 17 DATA OUT 16 O 3-state serial output for the A/D conversion result. DATA OUT is in the high-impedance state when CS is high and active when CS is low. With a valid CS, DATA OUT is removed from the high-impedance state and is driven to the logic level corresponding to the MSB/LSB value of the previous conversion result. The next falling edge of I/O CLOCK drives DATA OUT to the logic level corresponding to the next MSB/LSB, and the remaining bits are shifted out in order. EOC 19 O End-of-convertions status. Used to indicate the end of conversion (EOC) to the host processor. EOC goes from a high to a low logic level after the falling edge of the last I/O CLOCK and remains low until the conversion is complete and the data is ready for transfer. GND 10 Ground. GND is the ground return terminal for the internal circuitry. Unless otherwise noted, all voltage measurements are with respect to GND. I/O CLOCK 18 I Input /output clock. I/O CLOCK receives the serial input and performs the following four functions: 1. It clocks the eight input data bits into the input data register on the first eight rising edges of I/O CLOCK with the multiplexer address available after the fourth rising edge. 2. On the fourth falling edge of I/O CLOCK, the analog input voltage on the selected multiplexer input begins charging the capacitor array and continues to do so until the last falling edge of I/O CLOCK. 3. The remaining 11 bits of the previous conversion data are shifted out on DATA OUT. Data changes on the falling edge of I/O CLOCK. 4. Control of the conversion is transferred to the internal state controller on the falling edge of the last I/O CLOCK. REF+ 14 I/O Positive reference voltage The upper reference voltage value (nominally VCC) is applied to REF+. The maximum analog input voltage range is determined by the difference between the voltage applied to terminals REF+ and REF–. REF– 13 I/O Negative reference voltage. The lower reference voltage value (nominally ground) is applied to REF–. This pin is connected to analog ground (GND of the ADC) when internal reference is used. VCC 20 Positive supply voltage Submit Documentation Feedback Copyright © 2009, Texas Instruments Incorporated Product Folder Link(s): TLV2553-Q1 3 TLV2553-Q1 SLAS579 – APRIL 2009 ..................................................................................................................................................................................................... www.ti.com ABSOLUTE MAXIMUM RATINGS (1) over operating free-air temperature range (unless otherwise noted) VALUE VCC Supply voltage range (2) VI Input voltage range (any input) –0.3 V to VCC + 0.3 VO Output voltage range –0.3 V to VCC + 0.3 Vref+ Positive reference voltage range –0.3 V to VCC + 0.3 Vref– Negative reference voltage range –0.3 V to VCC + 0.3 II Peak input current (any input) –0.5 V to 6.5 V ±20 mA Peak total input current (all inputs) ±30 mA TJ Operating virtual junction temperature range –40°C to 150°C TA Operating free-air temperature range –40°C to 85°C Tstg Storage temperature range –65°C to 150°C Lead temperature 1,6 mm (1/16 inch) from the case for 10 seconds (1) (2) 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. All voltage values are with respect to the GND terminal with REF– and GND wired together (unless otherwise noted). RECOMMENDED OPERATING CONDITIONS MIN VCC Supply voltage I/O CLOCK frequency VCC = 4.5 V to 5.5 V VCC = 4.5 V to 5.5 V Aperature jitter VCC = 4.5 V to 5.5 V Analog input voltage (1) VIH High-level control input voltage VIL Low-level control input voltage TA Operating free-air temperature (1) 4 MAX 5.5 16-bit I/O 0.01 15 12-bit I/O 0.01 15 18-bit I/O 0.01 15 VCC = 2.7 to 3.6 V Tolerable clock jitter, I/O CLOCK NOM 2.7 0.01 100 0 VCC = 3 V to 3.6 V 0 VCC = 2.7 V to 3 V 0 VCC = 4.5 V to 5.5 V 2 VCC = 2.7 V to 3.6 V 2.1 MHz ns ps REF+ – REF– V V VCC = 4.5 V to 5.5 V 0.8 VCC = 2.7 V to 3.6 V 0.6 –40 V 10 0.38 VCC = 4.5 V to 5.5 V UNIT 85 V °C Analog input voltages greater than the voltage applied to REF+ convert as all ones (111111111111), while input voltages less than the voltage applied to REF– convert as all zeros (000000000000). Submit Documentation Feedback Copyright © 2009, Texas Instruments Incorporated Product Folder Link(s): TLV2553-Q1 TLV2553-Q1 www.ti.com ..................................................................................................................................................................................................... SLAS579 – APRIL 2009 ELECTRICAL CHARACTERISTICS over recommended operating free-air temperature range, when VCC = 5 V: VREF+ = 5 V, I/O CLOCK frequency = 15 MHz, when VCC = 2.7 V: VREF+ = 2.5 V, I/O CLOCK frequency = 10 MHz (unless otherwise noted) PARAMETER VOH TEST CONDITIONS VCC = 4.5 V, IOH = –1.6 mA VCC = 2.7 V, IOH = –0.2 mA High-level output voltage VOL VCC = 4.5 V, IOH = –20 µA VCC = 2.7 V, IOH = –20 µA VCC = 4.5 V, IOL = –1.6 mA VCC = 2.7 V, IOL = –0.8 mA Low-level output voltage VCC = 4.5 V, IOL = –20 µA VCC = 2.7 V, IOL = –20 µA MIN 0.4 30 pF 1 2.5 VO = 0 V, CS = VCC –1 –2.5 CS = 0 V, External reference ICC(PD) Power-down current For all digital inputs, Software power down 0 ≤ VI ≤ 0.5 V or VI ≥ VCC – 0.5 V, Auto power down I/O CLOCK = 0 V IIH High-level input current IIL Low-level input current tconvert Conversion time (13.5 × (1/fOSC) + 25 ns) VCC = 5 V 1.2 VCC = 2.7 V 0.9 Input impedance (2) Ci Input capacitance (1) (2) Analog inputs µA mA 0.1 1 0.1 10 VI = VCC 0.005 2.5 µA VI = 0 V –0.005 –2.5 µA Selected channel at VCC , Unselected channel at 0 V 1 Selected channel at 0 V, Unselected channel at VCC –1 µA µA VCC = 4.5 V to 5.5 V 3.27 VCC = 2.7 V to 3.6 V 2.56 MHz VCC = 4.5 V to 5.5 V 4.15 VCC = 2.7 V to 3.6 V 5.54 Internal oscillator frequency voltage Zi V 0.1 VO = VCC, CS = VCC Operating supply current Internal oscillator frequency V VCC – 0.1 ICC fOSC UNIT 2.4 High-impedance off-state output current Selected channel leakage current MAX 30 pF IOZ Ilkg TYP (1) 3.6 4.1 VCC = 4.5 V 500 VCC = 2.7 V 600 Analog inputs 45 55 Control inputs 5 15 µs V Ω pF All typical values are at VCC = 5 V, TA = 25°C. The switch resistance is very nonlinear and varies with input voltage and supply voltage. This is the worst case. Submit Documentation Feedback Copyright © 2009, Texas Instruments Incorporated Product Folder Link(s): TLV2553-Q1 5 TLV2553-Q1 SLAS579 – APRIL 2009 ..................................................................................................................................................................................................... www.ti.com EXTERNAL REFERENCE SPECIFICATIONS (1) PARAMETER –0.1 0 0.1 VCC = 2.7 V to 3.6 V –0.1 0 0.1 VCC = 4.5 V to 5.5 V 2 VCC VCC = 2.7 V to 3.6 V 2 VCC External reference input voltage difference VCC = 4.5 V to 5.5 V (REF+ – REF–) VCC = 2.7 V to 3.6 V 1.9 VCC 1.9 VCC Reference input voltage, REF– VREF+ Reference input voltage, REF+ External reference supply current CS = 0 V VCC = 5 V ZREF Reference input impedance VCC = 2.7 V (1) (2) MAX VCC = 4.5 V to 5.5 V VREF– IREF MIN TYP (2) TEST CONDITIONS VCC = 4.5 V to 5.5 V 0.94 VCC = 2.7 V to 3.6 V 0.62 Static 1 During sampling/conversion 6 Static 1 During sampling/conversion 6 UNIT V V V mA MΩ 9 kΩ MΩ 9 kΩ Add a 0.1-µF capacitor between REF+ and REF– pins when external reference is used. All typical values are at VCC = 5 V, TA = 25°C. OPERATING CHARACTERISTICS over recommended operating free-air temperature range, when VCC = 5 V: VREF+ = 5 V, I/O CLOCK frequency = 15 MHz, when VCC = 2.7 V: VREF+ = 2.5 V, I/O CLOCK frequency = 10 MHz (unless otherwise noted) PARAMETER TEST CONDITIONS (2) MIN TYP (1) MAX UNIT –1 1 LSB –1 1 LSB INL Integral linearity error DNL Differential linearity error EO Offset error (3) See (4) –2 2 mV EG Gain error (3) See (4) –3 3 mV ET Total unadjusted error (5) Self-test output code (6) (see Table 2) (1) (2) (3) (4) (5) (6) 6 ±1.5 Address data input = 1011 2048 Address data input = 1100 0 Address data input = 1101 4095 LSB All typical values are at VCC = 5 V, TA = 25°C. Linearity error is the maximum deviation from the best straight line through the A/D transfer characteristics. Gain error is the difference between the actual midstep value and the nominal midstep value in the transfer diagram at the specified gain point after the offset error has been adjusted to zero. Offset error is the difference between the actual midstep value and the nominal midstep value at the offset point. Analog input voltages greater than the voltage applied to REF+ convert as all ones (111111111111), while input voltages less than the voltage applied to REF– convert as all zeros (000000000000). Total unadjusted error comprises linearity, zero-scale errors, and full-scale errors. Both the input address and the output codes are expressed in positive logic. Submit Documentation Feedback Copyright © 2009, Texas Instruments Incorporated Product Folder Link(s): TLV2553-Q1 TLV2553-Q1 www.ti.com ..................................................................................................................................................................................................... SLAS579 – APRIL 2009 TIMING CHARACTERISTICS over recommended operating free-air temperature range, VREF+ = 5 V, I/O CLOCK frequency = 15 MHz, VCC = 5 V, Load = 25 pF (unless otherwise noted) PARAMETER tw1 Pulse duration I/O CLOCK high or low tsu1 Setup time DATA IN valid before I/O CLOCK rising edge (see Figure 26) th1 Hold time DATA IN valid after I/O CLOCK rising edge (see Figure 26) (1) tsu2 Setup time CS low before first rising I/O CLOCK edge th2 Hold time CS pulse duration high time (see Figure 27) th3 (see Figure 27) MIN MAX 26.7 100000 UNIT ns 12 ns 0 ns 25 ns 100 ns Hold time CS low after last I/O CLOCK falling edge (see Figure 27) 0 ns th4 Hold time DATA OUT valid after I/O CLOCK falling edge (see Figure 28) 2 ns th5 Hold time CS high after EOC rising edge when CS is toggled (see Figure 31) 0 ns Load = 25 pF 28 Load = 10 pF 20 td1 Delay time CS falling edge to DATA OUT valid (MSB or LSB) (see Figure 25) td2 Delay time CS rising edge to DATA OUT high impedance (see Figure 25) td3 Delay time I/O CLOCK falling edge to next DATA OUT bit valid (see Figure 28) td4 ns 10 ns 20 ns Delay time last I/O CLOCK falling edge to EOC falling edge 55 ns td5 Delay time last I/O CLOCK falling edge to CS falling edge to abort conversion 1.5 µs tt1 Transition time I/O CLOCK (1) (see Figure 28) 1 µs tt2 Transition time DATA OUT (see Figure 28) 5 ns tt3 Transition time EOC, CL = 7 pF (see Figure 30) 2.4 ns tt4 Transition time DATA IN, CS 10 µs tcycle Total cycle time (sample, conversion and delays) (1) (2) µs tsample Channel acquisition time (sample) at 1 kΩ (1) (see Figure 33 through Figure 38) 2 Source impedance = 25 Ω 600 Source impedance = 100 Ω 650 Source impedance = 500 Ω 700 Source impedance = 1 kΩ (1) (2) ns 1000 I/O CLOCK period = 8 × [1/(I/O CLOCK frequency)] or 12 × [1/(I/O CLOCK frequency)] or 16 × [1/(I/O CLOCK frequency)], depending on I/O format selected tconvert(max) + I/O CLOCK period (8/12/16 CLKs) Submit Documentation Feedback Copyright © 2009, Texas Instruments Incorporated Product Folder Link(s): TLV2553-Q1 7 TLV2553-Q1 SLAS579 – APRIL 2009 ..................................................................................................................................................................................................... www.ti.com TIMING CHARACTERISTICS over recommended operating free-air temperature range, VREF+ = 2.5 V, I/O CLOCK frequency = 10 MHz, VCC = 2.7 V, Load = 25 pF (unless otherwise noted) MIN MAX tw1 Pulse duration I/O CLOCK high or low PARAMETER 40 100000 tsu1 Setup time DATA IN valid before I/O CLOCK rising edge (see Figure 26) 22 ns th1 Hold time DATA IN valid after I/O CLOCK rising edge (see Figure 26) 0 ns (1) tsu2 Setup time CS low before first rising I/O CLOCK edge th2 Hold time CS pulse duration high time (see Figure 27) th3 (see Figure 27) UNIT ns 33 ns 100 ns Hold time CS low after last I/O CLOCK falling edge (see Figure 27) 0 ns th4 Hold time DATA OUT valid after I/O CLOCK falling edge (see Figure 28) 2 ns th5 Hold time CS high after EOC rising edge when CS is toggled (see Figure 31) 0 ns Load = 25 pF 30 Load = 10 pF 22 td1 Delay time CS falling edge to DATA OUT valid (MSB or LSB) (see Figure 25) td2 Delay time CS rising edge to DATA OUT high impedance (see Figure 25) td3 Delay time I/O CLOCK falling edge to next DATA OUT bit valid (see Figure 28) td4 ns 10 ns 33 ns Delay time last I/O CLOCK falling edge to EOC falling edge 75 ns td5 Delay time last I/O CLOCK falling edge to CS falling edge to abort conversion 1.5 µs tt1 Transition time I/O CLOCK (1) (see Figure 28) 1 µs tt2 Transition time DATA OUT (see Figure 28) 5 ns tt3 Transition time EOC, CL = 7 pF (see Figure 30) 4 ns tt4 Transition time DATA IN, CS 10 µs tcycle Total cycle time (sample, conversion and delays) (1) (2) µs tsample Channel acquisition time (sample), at 1 kΩ (1) (see Figure 33 through Figure 38) 2 Source impedance = 25 Ω (1) (2) 8 800 Source impedance = 100 Ω 850 Source impedance = 500 Ω 1000 Source impedance = 1 kΩ 1600 ns I/O CLOCK period = 8 × [1/(I/O CLOCK frequency)] or 12 × [1/(I/O CLOCK frequency)] or 16 × [1/(I/O CLOCK frequency)], depending on I/O format selected tconvert(max) + I/O CLOCK period (8/12/16 CLKs) Submit Documentation Feedback Copyright © 2009, Texas Instruments Incorporated Product Folder Link(s): TLV2553-Q1 TLV2553-Q1 www.ti.com ..................................................................................................................................................................................................... SLAS579 – APRIL 2009 TYPICAL CHARACTERISTICS SUPPLY CURRENT vs FREE-AIR TEMPERATURE ICC − Supply Current − mA 0.620 0.43 VCC = 3.3 V VREF+ = 2.5 V VREF− = 0 V I/O CLOCK = 10 MHz 0.42 External Reference Current − mA 0.625 EXTERNAL REFERENCE CURRENT vs FREE-AIR TEMPERATURE 0.615 0.610 0.605 0.600 0.595 0.590 0.585 0.580 −40 0.41 VCC = 3.3 V VREF+ = 2.5 V VREF− = 0 V I/O CLOCK = 10 MHz 0.40 0.39 0.38 0.37 0.36 0.35 0.34 −25 −10 5 20 35 50 65 0.33 −40 80 −25 −10 5 Figure 1. 0.40 50 65 80 65 80 AUTO POWER DOWN vs FREE-AIR TEMPERATURE 0.06 VCC = 3.3 V VREF+ = 2.5 V VREF− = 0 V I/O CLOCK = 10 MHz 0.05 0.35 0.30 VCC = 3.3 V VREF+ = 2.5 V VREF− = 0 V I/O CLOCK = 10 MHz 0.04 Current − µ A Current − µ A 35 Figure 2. SOFTWARE POWER DOWN vs FREE-AIR TEMPERATURE 0.45 20 TA − Free-Air Temperature − °C TA − Free-Air Temperature − °C 0.25 0.20 0.15 0.03 0.02 0.10 0.01 0.05 0.00 −40 −25 −10 5 20 35 50 65 80 0.00 −40 TA − Free-Air Temperature − °C Figure 3. −25 −10 5 20 35 50 TA − Free-Air Temperature − °C Figure 4. Submit Documentation Feedback Copyright © 2009, Texas Instruments Incorporated Product Folder Link(s): TLV2553-Q1 9 TLV2553-Q1 SLAS579 – APRIL 2009 ..................................................................................................................................................................................................... www.ti.com TYPICAL CHARACTERISTICS (continued) MAXIMUM DIFFERENTIAL NONLINEARITY vs FREE-AIR TEMPERATURE 0.9 0.8 0.0 VCC = 2.7 V VREF+ = 2.5 V VREF− = 0 V I/O CLOCK = 10 MHz Minimum Differential Nonlinearity − LSB Maximum Differential Nonlinearity − LSB 1.0 0.7 0.6 0.5 0.4 0.3 0.2 0.1 0.0 −40 −25 −10 5 20 MINIMUM DIFFERENTIAL NONLINEARITY vs FREE-AIR TEMPERATURE 35 50 65 −0.1 VCC = 2.7 V VREF+ = 2.5 V VREF− = 0 V I/O CLOCK = 10 MHz −0.2 −0.3 −0.4 −0.5 −0.6 −0.7 −0.8 −40 80 −25 TA − Free-Air Temperature − °C −10 5 Figure 5. −0.1 Minimum Integral Nonlinearity − LSB Maximum Integral Nonlinearity − LSB 65 80 0.0 VCC = 2.7 V VREF+ = 2.5 V VREF− = 0 V I/O CLOCK = 10 MHz 0.6 0.5 0.4 0.3 0.2 0.1 −25 −10 5 20 35 50 65 80 VCC = 2.7 V VREF+ = 2.5 V VREF− = 0 V I/O CLOCK = 10 MHz −0.2 −0.3 −0.4 −0.5 −0.6 −0.7 −40 TA − Free-Air Temperature − °C Figure 7. 10 50 MINIMUM INTEGRAL NONLINEARITY vs FREE-AIR TEMPERATURE 0.8 0.0 −40 35 Figure 6. MAXIMUM INTEGRAL NONLINEARITY vs FREE-AIR TEMPERATURE 0.7 20 TA − Free-Air Temperature − °C −25 −10 5 20 35 50 65 80 TA − Free-Air Temperature − °C Figure 8. Submit Documentation Feedback Copyright © 2009, Texas Instruments Incorporated Product Folder Link(s): TLV2553-Q1 TLV2553-Q1 www.ti.com ..................................................................................................................................................................................................... SLAS579 – APRIL 2009 TYPICAL CHARACTERISTICS (continued) DNL − Differential Nonlinearity − LSB DIFFERENTIAL NONLINEARITY vs DIGITAL OUTPUT CODE 0.5 0.4 VCC = 2.7 V, VREF+ = 2.5 V, VREF− = 0 V, I/O CLOCK = 10 MHz, TA = 25°C 0.3 0.2 0.1 0.0 −0.1 −0.2 −0.3 −0.4 −0.5 0 1024 2048 3072 4096 Digital Output Code Figure 9. INL − Integral Nonlinearity − LSB INTEGRAL NONLINEARITY vs DIGITAL OUTPUT CODE 0.8 VCC = 2.7 V, VREF+ = 2.5 V, VREF− = 0 V, I/O CLOCK = 10 MHz, TA = 25°C 0.6 0.4 0.2 0.0 −0.2 −0.4 −0.6 −0.8 0 1024 2048 3072 4096 Digital Output Code Figure 10. Submit Documentation Feedback Copyright © 2009, Texas Instruments Incorporated Product Folder Link(s): TLV2553-Q1 11 TLV2553-Q1 SLAS579 – APRIL 2009 ..................................................................................................................................................................................................... www.ti.com TYPICAL CHARACTERISTICS (continued) GAIN ERROR vs FREE-AIR TEMPERATURE OFFSET ERROR vs FREE-AIR TEMPERATURE 0.6 1.4 1.2 EG − Gain Error − mV EO − Offset Error − mV 0.5 0.4 0.3 0.2 1.0 0.8 0.6 0.4 0.1 0.0 −40 VCC = 3.3 V VREF+ = 2.5 V VREF− = 0 V I/O CLOCK = 10 MHz −25 −10 5 20 0.2 35 50 65 VCC = 3.3 V VREF+ = 2.5 V VREF− = 0 V I/O CLOCK = 10 MHz 0.0 −40 80 −25 −10 Figure 11. 65 80 0.7 External Reference Current − mA ICC − Supply Current − mA 50 0.8 VCC = 5.5 V VREF+ = 4.096 V VREF− = 0 V I/O CLOCK = 15 MHz 0.94 0.92 0.90 0.88 0.86 0.6 0.5 0.4 0.3 0.2 0.1 −25 −10 5 20 35 50 65 80 VCC = 5.5 V VREF+ = 4.096 V VREF− = 0 V I/O CLOCK = 15 MHz 0.0 −40 TA − Free-Air Temperature − °C Figure 13. 12 35 EXTERNAL REFERENCE CURRENT vs FREE-AIR TEMPERATURE 0.98 0.84 −40 20 Figure 12. SUPPLY CURRENT vs FREE-AIR TEMPERATURE 0.96 5 TA − Free-Air Temperature − °C TA − Free-Air Temperature − °C −25 −10 5 20 35 50 65 80 TA − Free-Air Temperature − °C Figure 14. Submit Documentation Feedback Copyright © 2009, Texas Instruments Incorporated Product Folder Link(s): TLV2553-Q1 TLV2553-Q1 www.ti.com ..................................................................................................................................................................................................... SLAS579 – APRIL 2009 TYPICAL CHARACTERISTICS (continued) SOFTWARE POWER DOWN vs FREE-AIR TEMPERATURE AUTO POWER DOWN vs FREE-AIR TEMPERATURE 0.14 0.45 VCC = 5.5 V VREF+ = 4.096 V VREF− = 0 V I/O CLOCK = 15 MHz 0.40 0.35 0.12 Current − µ A Current − µ A 0.10 0.30 0.25 0.20 0.08 0.06 0.15 0.04 VCC = 5.5 V VREF+ = 4.096 V VREF− = 0 V I/O CLOCK = 15 MHz 0.10 0.02 0.05 0.00 −40 −25 −10 5 20 35 50 65 0.00 −40 80 −25 TA − Free-Air Temperature − °C −10 Figure 15. VCC = 5.5 V VREF+ = 4.096 V VREF− = 0 V I/O CLOCK = 15 MHz Minimum Differential Nonlinearity − LSB Maximum Differential Nonlinearity − LSB 50 65 80 0.00 0.7 0.6 0.5 0.4 0.3 0.2 0.1 0.0 −40 35 MINIMUM DIFFERENTIAL NONLINEARITY vs FREE-AIR TEMPERATURE 1.0 0.8 20 Figure 16. MAXIMUM DIFFERENTIAL NONLINEARITY vs FREE-AIR TEMPERATURE 0.9 5 TA − Free-Air Temperature − °C −25 −10 5 20 35 50 65 80 −0.05 −0.10 VCC = 5.5 V VREF+ = 4.096 V VREF− = 0 V I/O CLOCK = 15 MHz −0.15 −0.20 −0.25 −0.30 −0.35 −0.40 −0.45 −40 TA − Free-Air Temperature − °C Figure 17. −25 −10 5 20 35 50 65 80 TA − Free-Air Temperature − °C Figure 18. Submit Documentation Feedback Copyright © 2009, Texas Instruments Incorporated Product Folder Link(s): TLV2553-Q1 13 TLV2553-Q1 SLAS579 – APRIL 2009 ..................................................................................................................................................................................................... www.ti.com TYPICAL CHARACTERISTICS (continued) MAXIMUM INTEGRAL NONLINEARITY vs FREE-AIR TEMPERATURE MINIMUM INTEGRAL NONLINEARITY vs FREE-AIR TEMPERATURE 0.90 0.86 −0.330 VCC = 5.5 V VREF+ = 4.096 V VREF− = 0 V I/O CLOCK = 15 MHz Minimum Integral Nonlinearity − LSB Maximum Integral Nonlinearity − LSB 0.88 −0.329 0.84 0.82 0.80 0.78 0.76 0.74 −40 −25 −10 5 20 35 50 65 80 −0.331 VCC = 5.5 V VREF+ = 4.096 V VREF− = 0 V I/O CLOCK = 15 MHz −0.332 −0.333 −0.334 −0.335 −0.336 −0.337 −0.338 −40 −25 −10 5 20 35 50 65 80 TA − Free-Air Temperature − °C TA − Free-Air Temperature − °C Figure 19. Figure 20. DNL − Differential Nonlinearity − LSB DIFFERENTIAL NONLINEARITY vs DIGITAL OUTPUT CODE 0.3 VCC = 5.5 V, VREF+ = 4.096 V, VREF− = 0 V, I/O CLOCK = 15 MHz, TA = 25°C 0.2 0.1 0.0 −0.1 −0.2 −0.3 0 1024 2048 3072 4096 Digital Output Code Figure 21. 14 Submit Documentation Feedback Copyright © 2009, Texas Instruments Incorporated Product Folder Link(s): TLV2553-Q1 TLV2553-Q1 www.ti.com ..................................................................................................................................................................................................... SLAS579 – APRIL 2009 TYPICAL CHARACTERISTICS (continued) INL − Integral Nonlinearity − LSB INTEGRAL NONLINEARITY vs DIGITAL OUTPUT CODE 0.8 0.6 0.4 0.2 0.0 −0.2 −0.4 −0.6 VCC = 5.5 V, VREF+ = 4.096 V, VREF− = 0 V, I/O CLOCK = 15 MHz, TA = 25°C −0.8 0 1024 2048 3072 4096 Digital Output Code Figure 22. OFFSET ERROR vs FREE-AIR TEMPERATURE GAIN ERROR vs FREE-AIR TEMPERATURE 0.00 EO − Offset Error − mV −0.10 −0.1 −0.2 EG − Gain Error − mV −0.05 0.0 VCC = 5.5 V VREF+ = 4.096 V VREF− = 0 V I/O CLOCK = 15 MHz −0.15 −0.20 −0.25 −0.30 −0.35 −0.3 −0.4 −0.5 −0.6 −0.7 −0.40 −0.8 −0.45 −0.9 −0.50 −40 −25 −10 5 20 35 50 65 80 VCC = 5.5 V VREF+ = 4.096 V VREF− = 0 V I/O CLOCK = 15 MHz −1.0 −40 TA − Free-Air Temperature − °C Figure 23. −25 −10 5 20 35 50 65 80 TA − Free-Air Temperature − °C Figure 24. Submit Documentation Feedback Copyright © 2009, Texas Instruments Incorporated Product Folder Link(s): TLV2553-Q1 15 TLV2553-Q1 SLAS579 – APRIL 2009 ..................................................................................................................................................................................................... www.ti.com Parameter Measurement Information VIH CS Data Valid VIL td1 VIH DATA IN td2 VIL th1 VOH Data Out VOL Figure 25. DATA OUT to Hi-Z Voltage Waveforms VIH VIL CS th2 th3 tsu2 tsu1 I/O CLOCK VIH VIL Figure 26. DATA IN and I/O CLOCK Voltage tt1 tt1 VIH VIL I/O CLOCK I/O CLK Period VIH I/O CLOCK Last Clock td3 VIL th4 VOH Data Out VOL tt2 Figure 27. CS and I/O CLOCK Voltage Waveforms I/O CLOCK Figure 28. I/O CLOCK and DATA OUT Voltage Waveforms VIH Last Clock VIL tt3 VOL tconvert td2 tt3 VOH EOC VOL VOH EOC VOH Data Out tt3 MSB Valid Figure 29. I/O CLOCK and EOC Voltage Waveforms th5 EOC VIL 1 VOH I/O CLOCK VOL EOC Figure 31. CS and EOC Waveforms 16 Figure 30. EOC and DATA OUT Voltage Waveforms VIH CS VOL VIH VIL VOH VOL Figure 32. I/O CLOCK and DATA OUT Voltage Submit Documentation Feedback Copyright © 2009, Texas Instruments Incorporated Product Folder Link(s): TLV2553-Q1 TLV2553-Q1 www.ti.com ..................................................................................................................................................................................................... SLAS579 – APRIL 2009 Parameter Measurement Information (continued) Shift in New Multiplexer Address, Simultaneously Shift Out Previous Conversion Result CS Access Cycle 1 I/O CLOCK ÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎ DATA OUT 3 2 4 5 6 7 8 9 10 11 12 D7 D6 Output Data Format D5 D4 D3 D2 D1 3 2 Hi−Z State MSB−1 MSB−2 MSB−3 MSB−4 MSB−5 MSB−6 MSB−7 MSB−8 MSB−9 LSB+1 Channel Address 1 ÎÎÎÎÎÎÎÎÎÎÎÎÎ ÎÎÎÎÎÎÎÎÎÎÎÎÎ ÎÎÎÎÎÎÎÎÎÎÎÎÎ ÎÎÎÎÎÎÎÎÎÎÎÎÎ Previous Conversion Data MSB DATA IN Sample Cycle LSB MSB D0 MSB−1 MSB−2 D7 D6 D5 A/D Conversion Interval tCONV EOC Initialize Initialize Figure 33. Timing for 12-Clock Transfer Using CS With DATA OUT Set for MSB First Shift in New Multiplexer Address, Simultaneously Shift Out Previous Conversion Result CS Access Cycle 1 I/O CLOCK DATA OUT DATA IN ÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎ Sample Cycle 3 2 4 5 6 7 8 Previous Conversion Data MSB 10 11 D6 D5 Output Data Format D4 D3 D2 D1 D0 12 1 ÎÎÎÎÎÎÎÎÎÎÎÎ ÎÎÎÎÎÎÎÎÎÎÎÎ ÎÎÎÎÎÎÎÎÎÎÎÎ ÎÎÎÎÎÎÎÎÎÎÎÎ MSB−1 MSB−2 MSB−3 MSB−4 MSB−5 MSB−6 MSB−7 MSB−8 MSB−9 LSB+1 Channel Address D7 9 LSB Low Level MSB D7 2 3 MSB−1 MSB−2 D6 D5 A/D Conversion Interval tCONV EOC Initialize Initialize NOTE: To minimize errors caused by noise at CS, the internal circuitry waits for a setup time after the CS falling edge before responding to control input signals. Therefore, no attempt should be made to clock in an address until the minimum CS setup time has elapsed. Figure 34. Timing for 12-Clock Transfer Not Using CS With DATA OUT Set for MSB First Submit Documentation Feedback Copyright © 2009, Texas Instruments Incorporated Product Folder Link(s): TLV2553-Q1 17 TLV2553-Q1 SLAS579 – APRIL 2009 ..................................................................................................................................................................................................... www.ti.com Parameter Measurement Information (continued) Shift in New Multiplexer Address, Simultaneously Shift Out Previous Conversion Result CS Access Cycle 1 2 Sample Cycle 3 4 5 7 6 I/O CLOCK ÎÎÎ ÎÎÎ ÎÎÎ ÎÎÎ DATA OUT DATA IN Previous Conversion Data 8 1 ÎÎÎ ÎÎÎÎÎÎ ÎÎÎ ÎÎÎÎÎÎ ÎÎÎ ÎÎÎÎÎÎ ÎÎÎ ÎÎÎÎÎÎ 2 3 4 5 6 7 Hi−Z State MSB MSB−1 MSB−2 MSB−3 MSB−4 MSB−5 Channel Address D7 D6 D5 LSB+1 Output Data Format D4 D3 D2 D1 LSB MSB D0 D7 MSB−1 MSB−2 MSB−3 MSB−4 MSB−5 MSB−6 D6 D5 D4 D3 D2 D1 A/D Conversion Interval tCONV EOC Initialize Initialize Figure 35. Timing for 8-Clock Transfer Using CS With DATA OUT Set for MSB First Shift in New Multiplexer Address, Simultaneously Shift Out Previous Conversion Result CS 1 Access Cycle 3 2 I/O CLOCK Sample Cycle 4 5 7 6 8 1 2 3 4 5 6 7 Previous Conversion Data ÎÎÎÎ ÎÎÎÎ ÎÎÎÎ DATA OUT MSB D7 DATA IN MSB−1 MSB−2 MSB−3 MSB−4 MSB−5 Channel Address D6 D5 LSB+1 Output Data Format D4 D3 D2 D1 ÎÎÎÎÎÎÎÎÎ ÎÎÎ ÎÎÎÎÎÎ ÎÎÎÎÎÎÎÎÎ LSB Low Level D0 MSB D7 MSB−1 MSB−2 MSB−3 MSB−4 MSB−5 MSB−6 D6 D5 D4 D3 D2 D1 A/D Conversion Interval tCONV EOC Initialize Initialize NOTE: To minimize errors caused by noise at CS, the internal circuitry waits for a setup time after the CS falling edge before responding to control input signals. Therefore, no attempt should be made to clock in an address until the minimum CS setup time has elapsed. Figure 36. Timing for 8-Clock Transfer Not Using CS With DATA OUT Set for MSB First 18 Submit Documentation Feedback Copyright © 2009, Texas Instruments Incorporated Product Folder Link(s): TLV2553-Q1 TLV2553-Q1 www.ti.com ..................................................................................................................................................................................................... SLAS579 – APRIL 2009 Parameter Measurement Information (continued) Shift in New Multiplexer Address, Simultaneously Shift Out Previous Conversion Result CS Access Cycle 1 Sample Cycle 3 2 4 I/O CLOCK ÎÎÎÎ ÎÎÎÎ ÎÎÎÎ ÎÎÎÎ DATA OUT MSB DATA IN D7 5 6 7 8 9 10 11 12 Pad Zeros MSB−1 MSB−2 MSB−3 MSB−4 MSB−5 MSB−6 MSB−7 MSB−8 MSB−9 LSB+1 D6 Output Data Format D5 D4 D3 D2 D1 1 ÎÎÎ ÎÎÎÎÎÎÎÎÎÎÎÎÎÎ ÎÎÎ ÎÎÎÎÎÎÎÎÎÎÎÎÎÎ ÎÎÎ ÎÎÎÎÎÎÎÎÎÎÎÎÎÎ ÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎ Previous Conversion Data Channel Address 16 Hi−Z State LSB MSB D0 D7 A/D Conversion Interval tCONV EOC Initialize Initialize Figure 37. Timing for 16-Clock Transfer Using CS With DATA OUT Set for MSB First Shift in New Multiplexer Address, Simultaneously Shift Out Previous Conversion Result CS Access Cycle 1 2 3 Sample Cycle 4 I/O CLOCK ÎÎÎÎ ÎÎÎÎ ÎÎÎÎ ÎÎÎÎ DATA OUT MSB DATA IN D7 5 6 7 8 9 10 11 12 ÎÎÎ ÎÎÎÎÎÎÎÎÎÎÎÎÎÎ ÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎ ÎÎÎ ÎÎÎÎÎÎÎÎÎÎÎÎÎÎ ÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎÎ MSB−1 MSB−2 MSB−3 MSB−4 MSB−5 MSB−6 MSB−7 MSB−8 MSB−9 D6 D5 Output Data Format D4 D3 D2 D1 1 Pad Zeros Previous Conversion Data Channel Address 16 LSB+1 LSB Low Level MSB D0 D7 A/D Conversion Interval tCONV EOC Initialize Initialize NOTE: To minimize errors caused by noise at CS, the internal circuitry waits for a setup time after the CS falling edge before responding to control input signals. Therefore, no attempt should be made to clock in an address until the minimum CS setup time has elapsed. Figure 38. Timing for 16-Clock Transfer Not Using CS With DATA OUT Set for MSB First Submit Documentation Feedback Copyright © 2009, Texas Instruments Incorporated Product Folder Link(s): TLV2553-Q1 19 TLV2553-Q1 SLAS579 – APRIL 2009 ..................................................................................................................................................................................................... www.ti.com PRINCIPLES OF OPERATION Detailed Description Initially, with chip select (CS) high, I/O CLOCK and DATA IN are disabled and DATA OUT is in the high-impedance state. CS going low begins the conversion sequence by enabling I/O CLOCK and DATA IN and removes DATA OUT from the high-impedance state. The input data is an 8-bit data stream consisting of a 4-bit address or command (D7–D4) and a 4-bit configuration data (D3–D0). Configuration register 1 (CFGR1), which controls output data format configuration, consists of a 2-bit data length select (D3–D2), an output MSB or LSB first bit (D1), and a unipolar or bipolar output select bit (D0) that are applied to any command (from DATA IN) except for command 1111b. The I/O CLOCK sequence applied to the I/O CLOCK terminal transfers this data to the input data register. During this transfer, the I/O CLOCK sequence also shifts the previous conversion result from the output data register to DATA OUT. I/O CLOCK receives the input sequence of 8, 12, or 16 clock cycles long depending on the data-length selection in the input data register. Sampling of the analog input begins on the fourth falling edge of the input I/O CLOCK sequence and is held after the last falling edge of the I/O CLOCK sequence. The last falling edge of the I/O CLOCK sequence also takes EOC low and begins the conversion. Converter Operation The operation of the converter is organized as a succession of three distinct cycles: 1) the data I/O cycle, 2) the sampling cycle, and 3) the conversion cycle. The first two are partially overlapped. Data I/O Cycle The data I/O cycle is defined by the externally provided I/O CLOCK and lasts 8, 12, or 16 clock periods, depending on the selected output data length. During the I/O cycle, the following two operations take place simultaneously. An 8-bit data stream consisting of address/command and configuration information is provided to DATA IN. This data is shifted into the device on the rising edge of the first eight I/O CLOCK clocks. DATA INPUT is ignored after the first eight clocks during 12- or 16-clock I/O transfers. The data output, with a length of 8, 12, or 16 bits, is provided serially on DATA OUT. When CS is held low, the first output data bit occurs on the rising edge of EOC. When CS is toggled between conversions, the first output data bit occurs on the falling edge of CS. This data is the result of the previous conversion period, and after the first output data bit, each succeeding bit is clocked out on the falling edge of each succeeding I/O CLOCK. Sampling Cycle During the sampling cycle, one of the analog inputs is internally connected to the capacitor array of the converter to store the analog input signal. The converter starts sampling the selected input immediately after the four address/command bits have been clocked into the input data register. Sampling starts on the fourth falling edge of I/O CLOCK. The converter remains in the sampling mode until the eighth, twelfth, or sixteenth falling edge of the I/O CLOCK depending on the data-length selection. After the 8-bit data stream has been clocked in, DATA IN should be held at a fixed digital level until EOC goes high (indicating that the conversion is complete) to maximize the sampling accuracy and minimize the influence of external digital noise. Conversion Cycle A conversion cycle is started only after the I/O cycle is completed, which minimizes the influence of external digital noise on the accuracy of the conversion. This cycle is transparent to the user because it is controlled by an internal clock (oscillator). The total conversion time is equal to 13.5 OSC clocks plus a small delay (~25 ns) to start the OSC. During the conversion period, the device performs a successive-approximation conversion on the analog input voltage. EOC goes low at the start of the conversion cycle and goes high when the conversion is complete and the output data register is latched. After EOC goes low, the analog input can be changed without affecting the conversion result. Since the delay from the falling edge of the last I/O CLOCK to the falling edge of EOC is fixed, any time-varying analog input signals can be digitized at a fixed rate without introducing systematic harmonic distortion or noise due to timing uncertainty. 20 Submit Documentation Feedback Copyright © 2009, Texas Instruments Incorporated Product Folder Link(s): TLV2553-Q1 TLV2553-Q1 www.ti.com ..................................................................................................................................................................................................... SLAS579 – APRIL 2009 Power Up and Initialization After power up, CS must be taken from high to low to begin an I/O cycle. The EOC pin is initially high, and the configuration register is set to all zeroes. The contents of the output data register are random, and the first conversion result should be ignored. To initialize during operation, CS is taken high and is then returned low to begin the next I/O cycle. The first conversion after the device has returned from the power-down state may not read accurately due to internal device settling. Table 1. Operational Terminology Current (N) I/O cycle The entire I/O CLOCK sequence that transfers address and control data into the data register and clocks the digital result from the previous conversion from DATA OUT Current (N) conversion cycle The conversion cycle starts immediately after the current I/O cycle. The end of the current I/O cycle is the last clock falling edge in the I/O CLOCK sequence. The current conversion result is loaded into the output register when conversion is complete. Current (N) conversion result The current conversion result is serially shifted out on the next I/O cycle. Previous (N – 1) conversion cycle The conversion cycle just prior to the current I/O cycle Next (N + 1) I/O cycle The I/O period that follows the current conversion cycle Example In 12-bit mode, the result of the current conversion cycle is a 12-bit serial-data stream clocked out during the next I/O cycle. The current I/O cycle must be exactly 12 bits long to maintain synchronization, even when this corrupts the output data from the previous conversion. The current conversion is begun immediately after the twelfth falling edge of the current I/O cycle. Data Input The data input is internally connected to an 8-bit serial-input address and control register. The register defines the operation of the converter and the output data length. The host provides the input data byte with the MSB first. Each data bit is clocked in on the rising edge of the I/O CLOCK sequence (see Table 2 for the data input-register format). Table 2. Command Set (CMR) and Configuration SDI D[7:4] (1) COMMAND BINARY HEX 0000 0 SELECT analog input channel 0 0001 1 SELECT analog input channel 1 0010 2 SELECT analog input channel 2 0011 3 SELECT analog input channel 3 0100 4 SELECT analog input channel 4 0101 5 SELECT analog input channel 5 0110 6 SELECT analog input channel 6 0111 7 SELECT analog input channel 7 1000 8 SELECT analog input channel 8 1001 9 SELECT analog input channel 9 1010 A SELECT analog input channel 10 1011 B SELECT TEST, Voltage = (VREF+ + VREF–)/2 1100 C SELECT TEST, Voltage = REFM 1101 D SELECT TEST, Voltage = REFP 1110 E SW POWERDOWN (analog + reference) 1111 F Reserved CFGR1 SDI D[3:0] CONFIGURATION 01: 8-bit output length D[3:2] X0: 12-bit output length (1) 11: 16-bit output length D1 D0 0: MSB out first 1: LSB out first 0: Unipolar binary 1: Bipolar 2s complement Select 12-bit output mode to achieve 200-KSPS sampling rate. Submit Documentation Feedback Copyright © 2009, Texas Instruments Incorporated Product Folder Link(s): TLV2553-Q1 21 TLV2553-Q1 SLAS579 – APRIL 2009 ..................................................................................................................................................................................................... www.ti.com Data Input – Address/Command Bits The four MSBs (D7–D4) of the input data register are the address or command. These can be used to address one of the 11 input channels, address one of three reference-test voltages, or activate software power-down mode. All address/command bits affect the current conversion, which is the conversion that immediately follows the current I/O cycle. They also have access to CFGR1 except for command 1111b, which is reserved. Data Output Length CFGR1 bits (D3 and D2) of the data register select the output data length. The data-length selection is valid for the current I/O cycle (the cycle in which the data is read). The data-length selection, being valid for the current I/O cycle, allows device start-up without losing I/O synchronization. A data length of 8, 12, or 16 bits can be selected. Since the converter has 12-bit resolution, a data length of 12 bits is suggested. With D3 and D2 set to 00 or 10, the device is in the 12-bit data-length mode and the result of the current conversion is output as a 12-bit serial data stream during the next I/O cycle. The current I/O cycle must be exactly 12 bits long for proper synchronization, even when this means corrupting the output data from a previous conversion. The current conversion is started immediately after the twelfth falling edge of the current I/O cycle. With bits D3 and D2 set to 11, the 16-bit data-length mode is selected, which allows convenient communication with 16-bit serial interfaces. In the 16-bit mode, the result of the current conversion is output as a 16-bit serial data stream during the next I/O cycle with the four LSBs always reset to 0 (pad bits). The current I/O cycle must be exactly 16 bits long to maintain synchronization even when this means corrupting the output data from the previous conversion. The current conversion is started immediately after the sixteenth falling edge of the current I/O cycle. With bits D3 and D2 set to 01, the 8-bit data-length mode is selected, which allows fast communication with 8-bit serial interfaces. In the 8-bit mode, the result of the current conversion is output as an 8-bit serial data stream during the next I/O cycle. The current I/O cycle must be exactly eight bits long to maintain synchronization, even when this means corrupting the output data from the previous conversion. The four LSBs of the conversion result are truncated and discarded. The current conversion is started immediately after the eighth falling edge of the current I/O cycle. Since the D3 and D2 register settings take effect on the I/O cycle when the data length is programmed, there can be a conflict with the previous cycle if the data-word length was changed. This may occur when the data format is selected to be least significant bit first, since at the time the data length change becomes effective (six rising edges of I/O CLOCK), the previous conversion result has already started shifting out. In actual operation, when different data lengths are required within an application and the data length is changed between two conversions, no more than one conversion result can be corrupted and only when it is shifted out in LSB-first format. LSB Out First D1 in the CFGR1 controls the direction of the output (binary) data transfer. When D1 is reset to 0, the conversion result is shifted out MSB first. When set to 1, the data is shifted out LSB first. Selection of MSB first or LSB first always affects the next I/O cycle and not the current I/O cycle. When changing from one data direction to another, the current I/O cycle is never disrupted. Bipolar Output Format D0 in the CFGR1 controls the binary data format used to represent the conversion result. When D0 is cleared to 0, the conversion result is represented as unipolar (unsigned binary) data. Nominally, the conversion result of an input voltage equal to or less than VREF– is a code with all zeros (000...0) and the conversion result of an input voltage equal to or greater than VREF+ is a code of all ones (111...1). The conversion result of (VREF+ + VREF–)/2 is a code of a one followed by zeros (100...0). When D0 is set to 1, the conversion result is represented as bipolar (signed binary) data. Nominally, conversion of an input voltage equal to or less than VREF– is a code of a one followed by zeros (100...0), and the conversion of an input voltage equal to or greater than VREF+ is a code of a zero followed by all ones (011...1). The conversion result of (VREF+ + VREF–)/2 is a code of all zeros (000...0). The MSB is interpreted as the sign bit. The bipolar data format is related to the unipolar format in that the MSBs are always each other's complement. 22 Submit Documentation Feedback Copyright © 2009, Texas Instruments Incorporated Product Folder Link(s): TLV2553-Q1 TLV2553-Q1 www.ti.com ..................................................................................................................................................................................................... SLAS579 – APRIL 2009 Selection of the unipolar or bipolar format always affects the current conversion cycle, and the result is output during the next I/O cycle. When changing between unipolar and bipolar formats, the data output during the current I/O cycle is not affected. Reference An external reference can be used through two reference input pins, REF+ and REF–. 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 REF+, REF–, and the analog input should not exceed the positive supply or be lower 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 REF+ and at zero when the input signal is equal to or lower than REF–. Analog Supply VCC REF+ Sample C1 0.1 µF Decoupling Cap Convert ∼50 pF CDAC REF− GND Figure 39. Reference Block EOC Output Pin 19 outputs the status of the ADC conversion. When programmed as EOC, the output indicates the beginning and the end of conversion. In the reset state, EOC is always high. During the sampling period (beginning after the fourth falling edge of the I/O CLOCK sequence), EOC remains high until the internal sampling switch of the converter is safely opened. The opening of the sampling switch occurs after the eighth, twelfth, or sixteenth I/O CLOCK falling edge, depending on the data-length selection in the input data register. After the EOC signal goes low, the analog input signal can be changed without affecting the conversion result. The EOC signal goes high again after the conversion is completed and the conversion result is latched into the output data register. The rising edge of EOC returns the converter to a reset state and a new I/O cycle begins. On the rising edge of EOC, the first bit of the current conversion result is on DATA OUT when CS is low. When CS is toggled between conversions, the first bit of the current conversion result occurs on DATA OUT at the falling edge of CS. Chip-Select Input (CS) CS enables and disables the device. During normal operation, CS should be low. Although the use of CS is not necessary to synchronize a data transfer, it can be brought high between conversions to coordinate the data transfer of several devices sharing the same bus. Submit Documentation Feedback Copyright © 2009, Texas Instruments Incorporated Product Folder Link(s): TLV2553-Q1 23 TLV2553-Q1 SLAS579 – APRIL 2009 ..................................................................................................................................................................................................... www.ti.com When CS is brought high, the serial-data output is immediately brought to the high-impedance state, releasing its output data line to other devices that may share it. After an internally generated debounce time, I/O CLOCK is inhibited, thus preventing any further change in the internal state. When CS is subsequently brought low again, the device is reset. CS must be held low for an internal debounce time before the reset operation takes effect. After CS is debounced low, I/O CLOCK must remain inactive (low) for a minimum time before a new I/O cycle can start. CS can interrupt any ongoing data transfer or any ongoing conversion. When CS is debounced low long enough before the end of the current conversion cycle, the previous conversion result is saved in the internal output buffer and shifted out during the next I/O cycle. When CS is held low continuously for multiple cycles, the first data bit of the newly completed conversion occurs on DATA OUT on the rising edge of EOC. Note that the first cycle in the series still requires a transition CS from high to low. When a new conversion is started after the last falling edge of I/O CLOCK, EOC goes low and the serial output is forced low until EOC goes high again. When CS is toggled between conversions, the first data bit occurs on DATA OUT on the falling edge of CS. On each subsequent falling edge of I/O CLOCK after the first data bit appears, the data is changed to the next bit in the serial conversion result until the required number of bits has been output. Power-Down Features When command (D7–D4) 1110b is clocked into the input data register during the first four I/O CLOCK cycles, the software power-down mode is selected. Software power down is activated on the falling edge of the fourth I/O CLOCK pulse. During software power-down, all internal circuitry is put in a low-current standby mode. No conversions is performed. The internal output buffer keeps the previous conversion cycle data results, provided that all digital inputs are held above VCC – 0.5 V or below 0.5 V. The I/O logic remains active so the current I/O cycle must be completed even when the power-down mode is selected. Upon power-on reset and before the first I/O cycle, the converter normally begins in the power-down mode. The device remains in the software power-down mode until a valid input address (other than command 1110b or 1111b) is clocked in. Upon completion of that I/O cycle, a normal conversion is performed with the results being shifted out during the next I/O cycle. The ADC also has an auto power-down mode. This is transparent to users. The ADC gets into auto power-down within one I/O CLOCK cycle after the conversion is complete and resumes, with a small delay, after an active CS is sent to the ADC. The resumption is fast enough to be used between cycles. Analog MUX The 11 analog inputs, 3 internal voltages, and power-down mode are selected by the input multiplexer according to the input addresses shown in Table 2. The input multiplexer is a break-before-make type to reduce input-to-input noise rejection resulting from channel switching. Sampling of the analog input starts on the falling edge of the fourth I/O CLOCK and continues for the remaining I/O CLOCK pulses. The sample is held on the falling edge of the last I/O CLOCK pulse. The three internal test inputs are applied to the multiplexer, then sampled and converted in the same manner as the external analog inputs. The first conversion after the device has returned from the power-down state may not read accurately due to internal device settling. 24 Submit Documentation Feedback Copyright © 2009, Texas Instruments Incorporated Product Folder Link(s): TLV2553-Q1 PACKAGE OPTION ADDENDUM www.ti.com 18-Dec-2008 PACKAGING INFORMATION Orderable Device Status (1) Package Type Package Drawing TLV2553IDWRQ1 ACTIVE SOIC DW Pins Package Eco Plan (2) Qty 20 2000 Green (RoHS & no Sb/Br) Lead/Ball Finish CU NIPDAU MSL Peak Temp (3) Level-1-260C-UNLIM (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) Eco Plan - The planned eco-friendly classification: Pb-Free (RoHS), Pb-Free (RoHS Exempt), or Green (RoHS & no Sb/Br) - please check http://www.ti.com/productcontent for the latest availability information and additional product content details. TBD: The Pb-Free/Green conversion plan has not been defined. Pb-Free (RoHS): TI's terms "Lead-Free" or "Pb-Free" mean semiconductor products that are compatible with the current RoHS requirements for all 6 substances, including the requirement that lead not exceed 0.1% by weight in homogeneous materials. Where designed to be soldered at high temperatures, TI Pb-Free products are suitable for use in specified lead-free processes. Pb-Free (RoHS Exempt): This component has a RoHS exemption for either 1) lead-based flip-chip solder bumps used between the die and package, or 2) lead-based die adhesive used between the die and leadframe. The component is otherwise considered Pb-Free (RoHS compatible) as defined above. Green (RoHS & no Sb/Br): TI defines "Green" to mean Pb-Free (RoHS compatible), and free of Bromine (Br) and Antimony (Sb) based flame retardants (Br or Sb do not exceed 0.1% by weight in homogeneous material) (3) MSL, Peak Temp. -- The Moisture Sensitivity Level rating according to the JEDEC industry standard classifications, and peak solder temperature. Important Information and Disclaimer:The information provided on this page represents TI's knowledge and belief as of the date that it is provided. TI bases its knowledge and belief on information provided by third parties, and makes no representation or warranty as to the accuracy of such information. Efforts are underway to better integrate information from third parties. TI has taken and continues to take reasonable steps to provide representative and accurate information but may not have conducted destructive testing or chemical analysis on incoming materials and chemicals. TI and TI suppliers consider certain information to be proprietary, and thus CAS numbers and other limited information may not be available for release. In no event shall TI's liability arising out of such information exceed the total purchase price of the TI part(s) at issue in this document sold by TI to Customer on an annual basis. OTHER QUALIFIED VERSIONS OF TLV2553-Q1 : • Catalog: TLV2553 NOTE: Qualified Version Definitions: • Catalog - TI's standard catalog product Addendum-Page 1 IMPORTANT NOTICE Texas Instruments Incorporated and its subsidiaries (TI) reserve the right to make corrections, modifications, enhancements, improvements, and other changes to its products and services at any time and to discontinue any product or service without notice. Customers should obtain the latest relevant information before placing orders and should verify that such information is current and complete. All products are sold subject to TI’s terms and conditions of sale supplied at the time of order acknowledgment. TI warrants performance of its hardware products to the specifications applicable at the time of sale in accordance with TI’s standard warranty. Testing and other quality control techniques are used to the extent TI deems necessary to support this warranty. Except where mandated by government requirements, testing of all parameters of each product is not necessarily performed. TI assumes no liability for applications assistance or customer product design. Customers are responsible for their products and applications using TI components. To minimize the risks associated with customer products and applications, customers should provide adequate design and operating safeguards. TI does not warrant or represent that any license, either express or implied, is granted under any TI patent right, copyright, mask work right, or other TI intellectual property right relating to any combination, machine, or process in which TI products or services are used. Information published by TI regarding third-party products or services does not constitute a license from TI to use such products or services or a warranty or endorsement thereof. Use of such information may require a license from a third party under the patents or other intellectual property of the third party, or a license from TI under the patents or other intellectual property of TI. Reproduction of TI information in TI data books or data sheets is permissible only if reproduction is without alteration and is accompanied by all associated warranties, conditions, limitations, and notices. Reproduction of this information with alteration is an unfair and deceptive business practice. TI is not responsible or liable for such altered documentation. Information of third parties may be subject to additional restrictions. Resale of TI products or services with statements different from or beyond the parameters stated by TI for that product or service voids all express and any implied warranties for the associated TI product or service and is an unfair and deceptive business practice. TI is not responsible or liable for any such statements. TI products are not authorized for use in safety-critical applications (such as life support) where a failure of the TI product would reasonably be expected to cause severe personal injury or death, unless officers of the parties have executed an agreement specifically governing such use. Buyers represent that they have all necessary expertise in the safety and regulatory ramifications of their applications, and acknowledge and agree that they are solely responsible for all legal, regulatory and safety-related requirements concerning their products and any use of TI products in such safety-critical applications, notwithstanding any applications-related information or support that may be provided by TI. Further, Buyers must fully indemnify TI and its representatives against any damages arising out of the use of TI products in such safety-critical applications. TI products are neither designed nor intended for use in military/aerospace applications or environments unless the TI products are specifically designated by TI as military-grade or "enhanced plastic." Only products designated by TI as military-grade meet military specifications. Buyers acknowledge and agree that any such use of TI products which TI has not designated as military-grade is solely at the Buyer's risk, and that they are solely responsible for compliance with all legal and regulatory requirements in connection with such use. TI products are neither designed nor intended for use in automotive applications or environments unless the specific TI products are designated by TI as compliant with ISO/TS 16949 requirements. Buyers acknowledge and agree that, if they use any non-designated products in automotive applications, TI will not be responsible for any failure to meet such requirements. Following are URLs where you can obtain information on other Texas Instruments products and application solutions: Products Applications Audio www.ti.com/audio Communications and Telecom www.ti.com/communications Amplifiers amplifier.ti.com Computers and Peripherals www.ti.com/computers Data Converters dataconverter.ti.com Consumer Electronics www.ti.com/consumer-apps DLP® Products www.dlp.com Energy and Lighting www.ti.com/energy DSP dsp.ti.com Industrial www.ti.com/industrial Clocks and Timers www.ti.com/clocks Medical www.ti.com/medical Interface interface.ti.com Security www.ti.com/security Logic logic.ti.com Space, Avionics and Defense www.ti.com/space-avionics-defense Power Mgmt power.ti.com Transportation and Automotive www.ti.com/automotive Microcontrollers microcontroller.ti.com Video and Imaging www.ti.com/video RFID www.ti-rfid.com Wireless www.ti.com/wireless-apps RF/IF and ZigBee® Solutions www.ti.com/lprf TI E2E Community Home Page e2e.ti.com Mailing Address: Texas Instruments, Post Office Box 655303, Dallas, Texas 75265 Copyright © 2011, Texas Instruments Incorporated