TLV2553 SLAS354B - SEPTEMBER 2001 - REVISED SEPTEMBER 2002 12-BIT, 200-KSPS, 11-CHANNEL, LOW-POWER, SERIAL ADC FEATURES D D D D D D D D D D D D 12-Bit-Resolution A/D Converter Up to 200 KSPS (150 KSPS for 3 V) Throughput Over Operating Temperature Range With 12-Bit Output Mode 11 Analog Input Channels 3 Built-In Self-Test Modes Inherent Sample and Hold Function Linearity Error . . . 1 LSB Max On-Chip Conversion Clock Unipolar or Bipolar Output Operation Programmable MSB or 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) 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, highimpedance 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 = -40C to 85C. See available options table for package options. APPLICATIONS D D D D Process Control Portable Data Logging Battery-Powered Instruments Automotive DESCRIPTION The TLV2553 is a 12-bit, switched-capacitor, successive-approximation, analog-to-digital converter. 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. DW AND PW PACKAGE (TOP VIEW) AIN0 AIN1 AIN2 AIN3 AIN4 AIN5 AIN6 AIN7 AIN8 GND 1 20 2 19 3 18 4 17 5 16 6 15 7 14 8 13 9 12 10 11 VCC EOC I/O CLOCK DATA IN DATA OUT CS REF + REF - AIN10 AIN9 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 2002, 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. www.ti.com 1 TLV2553 SLAS354B - SEPTEMBER 2001 - REVISED SEPTEMBER 2002 AVAILABLE OPTIONS PACKAGE SMALL OUTLINE TA 20-TSSOP (PW) 20-SOWB (DW) TLV2553IPW TLV2553IDW - 40C to 85C 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 Self Test 14-Channel Analog Multiplexer Low Power 12-Bit SAR ADC Sample and Hold 4 Reference CTRL Input Address Register 19 12 Output Data Register 12 12-to-1 Data Selector and Driver DATA IN CS I/O CLOCK 17 15 18 Control Logic and I/O Counters 10 GND 2 www.ti.com EOC 4 Internal OSC 16 DATA OUT TLV2553 SLAS354B - SEPTEMBER 2001 - REVISED SEPTEMBER 2002 Terminal Functions TERMINAL I/O DESCRIPTION NAME NO. AIN0 - AIN10 1 - 9, 11, 12 I Analog input. These 11 analog-signal inputs are internally multiplexed. CS 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. DATA IN 17 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. DATA OUT 16 O The 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(most significant bit)/LSB(least significant bit) 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 Status output, 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 www.ti.com 3 TLV2553 SLAS354B - SEPTEMBER 2001 - REVISED SEPTEMBER 2002 absolute maximum ratings over operating free-air temperature range (unless otherwise noted) Supply voltage range, VCC (see Note 1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . - 0.5 V to 6.5 V Input voltage range, VI (any input) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . - 0.3 V to VCC + 0.3 V Output voltage range, VO . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . - 0.3 V to VCC + 0.3 V Positive reference voltage, Vref + . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3 V to VCC + 0.3 V Negative reference voltage, Vref - . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3 V to VCC + 0.3 V Peak input current, II (any input) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 mA Peak total input current (all inputs) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 mA Operating virtual junction temperature range, TJ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -40C to 150C Operating free-air temperature range, TA: I . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -40C to 85C Storage temperature range, Tstg . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . - 65C to 150C Lead temperature 1,6 mm (1/16 inch) from the case for 10 seconds . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 260C Stresses beyond those listed under "absolute maximum ratings" may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated under "recommended operating conditions" is not implied. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability. NOTE 1: All voltage values are with respect to the GND terminal with REF - and GND wired together (unless otherwise noted). recommended operating conditions PARAMETERS MIN Supply voltage, VCC I/O CLOCK frequency Tolerable clock jitter, I/O CLOCK Aperature jitter VCC = 4.5 V to 5.5 V VCC = 2.7 V to 3.6 V VCC = 4.5 V to 5.5 V VCC = 4.5 V to 5.5 V VCC = 4.5 V to 5.5 V NOM MAX UNIT V 2.7 5.5 16-bit I/O 0.01 15 12-bit I/O 0.01 15 8-bit I/O 0.01 15 0.01 10 0.38 100 (REF+) - (REF-) VCC = 3.0 V to 3.6 V VCC = 2.7 V to 3.0 V 0 (REF+ ) -(REF-) 0 (REF+) -(REF-) High level control input voltage, High-level voltage VIH VCC = 4.5 V to 5.5 V VCC = 2.7 V to 3.6 V 2.0 Low level control input voltage Low-level voltage, VIL VCC = 4.5 V to 5.5 V VCC = 2.7 V to 3.6 V Operating free-air temperature, TA TLV2553I V V 2.1 0.8 0.6 -40 ns ps 0 Analog input voltage (see Note 2) MHz 85 V C NOTE 2: 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). 4 www.ti.com TLV2553 SLAS354B - SEPTEMBER 2001 - REVISED SEPTEMBER 2002 electrical characteristics over recommended operating free-air temperature range, VREF+ = 5 V, I/O CLOCK frequency = 15 MHz when VCC = 5 V, VREF+ = 2.5 V, I/O CLOCK frequency = 10 MHz when VCC = 2.7 V (unless otherwise noted) PARAMETER VOH VOL TEST CONDITIONS High level output voltage High-level Low level output voltage Low-level MIN TYP MAX VCC = 4.5 V, IOH = -1.6 mA VCC = 2.7 V, IOH = -0.2 mA 30 pF 2.4 VCC = 4.5 V, IOH = -20 A VCC = 2.7 V, IOH = -20 A 30 pF VCC -0.1 VCC = 5.5 V, IOL = 1.6 mA VCC = 3.6 V, IOH = 0.8 mA 30 pF 0.4 VCC = 5.5 V, IOL = -20 A VCC = 3.6 V, IOH = -20 A 30 pF 0.1 V V IOZ High impedance off-state High-impedance off state output current VO = VCC, VO = 0 V, CS at VCC 1 2.5 CS at VCC -1 -2.5 ICC Operating supply current CS at 0 V, V Ext. Ext Ref ICC(PD) Power-down current For all digital inputs, 0 VI 0.5 V or VI VCC - 0.5 0 5 V, V I/O CLOCK = 0 V IIH IIL High-level input current Ilkg lk Selected channel leakage current VCC = 4.5 V to 5.5 V VCC = 2.7 V to 3.6 V tconvertt Conversion time = 13.5X 13 5X [f(OSC)] + 25 ns VCC = 4.5 V to 5.5 V VCC = 2.7 V to 3.6 V Internal oscillator frequency voltage Ci Input capacitance 0.9 Software power down 0.1 Auto power down Analog inputs 1 A mA A 0.1 10 0.005 2.5 A -0.005 -2.5 A 1 A Selected channel at 0 V, Unselected channel at VCC Internal oscillator frequency Input impedance 1.2 Selected channel at VCC , Unselected channel at 0 V f(OSC) Zi VCC = 5 V VCC = 2.7 V VI = VCC VI = 0 V Low-level input current UNIT -1 3.27 MHz 2.56 4.15 5.54 3.6 4.1 VCC = 4.5 V VCC = 2.7 V 500 600 Analog inputs 45 55 Control inputs 5 15 s V pF All typical values are at VCC = 5 V, TA = 25C. The switch resistance is very nonlinear and varies with input voltage and supply voltage. This is the worst case. www.ti.com 5 TLV2553 SLAS354B - SEPTEMBER 2001 - REVISED SEPTEMBER 2002 external reference specifications MIN TYP MAX voltage REF- REF Reference input voltage, VCC = 4.5 V to 5.5 V VCC = 2.7 V to 3.6 V -0.1 0 0.1 -0.1 0 0.1 Reference input voltage, voltage REF+ VCC = 4.5 V to 5.5 V VCC = 2.7 V to 3.6 V 2 External reference input voltage g difference,, (REF+) - (REF-) VCC = 4.5 V to 5.5 V VCC = 2.7 V to 3.6 V 1.9 External reference supply current CS at 0 V PARAMETER TEST CONDITIONS 2 1.9 VCC = 4.5 V to 5.5 V VCC = 2.7 V to 3.6 V VCC = 5 V Reference input impedance 7V VCC = 2 2.7 During sampling/conversion 6 Static 1 During sampling/conversion All typical values are at TA = 25C. NOTE: Add a 0.1-F capacitor between REF+ and REF- pins when external reference is used. V VCC VCC V 0.62 1 V VCC VCC 0.94 Static UNIT mA M 9 k M 6 9 k operating characteristics over recommended operating free-air temperature range, VREF+ = 5 V, I/O CLOCK frequency = 15 MHz when VCC = 5 V, VREF+ = 2.5 V, I/O CLOCK frequency = 10 MHz when VCC = 2.7 V (unless otherwise noted) PARAMETER TEST CONDITIONS MIN TYP MAX UNIT INL Integral linearity error (see Note 3) -1 1 LSB DNL Differential linearity error -1 1 LSB EO Offset error (see Note 4) See Note 2 -2 2 mV EG Gain error (see Note 4) See Note 2 -3 3 ET Total unadjusted error (see Note 5) 1.5 Address data input = 1011 Self-test output code (see Table 2 and Note 6) mV LSB 2048 Address data input = 1100 0 Address data input = 1101 4095 All typical values are at TA = 25C. NOTES: 2. 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). 3. Linearity error is the maximum deviation from the best straight line through the A/D transfer characteristics. 4. 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. 5. Total unadjusted error comprises linearity, zero-scale, and full-scale errors. 6. Both the input address and the output codes are expressed in positive logic. 6 www.ti.com TLV2553 SLAS354B - SEPTEMBER 2001 - REVISED SEPTEMBER 2002 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 MIN tw1 tsu1 Pulse duration I/O CLOCK high or low 26.7 th1 Hold time DATA IN valid after I/O CLOCK rising edge (see Figure 26) tsu2 Setup time DATA IN valid before I/O CLOCK rising edge (see Figure 26) TYP MAX UNIT 100000 ns 12 ns 0 ns Setup time CS low before first rising I/O CLOCK edge (see Note 7 and Figure 27) 25 ns th2 th3 Hold time CS pulse duration high time (see Figure 27) 100 ns Hold time CS low after last I/O CLOCK falling edge (see Figure 27) 0 ns th4 th5 Hold time DATA OUT valid after I/O CLOCK falling edge (see Figure 28) 2 ns Hold time CS high after EOC rising edge when CS is toggled (see Figure 31) 0 ns Load = 25 pF 28 ns Load = 10 pF 20 ns 10 ns td1 Delay y time CS falling g edge g 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) 20 ns td4 td5 Delay time Last I/O CLOCK falling edge to EOC falling edge 55 ns Delay time last I/O CLOCK falling edge to CS falling edge to abort conversion 1.5 s tt1 tt2 Transition time I/O CLOCK (see Note 7 and Figure 28) 1 s Transition time DATA OUT (see Figure 28) 5 ns tt3 tt4 Transition time INT/EOC, CL at 7 pF (see Figure 30) 2.4 ns Transition time DATA IN, CS 10 s tcycle Total cycle time (sample, conversion and delays) (see Note 7) MAX(tconvert) + I/O period (8/12/16 CLKs) s tsample l Channel acquisition q time ((sample), ), at 1 k See Figures 33-38 and Note 7 2 Source impedance = 25 600 Source impedance = 100 650 Source impedance = 500 700 Source impedance = 1 k ns 1000 NOTE 7: I/O CLOCK period = 8X [1/(I/O CLOCK frequency)] or 12X [1/(I/O CLOCK frequency)] or 16X [1/(I/O CLOCK frequency)] depends on I/O format selected. www.ti.com 7 TLV2553 SLAS354B - SEPTEMBER 2001 - REVISED SEPTEMBER 2002 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) PARAMETER MIN TYP MAX UNIT 100000 ns tw1 tsu1 Pulse duration I/O CLOCK high or low 40 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 tsu2 Setup time CS low before first rising I/O CLOCK edge (see Note 7 and Figure 27) 33 ns th2 th3 Hold time CS pulse duration high time (see Figure 27) 100 ns Hold time CS low after last I/O CLOCK falling edge (see Figure 27) 0 ns th4 th5 Hold time DATA OUT valid after I/O CLOCK falling edge (see Figure 28) 2 ns Hold time CS high after EOC rising edge when CS is toggled (see Figure 31) 0 ns Load = 25 pF 30 ns Load = 10 pF 22 ns 10 ns td1 Delay y time CS falling g edge g 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) 33 ns td4 td5 Delay time Last I/O CLOCK falling edge to EOC falling edge 75 ns Delay time last I/O CLOCK falling edge to CS falling edge to abort conversion 1.5 s tt1 tt2 Transition time I/O CLOCK (see Note 7 and Figure 28) 1 s Transition time DATA OUT (see Figure 28) 5 ns tt3 tt4 Transition time INT/EOC, CL at 7 pF (see Figure 30) 4 ns Transition time DATA IN, CS 10 s tcycle Total cycle time (sample, conversion and delays) (see Note 7) MAX(tconvert) + I/O period (8/12/16 CLKs) s tsample l Channel acquisition q time ((sample), ), at 1 k See Figures 33-38 and Note 7 2 Source impedance = 25 800 Source impedance = 100 850 Source impedance = 500 1000 Source impedance = 1 k 1600 ns NOTE 7: I/O CLOCK period = 8X [1/(I/O CLOCK frequency)] or 12X [1/(I/O CLOCK frequency)] or 16X [1/(I/O CLOCK frequency)] depends on I/O format selected. 8 www.ti.com TLV2553 SLAS354B - SEPTEMBER 2001 - REVISED SEPTEMBER 2002 TYPICAL CHARACTERISTICS SUPPLY CURRENT vs FREE-AIR TEMPERATURE I CC - Supply Current - mA 0.620 0.615 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 0.610 0.605 0.600 0.595 0.590 0.585 0.58 -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 Figure 1 0.40 35 50 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 0.30 VCC = 3.3 V VREF+ = 2.5 V VREF- = 0 V I/O CLOCK = 10 MHz 0.04 Current - A Current - A 0.35 20 Figure 2 SOFTWARE POWER DOWN vs FREE-AIR TEMPERATURE 0.45 5 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 0.0 -40 -25 -10 5 20 35 50 65 0 -40 80 TA - Free-Air Temperature - C -25 -10 5 20 35 50 65 80 TA - Free-Air Temperature - C Figure 3 Figure 4 www.ti.com 9 TLV2553 SLAS354B - SEPTEMBER 2001 - REVISED SEPTEMBER 2002 TYPICAL CHARACTERISTICS 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 0.7 0.6 0.5 0.4 0.3 0.2 0.1 0.0 -40 -25 -10 5 20 -0.1 Minimum Differential Nonlinearity - LSB Maximum Differential Nonlinearity - LSB 1.0 MINIMUM DIFFERENTIAL NONLINEARITY vs FREE-AIR TEMPERATURE 35 50 65 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 Figure 5 -0.1 Minimum Integral Nonlinearity - LSB Maximum Integral Nonlinearity - LSB 50 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 -25 -10 5 20 35 50 65 TA - Free-Air Temperature - C Figure 7 10 35 MINIMUM INTEGRAL NONLINEARITY vs FREE-AIR TEMPERATURE 0.8 0.0 -40 20 Figure 6 MAXIMUM INTEGRAL NONLINEARITY vs FREE-AIR TEMPERATURE 0.7 5 TA - Free-Air Temperature - C Figure 8 www.ti.com 80 TLV2553 SLAS354B - SEPTEMBER 2001 - REVISED SEPTEMBER 2002 TYPICAL CHARACTERISTICS DNL - Differential Nonlinearity - LSB DIFFERENTIAL NONLINEARITY vs DIGITAL OUTPUT CODE 0.5 VCC = 2.7 V, VREF+ = 2.5 V, VREF- = 0 V, I/O CLOCK = 10 MHz, TA = 25C 0.4 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 = 25C 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 www.ti.com 11 TLV2553 SLAS354B - SEPTEMBER 2001 - REVISED SEPTEMBER 2002 TYPICAL CHARACTERISTICS GAIN ERROR vs FREE-AIR TEMPERATURE OFFSET ERROR vs FREE-AIR TEMPERATURE 1.4 0.6 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 0.0 -40 80 VCC = 3.3 V VREF+ = 2.5 V VREF- = 0 V I/O CLOCK = 10 MHz -25 -10 SUPPLY CURRENT vs FREE-AIR TEMPERATURE 65 80 0.7 External Reference Current - mA I CC - 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 0 -40 80 TA - Free-Air Temperature - C VCC = 5.5 V VREF+ = 4.096 V VREF- = 0 V I/O CLOCK = 15 MHz -25 -10 5 20 35 50 65 TA - Free-Air Temperature - C Figure 13 12 35 EXTERNAL REFERENCE CURRENT vs FREE-AIR TEMPERATURE 0.98 0.84 -40 20 Figure 12 Figure 11 0.96 5 TA - Free-Air Temperature - C TA - Free-Air Temperature - C Figure 14 www.ti.com 80 TLV2553 SLAS354B - SEPTEMBER 2001 - REVISED SEPTEMBER 2002 TYPICAL CHARACTERISTICS 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 - A Current - 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 0.0 -40 -25 -10 5 20 35 50 65 0 -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 -25 -10 5 20 35 50 65 80 TA - Free-Air Temperature - C Figure 17 Figure 18 www.ti.com 13 TLV2553 SLAS354B - SEPTEMBER 2001 - REVISED SEPTEMBER 2002 TYPICAL CHARACTERISTICS MAXIMUM INTEGRAL NONLINEARITY vs FREE-AIR TEMPERATURE MINIMUM INTEGRAL NONLINEARITY vs FREE-AIR TEMPERATURE 0.90 -0.329 0.86 Minimum Integral Nonlinearity - LSB Maximum Integral Nonlinearity - LSB -0.330 VCC = 5.5 V VREF+ = 4.096 V VREF- = 0 V I/O CLOCK = 15 MHz 0.88 0.84 0.82 0.80 0.78 0.76 0.74 -40 -25 -10 5 20 35 50 65 -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 80 -25 TA - Free-Air Temperature - C -10 5 20 35 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 = 25C 0.2 0.1 -0.0 -0.1 -0.2 -0.3 0 1024 2048 Digital Output Code Figure 21 14 50 TA - Free-Air Temperature - C www.ti.com 3072 4096 65 80 TLV2553 SLAS354B - SEPTEMBER 2001 - REVISED SEPTEMBER 2002 TYPICAL CHARACTERISTICS 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 = 25C -0.8 0 1024 2048 3072 4096 Digital Output Code Figure 22 OFFSET ERROR vs FREE-AIR TEMPERATURE GAIN ERROR vs FREE-AIR TEMPERATURE -0.0 -0.00 EO - Offset Error - mV -0.10 VCC = 5.5 V VREF+ = 4.096 V VREF- = 0 V I/O CLOCK = 15 MHz -0.1 -0.2 EG - Gain Error - mV -0.05 -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 -0.5 -40 -25 -10 5 20 35 50 65 VCC = 5.5 V VREF+ = 4.096 V VREF- = 0 V I/O CLOCK = 15 MHz -1 -40 80 TA - Free-Air Temperature - C -25 -10 5 20 35 50 65 80 TA - Free-Air Temperature - C Figure 23 Figure 24 www.ti.com 15 TLV2553 SLAS354B - SEPTEMBER 2001 - REVISED SEPTEMBER 2002 PARAMETER MEASUREMENT INFORMATION Data Valid VIH VIL CS td1 VIH VIL DATA IN th1 td2 VOH VOL Data Out I/O CLOCK Figure 25. DATA OUT to Hi-Z Voltage Waveforms th2 VIH VIL Figure 26. DATA IN and I/O CLOCK Voltage tt1 tt1 VIH VIL CS tsu1 VIH VIL I/O CLOCK I/O CLK Period th3 tsu2 I/O CLOCK td3 VIH VIL Last Clock th4 VOH VOL Data Out tt2 Figure 27. CS and I/O CLOCK Voltage Waveforms I/O CLOCK Figure 28. I/O CLOCK and DATA OUT Voltage Waveforms tt3 VIH VIL Last Clock tconvert VOH td2 EOC VOL tt3 VOH VOL EOC tt3 Data Out MSB Valid Figure 30. EOC and DATA OUT Voltage Waveforms Figure 29. I/O CLOCK and EOC Voltage Waveforms 1 CS th5 EOC VIH VIL I/O CLOCK VOH VOL EOC VIH VIL VOH VOL Figure 32. I/O CLOCK and DATA OUT Voltage Figure 31. CS and EOC Waveforms 16 VOH VOL www.ti.com TLV2553 SLAS354B - SEPTEMBER 2001 - REVISED SEPTEMBER 2002 PARAMETER MEASUREMENT INFORMATION timing diagrams Shift in New Multiplexer Address, Simultaneously Shift Out Previous Conversion Result CS Access Cycle 1 3 2 Sample Cycle 4 I/O CLOCK 5 6 7 8 9 10 11 12 Previous Conversion Data DATA OUT MSB III DATA IN D7 D6 Output Data Format D5 D4 D3 D2 D1 LSB MSB MSB-1 MSB-2 IIIIIIIIIIII D0 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 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 3 2 Sample Cycle 4 5 6 7 8 9 10 11 12 MSB-1 MSB-2 MSB-3 MSB-4 MSB-5 MSB-6 MSB-7 MSB-8 MSB-9 LSB+1 LSB 1 I/O CLOCK 2 3 Previous Conversion Data DATA OUT DATA IN III III MSB Channel Address D7 D6 D5 Output Data Format D4 D3 D2 D1 D0 Low Level MSB IIIIIIIIIIII IIIIIIIIIIII D7 MSB-1 MSB-2 D6 D5 A/D Conversion Interval tCONV EOC Initialize Initialize Figure 34. Timing for 12-Clock Transfer Not Using CS With DATA OUT Set for MSB First NOTE A: 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. www.ti.com 17 TLV2553 SLAS354B - SEPTEMBER 2001 - REVISED SEPTEMBER 2002 PARAMETER MEASUREMENT INFORMATION timing diagrams (continued) Shift in New Multiplexer Address, Simultaneously Shift Out Previous Conversion Result CS Access Cycle 1 2 3 Sample Cycle 4 5 7 6 8 1 2 3 4 5 6 7 I/O CLOCK Previous Conversion Data Hi-Z State DATA OUT MSB Channel Address IIII D7 DATA IN MSB-1 MSB-2 MSB-3 MSB-4 MSB-5 D6 D5 LSB+1 LSB Output Data Format D4 D3 D2 MSB-1 MSB-2 MSB-3 MSB-4 MSB-5 MSB-6 MSB IIIIIIIII D1 D0 D7 D6 D4 D5 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 DATA OUT MSB IIII D7 DATA IN MSB-1 MSB-2 MSB-3 MSB-4 MSB-5 Channel Address D6 D5 LSB+1 LSB Output Data Format D4 D3 D2 D1 D0 A/D Conversion Interval Low Level MSB IIIIIIII D7 MSB-1 MSB-2 MSB-3 MSB-4 MSB-5 MSB-6 D6 D5 D4 D3 D2 D1 tCONV EOC Initialize Initialize Figure 36. Timing for 8-Clock Transfer Not Using CS With DATA OUT Set for MSB First NOTE A: 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. 18 www.ti.com TLV2553 SLAS354B - SEPTEMBER 2001 - REVISED SEPTEMBER 2002 PARAMETER MEASUREMENT INFORMATION timing diagrams (continued) Shift in New Multiplexer Address, Simultaneously Shift Out Previous Conversion Result CS Access Cycle 1 Sample Cycle 3 2 4 I/O CLOCK 5 6 7 8 9 10 11 12 Pad Zeros Previous Conversion Data DATA OUT MSB IIII DATA IN MSB-1 MSB-2 MSB-3 MSB-4 MSB-5 MSB-6 MSB-7 MSB-8 MSB-9 Channel Address D7 D6 Output Data Format D5 D4 D3 D2 D1 D0 16 LSB+1 1 Hi-Z State LSB MSB IIIIIIIIIIIIIIII 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 NOTE A: 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. Shift in New Multiplexer Address, Simultaneously Shift Out Previous Conversion Result CS Access Cycle 1 2 3 Sample Cycle 4 I/O CLOCK 5 6 7 8 9 10 11 12 MSB IIII IIII DATA IN MSB-1 MSB-2 MSB-3 MSB-4 MSB-5 MSB-6 MSB-7 MSB-8 MSB-9 Channel Address D7 D6 D5 Output Data Format D4 D3 D2 D1 D0 1 Pad Zeros Previous Conversion Data DATA OUT 16 LSB+1 LSB Low Level MSB IIIIIIIIIIIIIIII IIIIIIIIIIIIIIII D7 A/D Conversion Interval tCONV EOC Initialize Initialize Figure 38. Timing for 16-Clock Transfer Not Using CS With DATA OUT Set for MSB First www.ti.com 19 TLV2553 SLAS354B - SEPTEMBER 2001 - REVISED SEPTEMBER 2002 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. 20 www.ti.com TLV2553 SLAS354B - SEPTEMBER 2001 - REVISED SEPTEMBER 2002 PRINCIPLES OF OPERATION 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. 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). www.ti.com 21 TLV2553 SLAS354B - SEPTEMBER 2001 - REVISED SEPTEMBER 2002 PRINCIPLES OF OPERATION Table 2. Command Set (CMR) and Configuration SDI D[7:4] Binary, HEX COMMAND 0000b 0h SELECT analog input channel 0 0001b 1h SELECT analog input channel 1 CFGR1 0010b 2h SELECT analog input channel 2 0011b 3h SELECT analog input channel 3 SDI D[3:0] 0100b 4h SELECT analog input channel 4 D[3:2] 0101b 5h SELECT analog input channel 5 0110b 6h SELECT analog input channel 6 D1 0111b 7h SELECT analog input channel 7 D0 1000b 8h SELECT analog input channel 8 1001b 9h SELECT analog input channel 9 1010b Ah SELECT analog input channel 10 1011b Bh SELECT TEST, 1100b Ch SELECT TEST, Voltage = REFM 1101b Dh SELECT TEST, Voltage = REFP 1110b Eh SW POWERDOWN (analog + reference) 1111b Fh Reserved CONFIGURATION 01: 8-bit output length X0: 12-bit output length (see Note) 11: 16-bit output length 0: MSB out first 1: LSB out first 0: Unipolar binary 1: Bipolar 2s complement NOTE: Select 12-bit output mode to achieve 200 KSPS sampling rate. Voltage = (VREF+ + VREF-)/2 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. 22 www.ti.com TLV2553 SLAS354B - SEPTEMBER 2001 - REVISED SEPTEMBER 2002 PRINCIPLES OF OPERATION data output length (continued) 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. 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-. www.ti.com 23 TLV2553 SLAS354B - SEPTEMBER 2001 - REVISED SEPTEMBER 2002 PRINCIPLES OF OPERATION Analog Supply VCC REF+ Sample C1 0.1 F 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. 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. 24 www.ti.com TLV2553 SLAS354B - SEPTEMBER 2001 - REVISED SEPTEMBER 2002 PRINCIPLES OF OPERATION chip-select input (CS) (continued) 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 1 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, three 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. www.ti.com 25 PACKAGE OPTION ADDENDUM www.ti.com 18-Sep-2008 PACKAGING INFORMATION Orderable Device Status (1) Package Type Package Drawing Pins Package Eco Plan (2) Qty TLV2553IDW ACTIVE SOIC DW 20 25 Green (RoHS & no Sb/Br) CU NIPDAU Level-1-260C-UNLIM TLV2553IDWG4 ACTIVE SOIC DW 20 25 Green (RoHS & no Sb/Br) CU NIPDAU Level-1-260C-UNLIM TLV2553IDWR ACTIVE SOIC DW 20 2000 Green (RoHS & no Sb/Br) CU NIPDAU Level-1-260C-UNLIM TLV2553IDWRG4 ACTIVE SOIC DW 20 2000 Green (RoHS & no Sb/Br) CU NIPDAU Level-1-260C-UNLIM TLV2553IPW ACTIVE TSSOP PW 20 70 Green (RoHS & no Sb/Br) CU NIPDAU Level-1-260C-UNLIM TLV2553IPWG4 ACTIVE TSSOP PW 20 70 Green (RoHS & no Sb/Br) CU NIPDAU Level-1-260C-UNLIM TLV2553IPWR ACTIVE TSSOP PW 20 2000 Green (RoHS & no Sb/Br) CU NIPDAU Level-1-260C-UNLIM TLV2553IPWRG4 ACTIVE TSSOP PW 20 2000 Green (RoHS & no Sb/Br) CU NIPDAU Level-1-260C-UNLIM Lead/Ball Finish MSL Peak Temp (3) (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. Addendum-Page 1 PACKAGE MATERIALS INFORMATION www.ti.com 14-Jul-2012 TAPE AND REEL INFORMATION *All dimensions are nominal Device TLV2553IPWR Package Package Pins Type Drawing TSSOP PW 20 SPQ Reel Reel A0 Diameter Width (mm) (mm) W1 (mm) 2000 330.0 16.4 Pack Materials-Page 1 6.95 B0 (mm) K0 (mm) P1 (mm) 7.1 1.6 8.0 W Pin1 (mm) Quadrant 16.0 Q1 PACKAGE MATERIALS INFORMATION www.ti.com 14-Jul-2012 *All dimensions are nominal Device Package Type Package Drawing Pins SPQ Length (mm) Width (mm) Height (mm) TLV2553IPWR TSSOP PW 20 2000 367.0 367.0 38.0 Pack Materials-Page 2 IMPORTANT NOTICE Texas Instruments Incorporated and its subsidiaries (TI) reserve the right to make corrections, enhancements, improvements and other changes to its semiconductor products and services per JESD46C and to discontinue any product or service per JESD48B. Buyers should obtain the latest relevant information before placing orders and should verify that such information is current and complete. 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