TLV5510 2.7-V TO 3.6-V 8-BIT HIGH-SPEED ANALOG-TO-DIGITAL CONVERTER SLAS124C– DECEMBER 1997 – REVISED DECEMBER 1999 D D D D D D D 8-Bit Resolution Integral Linearity Error ± 0.75 LSB Max (25°C) ± 1 LSB Max (– 35°C to 85°C) Differential Linearity Error ± 0.5 LSB (25°C) ± 0.75 LSB Max (– 35°C to 85°C) Maximum Conversion Rate 10 Mega-Samples per Second (MSPS) Min 2.7-V to 3.6-V Single-Supply Operation Low Power Consumption . . . 42 mW Typ at 3V Low Voltage Replacement for CXD1175 OE DGND D1(LSB) D2 D3 D4 D5 D6 D7 D8(MSB) VDDD CLK 1 24 2 23 3 22 4 21 5 20 6 19 7 18 8 17 9 16 10 15 11 14 12 13 DGND REFB REFBS AGND AGND ANALOG IN VDDA REFT REFTS VDDA VDDA VDDD † Also available in tape and reel and ordered as the TLV5510INSR. Applications D D D D PW OR NS PACKAGE† (TOP VIEW) Communications Digital Imaging Video Conferencing High-Speed Data Conversion AVAILABLE OPTIONS PACKAGE TA – 35°C to 85°C TSSOP (PW) SOP (NS) TLV5510IPW TLV5510INS description The TLV5510 is a CMOS 8-bit resolution semiflash analog-to-digital converter (ADC) with a 2.7-V to 3.6-V single power supply and an internal reference voltage source. It converts a wide band analog signal (such as a video signal) to a digital signal at a sampling rate of dc to 10 MHz. functional block diagram Resistor Reference Divider OE REFB 200 Ω NOM Lower Sampling Comparators (4 Bit) REFT REFBS Lower Encoder (4 Bit) D1(LSB) Lower Data Latch 60 Ω NOM AGND D3 D4 Lower Sampling Comparators (4 Bit) AGND VDDA Lower Encoder (4 Bit) D5 40 Ω NOM REFTS ANALOG IN CLK D2 Upper Sampling Comparators (4 Bit) Upper Data Latch Upper Encoder (4 Bit) D6 D7 D8(MSB) Clock Generator 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 1999, Texas Instruments Incorporated PRODUCTION DATA information is current as of publication date. Products conform to specifications per the terms of Texas Instruments standard warranty. Production processing does not necessarily include testing of all parameters. POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 1 TLV5510 2.7-V TO 3.6-V 8-BIT HIGH-SPEED ANALOG-TO-DIGITAL CONVERTER SLAS124C– DECEMBER 1997 – REVISED DECEMBER 1999 schematics of inputs and outputs EQUIVALENT OF ANALOG INPUT EQUIVALENT OF EACH DIGITAL INPUT VDDA EQUIVALENT OF EACH DIGITAL OUTPUT VDDD VDDD D1 – D8 OE, CLK ANALOG IN AGND DGND DGND Terminal Functions TERMINAL NAME AGND ANALOG IN CLK NO. I/O 20, 21 DESCRIPTION Analog ground 19 I Analog input 12 I Clock input DGND 2, 24 D1 – D8 3 – 10 O Digital data out. D1:LSB, D8:MSB 1 I Output enable. When OE = low, data is enabled. When OE = high, D1 – D8 is high impedance. OE Digital ground VDDA VDDD 14, 15, 18 Analog supply voltage 11, 13 Digital supply voltage REFB 23 REFBS 22 REFT 17 REFTS 16 I Reference voltage in (bottom) Reference voltage (bottom). When using the internal voltage divider to generate a nominal 2-V reference, this terminal is shorted to the REFB terminal and the REFTS terminal is shorted to the REFT terminal (see Figure 21). I Reference voltage in (top) Reference voltage (top). When using the internal voltage divider to generate a nominal 2-V reference, this terminal is shorted to the REFT terminal and the REFBS terminal is shorted to the REFB terminal (see Figure 21). absolute maximum ratings over operating free-air temperature range (unless otherwise noted)† Supply voltage, VDDA, VDDD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7 V Reference voltage input range, REFT, REFB, REFBS, REFTS . . . . . . . . . . . . . . . . . . . . . . . . . AGND to VDDA Analog input voltage range, VI(ANLG) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . AGND to VDDA Digital input voltage range, VI(DGTL) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . DGND to VDDD Digital output voltage range, VO(DGTL) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . DGND to VDDD Operating free-air temperature range, TA . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . – 35°C to 85°C Storage temperature range, Tstg . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . – 55°C to 150°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. 2 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 TLV5510 2.7-V TO 3.6-V 8-BIT HIGH-SPEED ANALOG-TO-DIGITAL CONVERTER SLAS124C– DECEMBER 1997 – REVISED DECEMBER 1999 recommended operating conditions Supply voltage MIN NOM MAX VDDA – AGND VDDD – DGND 2.7 3 3.6 2.7 3 3.6 AGND – DGND – 100 0 100 Reference input voltage (top), REFT REFB+2 Reference input voltage (bottom), REFB 0 Analog input voltage range, VI(ANLG) (see Note 1) 0.6 V mV VDDA–0.3 V REFT– 2 V REFT V REFB 2.5 High-level input voltage, VIH UNIT V Low-level input voltage, VIL 0.5 Pulse duration, clock high, tw(H) 10 Pulse duration, clock low, tw(L) 10 V ns ns Clock frequency, f(CLK) Sampling frequency, fs NOTE 1: REFT – REFB ≤ 2.4 V maximum 10 MHz 10 MSPS electrical characteristics at VDDD = VDDA = 3 V, REFT = 2.5 V, REFB = 0.5 V, f(CLK) = 10 MHz, TA = 25°C (unless otherwise noted) digital I/O TEST CONDITIONS† PARAMETER MIN TYP MAX IIH IIL High-level input current Low-level input current VDDD = MAX, VDDD = MAX, VIH = VDDD VIL = 0 5 IOH IOL High-level output current OE = GND, Low-level output current OE = GND, VDDD = MIN, VDDD = MIN, VOH = VDDD – 0.5 V VOL = 0.4 V IOZH High-level high-impedance-state output leakage current OE = VDDD, VDDD = MAX VOH = VDDD 15 IOZL Low-level high-impedance-state output leakage current OE = VDDD, VDDD = MIN VOL = 0 15 5 – 1.6 UNIT µA mA 2.6 µA † Conditions marked MIN or MAX are as stated in recommended operating conditions. power PARAMETER IDD Supply current TEST CONDITIONS† MIN fsin = 1 MHz sine wave, reference resistor dissipation is separate Iref Reference voltage current ∆REF = REFT – REFB = 2 V † Conditions marked MIN or MAX are as stated in recommended operating conditions. POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 6 TYP MAX 4 10 UNIT mA 10 14 mA 3 TLV5510 2.7-V TO 3.6-V 8-BIT HIGH-SPEED ANALOG-TO-DIGITAL CONVERTER SLAS124C– DECEMBER 1997 – REVISED DECEMBER 1999 electrical characteristics at VDDD = VDDA = 3 V, REFT = 2.5 V, REFB = 0.5 V, f(CLK) = 10 MHz, TA = 25°C (unless otherwise noted) (continued) static performance TEST CONDITIONS† PARAMETER Self-bias (1), at REFB Short REFB to REFBS, REFBS Short REFT to REFTS Self-bias (2), at REFT Short REFB to AGND, Short REFT to REFTS Rref Reference voltage resistor Between REFT and REFB Ci Analog input capacitance VI(ANLG) = 1.5 V + 0.07 Vrms TA = 25°C f(CLK) = 10 MHz,, VI = 0.5 V to 2.5 V TA = – 35°C to 85°C Self-bias (1), REFT – REFB Integral nonlinearity (INL) TYP MAX 0.54 0.60 0.72 1.8 2 2.4 2.25 2.5 3 140 200 260 16 EZS Zero-scale error ∆REF = REFT – REFB = 2 V EFS Full-scale error ∆REF = REFT – REFB = 2 V † Conditions marked MIN or MAX are as stated in recommended operating conditions. UNIT V Ω pF ± 0.3 ± 0.75 ± 0.2 ± 0.5 ±1 TA = 25°C TA = – 35°C to 85°C f(CLK) = 10 MHz,, VI = 0.5 V to 2.5 V Differential nonlinearity (DNL) MIN LSB ± 0.75 – 18 – 43 – 68 mV – 20 0 20 mV operating characteristics at VDDD = VDDA = 3 V, REFT = 2.5 V, REFB = 0.5 V, f(CLK) = 10 MHz, TA = 25°C (unless otherwise noted) PARAMETER fconv Maximum conversion rate BW Analog input bandwidth td(D) tAJ Digital output delay time td(s) Sampling delay time ten Enable time, OE↓ to valid data tdis Disable time, OE↑ to high impedance TEST CONDITIONS fI = 1-kHz ramp wave form, VI(ANLG) = 0.5 V – 2.5 V At – 3 dB 36 CL ≤ 10 pF (see Note 1 and Figure 1) 18 MAX UNIT 10 MSPS MHz MHz 30 ns 30 ps 4 ns CL = 10 pF 15 ns CL = 10 pF 10 ns Input tone = 1 MHz TA = 25°C Full range 41 Input tone = 1.4 1 4 MHz TA = 25°C Full range 38 Input tone = 1.4 1 4 MHz TA = 25°C Full range 38 NOTE 2: CL includes probe and jig capacitance. 4 0.2 17 Aperture jitter time Signal to noise ratio Signal-to-noise TYP At – 1 dB Spurious free dynamic range (SFDR) SNR MIN POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 41 dB 38 37 dB TLV5510 2.7-V TO 3.6-V 8-BIT HIGH-SPEED ANALOG-TO-DIGITAL CONVERTER SLAS124C– DECEMBER 1997 – REVISED DECEMBER 1999 PARAMETER MEASUREMENT INFORMATION tw(H) tw(L) CLK (Clock) ANALOG IN (Input Signal) D1 – D8 (Output Data) N+2 N+1 N N+4 N+3 N–3 N–2 N–1 N N+1 tpd Figure 1. I/O Timing Diagram TYPICAL CHARACTERISTICS POWER DISSIPATION vs SAMPLING FREQUENCY ANALOG INPUT BANDWIDTH 0 12 TA = 25°C VDDA = 2.7 V, VREFB = 0.5 V, VREFT = 2.5 V, Fclk = 10 MHz –1 –2 8 Gain – dB Power Dissipation – mW 10 6 –3 –4 –5 4 –6 2 –7 0 0 2 4 6 8 10 12 TA = 25°C VDDA = 2.7 V, VREFB = 0.5 V, VREFT = 2.5 V, Fclk = 10 MHz –8 100 Sampling Frequency – MHz Figure 2 101 fI – Input Frequency – MHz 102 Figure 3 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 5 TLV5510 2.7-V TO 3.6-V 8-BIT HIGH-SPEED ANALOG-TO-DIGITAL CONVERTER SLAS124C– DECEMBER 1997 – REVISED DECEMBER 1999 TYPICAL CHARACTERISTICS SIGNAL-TO-NOISE RATIO vs INPUT FREQUENCY 60 TA = 25°C VDDA = 3 V, VREFB = 0.5 V, VREFT = 2.5 V, Fclk = 10 MHz Signal-To-Noise Ratio – dB 50 40 30 20 10 0 0 0.5 1 1.5 2 2.5 3 Input Frequency – MHz DNL – Differential Nonlinearity – LSB Figure 4 DIFFERENTIAL NONLINEARITY vs SAMPLES (Under Recommended Operating Conditions) 0.5 0.4 0.3 0.2 0.1 0 –0.1 –0.2 –0.3 –0.4 –0.5 0 20 40 60 80 100 120 140 160 Samples Figure 5 6 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 180 200 220 240 253 TLV5510 2.7-V TO 3.6-V 8-BIT HIGH-SPEED ANALOG-TO-DIGITAL CONVERTER SLAS124C– DECEMBER 1997 – REVISED DECEMBER 1999 TYPICAL CHARACTERISTICS EFFECTIVE NUMBER OF BITS vs TEMPERATURE 6.5 VDDA = 3 V, VREFB = 0.5 V, VREFT = 2.5 V, Fclk = 10 MHz, fsin = 1 MHz Effective Number Of Bits 6.45 6.4 6.35 6.3 6.25 –40 –20 40 0 20 Ambient Temperature – °C 60 80 Figure 6 INL – Integral Nonlinearity – LSB INTEGRAL NONLINEARITY vs SAMPLES (Under Recommended Operating Conditions) 0.75 0.6 0.5 0.4 0.3 0.2 0.1 0 –0.1 –0.2 –0.3 –0.4 –0.5 –0.6 –0.75 0 20 40 60 80 100 120 140 160 180 200 220 240 254 Samples Figure 7 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 7 TLV5510 2.7-V TO 3.6-V 8-BIT HIGH-SPEED ANALOG-TO-DIGITAL CONVERTER SLAS124C– DECEMBER 1997 – REVISED DECEMBER 1999 TYPICAL CHARACTERISTICS Fast Fourier Transformer – dB FAST FOURIER TRANSFORMER vs FREQUENCY (Under Recommended Operating Conditions) 0 –20 –40 –60 –80 –100 –120 –140 –160 –180 –200 0 0.5 1 1.5 2 2.5 3.5 3 4 4.5 5 f – Frequency – MHz Figure 8 INTEGRAL LINEARITY ERROR vs FREQUENCY DIFFERENTIAL LINEARITY ERROR vs FREQUENCY 1.8 1.8 INL – Integral Linearity – LSB 1.6 1.4 TA = 25°C 1.2 1 TA = –35°C 0.8 VDDD = 2.7 V, VDDA = 2.7 V, VREFT = 2.5 V, VREFB = 0.5 V 1.6 DNL – Differential Linearity – LSB VDDD = 2.7 V, VDDA = 2.7 V, VREFT = 2.5 V, VREFB = 0.5 V TA = 85°C 0.6 0.4 0.2 1.4 1.2 TA = 25°C 1 0.8 0.6 TA = 85°C 0.4 0.2 0 0 5 7 15 17 9 11 13 fCLK – Frequency – MHz 19 21 5 7 Figure 9 8 TA = –35°C 15 17 9 11 13 fCLK – Frequency – MHz Figure 10 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 19 21 TLV5510 2.7-V TO 3.6-V 8-BIT HIGH-SPEED ANALOG-TO-DIGITAL CONVERTER SLAS124C– DECEMBER 1997 – REVISED DECEMBER 1999 TYPICAL CHARACTERISTICS INTEGRAL LINEARITY ERROR vs FREQUENCY DIFFERENTIAL LINEARITY ERROR vs FREQUENCY 1.8 1.4 1.2 TA = 25°C 1 0.8 0.6 VDDD = 3 V, VDDA = 3 V, VREFT = 2.5 V, VREFB = 0.5 V 1.6 DNL – Differential Linearity – LSB 1.6 INL – Integral Linearity – LSB 1.8 VDDD = 3 V, VDDA = 3 V, VREFT = 2.5 V, VREFB = 0.5 V TA = 85°C 0.4 TA = –35°C 0.2 1.4 1.2 1 TA = 25°C 0.8 0.6 TA = 85°C 0.4 TA = –35°C 0.2 0 5 7 15 17 9 11 13 fCLK – Frequency – MHz 19 0 21 5 7 Figure 11 19 21 Figure 12 INTEGRAL LINEARITY ERROR vs FREQUENCY DIFFERENTIAL LINEARITY ERROR vs FREQUENCY 1.8 1.8 VDDD = 3.3 V, VDDA = 3.3 V, VREFT = 2.5 V, VREFB = 0.5 V 1.4 1.2 1 TA = 25°C 0.8 TA = 85°C 0.6 VDDD = 3.3 V, VDDA = 3.3 V, VREFT = 2.5 V, VREFB = 0.5 V 1.6 DNL – Differential Linearity – LSB 1.6 INL – Integral Linearity – LSB 15 17 9 11 13 fCLK – Frequency – MHz 0.4 TA = –35°C 0.2 1.4 1.2 1 TA = 25°C 0.8 0.6 TA = 85°C 0.4 0.2 0 5 7 9 11 13 15 17 fCLK – Frequency – MHz 19 21 TA = –35°C 0 5 7 Figure 13 15 17 9 11 13 fCLK – Frequency – MHz 19 21 Figure 14 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 9 TLV5510 2.7-V TO 3.6-V 8-BIT HIGH-SPEED ANALOG-TO-DIGITAL CONVERTER SLAS124C– DECEMBER 1997 – REVISED DECEMBER 1999 TYPICAL CHARACTERISTICS EFFECTIVE NUMBER OF BITS vs INPUT SINEWAVE FREQUENCY EFFECTIVE NUMBER OF BITS vs INPUT SINEWAVE FREQUENCY 8 VDDD = 2.7 V, VDDA = 2.7 V VDDD = 3 V, VDDA = 3 V ENOB – Effective Number of Bits – Bits ENOB – Effective Number of Bits – Bits 8 7.5 7 TA = –35°C 6.5 6 TA = 25°C 5.5 TA = 85°C 7.5 7 TA = –35°C 6.5 TA = 85°C 5.5 5 0 0.2 0.4 0.6 0.8 1 1.2 TA = 25°C 6 5 1.4 0 0.2 f – Input Sinewave Frequency – MHz 0.4 Figure 15 Figure 16 EFFECTIVE NUMBER OF BITS vs INPUT SINEWAVE FREQUENCY ENOB – Effective Number of Bits – Bits 8 VDDD = 3.3 V, VDDA = 3.3 V 7.5 TA = –35°C 7 TA = 25°C TA = 85°C 6.5 6 5.5 5 0 0.2 0.4 0.6 0.8 1 1.2 f – Input Sinewave Frequency – MHz Figure 17 10 0.6 0.8 1 1.2 f – Input Sinewave Frequency – MHz POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 1.4 1.4 TLV5510 2.7-V TO 3.6-V 8-BIT HIGH-SPEED ANALOG-TO-DIGITAL CONVERTER SLAS124C– DECEMBER 1997 – REVISED DECEMBER 1999 APPLICATION INFORMATION The following notes are design recommendations that should be used with the TLV5510. D D D D D D External analog and digital circuitry should be physically separated and shielded as much as possible to reduce system noise. RF breadboarding or printed-circuit-board (PCB) techniques should be used throughout the evaluation and production process. Breadboards should be copper clad for bench evaluation. Since AGND and DGND are connected internally, the ground lead in must be kept as noise free as possible. A good method to use is twisted-pair cables for the supply lines to minimize noise pickup. An analog and digital ground plane should be used on PCB layouts when additional logic devices are used. The AGND and DGND terminals of the device should be tied to the analog ground plane. VDDA to AGND and VDDD to DGND should be decoupled with 1-µF and 0.01-µF capacitors, respectively, placed as close as possible to the appropriate device terminals. A ceramic chip capacitor is recommended for the 0.01-µF capacitor. Care should be exercised to assure a solid noise-free ground connection for the analog and digital grounds. VDDA, AGND, and ANALOG IN terminals should be shielded from the higher frequency terminals, CLK and D0–D7. If possible, AGND traces should be placed on both sides of the ANALOG IN traces on the PCB for shielding. In testing or application of the device, the resistance of the driving source connected to the analog input should be 10 Ω or less within the analog frequency range of interest. POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 11 TLV5510 2.7-V TO 3.6-V 8-BIT HIGH-SPEED ANALOG-TO-DIGITAL CONVERTER SLAS124C– DECEMBER 1997 – REVISED DECEMBER 1999 APPLICATION INFORMATION VDDA 3.3 V VDDD 3.3 V FB2 + C10 FB3 C3 FB1 14 VDDA DVDDD C4 15 VDDA DVDDD C5 18 16 C6 From Clamp Output 17 REFTS REFT D8 D7 D6 D4 C1 19 Buffer D3 ANALOG IN C2 R1 D2 D1 A 22 C7 23 20 21 C8 11 C9 VDDA D5 Video Input (2VPP) 13 REFBS CLK REFB OE AGND DGND AGND DGND 10 9 8 7 6 5 4 3 12 1 2 24 D Output Enable Clock LOCATION DESCRIPTION C1, C3, C4 – C9 0.1 µF Capacitor C2 10 pF Capacitor C10 47 µF Capacitor FB1, FB2, FB3 R1 Ferrite bead 75 Ω Resistor Figure 18. Application and Test Schematic Using Internal Reference 12 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 TLV5510 2.7-V TO 3.6-V 8-BIT HIGH-SPEED ANALOG-TO-DIGITAL CONVERTER SLAS124C– DECEMBER 1997 – REVISED DECEMBER 1999 PRINCIPLES OF OPERATION functional description The TLV5510 is a semiflash ADC featuring two lower comparator blocks of four bits each. As shown in Figure 19, input voltage VI(1) is sampled with the falling edge of CLK1 to the upper comparators block and the lower comparators block(A), S(1). The upper comparators block finalizes the upper data UD(1) with the rising edge of CLK2, and simultaneously, the lower reference voltage generates the voltage RV(1) corresponding to the upper data. The lower comparators block (A) finalizes the lower data LD(1) with the rising edge of CLK3. UD(1) and LD(1) are combined and output as OUT(1) with the rising edge of CLK4. According to the above internal operation described, output data is delayed 2.5 clocks from the analog input voltage sampling point. Input voltage VI(2) is sampled with the falling edge of CLK2. UD(2) is finalized with the rising edge of CLK3, and LD(2) is finalized with the rising edge of CLK4 at the lower comparators block(B). OUT(2) is output with the rising edge of CLK5. VI(1) VI(2) VI(3) VI(4) ANALOG IN (Sampling Points) CLK1 CLK2 CLK3 CLK4 CLK (Clock) Upper Comparators Block S(1) C(1) S(2) C(2) S(3) C(3) S(4) C(4) Upper Data UD(0) UD(1) UD(2) UD(3) Lower Reference Voltage RV(0) RV(1) RV(2) RV(3) S(1) Lower Comparators Block (A) H(1) Lower Data (B) D1 – D8 (Data Output) S(3) H(3) LD(– 1) Lower Data (A) Lower Comparators Block (B) C(1) H(0) C(0) LD(1) S(2) LD(– 2) OUT(– 2) C(3) H(2) C(2) LD(0) OUT(–1) S(4) H(4) LD(2) OUT(0) OUT(1) Figure 19. Internal Functional Timing Diagram POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 13 TLV5510 2.7-V TO 3.6-V 8-BIT HIGH-SPEED ANALOG-TO-DIGITAL CONVERTER SLAS124C– DECEMBER 1997 – REVISED DECEMBER 1999 PRINCIPLES OF OPERATION functional description (continued) The MSB comparator block converts on the falling edge of each applied clock cycle. The LSB comparator blocks CB-A and CB-B convert on the falling edges of the first and second following clock cycles, respectively. The timing diagram of the conversion algorithm is shown in Figure 19. analog input operation The analog input stage to the TLV5510 is a chopper-stabilized comparator and is equivalently shown below: φ2 S2 φ1 To Encoder Logic VDDA Cs φ2 S3 φ1 φ1 ANALOG IN S1 Vref(N) To Encoder Logic φ2 Cs φ2 S(N) φ1 To Encoder Logic Cs Figure 20. External Connections for Using the Internal Reference Resistor Divider Figure 20 depicts the analog input for the TLV5510. The switches shown are controlled by two internal clocks, φ1 and φ2. These are nonoverlapping clocks that are generated from the CLK input. During the sampling period, φ1, S1 is closed and the input signal is applied to one side of the sampling capacitor, Cs. Also during the sampling period, S2 through S(N) are closed. This sets the comparator input to approximately 2.5 V. The delta voltage is developed across Cs. During the comparison phase, φ2, S1 is switched to the appropriate reference voltage for the bit value N, i.e., Vref(N). S2 is opened and Vref(N) – VCs toggles the comparator output to the appropriate digital 1 or 0. The small resistance values for the switch, S1, and small value of the sampling capacitor combine to produce the wide analog input bandwidth of the TLV5510. The source impedance driving the analog input of the TLV5510 should be less than 100 Ω across the range of input frequency spectrum. reference inputs – REFB, REFT, REFBS, REFTS The range of analog inputs that can be converted are determined by REFB and REFT, REFT being the maximum reference voltage and REFB being the minimum reference voltage. The TLV5510 is tested with REFT = 2.5 V or 2 V and REFB = 0.5 V or 0 V producing a 2-V full-scale range. The TLV5510 can operate with REFT – REFB = 2.4 V, but the power dissipation in the reference resistor increases significantly (49 mW at 3.3 V nominally). It is recommended that a 0.1 µF capacitor be attached to REFB and REFT whether using externally or internally generated voltages. 14 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 TLV5510 2.7-V TO 3.6-V 8-BIT HIGH-SPEED ANALOG-TO-DIGITAL CONVERTER SLAS124C– DECEMBER 1997 – REVISED DECEMBER 1999 PRINCIPLES OF OPERATION internal reference voltage conversion Three internal resistors allow the device to generate an internal reference voltage. These resistors are brought out on terminals VDDA, REFTS, REFT, REFB, REFBS, and AGND. Two different bias voltages are possible without the use of external resistors. The internal resistors are provided to develop REFT and REFB as listed in Table 1 (bias option 1) with only two external connections. This is developed with a 3-resistor network connected to VDDA. When using this feature, connect REFT to REFTS and connect REFB to REFBS. For applications where the variance associated with VDDA is acceptable, this internal voltage reference saves space and cost (see Figure 21). A second internal bias option (bias two option) is shown in Figure 22. Using this scheme REFB = AGND and REFT is as shown in Table 1 (bias option 2). These bias voltage options can be used to provide the values listed in the following table. Table 1. Bias Voltage Options for Different VDDA BIAS OPTION BIAS VOLTAGE VDDA 2.7 V 1 2 VREFB 0.54 VREFT 2.34 VREFT – VREFB 1.8 3V 0.6 2.60 2 3.3 V 0.66 2.86 2.2 3.6 V 0.72 3.12 2.4 2.7 V AGND 2.25 2.25 3V AGND 2.5 2.5 3.3 V AGND 2.75 2.75 3.6 V AGND 3 3 To use the internally-generated reference voltage, terminal connections should be made as shown in Figure 21 or Figure 22. TLV5510 VDDA 18 R1 40 Ω NOM REFTS 16 17 0.1 µF REFT REFB 2.63 V dc Rref 200 Ω NOM 23 22 0.1 µF REFBS AGND R2 60 Ω NOM 21 Figure 21. External Connections Using the Internal Bias One Option POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 15 TLV5510 2.7-V TO 3.6-V 8-BIT HIGH-SPEED ANALOG-TO-DIGITAL CONVERTER SLAS124C– DECEMBER 1997 – REVISED DECEMBER 1999 PRINCIPLES OF OPERATION TLV5510 18 VDDA (Analog Supply) R1 40 Ω NOM REFTS 16 17 0.1 µF REFT REFB Rref 200 Ω NOM 23 22 REFBS R2 60 Ω NOM AGND 21 Figure 22. External Connections for Using the Internal Reference Resistor Divider functional operation The TLV5510 functions as shown in the Table 2. Table 2. Functional Operation 16 DIGITAL OUTPUT CODE INPUT SIGNAL VOLTAGE STEP REFT 255 1 1 1 1 1 1 1 1 • • • • • • • • • • • • • • • • • • • • • 128 1 0 0 0 0 0 0 0 • 127 0 1 1 1 1 1 1 1 • • • • • • • • • • MSB LSB • • • • • • • • • • REFB 0 0 0 0 0 0 0 0 0 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 TLV5510 2.7-V TO 3.6-V 8-BIT HIGH-SPEED ANALOG-TO-DIGITAL CONVERTER SLAS124C– DECEMBER 1997 – REVISED DECEMBER 1999 MECHANICAL DATA PW (R-PDSO-G**) PLASTIC SMALL-OUTLINE PACKAGE 14 PINS SHOWN 0,30 0,19 0,65 14 0,10 M 8 0,15 NOM 4,50 4,30 6,60 6,20 Gage Plane 0,25 1 7 0°– 8° A 0,75 0,50 Seating Plane 0,15 0,05 1,20 MAX PINS ** 0,10 8 14 16 20 24 28 A MAX 3,10 5,10 5,10 6,60 7,90 9,80 A MIN 2,90 4,90 4,90 6,40 7,70 9,60 DIM 4040064/F 01/97 NOTES: A. B. C. D. All linear dimensions are in millimeters. This drawing is subject to change without notice. Body dimensions do not include mold flash or protrusion not to exceed 0,15. Falls within JEDEC MO-153 POST OFFICE BOX 655303 • DALLAS, TEXAS 75265 17 TLV5510 2.7-V TO 3.6-V 8-BIT HIGH-SPEED ANALOG-TO-DIGITAL CONVERTER SLAS124C– DECEMBER 1997 – REVISED DECEMBER 1999 MECHANICAL DATA NS (R-PDSO-G**) PLASTIC SMALL-OUTLINE PACKAGE 14 PIN SHOWN PINS ** 14 16 20 24 A MAX 10,50 10,50 12,90 15,30 A MIN 9,90 9,90 12,30 14,70 DIM 0,51 0,35 1,27 14 0,25 M 8 0,15 NOM 5,60 5,00 8,20 7,40 Gage Plane 1 7 0,25 0°– 10° A 1,05 0,55 Seating Plane 2,00 MAX 0,05 MIN 0,10 4040062 / B 2/95 NOTES: A. All linear dimensions are in millimeters. B. This drawing is subject to change without notice. C. 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