CXD1179Q 8-bit 35MSPS Video A/D Converter with Clamp Function Description The CXD1179Q is an 8-bit CMOS A/D converter for video with synchronizing clamp function. The adoption of 2 step-parallel method achieves ultra-low power consumption and a maximum conversion speed of 35MSPS. Features • Resolution: 8-bit ± 1/2LSB (DL) • Maximum sampling frequency: 35MSPS • Low power consumption: 80 mW (at 35MSPS typ.) (reference current excluded) • Synchronizing clamp function • Clamp ON/OFF function • • • • • • Absolute Maximum Ratings (Ta=25 °C) • Supply voltage VDD 7 • Reference voltage VRT, VRB VDD + 0.5 to VSS – 0.5 • Input voltage VIN VDD + 0.5 to VSS – 0.5 (Analog) • Input voltage VI VDD + 0.5 to VSS – 0.5 Reference voltage self bias circuit Input CMOS compatible 3-state TTL compatible output Single 5V power supply Low input capacitance: 8 pF Reference impedance: 330 Ω (typ.) Applications Wide range of applications that require high-speed A/D conversion such as TV and VCR. Structure Silicon gate CMOS IC 32 pin QFP (Plastic) (Digital) • Output voltage VO (Digital) • Storage temperature Tstg V V V V VDD + 0.5 to VSS – 0.5 V –55 to +150 °C Recommended Operating Conditions • Supply voltage AVDD, AVSS 4.75 to 5.25 V DVDD, DVSS | DVSS – AVSS | 0 to 100 mV • Reference input voltage VRB 0 and above V VRT 2.7 and below V • Analog input VIN 1.8 Vp-p above • Clock pulse width Tpw1, Tpw0 13 ns (min) to 1.1 µs (max) • Operating ambient temperature Topr –40 to +85 °C Sony reserves the right to change products and specifications without prior notice. This information does not convey any license by any implication or otherwise under any patents or other right. Application circuits shown, if any, are typical examples illustrating the operation of the devices. Sony cannot assume responsibility for any problems arising out of the use of these circuits. —1— E91Z07G86-TE CXD1179Q Block Diagram DVss 28 OE 30 Reference supply DVss 31 D0 (LSB) 25 VRBS 24 VRB 1 23 AVss D1 2 D2 3 Lower data latch Lower encoder (4 BIT) Lower sampling comparator (4 BIT) 22 AVss 21 VIN D3 4 D4 5 D5 6 D6 7 D7 (MSB) 8 Lower encoder (4 BIT) Lower sampling comparator (4 BIT) 20 AVDD 19 AVDD Upper data latch Upper encoder (4 BIT) Upper sampling comparator (4 BIT) 18 VRT 17 VRTS 16 AVDD DVDD 10 TEST (DVDD) 11 CLK 12 TEST (OPEN) Clock generator 9 15 CLP 14 TEST (VDD or Vss) NC 32 29 27 26 CLE CCP VREF —2— 13 TEST (VDD or Vss) CXD1179Q Pin Description Pin No. Symbol 1 to 8 D0 to D7 Equivalent circuit Di Description D0 (LSB) to D7 (MSB) output DVDD 9 TEST 9 Leave open during normal usage. DVSS 10 DVDD Digital +5 V DVDD 12 CLK Clock input 12 DVSS DVDD 11 11, 13, 14 TEST Fix Pin 11 to VDD, Pins 13 and 14 to VDD or VSS during normal usage. 13 14 DVSS —3— CXD1179Q Pin No. Symbol Equivalent circuit Description DVDD 15 CLP Inputs clamp pulse to Pin 15 (CLP). Clamps the signal voltage during Low interval. 15 DVSS 16, 19, 20 AVDD Analog +5 V AVDD 17 Generates about +2.6 V when shorted with VRT. VRTS 17 18 AVDD VRT Reference voltage (top) 18 24 24 VRB Reference voltage (bottom) AVSS AVDD 21 VIN Analog input 21 AVSS 22, 23 Analog ground AVSS AVSS 25 Generates about +0.6 V when shorted with VRB. VRBS 25 —4— CXD1179Q Pin No. Symbol Equivalent circuit Description AVDD 26 VREF Clamp reference voltage input. Clamps so that the reference voltage and the input signal during clamp interval are equal. 26 AVSS AVDD 27 CCP Integrates the clamp control voltage. The relationship between the changes in CCP voltage and in VIN voltage is positive phase. 27 AVSS 28, 31 DVSS Digital ground DVDD 29 CLE 29 CLAMP PULSE DVSS The clamp function is enabled when CLE = Low. The clamp function is set to off and the converter functions as a normal A/D converter when CLE = High. The clamp pulse can be measured by connecting CLE to DVDD through a several hundred Ω resistor. DVDD 30 OE Data is output when OE = Low. Pins D0 to D7 are at high impedance when OE = High. 30 DVSS 32 NC NC pin —5— CXD1179Q Digital Output The following table shows the relationship between analog input voltage and digital output code. TPW1 Input signal voltage Step Digital output code MSB LSB VRT : : : : VRB 0 : 127 128 : 255 1 1 1 1 1 : 1 0 0 0 0 0 1 1 1 1 : 0 0 0 0 0 1 1 1 0 0 0 1 1 1 0 0 0 TPW0 Clock 2V Analog input Data output 2V N N+1 N–3 N–2 N+2 N+3 N–1 N Td = 13ns : Analog signal sampling point Timing Chart I. tr = 4.5ns tf = 4.5ns 5V 90% OE input 2.5V 10% 0V tPZL tPLZ VOH output 1 1.3V 10% VOL (≠ DVSS) tPHZ tPZH VOH (≠ DVDD) 90% output 2 1.3V VOL Timing Chart II. —6— N+4 N+1 CXD1179Q Electrical Characteristics Analog characteristics (Fc = 35MSPS, VDD = 5 V, VRB = 0.5 V, VRT = 2.5 V, Ta = 25 °C) Item Symbol Conditions Min. 0.5 Typ. Max. Unit 35 MSPS Conversion speed Fc VDD = 4.75 to 5.25 V Ta = –40 to +85 °C VIN = 0.5 to 2.5 V fIN = 1 kHz ramp Analog input band width (–1 dB) BW Envelope Offset voltage∗1 EOT Potential difference to VRT –60 –40 –20 EOB Potential difference to VRB +55 +75 +95 Integral non-linearity error EL +0.5 +1.3 –1.0 ±0.3 ±0.5 End point Differential non-linearity error ED Differential gain error DG Differential phase error DP Aperture jitter Sampling delay taj tsd Clamp offset voltage∗2 Eoc Clamp pulse delay tcpd NTSC 40 IRE mod ramp Fc = 14.3MSPS VIN = DC, PWS = 3 µs MHz 25 mV LSB 1 % 0.5 deg 30 ps 2 ns VREF = 0.5 V –20 0 +20 VREF = 2.5 V –30 –10 +10 25 mV ns ∗1 The offset voltage EOB is a potential difference between VRB and a point of position where the voltage drops equivalent to 1/2 LSB of the voltage when the output data changes from “00000000” to “00000001”. EOT is a potential difference between VRT and a potential of point where the voltage rises equivalent to 1/2LSB of the voltage when the output data changes from “11111111” to “11111110”. ∗2 Clamp offset voltage varies individually. When using with R, G, B 3 channels, color sliding may be generated. —7— CXD1179Q DC characteristics (Fc = 35MSPS, VDD = 5 V, VRB = 0.5 V, VRT = 2.5 V, Ta = 25 °C) Item Symbol Supply current IDD Reference pin current IREF Analog input capacitance CIN Reference resistance (VRT to VRB) RREF VRB1 Self-bias I VRT1 – VRB1 Self-bias II VRT2 Digital input voltage Digital input current VIH VIL IIH IIL IOL IOZH IOZL Timing Min. Fc = 35MSPS NTSC ramp wave input 4.5 Shorts VRB and VRBS Shorts VRT and VRTS VRB = AGND Shorts VRT and VRTS VDD = 4.75 to 5.25 V Ta = –40 to +85 °C OE = VSS VDD = min OE = VDD VDD = max Typ. Max. Unit 16 22 mA 6.1 8.7 mA pF 8 VIN = 1.5 V + 0.07 Vrms VDD = max IOH Digital output current Conditions 230 330 440 0.52 0.56 0.60 1.96 2.10 2.24 2.13 2.33 2.53 3.5 0.5 VIH = VDD 5 VIL = 0 V 5 VOH = VDD – 0.5 V –1.1 –2.5 VOL = 0.4 V 6.5 3.7 Ω V V V µA mA VOH = VDD 16 VOL = 0 V 16 µA (Fc = 35MSPS, VDD = 5 V, VRB = 0.5 V, VRT = 2.5 V, Ta = 25 °C) Item Symbol Conditions Min. Typ. Max. Unit Output data delay TDL With TTL 1 gate and 10 pF load VDD = 4.75 to 5.25 V Ta = –40 to +85 °C 7 13 18 ns Tri-state output enable time tPZH tPZL RL = 1 kΩ, CL = 15 pF OE = 5 V → 0 V VDD = 4.75 to 5.25 V Ta = –40 to +85 °C 5 8 14 ns Tri-state output disable time tPHZ tPLZ RL = 1 kΩ, CL = 15 pF OE = 0V → 5 V VDD = 4.75 to 5.25 V Ta = –40 to +85 °C 4 6.5 11 ns Clamp pulse width∗1 tcpw Fc = 14MSPS, CIN = 10 µF for NTSC wave 1.75 2.75 3.75 µs ∗1 The clamp pulse width is for NTSC as an example. Adjust the rate to the clamp pulse cycle (1/15.75 kHz for NTSC) for other processing systems to equal the values for NTSC. —8— CXD1179Q Electrical Characteristics Measurement Circuit Integral non-linearity error Differential non-linearity error Offset voltage Tri-state output measurement circuit } measurement circuit +V Measurement point S2 S1: ON IF A < B S2: ON IF B > A DVDD S1 RL –V VIN 8 DUT CXD1179Q “0” DVM To output pin A<B A>B COMPARATOR A8 B8 to to A1 B1 A0 B0 8 BUFFER 8 CONTROLLER } 000 · · · 00 to 111 · · · 10 Note) CL includes capacitance of the probe and others. measurement circuit 2.5V ERROR RATE Fc – 1kHz CX20202A-1 S.G. COUNTER H.P.F 0.5V 1 VIN CXD 1179Q AMP 100 NTSC TTL 8 ECL 1 10bit D/A 2 620 2.5V –5.2V BURST IAE SIGNAL SOURCE 8 2 40 IRE MODULATION VECTOR SCOPE CLK 0 0.5V –40 S.G. (CW) SYNC 620 D.G D.P. TTL FC –5.2V ECL Digital output current measurement circuit 2.5V 0.5V VDD VRT VIN VRB CLK OE GND 2.5V IOL 0.5V VOL RL “1” CLK (35MHz) Maximum operational speed Differential gain error Differential phase error CL VDD VRT VIN VRB CLK OE GND + – —9— IOH VOH + – CXD1179Q Vi (1) Vi (2) Vi (3) Vi (4) Analog input External clock Upper comparators block S (1) Upper data Lower data B Digital output C (2) S (3) MD (1) RV (0) H (1) C (3) C (1) C (0) RV (3) S (3) H (3) C (3) LD (1) S (2) LD (–2) H (2) C (2) LD (0) Out (–2) C (4) MD (3) RV (2) LD (–1) H (0) S (4) MD (2) RV (1) S (1) Lower data A Lower comparators B block S (2) MD (0) Lower reference voltage Lower comparators A block C (1) Out (–1) S (4) H (4) LD (2) Out (0) Out (1) Timing Chart 3 Operation (See Block Diagram and Timing Chart 3) 1. The CXD1179Q is a 2-step parallel system A/D converter featuring a 4-bit upper comparators group and 2 lower comparators groups of 4-bit each. The reference voltage that is equal to the voltage between VRT – VRB/16 is constantly applied to the upper 4-bit comparator block. Voltage that corresponded to the upper data is fed through the reference supply to the lower data. VRTS and VRBS pins serve for the self generation of VRT (Reference voltage top) and VRB (Reference voltage bottom). —10— CXD1179Q 2. This IC uses an offset cancel type comparator and the comparator operates synchronously with an external clock. These modes are respectively indicated on the timing chart with S, H, C symbols. That is, the comparator performs input sampling (auto zero) mode, input hold mode and comparison mode using the external clock. 3. The operation of respective parts is as indicated in the chart. For instance input voltage Vi (1) is sampled with the falling edge of the first clock by means of the upper comparator block and the lower comparator A block. The upper comparators block finalizes comparison data MD (1) with the rising edge of the first clock. Simultaneously the reference supply generates the lower reference voltage RV (1) that corresponded to the upper results. The lower comparator block finalizes comparison data LD (1) with the rising edge of the second clock. MD (1) and LD (1) are combined and output as Out (1) with the rising edge of the 3rd clock. Accordingly there is a 2.5 clock delay from the analog input sampling point to the digital data output. Operation Notes 1. Power supply and ground To reduce noise effects, separate the analog and digital systems close to the device. For both the digital and analog power supply pins, use a ceramic capacitor of about 0.1 µF set as close as possible to the pin to bypass to the respective grounds. 2. Analog input Compared with the flash type A/D converter, the input capacitance of the analog input is rather small. However it is necessary to conduct the drive with an amplifier featuring sufficient band and drive capability. When driving with an amplifier of low output impedance, parasite oscillation may occur. That may be prevented by inserting a resistance of about 100 Ω in series between the amplifier output and A/D input. 3. Clock input The clock line wiring should be as short as possible also, to avoid any interference with other signals, separate it from other circuits. 4. Reference input Voltage between VRT to VRB is compatible with the dynamic range of the analog input. Bypassing VRT and VRB pins to analog ground, by means of a capacitor about 0.1 µF, the stable characteristics of the reference voltage are obtained. By shorting VRT and VRTS, VRB and VRBS, the self-bias function that generates VRT = about 2.6 V and VRB = about 0.6 V, is activated. 5. Timing Analog input is sampled with the falling edge of CLK and output as digital data with a delay of 2.5 clocks and with the following rising edge. The delay from the clock rising edge to the data output is about 13ns. 6. OE pin By connecting OE to DVSS output mode is obtained. By connecting OE to DVDD high impedance is obtained. —11— CXD1179Q Application Circuit (1) When clamp is used (self bias used) +5V (Digital) ACO4 0.1µ CLOCK IN OPEN CLAMP PULSE IN CK ∗ LATCH Q 16 0.01µ +5V (Analog) VIDEO IN 10µ 15 14 13 12 11 10 9 17 8 D7 18 7 D6 19 6 D5 20 5 D4 21 4 D3 22 3 D2 23 2 D1 24 1 D0 75Ω 0.1µ 10P 0.01µ +5V (Analog) 25 26 VREF 20k 27 28 29 30 31 32 0.01µ GND (Digital) GND (Analog) ∗ The clamp pulse is latched by the sampling clock of ADC, but that is not necessary for basic clamp operation. However, slight small beat may be generated as vertical sag according to the relationship between the sampling frequency and the clamp pulse frequency. At such time, the latch circuit is effective in this case. —12— CXD1179Q (2) Digital clamp (self bias used) +5V (Digital) ACO4 0.1µ CLOCK IN CLAMP PULSE IN 15 16 0.01µ +5V (Analog) VIDEO IN 10µ 14 13 12 10 11 9 OPEN 17 8 18 7 19 6 20 5 21 4 22 3 23 2 24 1 75Ω 0.1µ 10P 0.01µ 25 26 27 28 29 30 31 Latch, Subtracter, Comparator, etc. Clamp Level setting data 32 DAC, PWM, etc. GND (Digital) GND (Analog) (3) When clamp is not used (self bias used) +5V (Digital) ACO4 0.1µ CLOCK IN OPEN 16 0.01µ +5V (Analog) VIDEO IN 15 14 13 12 11 10 9 17 8 D7 18 7 D6 19 6 D5 20 5 D4 21 4 D3 22 3 D2 23 2 D1 24 1 D0 75Ω 0.1µ 10P 0.01µ 25 26 27 28 29 30 31 32 GND (Digital) +5V (Digital) GND (Analog) —13— CXD1179Q Package Outline Unit : mm 32PIN QFP (PLASTIC) 9.0 ± 0.2 24 0.1 + 0.35 1.5 – 0.15 + 0.3 7.0 – 0.1 17 16 32 9 (8.0) 25 1 + 0.2 0.1 – 0.1 0.8 + 0.15 0.3 – 0.1 0.24 M + 0.1 0.127 – 0.05 0° to 10° PACKAGE MATERIAL EPOXY RESIN SONY CODE QFP-32P-L01 LEAD TREATMENT SOLDER PLATING EIAJ CODE QFP032-P-0707 LEAD MATERIAL 42 ALLOY PACKAGE MASS 0.2g JEDEC CODE —14— 0.50 8