0.35µ µm 14-BIT 10MSPS ADC BW1254X GENERAL DESCRIPTION bw1254x is a CMOS 14bit analog-to-digital converter (ADC). It converts the analog input signal into 14bit binary digital codes at a maximum sampling rate of 10MHz. The device is a monolithic ADC with an on-chip, high-performance, sample-and-hold Amplifier (SHA) and current reference and voltage reference. The structure allows both differential and single-ended input. TYPICAL APPLICATIONS — Imaging (Copiers, Scanners, Cameras) — Medical Instruments — Digital Communication Systems — uADSL System FEATURES — Resolution : 14bit — Maximum Conversion Rate : 10MHz — Package Type : 48TSSOP — Power Supply : 3.3V — Power Consumption : 120mW (typical) — Reference Voltage : Internal reference or 2V, 1V (dual reference) — Input Range : 0.5V ~ 2.5V (2.0VP-P) — Differential Linearity Error : ±0.7 LSB — Integral Linearity Error : ±1.5 LSB — Signal to Noise & Distortion Ratio : 72dB — Total Harmonic Distortion : 80dB — Out of Range Indicator — Digital Output : CMOS Level — Operating Temperature Range : 0°C ~ 70°C 1 0.35µ µm 14-BIT 10MSPS ADC BW1254X FUNCTIONAL BLOCK DIAGRAM Analog Input Reference Output SHA MDAC 1 MDAC 2 MDAC 3 FLASH 1 FLASH 2 FLASH 3 5 4 2 3 Voltage Reference CLOCK GEN. Clock 3 FLASH 4 DIGITAL LOGIC 14 Digital Output ORI 0.35µ µm 14-BIT 10MSPS ADC BW1254X CORE PIN DESCRIPTION Name I/O Type I/O Pad Pin Description REFTOP AB piar10_bb Reference Top Output/Force (2.0V) REFBOT AB piar10_bb Reference Bottom Output/Force (1.0V) BGR AB piar10_bb BGR output (1.23V) CML AB piar10_bb Internal Bias CML1 AB piar10_bb Internal Bias VDDA1 AP vdda Analog Power (3.3V) VBBA1 AG vbba Analog Sub Bias VSSA1 AG vssa Analog Ground AINT AI piar10_bb Analog Input + (Input Range : 1.0V ~ 2.0V) AINC AI piar10_bb Analog Input (Input Range : 1.0V ~ 2.0V) ITEST AB pia_bb open=use internal bias point STBY DI picc_bb VDD=power saving (standby), GND=normal CKIN DI picc_bb Sampling Clock Input D[13:0] DO poa_bb Digital Output ORI DO poa_bb Out of Range Indicator VBBA2 DG vbba Digital Sub Bias VSSA2 DG vssd Digital GND VDDA2 DP vddd Digital Power (3.3V) I/O Type Abbr. — AI: Analog Input — DI: Digital Input — AO: Analog Output — DO: Digital Output — AP: Analog Power — AG: Analog Ground — DP: Digital Power — DG: Digital Ground — AB: Analog Bidirectional — DB: Digital Bidirectional 3 0.35µ µm 14-BIT 10MSPS ADC BW1254X CORE CONFIGURATION VDDA1 VBBA1 VSSA2 VSSA1 VDDA2 VBBA2 AINT AINC bw1254x REFTOP REFBOT OR I BGR CML CML1 ITEST STBY CKIN 4 [MSB:LSB] DO[13:0] 0.35µ µm 14-BIT 10MSPS ADC BW1254X ABSOLUTE MAXIMUM RATINGS Characteristics Symbol Value Unit VDD 4.5 V Analog Input Voltage AINT/AINC VSS to VDD V Digital Input Voltage CLK VSS to VDD V Storage Temperature Range Tstg -45 to 150 °C Operating Temperature Range Topr 0 to 70 °C Supply Voltage NOTE: 1. Absolute maximum rating specifies the values beyond which the device may be damaged permanently. Exposure to ABSOLUTE MAXIMUM RATING conditions for extended periods may affect reliability. Each condition value is applied with the other values kept within the following operating conditions and function operation under any of these conditions is not implied. 2. All voltages are measured with respect to VSS unless otherwise specified. 3. 100pF capacitor is discharged through a 1.5kΩ resistor (Human body model) OPERATING CONDITIONS Characteristics Symbol Min Typ Max Unit VDDA1 VDDA2 VDDA3 3.15 3.3 3.45 V Analog Input Voltage AINT AINC 0.5 – 1.5 2.5 V Operating Temperature Toper 0 – 70 °C Supply Voltage NOTE: It is strongly recommended that all the supply pins (VDDA1, VDDA2, VDDA3) be powered from the same source to avoid power latch-up. 5 0.35µ µm 14-BIT 10MSPS ADC BW1254X DC ELECTRICAL CHARACTERISTICS Characteristics Symbol Min Typ Max Unit Test Condition Differential Nonlinearity DNL – ±0.7 ±1 LSB Internal Voltage Reference REFTOP=2V REFBOT=1V Integral Nonlinearity INL – ±1.5 – LSB Internal Voltage Reference REFTOP=2V REFBOT=1V Offset Voltage OFF – 10 – mV REFTOP=2V REFBOT=1V NOTE: Converter Specifications : VDDA1=VDDA2=VDDA3=3.3V, VSSA1=VSSA2=VSSA3=0V, Toper=25°C, REFTOP=2V, REFBOT=1V unless otherwise specified. AC ELECTRICAL CHARACTERISTICS Characteristics Symbol Min Typ Max Unit Test Condition Maximum Conversion Rate fc – 10 – MHz AIN=AINT-AINC Dynamic Supply Current IVDD – 36 – mA fc=10MHz (without system load) Signal-to-Noise & Distortion Ratio SNDR – 72 – dB AIN=1MHz, Differential Input Total Harmonic Distortion THD – 80 – dB AIN=1MHz, Differential Input NOTE: It is strongly recommended that all the supply pins (VDDA1, VDDA2, VDDA3) be powered from the same source to avoid power latch-up. 6 0.35µ µm 14-BIT 10MSPS ADC BW1254X I/O CHART Index AINT Input (V) Digital Output ~ 0.00081 0000 0000 0000 1LSB=0.806mV 0 1 0.00081 ~ 0.00161 0000 0000 0001 VREF=3.3V 2 0.00161 ~ 0.00242 0000 0000 0010 AGND=0.0V ~ ~ ~ 2047 1.64919 ~ 1.65000 0111 1111 1111 2048 1.65000 ~ 1.65081 1000 0000 0000 2049 1.65081 ~ 1.65161 1000 0000 0001 ~ ~ ~ 4093 3.29758 ~ 3.29839 1111 1111 1101 4094 3.29839 ~ 3.29919 1111 1111 1110 4095 3.29919 ~ 1111 1111 1111 TIMING DIAGRAM A1 AINT A2 A5 Input Sampling Period CKIN DO[13:0] D1 D2 D3 D4 D5 7 BW1254X 0.35µ µm 14-BIT 10MSPS ADC FUNCTIONAL DESCRIPTION 1. The BW1254X is a CMOS four step pipelined Analog-to-Digital Converter. It contains 5-bit flash A/D Converters, 4bit, two 3bit flash A/D converters and three multiplying D/A Convertors. The N-bit flash ADC is composed of 2N-1 latched comparators, and multiplying DAC is composed of 2*(2N+1) capacitors and two fully-differential amplifiers. 2. The BW1254X operates as follows. During the first "L" cycle of external clock the analog input data is sampled, and the input is held from the rising edge of the external clock, which is fed to the first 5-bit flash ADC, and the first multiplying DAC. Multiplying DAC reconstructs a voltage corresponding to the first 5-bit ADC's output, and finally amplifies a residue voltage by 24. The second and third flash ADC, and MDAC are worked as same manner. Finally amplified residue voltage at the third multiplying DAC is fed to the last 3-bit flash ADC decides final 3-bit digital digital code. 3. BW1254X has the error correction scheme, which handles the output from mismatch in the first, second, third and fourth flash ADC. MAIN BLOCK DESCRIPTION 1. SHA SHA (Sample-and-Hold Amplifier) is the circuit that samples the analog input signal and hold that value until next sample-time. It is good as small as its different value between analog input signal and output signal. SHA amp gain is higher than 70dB at 10MHz conversion rate, its settling-time must be shorten than 38ns with less than 1/2 LSB error voltage at 14bit resolution. This SHA is consist of fully differential op amp, switching tr. and sampling capacitor. The sampling clock is non-overlapping clock (Q1, Q2) and sampling capacitor value is about 4pF. SHA uses independent bias to protect interruption of any other circuit. SHA amp is designed that open-loop dc gain is higher than 70dB, phase margin is higher than 60 degrees. Its input block is designed to be the rail-to-rail architecture using complementary different pair. 2. FLASH The 5-bit flash converters compare analog signal (SAH output) with reference voltage, and that results transfer to MDAC and digital correction logic block. It is realized fully differential comparators of 31EA. Considering self-offset, dynamic feed through error, it should distinguish 40mV at least. First, the comparators charge the reference voltage at the sampling capacitors before transferred SHA output.That operation is performed on the phase of Q2, and discharging on the phase of Q1. That is, the comparators compare relative different values dual input voltage with dual reference voltage. Its output during Q1 operation is stored at the pre-latch block by Q1P. 3. MDAC MDAC is the most important block at this ADC and it decides the characteristics. MDAC is consist of two stage op amp, selection logic and capacitor array (c_array). c_array's compositions are the capacitors to charge the analog input and and the reference voltage, switches to control the path. Selection logic controls the c_array internal switches. If Q1 is high, selection's output are all low, the switches of tsw1 are off, the switches of tsw2 are all on. Therefore the capacitors of c_array can charge analog input values held at SHA. 8 0.35µ µm 14-BIT 10MSPS ADC BW1254X CORE EVALUATION GUIDE 1. ADC function is evaluated by external check on the bidirectional pads connected to input nodes of HOST DSP back-end circuit. 2. If User want the specific analog input range, the reference voltages may be forced. VDDA1 VBBA1 VSSA2 VSSA1 VDDA2 VBBA2 AINT AINC DO[13:0] [MSB:LSB] bw1254x REFTOP ORI REFBOT BGR CML CML1 ITEST STBY CKIN D[13:0] D[13:0 ] Digital Mux HOST DSP CORE D[13:0] Bidirectional PAD (ADC Function Test & externally forced Digital Input) 9 0.35µ µm 14-BIT 10MSPS ADC BW1254X PACKAGE CONFIGURATION 10u 0.1u 10u 0.1u 10u 0.1u 10u 0.1u 10u 0.1u 10u Analog Digital II Digital I 10u 10u 0.1u 0.1u 0.1u NOTE: NC denotes "No Connection". 10 1 BGR VDDA2 48 2 REFTOP VDDA2 47 3 REFBOT VSSA2 46 4 CML VSSA2 45 5 CML1 VBBA2 44 6 VDDA1 NC 43 7 VDDA1 CKIN 42 8 VBBA1 NC 41 9 VSSA1 DO[13] 40 10 VSSA1 DO[12] 39 11 AINT DO[11] 38 12 NC 13 AINC DO[9] 36 14 NC DO[8] 35 15 NC DO[7] 34 16 ITEST DO[6] 33 17 STBY DO[5] 32 18 VDDA3 DO[4] 31 19 VSSA3 DO[3] 30 20 NC DO[2] 29 21 NC DO[1] 28 22 NC DO[0] 27 23 NC ORI 26 24 NC TRIST 25 BW1254X DO[10] 37 0.1u 10u 50 Ω 0.35µ µm 14-BIT 10MSPS ADC BW1254X PACKAGE PIN DESCRIPTION Pin No. Name I/O Type Pin Description 1 BGR AB Reference Voltage Output 2 REFTOP AB Reference Top Output/Force 3 REFBOT AB Reference bottom Output/Force 4 CML AB Internal Bias 5 CML1 AB Internal Bias 6, 7 VDDA1 AP Analog Power (3.3V) 8 VBBA1 AG Analog Sub Bias 9, 10 VSSA1 AG Analog Ground 11 AINT AI Analog Input + 13 AINC AI Analog Input - 16 ITEST AB open=use internal bias circuit 17 STBY DI VDDA=Power saving (Standby), GNP=Normal 18 VDDA3 PP PAD Power (3.3V) 19 VSSA3 PG PAD Ground 25 TRIST DI Tri-state Buffer Input VDD=High Impedance, GND=Normal 26 ORI DO Out of Range Indicator Normal='Low' Out of Range='High' 27 DO[0] DO Digital Output (LSB) 28~39 DO[1:12] DO Digital Output 40 DO[13] DO Digital Output (MSB) 42 CKIN DI Sampling Clock Input 44 VBBA2 DG Digital Sub Bias 45, 46 VSSA2 DG Digital GND 47, 48 VDDA2 DP Digital Power (3.3V) NOTE: I/O TYPE PP and PG denote PAD Power and PAD Ground respectively. 11 0.35µ µm 14-BIT 10MSPS ADC BW1254X PACKAGE PIN DESCRIPTION (Continued) Configuration 12 BGR 1 48 VDDA2 REFTOP 2 47 VDDA2 REFBOT 3 46 VSSA2 CML 4 45 VSSA2 CML1 5 44 VBBA2 VDDA1 6 43 NC VDDA1 7 42 CKIN VBBA1 8 41 NC VSSA1 9 40 DO[13] VSSA1 10 39 DO[12] AINT 11 38 DO[11] NC 12 37 DO[10] AINC 13 36 DO[9] NC 14 35 DO[8] NC 15 34 DO[7] ITEST 16 33 DO[6] STBY 17 32 DO[5] VDDA3 18 31 DO[4] VSSA3 19 30 DO[3] NC 20 29 DO[2] NC 21 28 DO[1] NC 22 27 DO[0] NC 23 26 ORI NC 24 25 TRIST BW1254X 0.35µ µm 14-BIT 10MSPS ADC BW1254X USER GUIDE 1. Input Range — If you want to using the single-ended input, you should use he input range as below. AINT: 0.5V ~ 2.5V, AINC: 1.5V. — If you want to using the differential input, you should use the input range as below. AINT: 1.0V ~ 2.0V, AINC: 1.0V ~ 2.0V. AIN: AINT - AINC — If you want to changing input range (AIN span), you can force reference voltages. AIN span = -REF ~ +REF REF = REFTOP - REFBOT 2. Power Consumption/Speed Optimization Yon can optimize the power consumption, as control the ITEST voltage level precisely . You can optimize the ADC's speed also, as control the ITEST voltage level. 13 0.35µ µm 14-BIT 10MSPS ADC BW1254X PHANTOM CELL INFORMATION — Pins of the core can be assigned externally (Package pins) or internally (internal ports) depending on design methods. The term "External" implies that the pins should be assigned externally like power pins. The term "External/internal" implies that the applications of these pins depend on the user. VDDA VSSA VBBA AINT AINC ITEST VDDA VSSA VBBA REFBOT bw1254x RETOP 14bit 10MSPS ADC CML1 CML BGR STBY CKIN VDDD VSSD VBBD DO[13] DO[12] DO[11] DO[9] DO[10] DO[8] DO[7] DO[6] DO[5] DO[4] DO[3] DO[2] DO[1] DO[0] ORI 14 0.35µ µm 14-BIT 10MSPS ADC BW1254X PHANTOM CELL INFORMATION (Continued) Pin Name Pin Usage Pin Layout Guide VDDA External - Maintain the large width of lines as far as the pads. VSSA External - place the port positions to minimize the length of power lines. VBBA External - Do not merge the analog powers with anoter power from other VDDD External VSSD External VBBD External AINT External/Internal AINC External/Internal CKIN External/Internal - Separate from all other analog signals REFTOP External/Internal - Maintain the larger width and the shorter length as far as the pads. - Separate from all other digital lines. REFBOT External/Internal CML External/Internal CML1 External/Internal BGR External/Internal ITEST External/Internal STBY External/Internal ORI External/Internal DO[13] External/Internal DO[12] External/Internal DO[11] External/Internal DO[10] External/Internal DO[9] External/Internal DO[8] External/Internal DO[7] External/Internal DO[6] External/Internal DO[5] External/Internal DO[4] External/Internal DO[3] External/Internal DO[2] External/Internal DO[1] External/Internal DO[0] External/Internal blocks. - Use good power and ground source on board. - Do not overlap with digtal lines. - Maintain the shotest path to pads. - Separate from all other digital lines. - Separated from the analog clean signals if possible. - Do not exceed the length by 1,000um. 15 0.35µ µm 14-BIT 10MSPS ADC BW1254X FEEDBACK REQUEST It should be quite helpful to our ADC core development if you specify your system requirements on ADC in the following characteristic checking table and fill out the additional questions. We appreciate your interest in our products. Thank you very much. Characteristic Min Typ Max Unit Analog Power Supply Voltage V Digital Power Supply Voltage V Bit Resolution Bit Reference Input Voltage V Analog Input Voltage Operating Temperature Vpp °C Integral Non-linearity Error LSB Differential Non-linearity Error LSB Bottom Offset Voltage Error mV Top Offset Voltage Error mV Maximum Conversion Rate MSPS Dynamic Supply Current mA Power Dissipation mW Signal-to-noise Ratio Pipeline Delay Remarks dB CLK Digital Output Format (Provide detailed description & timing diagram) 1. Between single input-output and differential input-output configurations, which one is suitable for your system and why? 2. Please comment on the internal/external pin configurations you want our ADC to have, if you have any reason to prefer some type of configuration. 3. Freely list those functions you want to be implemented in our ADC, if you have any. 16 0.35µ µm 14-BIT 10MSPS ADC BW1254X HISTORY CARD Version Date ver 1.0 99.6. ver 1.1 02.4.16 Modified Items Comments Original version published (formal) Phantom information added and the datasheet format changed 17 0.35µ µm 14-BIT 10MSPS ADC BW1254X NOTES 18