LTC1604 Linear Technology, LTC1604 Datasheet

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... Two digitally selectable power shutdown modes provide power savings for low power systems. The LTC1604’s full-scale input range is 2.5V. Outstand- ing AC performance includes 90dB S/(N+D) and – 100dB THD at a sample rate of 333ksps. The unique differential input sample-and-hold can acquire single-ended or differential input signals up to its 15MHz bandwidth ...

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... REFCOMP Voltage (Note 4) ......... – 0. Digital Input Voltage (Note 4) ....................– 0.3V to 10V Digital Output Voltage .................. – 0. Power Dissipation ............................................. 500mW Operating Temperature Range LTC1604C............................................... LTC1604I ............................................ – Storage Temperature Range ................ – 150 C Lead Temperature (Soldering, 10 sec)................. 300 VERTER ...

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... I = 160 A DD OUT V = 4.75V 1.6mA DD OUT High OUT DD CS High (Note 11 OUT OUT DD LTC1604 LTC1604 LTC1604A MIN TYP MAX MIN TYP MAX –100 – 100 – 94 – 94 – – 88 – 88 ...

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... CS = 5V, SHDN = 0V, SHDN = 5V, SHDN = 0V (Note 5) CONDITIONS (Note 11) (Notes 11, 12) (Notes 11, 12) (Notes 11, 12 Low (Note 12) (Note 12 25pF L (Note 12) (Note 12 25pF 100pF L LTC1604C LTC1604I (Note 12) (Note 12) MIN TYP MAX UNITS 4.75 5.25 V – 4.75 – 5. 1.5 2 100 ...

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... G10 Distortion vs Input Frequency 0 –10 –20 –30 –40 –50 –60 –70 –80 THD 3RD –90 –100 2ND –110 10k 1k 100k INPUT FREQUENCY (Hz) 1604 G04 LTC1604 S/( Input Frequency and Amplitude 100 V = 0dB –20dB –40dB ...

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... LTC1604 W U TYPICAL PERFORMANCE CHARACTERISTICS Intermodulaton Distortion 333kHz SAMPLE f = 29.3kHz –20 IN1 f = 32.4kHz IN2 –40 –60 –80 –100 –120 –140 100 120 140 160 FREQUENCY (kHz) 1604 G06 PIN FUNCTIONS + A (Pin 1): Positive Analog Input. The ADC converts the ...

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... OUTPUT B15 TO B0 SAMPLING BUFFERS – ADC AGND AGND AGND AGND – 1604 TC01 LTC1604 10 DGND SHDN CONVST 31 CONTROL RD 30 LINES BUSY OGND 16-BIT PARALLEL D15 TO D0 ...

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... This device can also talk to 3V digital systems: the digital input pins (SHDN, CS, CONVST and RD) of the LTC1604 recognize HOLD inputs. The LTC1604 has a dedicated output HOLD supply pin (OV digital output pins (D0 to D15, BUSY) and allows the part to talk to either digital systems. The output is two’ ...

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... F04 operation with a narrow logic low CONVST pulse. Mode 1b shows a narrow logic high CONVST pulse. In mode 2 (Figure tied low. The falling edge of CONVST signal starts the conversion. Data outputs are in LTC1604 ), accuracy is unaffected. CONV less than 500ns or greater than 5 ...

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... LTC1604 U U APPLICATIONS INFORMATION CONVST t 6 BUSY DATA (N – 1) DATA D15 TO D0 Figure 5. Mode 1a. CONVST Starts a Conversion. Data Outputs Always Enabled (CONVST = CONVST t 6 BUSY DATA (N – 1) DATA D15 TO D0 Figure 6. Mode 1b. CONVST Starts a Conversion. Data Outputs Always Enabled ...

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... DATA (N – 1) D15 TO D0 Figure 9. ROM Mode Timing DIFFERENTIAL ANALOG INPUTS Driving the Analog Inputs The differential analog inputs of the LTC1604 are easy to drive. The inputs may be driven differentially single- ended input (i.e., the A – A inputs are sampled at the same instant. Any un- ...

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... If slower op amps are used, more settling time can be provided by increasing the time between conversions. The best choice for an op amp to drive the LTC1604 will depend on the application. Generally applications fall into two categories: AC applications where dynamic specifi- cations are most critical and time domain applications where DC accuracy and settling time are most critical ...

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... AGND Figure 11. RC Input Filter Input Range The 2.5V input range of the LTC1604 is optimized for low noise and low distortion. Most op amps also perform well over this same range, allowing direct coupling to the analog inputs and eliminating the need for special transla- tion circuitry ...

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... Figure 14b. Selectable 2.5V Input Range Full-Scale and Offset Adjustment Figure 15a shows the ideal input/output characteristics for the LTC1604. The code transitions occur midway between successive integer LSB values (i.e., – 0.5LSB, – 1.5LSB, – 2.5LSB,... FS – 1.5LSB, FS – 0.5LSB). The output is two’s complement binary with 1LSB = FS – ...

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... BOARD LAYOUT AND GROUNDING Wire wrap boards are not recommended for high resolu- tion or high speed A/D converters. To obtain the best performance from the LTC1604, a printed circuit board with ground plane is required. Layout should ensure that digital and analog signal lines are separated as much as possible ...

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... Figure 16. Power Supply Grounding Practice Figure 17. Histogram for 4096 Conversions Figure 18a. This FFT of the LTC1604’s Conversion of a Full-Scale 5kHz Sine Wave Shows Outstanding Response with a Very Low Noise Floor When Sampling at 333ksps DIGITAL SYSTEM OV OGND ...

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... N = [S/( – 1.76]/6.02 where N is the effective number of bits of resolution and S/( expressed in dB. At the maximum sampling rate of 333kHz the LTC1604 maintains above 14 bits up to the Nyquist input frequency of 167kHz (refer to Figure 19). Total Harmonic Distortion Total harmonic distortion (THD) is the ratio of the RMS sum of all harmonics of the input signal to the fundamental itself ...

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... The full-linear bandwidth is the input frequency at which the S/( has dropped to 84dB (13.66 effective bits). The LTC1604 has been designed to optimize input band- width, allowing the ADC to undersample input signals with 160 frequencies above the converter’s Nyquist Frequency. The noise floor stays very low at high frequencies ...

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... Plastic SSOP (0.209) (LTC DWG # 05-08-1640 – 8 0.0256 (0.65) BSC 0.010 – 0.015 (0.25 – 0.38) LTC1604 0.499 – 0.509* (12.67 – 12.93 0.301 – 0.311 (7.65 – 7.90 0.068 – 0.078 (1.73 – ...

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... LTC1604 U TYPICAL APPLICATION Using the LTC1604 and Two LTC1391s as an 8-Channel Differential 16-Bit ADC System 5V + LTC1391 CH0 CH0 CH1 D – – CH2 CH3 D OUT 12 5 CH4 CH5 CH6 CLK CH7 GND ...