18-Bit 1.6Msps SAR ADC 101dB SNR Up to 5V IN+ 0V 2.5V 2.5V to 5V VDD VREF LTC2379-18 Up to 5V IN– SPI I/O GND 0V Unrivaled Performance at Only 18mW The LTC®2379-18 leads a pin-compatible family of no-latency SAR ADCs featuring unrivaled 101dB SNR at 18-bits and 96dB SNR at 16-bits from 250ksps to 2Msps. Explicit Busy and Chain pins, along with a user-friendly SPI interface, simplify digital timing. A unique digital gain compression feature eliminates the need for a negative ADC driver supply while preserving the full resolution of the ADC, dramatically lowering the total power consumption of the signal chain. 0 Features n n n n n n n n n 1.6Msps Throughput Rate 101.2dB SNR (Typ) at fIN = 2kHz ±2LSB INL (Max), ±0.9LSB DNL (Max) 120dB THD (Typ) at fIN = 2kHz Low Power: 18mW at 1.6Msps, 18μW at 1.6ksps Power Down Mode: 2.25µW Fully Differential Input Range ±VREF Digital Gain Compression Eliminates Negative Rails –40°C to 125°C Guaranteed Temperature Range 16-pin MSOP and 4mm × 3mm DFN Packages –40 AMPLITUDE (dBFS) n fS = 1.6Msps fIN = 2kHz SNR = 101.2dB THD = –119.7dB –20 –60 –80 –100 –120 –140 –160 –180 0 100 200 300 400 500 600 700 800 FREQUENCY (kHz) Complete 18-Bit/16-Bit Pin-Compatible SAR ADC Family 250ksps 500ksps 1Msps 1.6Msps 18-Bit 101dB SNR 2376-18 2377-18 2378-18 2379-18 16-Bit 96dB SNR 2376-16 2377-16 2378-16 6.75mW 13.5mW Power Consumption 3.4mW L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. 2Msps 2380-16 18mW 19mW Digital Gain Compression ANALOG INPUT DIGITAL OUTPUT 5V 4.5V +FS = 011…111 ALL 262,144 CODES! 0.5V 0V –FS = 100…000 REFERENCE = 5V The LTC2379-18 family offers an innovative Digital Gain Compression (DGC) feature which eliminates the driver amplifier’s negative supply while preserving the full resolution of the ADC. When enabled, the ADC performs a digital scaling function that maps zero-scale code from 0V to 0.1 • VREF and full-scale code from VREF to 0.9 • VREF, allowing the amplifier to operate from a single positive supply. The elimination of the negative supply dramatically reduces the total power consumption of the signal chain and reduces component count while simplifying the design. VIN 6V LTC6655-5 VOUT_S 5V VCM LT6350 V+ 4.5V 3 4 8 OUT1 IN+ + 10V 0V –10V REF VDD LTC2379-18 – 1 2.5V 0.5V 2 – + VCM 5 V– 6 IN– OUT2 4.5V REF/DGC 0.5V LTC6655 Voltage Reference Features Low Noise: 0.25ppmP-P (0.1Hz to 10Hz) 1.25µVP-P for the LTC6655-5 Low Drift: 2ppm/°C Max High Accuracy: ±0.025% Max Sinks and Sources Current: ±5mA Fully Specified from –40°C to 125°C Available Output Voltages: 1.25V, 2.048V, 2.5V, 3V, 3.3V, 4.096V, 5V Available in an 8-Lead MSOP Package n n n n n n n The LTC®6655 is an ultra-stable very low noise voltage reference, with only 1.25µVP-P noise (0.1Hz to 10Hz), temperature drift less than 2ppm/°C, and initial voltage accuracy within ±0.025%. It can be powered from as little as 500mV above the output voltage, up to a maximum supply voltage of 13.2V. A shutdown mode allows the power consumption to be reduced to less than 20µA. The combination of extreme precision and high temperature operating range make the LTC6655 an ideal voltage reference for the most demanding automotive, industrial and instrumentation applications. www.linear.com/2379 n 1-800-4-LINEAR 1111C