CS5525 CS5526 16-bit/20-bit, Multi-range ADC with 4-bit Latch Features General Description The 16-bit CS5525 and the 20-bit CS5526 are highly in- z Delta-sigma A/D Converter tegrated A/D converters which include an - Linearity Error: 0.0015%FS instrumentation amplifier, a PGA (programmable gain - Noise-free Resolution: 18-bits amplifier), eight digital filters, and self and system cali- z Bipolar/Unipolar Input Ranges bration circuitry. - 25 mV, 55 mV, 100 mV, 1 V, 2.5 V and 5 V The converters are designed to provide their own nega- z Chopper Stabilized Instrumentation Amplifier tive supply which enables their on-chip instrumentation amplifiers to measure bipolar ground-referenced signals z On-chip Charge Pump Drive Circuitry 100 mV. By directly supplying NBV with -2.5 V and z 4-bit Output Latch with VA+ at 5 V, 2.5 V signals (with respect to ground) z Simple three-wire serial interface can be measured. - SPI and Microwire Compatible The digital filters provide programmable output update - Schmitt Trigger on Serial Clock (SCLK) rates between 3.76 Sps to 202 Sps (XIN = 32.768 kHz). z Programmable Output Word Rates Output word rates can be increased by approximately 3X by using XIN = 100 kHz. Each filter is designed to settle - 3.76 Sps to 202 Sps (XIN = 32.768 kHz) to full accuracy for its output update rate in one conver- - 11.47 Sps to 616 Sps (XIN = 100 kHz) sion cycle. The filters with word rates of 15 Sps or less z Output Settles in One Conversion Cycle (XIN = 32.768 kHz) reject both 50 and 60 Hz (3 Hz) line z Simultaneous 50/60 Hz Noise Rejection interference simultaneously. z System and Self-calibration with Low power, single conversion settling time, programma- Read/Write Registers ble output rates, and the ability to handle negative input signals make these single supply products ideal solu- z Single +5 V Analog Supply tions for isolated and non-isolated applications. +3.0 V or +5 V Digital Supply z Low-power Mode Consumption: 4.9 mW ORDERING INFORMATION See page 29. - 1.8 mW in 1 V, 2.5 V, and 5 V Input Ranges VA+ AGND VREF+ VREF- DGND VD+ Digital Filter Differential Calibration + CS AIN+ Programmable 4th Order Register X20 Gain Delta-Sigma - AIN- Modulator SCLK Control Register NBV SDI A0 Output SDO A1 Latch Register A2 Calibration Clock Calibration C A3 Memory Gen. CPD XIN XOUT Copyright Cirrus Logic, Inc. 2005 AUG 05 CS5525 CS5526 ANALOG CHARACTERISTICS (T = 25 C VA+, VD+ = 5 V 5% VREF+ = 2.5 V, VREF- = AGND, A NBV = -2.1 V, FCLK = 32.768 kHz, OWR (Output Word Rate) = 15 Sps, Bipolar Mode, Input Range = 100 mV See Notes 1 and 2.) CS5525 CS5526 Parameter Min Typ Max Min Typ Max Unit Accuracy Linearity Error - 0.0015 0.003 - 0.0007 0.0015 %FS No Missing Codes 16 - - 20 - - Bits Bipolar Offset (Note 3) - 12 - 16 32 LSB Unipolar Offset (Note 3) - 2 4- 32 64 LSB Offset Drift (Notes 3 and 4) - 20 - - 20 - nV/C Bipolar Gain Error - 8 31 - 8 31 ppm Unipolar Gain Error - 16 62 - 16 62 ppm Gain Drift (Note 4) - 1 3 - 1 3 ppm/C Voltage Reference Input Range (VREF+) - (VREF-) 1 2.5 3.0 1 2.5 3.0 V Common Mode Rejection dc - 110 - - 110 - dB 50, 60 Hz - 130 - - 130 - dB Input Capacitance - 16 - - 16 - pF CVF Current (Note 5) - 0.6 - - 0.6 - A/V Notes: 1. Applies after system calibration at any temperature within -40 C ~ +85 C. 2. Specifications guaranteed by design, characterization, and/or test. 3. Specification applies to the device only and does not include any effects by external parasitic thermocouples. LSB = LSB for the CS5525, and LSB for the CS5526. 16 20 4. Drift over specified temperature range after calibration at power-up at 25 C. 5. See the section of the data sheet which discusses input models on page 15. RMS NOISE (Notes 6 and 7) Input Range, (Bipolar/Unipolar Mode) Output Rate -3 dB Filter (Sps) Frequency 25 mV 55 mV 100 mV 1 V 2.5 V 5 V 3.76 3.27 90 nV 90 nV 130 nV 1.0 V 2.0 V 4.0 V 7.51 6.55 110 nV 130 nV 190 nV 1.5 V 3.0 V 7 V 15.0 12.7 170 nV 200 nV 250 nV 2.0 V 5.0 V 10 V 30.1 25.4 250 nV 300 nV 500 nV 4.0 V 10 V 15 V 60.0 50.4 500 nV 1.0 V 1.5 V 15 V 45 V 85 V 123.2 (Note 8) 103.6 2.0 V 4.0 V 8.0 V 72 V 190 V 350 V 168.9 (Note 8) 141.3 10 V 20.0 V 30 V 340 V 900 V 2.0 mV 202.3 (Note 8) 169.2 30 V 55 V 105 V 1.1 mV 2.4 mV 5.3 mV Notes: 6. Wideband noise aliased into the baseband. Referred to the input. Typical values shown for 25 C. 7. For Peak-to-Peak Noise multiply by 6.6 for all ranges and output rates. 8. For input ranges <100 mV and output word rates >60 Sps, 32.768 kHz chopping frequency is used. Specifications are subject to change without notice. 2 DS202F5