CS5503

Features:

Monolithic CMOS ADC with Filtering
- 6-pole, Low-pass Gaussian Filter
Up to 4 kHz Output Word Rates
- On Chip Self-calibration Circuitry
- Linearity Error: ±0.0003%
- Differential Nonlinearity:
          CS5501: 16-bit, No Missing Codes (DNL ±1/8 LSB)
          CS5503: 20-bit, No Missing Codes
System Calibration Capability
Flexible Serial Communications Port
- Microcontroller-compatible Formats
- 3-state Data and Clock Outputs
- UART Format (CS5501 only)
Pin-selectable Unipolar/Bipolar Ranges
Low Power Consumption: 25 mW
- 10 W Sleep Mode for Portable Applications


Pinout




Specifications

Parameter	Symbol	Min	Max	Units
DC Power Supplies:        Positive Digital                           Negative Digital                           Positive Analog                           Negative Analog	VD+ VD- VA+ VA-	-0.3 0.3 -0.3 0.3	(VA+)+0.3 -6.0 6.0 -6.0	V V V V
Input Current, Any Pin Except Supplies (Notes 10, 11)	Iin	-	±10	mA
Analog Input Voltage (AIN and VREF pins)	VINA	(VA-)-0.3	(VA+)+0.3	V
Digital Input Voltage	VIND	-0.3	(VA+)+0.3	V
Ambient Operating Temperature	TA	-55	125
Storage Temperature	Tstg	-65	150

Description

The CS5501 and CS5503 are CMOS A/D converters ideal for measuring low-frequency signals representing physical, chemical, and biological processes. They utilize charge-balance techniques to achieve 16-bit (CS5501) and 20-bit (CS5503) performance with up to 4 kSps word rates.

The converters CS5503 continuously sample at a rate set by the user in the form of either a CMOS clock or a crystal. Onchip digital filtering processes the data and updates the output register at up to a 4 kSps rate. The converters' lowpass, 6-pole Gaussian response filter is designed to allow corner frequency settings from 0.1 Hz to 10 Hz in the CS5501 and 0.5 Hz to 10 Hz in the CS5503. Thus, each converter rejects 50 Hz and 60 Hz line frequencies as well as any noise at spurious frequencies.

The CS5501 and CS5503 include on-chip self-calibration circuitry which can be initiated at any time or temperature to insure offset and full-scale errors of typically less than 1/2 LSB for the CS5501 and less than 4 LSB for the CS5503. The devices can also be applied in system calibration schemes to null offset and gain errors in the input channel.

Each device's serial port CS5503 offers two general purpose modes of operation for direct interface to shift registers or synchronous serial ports of industry-standard microcontrollers. In addition, the CS5501's serial port offers a third, UART-compatible mode of asynchronous communication.