Features True Differential Inputs Guaranteed performance from 200 kSPS to 500 kSPS External Reference Wide Input Common-Mode Voltage Range SPI™/QSPI™/MICROWIRE™/DSP compatible Serial Interface Description The ADC121S655 is a 12-bit, 200 kSPS to 500 kSPS sampling Analog-to-Digital (A/D) converter that features a fully differential, high impedance analog input and an external reference. The reference voltage can be varied from 1.0V to VA, with a corresponding resolution between 244µV and VA divided by 4096. The output serial data is binary 2's complement and is compatible with several standards, such as SPI™, QSPI™, MICROWIRE™, and many common DSP serial interfaces. The differential input, low power consumption, and small size make the ADC121S655 ideal for direct connection to transducers in battery operated systems or remote data acquisition applications. Operating from a single 5V supply, the supply current when operating at 500 kSPS is typically 1.8 mA. The supply current drops down to 0.3 µA typically when the ADC121S655 enters power-down mode. The ADC121S655 is available in the MSOP-8 package. Operation is guaranteed over the industrial temperature range of −40°C to +105°C and clock rates of 3.2 MHz to 8 MHz. Key Specification Conversion Rate 200 kSPS to 500 kSPS INL ± 0.95 LSB (max) DNL ± 0.85 LSB (max) Offset Error ± 3.0 LSB (max) Gain Error ± 5.5 LSB (max) SINAD 70 dB (min) Power Consumption at VA = 5V  Active, 500 kSPS 9 mW (typ)  Active, 200 kSPS 7 mW (typ)  Power-Down 1.5 µW (typ) Applications Automotive Navigation Portable Systems Medical Instruments Instrumentation and Control Systems Motor Control Direct Sensor Interface

Also Recommended ADC121S051▲ Single Ended Input, Smaller Package ADC121S625▲ 50 To 200Ksps Pin Compatible Alternative ADC121S705▲ 500Ksps To 1Msps Pin Compatible Alternative Pressure Sensor Application

Typical Application click for larger image Pressure Sensor Application	Block Diagram click for larger image
Typical Performance click for larger image typical DNL plot

Datasheets

Title		Size	Date	Other Language
	ADC121S655 12-Bit, 200 kSPS to 500 kSPS, Differential Input, Micro Power A/D Converter	540 Kbytes	11-May-07

Part Number(s) (NSID)	Top View	Availability	Current Reported Stock	Budgetary Pricing	Pack Size
ADC121S655CIMM/NOPB RoHS Status	MINI SOIC	Full production Lead Time: 6 weeks	Distributor Region Qty DIGI-KEY Worldwide 0	$1.70 each at 1K+ pcs	reel of 1000
ADC121S655CIMMX/NOPB RoHS Status	MINI SOIC	Full production Lead Time: 8 weeks	Distributor Region Qty DIGI-KEY Worldwide 0	$1.70 each at 1K+ pcs	reel of 3500

All information pertaining to the RoHS Compliance Standard can be found at http://www.national.com/en/packaging/leadfree.html.

Moisture Sensitivity Level Data for ADC121S655.

A RoHS compliance or an IPC 1752 report can be acquired at http://www.national.com/en/packaging/greennopb.html.

National's certificate of product compliance for ADC121S655 is located at RoHS Status.

Part Number(s) (NSID)	Weight (milligrams)	Type	Pins	MSL Rating	Peak Reflow	RoHS Status	CAD Symbols	Models	Package Marking Format
ADC121S655CIMM/NOPB	29.851	MINI SOIC	8	1	260	Detail	N/A	N/A	ZXTT X2AC
ADC121S655CIMMX/NOPB	29.851	MINI SOIC	8	1	260	Detail	N/A	N/A	ZXTT X2AC

All information pertaining to the RoHS Compliance Standard can be found at http://www.national.com/en/packaging/leadfree.html.

Moisture Sensitivity Level Data for ADC121S655.

A RoHS compliance or an IPC 1752 report can be acquired at http://www.national.com/en/packaging/greennopb.html.

National's certificate of product compliance for ADC121S655 is located at RoHS Status.

CAD Symbols and Models N/A

Models N/A

Reliability Metrics

Part Number	Process	EFR Reject	EFR Sample Size	PPM	LTA Rejects	LTA Device Hours	FITS	MTTF (Hours)
ADC121S655CIMM	CMOS7	0	21301	0	0	1584000	3	449464325
ADC121S655CIMMX	CMOS7	0	21301	0	0	1584000	3	449464325

Note: The Early Failure Rates (EFR) were calculated as point estimate PPM based on rejects and sample size for EFR. The Long Term Failure Rates were calculated at 60% confidence using the Arrhenius equation at 0.7eV activation energy and derating the assumed stress temperature of 150°C to an application temperature of 55°C.

For more information on Reliability Metrics, please click here.

All information pertaining to the RoHS Compliance Standard can be found at http://www.national.com/en/packaging/leadfree.html.

Moisture Sensitivity Level Data for ADC121S655.

A RoHS compliance or an IPC 1752 report can be acquired at http://www.national.com/en/packaging/greennopb.html.

National's certificate of product compliance for ADC121S655 is located at RoHS Status.