Datasheet

ManualsBrandsTEXAS INSTRUMENTS ManualsData collecting ICsData acquisition IC - AD converter (ADC) External SON 8 Exposed Pad

SAR

Control

OUT

Comparator

S/H Amp

CS/SHDN

DCLOCK

+In

REF

–In

CDAC

Serial

Interface

ADS7826

ADS7827

ADS7829

SLAS388–JUNE 2003

10/8/12-BIT HIGH SPEED 2.7 V microPOWER™ SAMPLING

ANALOG-TO-DIGITAL CONVERTER

FEATURES DESCRIPTION

• High Throughput at Low Supply Voltage

The ADS7826/27/29 is a family of 10/8/12-bit sampling

(2.7 V V

)

analog-to-digital converters (A/D) with assured specifi-

– ADS7829: 12-bit 125 KSPS

cations at 2.7-V supply voltage. It requires very little

– ADS7826: 10-bit 200 KSPS

power even when operating at the full sample rate. At

– ADS7827: 8-bit 250 KSPS

lower conversion rates, the high speed of the device

enables it to spend most of its time in the power down

• Very Wide Operating Supply VoltageL:

mode— the power dissipation is less than 60 µW at 7.5

2.7 V to 5.25 V (as Low as 2.0 V With Reduced

kHz.

Performance)

The ADS7826/27/29 also features operation from 2.0 V

• Rail-to-Rail, Pseudo Differential Input

to 5 V, a synchronous serial interface, and a differential

• Wide Reference Voltage: 50 mV to V

input. The reference voltage can be set to any level

within the range of 50 mV to V

• Micropower Auto Power-Down:

– Less Than 60 µW at 75 kHz, 2.7 V V

Ultra-low power and small package size make the

ADS7826/27/29 family ideal for battery operated sys-

• Low Power Down Current: 3 µA Max

tems. It is also a perfect fit for remote data acquisition

• Ultra Small Chip Scale Package:

modules, simultaneous multichannel systems, and iso-

8-pin 3 x 3 PDSO (SON, Same Size as QFN)

lated data acquisition. The ADS7826/27/29 family is

available in a 3 x 3 8-pin PDSO (SON, same size as

• SPI™ Compatible Serial Interface

QFN) package.

APPLICATIONS

• Battery Operated Systems

• Remote Data Acquisition

• Isolated Data Acquisition

• Simultaneous Sampling, Multichannel

Systems

microPOWER is a trademark of Texas Instruments.

Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas Instruments

semiconductor products and disclaimers thereto appears at the end of this data sheet.

PRODUCTION DATA information is current as of publication date.

Products conform to specifications per the terms of Texas Instruments

standard warranty. Production processing does not necessarily in-

cludetestingofallparameters.

Summary of content (26 pages)

PAGE 1
ADS7826 ADS7827 ADS7829 SLAS388 – JUNE 2003 10/8/12-BIT HIGH SPEED 2.7 V microPOWER™ SAMPLING ANALOG-TO-DIGITAL CONVERTER FEATURES DESCRIPTION • High Throughput at Low Supply Voltage (2.7 V VCC) – ADS7829: 12-bit 125 KSPS – ADS7826: 10-bit 200 KSPS – ADS7827: 8-bit 250 KSPS • Very Wide Operating Supply VoltageL: 2.7 V to 5.25 V (as Low as 2.
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ADS7826 ADS7827 ADS7829 www.ti.com SLAS388 – JUNE 2003 These devices have limited built-in ESD protection. The leads should be shorted together or the device placed in conductive foam during storage or handling to prevent electrostatic damage to the MOS gates.
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ADS7826 ADS7827 ADS7829 www.ti.com SLAS388 – JUNE 2003 SPECIFICATIONS At -40°C to 85°C, VCC = 2.7 V, Vref = 2.5 V, unless otherwise specified. TEST CONDITIONS PARAMETER ADS7829IB MIN TYP ADS7829 MAX MIN 0 Vref TYP ADS7826I MAX MIN 0 Vref TYP ADS7827I TYP MAX UNIT MAX MIN 0 Vref 0 Vref V V ANALOG INPUT Full-scale input span +In - (-In) Absolute input range +In -0.2 VCC +0.2 -0.2 VCC +0.2 -0.2 VCC +0.2 -0.2 VCC +0.2 -IN -0.2 1.0 -0.2 1.0 -0.2 1.0 -0.2 1.
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ADS7826 ADS7827 ADS7829 www.ti.com SLAS388 – JUNE 2003 SPECIFICATIONS (continued) At -40°C to 85°C, VCC = 2.7 V, Vref = 2.5 V, unless otherwise specified. ADS7829IB TEST CONDITIONS MIN VOH IOH = -250 µA 2.2 VOL IOL = 250 µA PARAMETER Data format TYP ADS7829 MAX MIN ADS7826I TYP MAX 2.1 MIN ADS7827I TYP MAX 2.1 0.4 Straight binary TYP UNIT MAX 2.1 0.4 Straight binary MIN V 0.4 Straight binary 0.4 V 3.
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ADS7826 ADS7827 ADS7829 www.ti.com SLAS388 – JUNE 2003 DEVICE INFORMATION PIN DESCRIPTION PDSO (SON−8) PACKAGE (TOP VIEW) REF 1 8 +VDD +IN 2 7 DCLOCK −IN 3 6 DOUT GND 4 5 CS/ SHDN Terminal Functions PIN NAME DESCRIPTION 1 Vref Reference input 2 +In Noninverting input 3 -In Inverting input. Connect to ground or to remote ground sense point.
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ADS7826 ADS7827 ADS7829 www.ti.com SLAS388 – JUNE 2003 TYPICAL CHARACTERISTICS At TA = 25°C, VCC = 2.7 V, Vref = 25 V, (unless otherwise specified) ADS7829 INTEGRAL LINEARITY Integral Linearity - LSB 1 0.8 0.6 0.4 0.2 0 -0.2 -0.4 -0.6 -0.8 -1 0 512 1024 1536 2048 2560 3072 3584 768 896 Decimal Code Figure 1 Integral Linearity - LSB ADS7826 INTEGRAL LINEARITY 1 0.8 0.6 0.4 0.2 0 -0.2 -0.4 -0.6 -0.
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ADS7826 ADS7827 ADS7829 www.ti.com SLAS388 – JUNE 2003 TYPICAL CHARACTERISTICS (continued) At TA = 25°C, VCC = 2.7 V, Vref = 25 V, (unless otherwise specified) Differential Linearity - LSB ADS7829 DIFFERENTIAL LINEARITY 1 0.8 0.6 0.4 0.2 0 -0.2 -0.4 -0.6 -0.8 -1 0 512 1024 1536 2048 2560 Decimal Code Figure 4 3072 3584 768 896 Differential Linearity - LSB ADS7826 DIFFERENTIAL LINEARITY 1 0.8 0.6 0.4 0.2 0 -0.2 -0.4 -0.6 -0.
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ADS7826 ADS7827 ADS7829 www.ti.com SLAS388 – JUNE 2003 TYPICAL CHARACTERISTICS (continued) At TA = 25°C, VCC = 2.7 V, Vref = 25 V, (unless otherwise specified) CHANGE IN MAXIMUM INTEGRAL LINEARITY vs FREE-AIR TEMPERATURE 0.2 0.2 0.15 0.15 Delta From 25 ° C − LSB Delta From 25° C − LSB CHANGE IN MINIMUM INTEGRAL LINEARITY vs FREE-AIR TEMPERATURE 0.1 ADS7826 0.05 0 −0.05 ADS7827 −0.1 0 ADS7827 −0.05 −0.15 −40 −20 0 20 40 60 −0.2 80 −20 0 60 Figure 8. 0.
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ADS7826 ADS7827 ADS7829 www.ti.com SLAS388 – JUNE 2003 TYPICAL CHARACTERISTICS (continued) At TA = 25°C, VCC = 2.7 V, Vref = 25 V, (unless otherwise specified) CHANGE IN QUIESCENT CURRENT vs FREE-AIR TEMPERATURE CHANGE IN MAXIMUM INTEGRAL LINEARITY vs SUPPLY VOLTAGE 0.5 50 Vref = 2.5 V 0.4 30 Delta From 2.7 V − LSB I O − Quiescent Current − mA 40 20 10 0 −10 −20 −30 0.3 ADS7829 0.2 0.1 0 ADS7827 −0.1 −40 −50 −40 ADS7826 −0.2 TA − Free-Air Temperature − ° C 3.2 3.7 4.2 4.
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ADS7826 ADS7827 ADS7829 www.ti.com SLAS388 – JUNE 2003 TYPICAL CHARACTERISTICS (continued) At TA = 25°C, VCC = 2.7 V, Vref = 25 V, (unless otherwise specified) CHANGE IN GAIN vs SUPPLY VOLTAGE CHANGE IN QUIESCENT CURRENT vs SUPPLY VOLTAGE 200 1.2 1 ADS7829 0.8 0.6 0.4 ADS7826 140 120 100 60 0 0 3.7 4.2 ADS7829 80 20 ADS7827 3.2 ADS7826 160 40 0.2 2.7 4.7 5.2 2.7 3.2 3.7 4.2 4.7 5.2 VCC − Supply Voltage − V VCC − Supply Voltage − V Figure 19. Figure 20.
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ADS7826 ADS7827 ADS7829 www.ti.com SLAS388 – JUNE 2003 TYPICAL CHARACTERISTICS (continued) At TA = 25°C, VCC = 2.7 V, Vref = 25 V, (unless otherwise specified) ADS7829 CHANGE IN INTEGRAL and DIFFERENTIAL LINEARITY vs REFERENCE VOLTAGE ADS7829 EFFECTIVE NUMBER OF BITS vs REFERENCE VOLTAGE 12 VCC = 5 V VCC = 5 V Effective Number of Bits - rms Data From 2.5 V Reference - LSB 0.20 0.15 Change in Integral Linearity - LSB 0.10 0.05 0 Change in Differential Linearity - LSB - 0.05 11.75 11.5 11.
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ADS7826 ADS7827 ADS7829 www.ti.com SLAS388 – JUNE 2003 TYPICAL CHARACTERISTICS (continued) At TA = 25°C, VCC = 2.7 V, Vref = 25 V, (unless otherwise specified) ADS7826 SIGNAL-TO-NOISE + DISTORTION vs FREQUENCY ADS7826 TOTAL HARMONIC DISTORTION vs FREQUENCY 100 THD - Total Harmonic Distortion - dB 0 Signal-To-Noise+Distortion - dB 90 80 70 60 50 40 30 20 10 - 10 - 20 - 30 - 40 - 50 - 60 - 70 - 80 - 90 - 100 0 1 10 100 1 1000 10 Figure 31.
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ADS7826 ADS7827 ADS7829 www.ti.com SLAS388 – JUNE 2003 THEORY OF OPERATION The ADS7826/27/29 is a family of micropower classic successive approximation register (SAR) analog-to-digital (A/D) converters. The architecture is based on capacitive redistribution which inherently includes a sample/hold function. The converter is fabricated on a 0.6 µm CMOS process.
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ADS7826 ADS7827 ADS7829 www.ti.com SLAS388 – JUNE 2003 SINAD = 6.02 × ENOB + 1.76 Serial Interface With lower reference voltages, extra care should be taken to provide a clean layout including adequate bypassing, a clean power supply, a low-noise reference, and a low-noise input signal. Because the LSB size is lower, the converter is more sensitive to external sources of error such as nearby digital signals and electromagnetic interference.
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ADS7826 ADS7827 ADS7829 www.ti.com SLAS388 – JUNE 2003 Table 1. Timing Specifications (VCC = 2.7 V and Above -40°C to 85°C SYMBOL DESCRIPTION tSAMPLE Analog input sample time MIN tCONV Conversion time TYP 1.5 ADS7829I or ADS7829IB 12 ADS7826I 11 ADS7827I tCYC Cycle time MAX UNIT 2.
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ADS7826 ADS7827 ADS7829 www.ti.com SLAS388 – JUNE 2003 1.
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ADS7826 ADS7827 ADS7829 www.ti.com SLAS388 – JUNE 2003 There is an important distinction between the power down mode that is entered after a conversion is complete and the full power-down mode which is enabled when CS is HIGH. While both shutdown the analog section, the digital section is completely shutdown only when CS is HIGH. Thus, if CS is left LOW at the end of a conversion and the converter is continually clocked, the power consumption is not as low as when CS is HIGH.
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ADS7826 ADS7827 ADS7829 www.ti.com SLAS388 – JUNE 2003 +3 V +3 V +3 V R8 26 kΩ R1 1 TC1 C2 0.1 µ F R3 500 kΩ R2 59 kΩ 0.4 V R7 5Ω R6 1 MΩ R9 1 kΩ OPA237 0.3 V U2 C1 10 µ F VREF MUX 0.2 V DCLOCK C3 0.1 µ F TC2 ADS7826/27/29 DOUT A0 CS/SHDN A1 Thermocouple TC3 R4 1 kΩ ISO Thermal Block C4 10 µ F R10 1 kΩ U1 R5 500 Ω U3 C5 0.1 µ F R11 1 kΩ 0.1 V R12 1 kΩ µP U4 Figure 39. Thermocouple Application Using a MUX to Scale the Input Range of the ADS7826/27/29 family +2.7V to +3.
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PACKAGE OPTION ADDENDUM www.ti.
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PACKAGE OPTION ADDENDUM www.ti.com 18-Oct-2013 LIFEBUY: TI has announced that the device will be discontinued, and a lifetime-buy period is in effect. NRND: Not recommended for new designs. Device is in production to support existing customers, but TI does not recommend using this part in a new design. PREVIEW: Device has been announced but is not in production. Samples may or may not be available. OBSOLETE: TI has discontinued the production of the device.
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PACKAGE MATERIALS INFORMATION www.ti.com 14-Mar-2013 TAPE AND REEL INFORMATION *All dimensions are nominal Device Package Package Pins Type Drawing ADS7826IDRBR SON DRB 8 SPQ Reel Reel A0 Diameter Width (mm) (mm) W1 (mm) B0 (mm) K0 (mm) P1 (mm) W Pin1 (mm) Quadrant 2500 330.0 12.4 3.3 3.3 1.1 8.0 12.0 Q2 ADS7826IDRBT SON DRB 8 250 180.0 12.4 3.3 3.3 1.1 8.0 12.0 Q2 ADS7827IDRBR SON DRB 8 2500 330.0 12.4 3.3 3.3 1.1 8.0 12.
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PACKAGE MATERIALS INFORMATION www.ti.com 14-Mar-2013 *All dimensions are nominal Device Package Type Package Drawing Pins SPQ Length (mm) Width (mm) Height (mm) ADS7826IDRBR SON DRB 8 2500 367.0 367.0 35.0 ADS7826IDRBT SON DRB 8 250 210.0 185.0 35.0 ADS7827IDRBR SON DRB 8 2500 367.0 367.0 35.0 ADS7827IDRBT SON DRB 8 250 210.0 185.0 35.0 ADS7829IBDRBR SON DRB 8 2500 367.0 367.0 35.0 ADS7829IBDRBT SON DRB 8 250 210.0 185.0 35.
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IMPORTANT NOTICE Texas Instruments Incorporated and its subsidiaries (TI) reserve the right to make corrections, enhancements, improvements and other changes to its semiconductor products and services per JESD46, latest issue, and to discontinue any product or service per JESD48, latest issue. Buyers should obtain the latest relevant information before placing orders and should verify that such information is current and complete.