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PGA308

Fault

Monitor

Front-End

GainSelect

IN1

REF

IN2

Auto-Zero

PGA

7-Bit+Sign

DAC

PGA308

16-Bit

DAC

Output

Amplifier

NOTE: (1)Ref=V orV selectable.

REF S

EXC

REF

4 10 1

OUT

GND

Input

Mux

Scale

Limit

DigitalInterface

(One-Wire)

OTP

(7Banks)

RAM

CoarseOffset

REF

16-Bit

DAC

Ref

(1)

Ref

(1)

FineOffset

OutputGain

FineGain

Output

Gain

Select

OUT

Select

3-Bit

DAC

Underscale

3-Bit

DAC

Overscale

D /V

OUT CLAMP

Bridge

Sensor

PGA308

www.ti.com

SBOS440B –JULY 2008–REVISED DECEMBER 2010

Single-Supply, Auto-Zero Sensor Amplifier

with Programmable Gain and Offset

Check for Samples: PGA308

FEATURES

DESCRIPTION

• Digital Calibration for Bridge Sensors

The PGA308 is a programmable analog sensor signal

conditioner. The analog signal path amplifies the

• Offset Select: Coarse and Fine

sensor signal and provides digital calibration for offset

• Gain Select: Coarse and Fine

and gain. Calibration is done via the 1W pin, a digital

• Bridge Fault Monitor

One-Wire, UART-compatible interface. For

• Input Mux for Lead Swap three-terminal sensor modules, 1W may be

connected to V

OUT

and the assembly programmed

• Over/Under Scale Limits

through the V

OUT

pin. Gain and offset calibration

• D

OUT

/ V

OUT

Clamp Function

parameters are stored onboard in seven banks of

• Seven Banks OTP Memory

one-time programmable (OTP) memory. The

power-on reset (POR) OTP bank may be

• One-Wire Digital UART Interface

programmed a total of four times.

• Operating Voltage: +2.7V to +5.5V

The all-analog signal path contains a 2×2 input

• Temperature Range: –40°C to +125°C

multiplexer (mux) to allow electronic sensor lead

• MSOP-10 and 3mm × 4mm DFN-10 Packages

swapping, a coarse offset adjust, an auto-zero

programmable gain instrumentation amplifier (PGA),

APPLICATIONS

a fine gain adjust, a fine offset adjust, and a

programmable gain output amplifier. Fault monitor

• Bridge Sensors

circuitry detects and signals sensor burnout,

• Remote 4-20mA Transmitters

overload, and system fault conditions.

• Strain, Load, Weigh Scales

Over/under-scale limits provide additional means for

• Automotive Sensors

system level diagnostics. The dual-use D

OUT

CLAMP

pin can be used as a programmable digital output or

EVALUATION TOOLS

as a V

OUT

over-voltage clamp.

• PGA308EVM (Hardware and Software)

For detailed application information, see the PGA308

– Calibration and Configuration

User's Guide (SBOU069) available for download at

– Sensor Emulation

www.ti.com.

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.

2All trademarks are the property of their respective owners.

PRODUCTION DATA information is current as of publication date.

Products conform to specifications per the terms of the Texas

Instruments standard warranty. Production processing does not

necessarily include testing of all parameters.

Summary of content (30 pages)

PAGE 1
PG A308 PGA308 PGA3 08 www.ti.com SBOS440B – JULY 2008 – REVISED DECEMBER 2010 Single-Supply, Auto-Zero Sensor Amplifier with Programmable Gain and Offset Check for Samples: PGA308 FEATURES DESCRIPTION • • • • • • • • • • • • The PGA308 is a programmable analog sensor signal conditioner. The analog signal path amplifies the sensor signal and provides digital calibration for offset and gain. Calibration is done via the 1W pin, a digital One-Wire, UART-compatible interface.
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PGA308 SBOS440B – JULY 2008 – REVISED DECEMBER 2010 www.ti.com This integrated circuit can be damaged by ESD. Texas Instruments recommends that all integrated circuits be handled with appropriate precautions. Failure to observe proper handling and installation procedures can cause damage. ESD damage can range from subtle performance degradation to complete device failure.
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PGA308 www.ti.com SBOS440B – JULY 2008 – REVISED DECEMBER 2010 ELECTRICAL CHARACTERISTICS Boldface limits apply over the specified temperature range, TA = –40°C to +125°C. At TA = +25°C, VS = +5V, GND = 0V, DOUT/VCLAMP = +5V, and VREF = +5V, unless otherwise noted. PGA308 PARAMETER VOUT/VIN Differential Signal Gains (1) (Front-End PGA + Output Amplifier) CONDITIONS MIN Front-End PGA gains (GF): 4, 6, 8, 12, 16, 32, 64, 100, 200, 400, 480, 600, 800, 960, 1200, 1600 Output Amplifier gains: 2, 2.4, 3, 3.
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PGA308 SBOS440B – JULY 2008 – REVISED DECEMBER 2010 www.ti.com ELECTRICAL CHARACTERISTICS (continued) Boldface limits apply over the specified temperature range, TA = –40°C to +125°C. At TA = +25°C, VS = +5V, GND = 0V, DOUT/VCLAMP = +5V, and VREF = +5V, unless otherwise noted.
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PGA308 www.ti.com SBOS440B – JULY 2008 – REVISED DECEMBER 2010 ELECTRICAL CHARACTERISTICS (continued) Boldface limits apply over the specified temperature range, TA = –40°C to +125°C. At TA = +25°C, VS = +5V, GND = 0V, DOUT/VCLAMP = +5V, and VREF = +5V, unless otherwise noted. PGA308 PARAMETER CONDITIONS MIN TYP MAX UNIT Over- and Under-Scale Limits Over-Scale Thresholds VLIM = 4V, register-selectable ratio of VLIM OS0 HL[2:0] (CFG1 register D[5:3]) = 000 0.97 0.9805 0.
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PGA308 SBOS440B – JULY 2008 – REVISED DECEMBER 2010 www.ti.com ELECTRICAL CHARACTERISTICS (continued) Boldface limits apply over the specified temperature range, TA = –40°C to +125°C. At TA = +25°C, VS = +5V, GND = 0V, DOUT/VCLAMP = +5V, and VREF = +5V, unless otherwise noted. PGA308 PARAMETER CONDITIONS MIN TYP MAX UNIT VREF Input Range 1.8 Input Resistance VS 43 V kΩ Digital Interface One-Wire Serial speed baud rate 4.8k 114k bits/s 0.
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PGA308 www.ti.
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PGA308 SBOS440B – JULY 2008 – REVISED DECEMBER 2010 www.ti.com PIN CONFIGURATIONS DGS PACKAGE MSOP-10 (TOP VIEW) DRK PACKAGE 3x4 DFN-10 (TOP VIEW) DOUT/VCLAMP 1 10 VREF 1W 2 9 VOUT GND 3 8 VFB VS 4 7 VSJ VIN1 5 6 VIN2 PGA308 DOUT/VCLAMP 1 10 VREF 1W 2 9 VOUT GND 3 8 VFB VS 4 7 VSJ VIN1 5 6 VIN2 PGA308 PIN DESCRIPTIONS PIN # 8 NAME DESCRIPTION 1 DOUT/VCLAMP Dual-use pin: Output voltage clamp limit for VOUT or programmable digital output.
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PGA308 www.ti.com SBOS440B – JULY 2008 – REVISED DECEMBER 2010 TYPICAL CHARACTERISTICS At TA = +25°C, VS = VREF = DOUT/VCLAMP = +5V, RL = 10kΩ and CL = 100pF connected to GND, unless otherwise noted. Gain format is presented: G = FE-PGA × Fine Gain × Output Gain.
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PGA308 SBOS440B – JULY 2008 – REVISED DECEMBER 2010 www.ti.com TYPICAL CHARACTERISTICS (continued) At TA = +25°C, VS = VREF = DOUT/VCLAMP = +5V, RL = 10kΩ and CL = 100pF connected to GND, unless otherwise noted. Gain format is presented: G = FE-PGA × Fine Gain × Output Gain.
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PGA308 www.ti.com SBOS440B – JULY 2008 – REVISED DECEMBER 2010 TYPICAL CHARACTERISTICS (continued) At TA = +25°C, VS = VREF = DOUT/VCLAMP = +5V, RL = 10kΩ and CL = 100pF connected to GND, unless otherwise noted. Gain format is presented: G = FE-PGA × Fine Gain × Output Gain. VOUT WITH VCLAMP LOW (1.25V) vs TEMPERATURE 4.99 1.30 4.98 1.29 4.97 1.28 VOUT with VCLAMP Low (V) VOUT with VCLAMP High (V) VOUT WITH VCLAMP HIGH (4.94V) vs TEMPERATURE 4.96 4.95 4.94 4.93 4.92 4.91 4.90 1.27 1.26 1.25 1.
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PGA308 SBOS440B – JULY 2008 – REVISED DECEMBER 2010 www.ti.com TYPICAL CHARACTERISTICS (continued) At TA = +25°C, VS = VREF = DOUT/VCLAMP = +5V, RL = 10kΩ and CL = 100pF connected to GND, unless otherwise noted. Gain format is presented: G = FE-PGA × Fine Gain × Output Gain. VCLAMP RESPONSE (CL = 10nF, CMP SEL = 0) OUTPUT VOLTAGE vs OUTPUT CURRENT VS CMP SEL = 0 (Comp Off), 2.5V VCLAMP, RL = 10kW, G = 32x1x2, 300Hz Triangle Wave VS - 0.1 50mV/div Output Voltage (V) VS - 0.2 VS - 0.3 VS - 0.4 VS = 2.
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PGA308 www.ti.com SBOS440B – JULY 2008 – REVISED DECEMBER 2010 TYPICAL CHARACTERISTICS (continued) At TA = +25°C, VS = VREF = DOUT/VCLAMP = +5V, RL = 10kΩ and CL = 100pF connected to GND, unless otherwise noted. Gain format is presented: G = FE-PGA × Fine Gain × Output Gain.
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PGA308 SBOS440B – JULY 2008 – REVISED DECEMBER 2010 www.ti.com TYPICAL CHARACTERISTICS (continued) At TA = +25°C, VS = VREF = DOUT/VCLAMP = +5V, RL = 10kΩ and CL = 100pF connected to GND, unless otherwise noted. Gain format is presented: G = FE-PGA × Fine Gain × Output Gain.
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PGA308 www.ti.com SBOS440B – JULY 2008 – REVISED DECEMBER 2010 FUNCTIONAL DESCRIPTION OVERVIEW VOLTAGE REFERENCE The PGA308 is an ideal building block for resistive bridge sensor conditioning and general data acquisition. Digitally-programmable coarse offset, fine offset, and gain may be controlled in real time or permanently programmed into the PGA308. The PGA308 VREF pin provides input from a reference voltage. The reference voltage is used by the Coarse Offset Adjust and Zero DACs.
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PGA308 SBOS440B – JULY 2008 – REVISED DECEMBER 2010 www.ti.com under-scale limit level. If over-scale/under-scale limiting is disabled, the PGA308 output voltage is driven within 100mV (IOUT < 4mA) of either VS or ground, depending on the selected fault polarity (high or low).
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PGA308 www.ti.com SBOS440B – JULY 2008 – REVISED DECEMBER 2010 Timeout on the One-Wire Interface The PGA308 includes a timeout mechanism. If synchronization between the controller and the PGA308 is lost for any reason, the timeout mechanism allows the One-Wire interface to reset communication. The timeout period is set to approximately 28ms (typical).
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PGA308 SBOS440B – JULY 2008 – REVISED DECEMBER 2010 www.ti.com OTP MEMORY BANKS PGA308 TRANSFER FUNCTION There are four one-time programmable (OTP) bank selection registers: BANK SEL1, BANK SEL2, BANK SEL3, and BANK SEL4. Bank selection may be set four times by programming the BANK SELx registers in order (1, 2, 3, 4). The default OTP bank used on POR is the location stored in the last programmed BANK SELx register.
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PGA308 www.ti.com SBOS440B – JULY 2008 – REVISED DECEMBER 2010 VS VREF VREF VS VS OTP (7 Banks) PGA308 POR Interface and Control Circuitry RAM Control Registers Alarm Register Digital Controls Input Mux Control(1) Bridge Sensor Fine Offset Adjust(1) (16-Bit) VREF Front-End PGA Out 0 < VZDAC < VREF Gain = x4 to x1600 16-Bit DAC Offset Due to Zero DAC -0.5VREF < Offset < +0.
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PGA308 SBOS440B – JULY 2008 – REVISED DECEMBER 2010 www.ti.com REVISION HISTORY NOTE: Page numbers for previous revisions may differ from page numbers in the current version. Changes from Revision A (April, 2009) to Revision B Page • Updated front page format to current standards ................................................................................................................... 1 • Added PGA Transfer Function section ....................................................................
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PACKAGE OPTION ADDENDUM www.ti.
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PACKAGE OPTION ADDENDUM www.ti.com 11-Apr-2013 Important Information and Disclaimer:The information provided on this page represents TI's knowledge and belief as of the date that it is provided. TI bases its knowledge and belief on information provided by third parties, and makes no representation or warranty as to the accuracy of such information. Efforts are underway to better integrate information from third parties.
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PACKAGE MATERIALS INFORMATION www.ti.com 19-Nov-2012 TAPE AND REEL INFORMATION *All dimensions are nominal Device Package Package Pins Type Drawing PGA308AIDGSR VSSOP DGS 10 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 5.3 3.4 1.4 8.0 12.0 Q1 PGA308AIDGST VSSOP DGS 10 250 330.0 12.4 5.3 3.4 1.4 8.0 12.0 Q1 PGA308AIDRKR VSON DRK 10 3000 330.0 12.4 3.3 4.3 1.1 8.0 12.
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PACKAGE MATERIALS INFORMATION www.ti.com 19-Nov-2012 *All dimensions are nominal Device Package Type Package Drawing Pins SPQ Length (mm) Width (mm) Height (mm) PGA308AIDGSR VSSOP DGS 10 2500 366.0 364.0 50.0 PGA308AIDGST VSSOP DGS 10 250 366.0 364.0 50.0 PGA308AIDRKR VSON DRK 10 3000 367.0 367.0 35.0 PGA308AIDRKT VSON DRK 10 250 210.0 185.0 35.
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