Datasheet

ManualsBrandsTEXAS INSTRUMENTS ManualsLinear ICsLinear IC - In-amp, Op-amp InAmp PDIP 14

PGA202/203

Covered by U.S. PATENT #4,883,422

PGA202/203

FEATURES

● DIGITALLY PROGRAMMABLE GAINS:

DECADE MODEL—PGA202

GAINS OF 1, 10, 100, 1000

BINARY MODEL—PGA203

GAINS OF 1, 2, 4, 8

● LOW BIAS CURRENT: 50pA max

● FAST SETTLING: 2

µs to 0.01%

● LOW NON-LINEARITY: 0.012% max

● HIGH CMRR: 80dB min

● NEW TRANSCONDUCTANCE CIRCUITRY

● LOW COST

DESCRIPTION

The PGA202 is a monolithic instrumentation ampli-

fier with digitally controlled gains of 1, 10, 100, and

1000. The PGA203 provides gains of 1, 2, 4, and 8.

Both have TTL or CMOS-compatible inputs for easy

microprocessor interface. Both have FET inputs and a

new transconductance circuitry that keeps the band-

width nearly constant with gain. Gain and offsets are

laser trimmed to allow use without any external com-

ponents. Both amplifiers are available in ceramic or

plastic packages. The ceramic package is specified

over the full industrial temperature range while the

plastic package covers the commercial range.

International Airport Industrial Park • Mailing Address: PO Box 11400 • Tucson, AZ 85734 • Street Address: 6730 S. Tucson Blvd. • Tucson, AZ 85706

Tel: (520) 746-1111 • Twx: 910-952-1111 • Cable: BBRCORP • Telex: 066-6491 • FAX: (520) 889-1510 • Immediate Product Info: (800) 548-6132

APPLICATIONS

● DATA ACQUISITION SYSTEMS

● AUTO-RANGING CIRCUITS

● DYNAMIC RANGE EXPANSION

● REMOTE INSTRUMENTATION

● TEST EQUIPMENT

Digitally Controlled Programmable-Gain

INSTRUMENTATION AMPLIFIER

Front

End

and

Logic

Circuits

114

Filter B

–

Adjust

Digital Common

Sense

OUT

REF

5.3pF*

30k *Ω

*±20%

30k *Ω

Filter A

SBOS002

Summary of content (11 pages)

PAGE 1
® PGA202/203 Digitally Controlled Programmable-Gain INSTRUMENTATION AMPLIFIER FEATURES APPLICATIONS ● DIGITALLY PROGRAMMABLE GAINS: DECADE MODEL—PGA202 GAINS OF 1, 10, 100, 1000 BINARY MODEL—PGA203 GAINS OF 1, 2, 4, 8 ● LOW BIAS CURRENT: 50pA max ● FAST SETTLING: 2µs to 0.01% ● LOW NON-LINEARITY: 0.
PAGE 2
SPECIFICATIONS ELECTRICAL At +25°C, VCC = ±15V unless otherwise noted. PGA202/203AG (1) PARAMETER CONDITION GAIN Error (2) MIN G < 1000 G = 1000 G < 1000 G = 1000 G < 100 G = 100 G = 1000 Nonlinearity Gain vs Temperature RATED OUTPUT Voltage Over Specified Temperature Current Impedance |IOUT | ≤ 5mA See Typical Perf. Curve |VOUT | ≤ 10V ANALOG INPUTS Common-Mode Range Absolute Max Voltage (3) Impedance, Differential Common-Mode No Damage ±10 ±5 ±10 MAX 0.05 0.1 0.002 0.02 3 40 100 0.25 1 0.
PAGE 3
PIN CONFIGURATION ABSOLUTE MAXIMUM RATINGS Top View DIP A0 1 14 Digital Common A1 2 13 –VCC +VCC 3 12 V OUT VREF 4 11 V OUT Sense Filter A 5 10 Filter B VOS Adjust 6 9 VOS Adjust –V IN 7 8 +V IN Supply Voltage ................................................................................... ±18V Internal Power Dissipation ............................................................. 750mW Analog and Digital Inputs .....................................................
PAGE 4
TYPICAL PERFORMANCE CURVES TA = +25°C, VS = ±15V unless otherwise noted.
PAGE 5
TYPICAL PERFORMANCE CURVES (CONT) TA = +25°C, VS = ±15V unless otherwise noted.
PAGE 6
TYPICAL PERFORMANCE CURVES (CONT) TA = +25°C, VS = ±15V unless otherwise noted.
PAGE 7
TYPICAL PERFORMANCE CURVES (CONT) DIN TA = +25°C, VCC = ±15V unless otherwise noted. 1 2 14 8 + SMALL SIGNAL RESPONSE 11 VIN PGA202 7 12 VOUT 4 – 13 5mV/Div 3 RL G = 10 +VCC –VCC 1µs/Div FIGURE 1. Basic Circuit Connections. DISCUSSION OF PERFORMANCE OFFSET ADJUSTMENT Figure 2 shows the offset adjustment circuits for the PGA202/ 203. The input offset and the output offset are both separately adjustable.
PAGE 8
OUTPUT SENSE An output sense has been provided to allow greater accuracy in connecting the load. By attaching this feedback point to the load at the load site, IR drops due to the load currents are eliminated since they are inside the feedback loop. Proper connection is shown in Figure 1. When more current is required, a power booster can be placed in the feedback loop as shown in Figure 4. Buffer errors are minimized by the loop gain of the output amplifier.
PAGE 9
INPUT CHARACTERISTICS Because the PGA202/203 have FET inputs, the bias currents drawn through input source resistors have a negligible effect on DC accuracy. The picoamp currents produce no more than microvolts through megohm sources. The inputs are also internally diode clamped to the supplies. Thus, input filtering and input series protection are easily achievable.
PAGE 10
8 14 8 + 11 12 PGA203 7 + VIN 11 12 PGA202 7 VOUT 4 – 2 1 4 – A0 2 VOUT 1 A1 1MΩ 1 8 2 + 11 12 PGA202 Gain Control 7 4 – VOUT = 2G VIN FIGURE 9. Floating Source Programmable Gain Instrumentation Amplifier. FIGURE 11. Programmable Differential In/Differential Out Amplifier. + OPA27 – +VCC 10k Ω VIN 200 Ω 14 8 + 11 12 PGA203 10k Ω 7 8 + VOUT 11 7 4 – 2 10kΩ 2 1 R 12 PGA203 4 – 14 1 – R OPA27 + IOUT Gain Control Gain Control RL FIGURE 10.
PAGE 11
IMPORTANT NOTICE Texas Instruments and its subsidiaries (TI) reserve the right to make changes to their products or to discontinue any product or service without notice, and advise customers to obtain the latest version of relevant information to verify, before placing orders, that information being relied on is current and complete.