LTC1992CMS8#PBF Linear Technology, LTC1992CMS8#PBF Datasheet

Page 1

... Single-Ended to Differential Conversion n Level Shifting n Trimmed Phase Response for Multichannel Systems n L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. Typical applicaTion Single-Supply, Single-Ended to Differential Conversion 5V 10k ...

Page 2

... S + – +OUT 4 MS8 PACKAGE 8-LEAD PLASTIC MSOP T = 150°C, θ = 250°C/W JMAX JA orDer inForMaTion LEAD FREE FINISH TAPE AND REEL LTC1992CMS8#PBF LTC1992CMS8#TRPBF LTC1992IMS8#PBF LTC1992IMS8#TRPBF LTC1992HMS8#PBF LTC1992HMS8#TRPBF LTC1992-1CMS8#PBF LTC1992-1CMS8#TRPBF LTC1992-1IMS8#PBF LTC1992-1IMS8#TRPBF LTC1992-1HMS8#PBF LTC1992-1HMS8#TRPBF LTC1992-2CMS8#PBF LTC1992-2CMS8#TRPBF LTC1992-2IMS8#PBF LTC1992-2IMS8#TRPBF LTC1992-2HMS8#PBF LTC1992-2HMS8#TRPBF LTC1992-5CMS8#PBF ...

Page 3

T noted the voltage on the V pin. V OCM OCM defined as (+V – – defined as (+ OUTDIFF SYMBOL PARAMETER V Supply Voltage ...

Page 4

LTC1992 Family elecTrical characTerisTics temperature range, otherwise specifications are at T noted the voltage on the V pin. V OCM OCM defined as (+V – – defined as (+ OUTDIFF SYMBOL PARAMETER I ...

Page 5

T noted the voltage on the V pin. V OCM OCM defined as (+V – – defined as (+ OUTDIFF LTC1992-1 only. SYMBOL PARAMETER G ...

Page 6

LTC1992 Family elecTrical characTerisTics temperature range, otherwise specifications are at T noted the voltage on the V pin. V OCM OCM defined as (+V – – defined as (+ OUTDIFF LTC1992-5 only. SYMBOL ...

Page 7

Typical perForMance characTerisTics Supply Current vs Supply Voltage 1.0 125°C 0.9 85°C 0.8 25°C 0.7 0.6 –40°C 0.5 0.4 0.3 0.2 0 TOTAL SUPPLY VOLTAGE (V) 1992 G01 Common ...

Page 8

LTC1992 Family Typical perForMance characTerisTics Output Voltage Swing vs Output Load ±5V S 5.0 4.9 –40°C 4.8 25°C 4.7 125°C 85°C 85°C 4.6 125°C 25°C 4.5 –40°C 4 –20 –15 –10 – LOAD ...

Page 9

Typical perForMance characTerisTics Differential Input Differential Gain vs Frequency ±2. 10k –6 –12 –18 –24 – 10000pF LOAD – 5000pF LOAD – ...

Page 10

LTC1992 Family Typical perForMance characTerisTics Differential Input Large-Signal Step Response 0V 2µs/DIV Single-Ended Input Large-Signal Step Response 2.5V 2µs/DIV Differential Input Small-Signal Step Response 0V 1µs/DIV 0 Applicable to the LTC1992 only. Differential Input Large-Signal Step Response +V = 2.5V ...

Page 11

Typical perForMance characTerisTics Single-Ended Input Small-Signal Step Response 2. – 2.5V OCM + 200mV IN –V = 100mV 0pF LOAD GAIN = 1 1µs/DIV THD ...

Page 12

LTC1992 Family Typical perForMance characTerisTics Differential Input Differential Gain vs Frequency ±2. –6 –12 –18 –24 – 10000pF LOAD – 5000pF LOAD – 1000pF LOAD C = 500pF ...

Page 13

Typical perForMance characTerisTics Differential Input Large-Signal Step Response +V = 2.5V S –V = –2. OCM +V = ±1.5V IN –V = 1.5V ± 0pF LOAD 0V 2µs/DIV 1992 G46 Single-Ended Input Large-Signal ...

Page 14

LTC1992 Family Typical perForMance characTerisTics Single-Ended Input Small-Signal Step Response 2. – 2.5V OCM + 200mV IN –V = 100mV 0pF LOAD 1µs/DIV 1992 G55 ...

Page 15

Typical perForMance characTerisTics Differential Input Differential Gain vs Frequency ±2. –6 –12 –18 –24 – 10000pF LOAD – 5000pF LOAD C = 1000pF –42 LOAD C = 500pF –48 ...

Page 16

LTC1992 Family Typical perForMance characTerisTics Differential Input Large-Signal Step Response +V = 2.5V S –V = –2. OCM +V = ±750mV IN –V = 750mV ± 0pF LOAD 0V 2µs/DIV 1992 G68 Single-Ended ...

Page 17

Typical perForMance characTerisTics Single-Ended Input Small-Signal Step Response 2. – 2.5V OCM + 100mV IN –V = 50mV 0pF LOAD 2µs/DIV 1992 G77 THD + ...

Page 18

LTC1992 Family Typical perForMance characTerisTics Differential Input Differential Gain vs Frequency ±2. –6 –12 – 10000pF –24 LOAD C = 5000pF LOAD – 1000pF LOAD –36 C ...

Page 19

Typical perForMance characTerisTics Differential Input Large-Signal Step Response +V = 2.5V S –V = –2. OCM +V = ± 300mV IN –V = 300mV ± 0pF LOAD 0V 2µs/DIV 1992 G90 Single-Ended Input ...

Page 20

LTC1992 Family Typical perForMance characTerisTics Single-Ended Input Small-Signal Step Response 2. – 2.5V OCM + 40mV IN –V = 20mV 0pF LOAD 5µs/DIV 1992 G99 ...

Page 21

Typical perForMance characTerisTics Differential Input Differential Gain vs Frequency ±2. – 10000pF –20 LOAD C = 5000pF LOAD – 1000pF LOAD C = 500pF LOAD – ...

Page 22

LTC1992 Family Typical perForMance characTerisTics Differential Input Large-Signal Step Response +V = 2.5V S –V = –2. OCM +V = ±150mV IN –V = 150mV ± 0pF LOAD 0V 2µs/DIV 1992 G112 Single-Ended ...

Page 23

Typical perForMance characTerisTics Single-Ended Input Small-Signal Step Response 2. – 2.5V OCM + 20mV IN –V = 10mV 0pF LOAD 10µs/DIV 1992 G121 THD + ...

Page 24

LTC1992 Family pin FuncTions –IN, +IN (Pins 1, 8): Inverting and Noninverting Inputs of the Amplifier. For the LTC1992 part, these pins are connected directly to the amplifier’s P-channel MOSFET input devices. The fixed gain LTC1992-X parts have preci- sion, ...

Page 25

DiagraMs (1992-X) PART LTC1992-1 30k 30k LTC1992-2 30k 60k LTC1992-5 30k 150k LTC1992-10 15k 150k applicaTions inForMaTion Theory of Operation The LTC1992 family consists of five fully differential, low power amplifiers. The LTC1992 is an unconstrained ...

Page 26

LTC1992 Family applicaTions inForMaTion Op Amp – –IN LTC1992 +IN • DIFFERENTIAL INPUT • HIGH OPEN-LOOP GAIN • SINGLE-ENDED OUTPUT Op Amp with Negative Feedback – LTC1992 + GAIN = – ...

Page 27

One servo controls the signal gain path. The differential input of op amp A1 creates the summing junction of this servo. Any voltage ...

Page 28

LTC1992 Family applicaTions inForMaTion A –A V INDIFF 4AV P-PDIFF A –A DIFFERENTIAL INPUT VOLTAGE INPUT COMMON MODE VOLTAGE +V = OUT –V = OUT V OUTDIFF V AMPDIFF V AMPCM OUTCM CMRR = OUTPUT BALANCE = ...

Page 29

– Figure 4. Basic Fully Differential Amplifier Application Circuits (Note: Single-Ended to Differential Conversion is Easily ...

Page 30

LTC1992 Family applicaTions inForMaTion The V input pin has a very high input impedance and OCM is easily driven by even the weakest of sources. Many ADCs provide a voltage reference output that defines either its common mode level or ...

Page 31

Typical Performance plots for small-signal step response, large-signal step response and gain over frequency to appraise the effects of capacitive loading. While the con- sequences are minor in most instances, consider these effects when designing application circuits with ...

Page 32

LTC1992 Family applicaTions inForMaTion A 2AV –A V INDIFF V INCM 4AV P-PDIFF A 2AV –A INPUT COMMON MODE LIMITS A. CALCULATE V MINIMUM AND MAXIMUM GIVEN R INCM V = (+V INCM(MAX (–V INCM(MIN ...

Page 33

Table 1. Input Signal Limitations for Some Common Applications Differential Input Signal Mid-Supply. (V OCM V must be less than the table value) INDIFF +V –V GAIN OCM (V) (V) (V/V) (V) 2.7 ...

Page 34

LTC1992 Family applicaTions inForMaTion Table 1. Input Signal Limitations for Some Common Applications Mid-Supply Referenced Single-Ended Input Signal, V common mode limits and the output clipping) +V –V GAIN OCM (V) (V) (V/V) (V) 2 ...

Page 35

Table 1. Input Signal Limitations for Some Common Applications Single Supply Ground Referenced Single-Ended Input Signal, V both the input common mode limits and the output clipping) +V –V GAIN OCM (V) (V) (V/V) (V) ...

Page 36

LTC1992 Family applicaTions inForMaTion V INDIFF +V – – OUTDIFF WHERE • FOR GROUND REFERENCED, SINGLE-ENDED INPUT SIGNAL, LET +V V OUTDIFF • COMMON MODE REJECTION: SET +V CMRR = • OUTPUT DC OFFSET ...

Page 37

V OCM OCM OCM Figure 7. Asymmetrical Feedback Application Circuits (Most Suitable in Applications with Dual, Split Supplies (e.g., ±5V), Ground Referenced Single-Ended Input Signals and ...

Page 38

LTC1992 Family Typical applicaTions Interfacing a Bipolar, Ground Referenced, Single-Ended Signal to a Unipolar Single Supply, Differential Input ADC ( –2. Gives a Digital Mid-Scale Code) IN ...

Page 39

Typical applicaTions Single-Ended to Differential Conversion Driving an ADC 5V 47µF 0.1µF 3 100 – MID LTC1992 OCM 8 + – 100 6 0.1µF –5V 2.2µF 10µF 5V 10µF 10 ...

Page 40

LTC1992 Family package DescripTion 0.889 0.127 (.035 .005) 5.23 3.20 – 3.45 (.206) (.126 – .136) MIN 0.42 0.038 0.65 (.0165 .0015) (.0256) TYP BSC RECOMMENDED SOLDER PAD LAYOUT NOTE: 1. DIMENSIONS IN MILLIMETER/(INCH) 2. DRAWING NOT TO SCALE 3. ...

Page 41

... Updated Part Markings Information furnished by Linear Technology Corporation is believed to be accurate and reliable. However, no responsibility is assumed for its use. Linear Technology Corporation makes no representa- tion that the interconnection of its circuits as described herein will not infringe on existing patent rights. LTC1992 Family ...

Page 42

... V MID 180pF LTC1992 2 BNC V OCM 60. – V OUTM 5 6 390pF 75k 0.1µF 1992 TA05a V = 24kHz INP (1V/DIV) CLK = 25kHz (LOGIC SQUARE WAVE) (5V/DIV 1kHz OUTP (0.5V/DIV 1kHz OUTM (0.5V/DIV) LT 0710 REV A • PRINTED IN USA  LINEAR TECHNOLOGY CORPORATION 2005 1992fa ...