The Best of Analog Dialogue A Brief History | President's Message | Preface and Introduction | Table of Contents | Subject Index Subject Index
A - B - C - D - E - F - G - H - I - J - K - L - M - N - O - P - Q - R - S - T - U - V - W - X - Y - Z
A
Addressing, data, DSP	200
AGC, see Automatic gain control
ALU, see Arithmetic and logic unit
Amplifier, audio, op amp as	180
Amplifier, difference, grounding with	86
Amplifier, instrumentation	59
offset, referred to input (RTI) and output (TRO)	59
Amplifier, isolation	110
as coupling	50
applications:
electronic instrumentation	115
noise & vibration measurement	111
temperature measurement	111
circuit practice	50
guidelines	50
high-linearity	110
Model 289	110
applications	111
principle	110
synchronizable	110
three-port	110
wideband	110
shielding & guarding	50
Amplifier, logarithmic, wideband, AD640	189
analysis, simplified	191
biasing accuracy in	192
block diagram	190
implementation	191
temperature stabilization	192
theory	190
Amplifier, operational (op amp)	9, 19, 32, 48, 66, 151, 177, 185, 202
as electrometer	48
as integrator	3
common-mode rejection (CMR)	15, 16
complementary bipolar (CB) process AD840 series	177
applications	179
comparative specifications	177
J-FET input (AD845)	178
speed and accuracy	177
testing	179
transimpedance (AD846)	178
wideband, high-slew-rate (AD847)	179
wideband, fast-settling (AD840/41/42)	178
current, bias	13, 14
current, difference, initial—and test	13, 14
decoupling	194
dielectric absorption in circuits	35
distortion	11
drift	13
with time	14
equivalent circuit	9
femtoampere (10-15 A) measurements with	48
gain test	10
high speed	66
choosing	67
impedance, input	14
test circuits	15
inputs, guarding	148
loop gain	10
measurements, bandwidth and slew rate	11
noise	19, 151, 202
calculations	155
curves	29
gain	21
input	16
model	20
response, dynamic	156
source impedance	203
spectral density	29
testing	157
open-loop gain	9, 10
overload recovery	12
response	32, 66
full-power	11, 12
unity gain	11
settling time	32, 67
and voltage swing	36-38
bibliography	42
factors affecting	33, 34
measuring	39, 40
minimizing—suggestions	36, 68
pole-zero mismatch	41
specifications, limitations of	39
specifying	36
thermal effects	36
signal gain	21
slew rate	11, 12, 35, 66
specifications	9
supply voltage, sensitivity to	14
tests (see also individual parameters)	10
CMR	16
full-power response	12
overload recovery	12
slew rate	12
voltage:
between inputs, maximum	15
common-mode, maximum	15
offset, initial—and test	13, 14
Amplifier trimming	185
Amplifier, voltage-controlled, AD534 multiplier as	77
Antilogarithmic and logarithmic analog computation, with AD538 y(z/x)m, multifunction	164
Antilogarithmic circuits, in multifunction module	55
Approximating functions with DSP building blocks	160
Arctangent computation with multifunction circuit	62
Arithmetic and logic unit (ALU), floating point, ADSP-3220	168
Arithmetic functions in DSP	199
Attenuation, digitally controlled, with DACs	92
Audio measurements, dB and true-rms	81
Automatic gain control (AGC), level-independent:
as tracking ADC	130
using LOGDAC™	130
B
Bangap principle	71
Bandgap voltage reference	71
Bandwidth, noise- vs. signal	22
Board, printed-circuit:
ground circuits	195
grounding	195
layout problems, avoiding	195
magnetic effects	195
problems of, static and dynamic	147
Bridge linearization, multiplier in (AD534)	78
Bypassing	84
A - B - C - D - E - F - G - H - I - J - K - L - M - N - O - P - Q - R - S - T - U - V - W - X - Y - Z
C
Cable capacitance, in electrometer circuits	49
Calibration	185
Capacitances, system, typical	121
Capacitor:
dielectric absorption, see Dielectric absorption
dissipation factor	7, 144
in integrator circuit	6
insulation resistance	6
leakage	144
performance table	6
problems of (see also Dielectric absorption, dissipation factor, leakage):
other effects	144
parasitic effects	144
problems in assembly	145
temperature	144
tolerance	144
CEG/DAC™ antialiasing D/A converter for video graphics:
algorithm	210
color transition smoothing	210
design	211
example	212
"jaggie" elimination	210
principles	211
Circuit practice (see also Practice), interference reduction for video converters	149
Circuits, printed: rules	149
CMOS (complementary metal-oxide semiconductors) & static electricity	69
circuit protection	69, 70
D/A converters, advantages	63
SCR "latch" mechanism	69
switches	116
dielectrically isolated	116
equivalent circuit	116
in DACs (see also DACs and Converters, D/A)	64
Codec (coder-decoder)	108
Communications, serial	184
sensor information	181
Components, passive	143
avoiding pitfalls	143
bibliography	148
Computation, algebraic
converters in	94
quotients	94
Computation, analog (see also specific functions):
converters in	94
D% ratio, AD534 in	77
Conditioning, signal-	184
with 6B Series	181
Controller, current-	96
Conversion, frequency-to-voltage with AD537	75
Conversion, high speed, bibliography	109
trouble—avoiding	109
Conversion, temperature-to-frequency, V/f used in	73-75
Converter, analog-to-digital (A/D, see also ADC)	45, 73, 97, 105, 118, 181, 196
12-bit, complete IC, AD574	97
analog features	97
digital controls	97
multiplexing 8-bit bus	99
standalone conversion	99
technology	100
"flash"	107, 196
10-bit AD9020/60	197
evaluation board	198
interpolation in	196
linearity improvement	198
performance	198
principles	198
Gray code	106
input loading, buffering (see also successive approximation)	87, 180
noise effects in	204
per-channel	45-47
ranging converter using multiplying DAC	92
subranging conversion	107
digitally corrected	108
trimming	185
successive approximation, input buffering	82, 87, 88, 180
testing	118
automatic	118
linearity	119
transition finding	118
Converter applications, circuit ideas	94
Converter, digital-to-analog (D/A, DAC)	63, 82, 92, 94, 105, 130, 206, 209
AD7520	63
applications	65
circuit ideas	94
CMOS:
advantages	63
equivalent circuit	64
variable output resistance effects	84
zeroing problems	83
current output, CMOS:
application problems	82
capacitive load	82, 83
displays	210
dither, in testing A/D converters	119
glitches	33, 106
monolithic	63
multiplying	63
application ideas for	92
gain control in	92
trimming	185
Converter, frequency-to-voltage (f/V)
inverse VFC	188
phase-locked loop	188
synchronous	188
Converter, high speed, applications, specs, testing	108
Converter, ohms-to-frequency	94
Converter, resistance-to-frequency	94
Converter, temperature-to-frequency, with AD537 VFC	75
Converter, voltage-to-frequency (V/f, VFC)	73, 187
AD537 IC	73
applications	74,75
as data encoder	75
as f/V converter	75
circuit ideas	94
interfacing with resistive transducer	75
performance	74
principle	73
single supply	73
square-wave out	73
two-wire operation	75
charge-balance type	187
circuit precautions	188
errors	187
multivibrator type	187
software calibration	187
synchronous	188
trimming gain	185
trimming gain and offset	185, 187
Converters, video (see also specific types)	105, 196, 209
Convolution	135
Cosine computation with multifunction circuit	62
Crest factor (ratio of peak to rms)	22
Current controller	96
Current-loop output, 6B Series	181
A - B - C - D - E - F - G - H - I - J - K - L - M - N - O - P - Q - R - S - T - U - V - W - X - Y - Z
D
Data acquisition	45, 103, 105, 181, 196
conventional	45-47
vs. converter-per-channel	45-47
high speed	105
practice	109
video	105
Decoupling	84, 87, 120
ineffective	85
op amps	193
Delays, matching, measuring unknowns with AD9500	176
Dielectric absorption (see also Capacitor)	7, 143
and settling time	35
in electrometer circuits	49
in sample-holds	52
Dielectric isolation	116
Digital signal processor, single-chip (DSP)	171, 199
architecture	171-173
arithmetic	172, 173, 199
choice of	199
data flow	173, 199
instruction set	173, 199
program sequencing	173, 199
vs."CISC"	201
vs. "RISC"	201
arithmetic computations	171-174, 199
data addressing	172, 173, 200
program sequencing	172, 173, 200
Displays: "jaggies", eliminating using CEG/DAC™	209
Divider (analog computing, see also multifunction)	55, 58
AD534 analog multiplier, basic connections	76
with AD538 y(z/x)m, multifunction circuit	164
errors	167
Double-precision arithmetic	168
Drift (see also Offset)
integrator	3
long term, vs. 1/f noise	205
op amp, with temperature	13
E
Electrometer	48
cable capacitance effects	49
input current limits	49
noise	49
resistors for	48
using op amps	48
voltage drift	49
A - B - C - D - E - F - G - H - I - J - K - L - M - N - O - P - Q - R - S - T - U - V - W - X - Y - Z
F
Filter, analog vs digital	135
Filter, digital	135, 171
adaptive	136
basics	135
characteristics
ease of design	136
efficiency	137
memory requirements	137
phase response	136
sensitivity to coefficient error	136
stability	136
design	135
hardware	140
Remez exchange algorithm	138
roundoff error	141
simulation in software	141
multipliers in	135
non-recursive	135
references	142
terminology	142
type:
finite impulse response (FIR)	136
infinite impulse response (IIR)	136
lattice	136
Filter, FIR (finite impulse-response)	135, 136
design	135
windowing approach	137
analog time-domain, digitally programmable	93
Filter, low-pass, voltage-controlled using AD534	79
Filter, programmable digitally, using an M-DAC	93
Filter, time domain, digitally programmed (analog FIR)	93
FIR, see Filters	135
Floating-point arithmetic chips	168
pipelined operation	170
Floating point, IEEE-754, single- and double precision	169
Fourier theorem in filter design	136
Functions, approximation	60, 160
analog, see Multifunction
DSP in	160
fast and simple	160
Newton-Raphson	160
errors	162
implementation	161
preparations	161
simpler implementations	162, 163
A - B - C - D - E - F - G - H - I - J - K - L - M - N - O - P - Q - R - S - T - U - V - W - X - Y - Z
G
Gain:
adjustment	63, 76, 92, 94, 130, 189, 206
automatic, TrimDAC7™(DAC-8840/41)	206, 207
logarithmic, with LOGDAC™	130
amplifier noise gain and signal gain	21
calibration, digital	96
digitally controlled	92
programmable, for trimming	95
trimming	185
DACs in (see also Trim)	96
Gaussian distribution, noise	151
Glitch, in D/A converters	106
Graphics, video, principles in brief	210
Grounding, amplifier: difference-input	86
Grounding	82, 149, 193
current path in	195
high-frequency	193
improper	85
low-frequency	193
proper	85, 86
Ground, op-amp	193
Guarding	124, 128
op-amp inputs	148
vs. shielding	128
H
High-speed-and-accuracy signal handling	82
High-speed circuits, ground rules: layout & wiring	149
A - B - C - D - E - F - G - H - I - J - K - L - M - N - O - P - Q - R - S - T - U - V - W - X - Y - Z
I
IEEE-754 floating-point standard, arithmetic chips for	168
IIR filter (see also Filter)	136
Instrumentation, electrical, isolation amplifiers in	111
Integration-complementary monolithic processing	100
Integrator, analog	3
errors:
bandwidth	4
gain	4
high-frequency	4
impedance	4
in hold	5
low frequency	5
due to finite gain	5
feedback capacitors in	6
for ac signals	7
frequency response	8
gain, open-loop, effective	8
leakage resistance	7
test circuit	8
Interference (see also Noise, interference)	120, 124
minimizing	149
proper techniques, diagrams	84
understanding	120
Isolation, dielectric, for CMOS switches	116
Isolator (see also Amplifier, isolation)
circuit practice	50
three-port	110
J
K
L
Leakage, in capacitors	144
Linearity, A/D converters, testing	119
Linearizing:
in 6B input/output signal conditioners	184
RTD (resistance temperature detector)	184
Logarithm and antilogarithm, analog computation using multifunction devices	55
AD538 y(z/x)m multifunction	164
log ratio with	167
LOGDAC™, M-DAC with linear analog response and exponential conversion gain	130
AD711x	130
AGC application	130
A - B - C - D - E - F - G - H - I - J - K - L - M - N - O - P - Q - R - S - T - U - V - W - X - Y - Z
M
MACBASIC, language for MACSYM II	104
MACSYM II Measurement And Control SYsteM, described, features, and software	103, 104
M-DAC (multiplying D/A converter, see also Converter)	93
Meter, dB	81
Meter, true-RMS	81
Microprocessor, DSP, single-chip ADSP-2100	171, 199
Benchmarks	171
computing with	172
example of FIR filter design	174
instruction set	173
memory communications	172
system development	173
Modulator, amplitude-, AD534 as	77
Multifunction, analog computing device, y(z/x)m, (see also individual functions)	55, 60 164
AD538 IC	164
dividers compared,	57, 166
division,	57, 166
minimizes noise	58
exponents, non-integer	61, 167
logarithms	57, 167
log of voltage ratio	58, 167
model 433, module	55-58, 59, 60-62
performance characteristics	57, 165-167
principles	55, 57, 165, 166
rms computation	58
root-sum-of-squares computation	60
square root computation	57
trig functions	61, 62
vector summation	58
Multiplier, analog (see also Multifunction)	55, 60, 76, 164
AD534 IC	76
applications	77-81
as divider, basic connections	76
as multiplier, basic connections	76
AD538 y(z/x)m, multifunction as multiplier	164
laser-trimmed	76
linearized transconductance	76
multifunction circuit as	55, 164
output as voltage-to-current converter	77
translinear	76
Multiplier, digital	135, 160, 168, 171, 199
floating point ADSP-3210	168
in filter design	135
Multiplier-divider, analog (see also Multifunction)	55, 164
AD538 y(z/x)m, multifunction as	164
applications	166
characteristics	165
how it works	165
A - B - C - D - E - F - G - H - I - J - K - L - M - N - O - P - Q - R - S - T - U - V - W - X - Y - Z
N
Noise (see also Noise, interference)	19, 120, 124, 151, 202
1/f, (see also flicker)	24, 152
and drift	205
spectral density	25
amplifier	151, 154
current	27
voltage	27
bandwidth, vs. signal bandwidth	22
bibliography	31, 157, 203
capacitively coupled, dealing with	121, 124
characterization of	22
combining	154
common-impedance	121
computation example	26, 27
crest factor	22, 154
current	20
defined	19
device (also inherent; intrinsic)	22, 120, 151, 202
interference (also induced)	22, 120, 151, 202
transmitted (arriving with the signal)	120, 151
density spectrum	153
equivalent resistance	155
filter:
brick-wall	156
skirts	25, 156
flicker (see also 1/f)	23, 24, 154
Gaussian distribution in	151, 203
in devices	151
induced	151
in feedback circuits	21
inherent	22
Johnson	23, 152, 203
low frequency, measurements	204
magnetically coupled	122, 126, 127
loop effects	128
op amp	19
calculations	155
model	20
random, sources	202
peak values	22
vs. rms	204
popcorn	23, 24, 152, 204
practical considerations	30
quantitative measures	152
random	152
bibliography	157
current	202
measuring	151
understanding	151
why ÖHz?	202
references, see bibliography
relevant points	25
resistors	27
rms value	22
measurement	80
vs. peak-to-peak	204
root-sum-of-squares (RSS) summation	21
shot (or Schottky)	23, 24, 152
applicability of formula	205
source impedance	203
spectral density	34
examples	153
"pink" noise	25
plots	29
spot noise	25, 153
summation using pink noise tangent approach	26
white noise	24
testing	157
thermal	23
transmitted	151
voltage	20
white	152, 153
why be concerned	151
Noise & vibration measurement, w/ isolation amplifiers	111
Noise figure	28, 155, 203
Noise gain	204
Noise, interference (see also Noise)	19, 22, 120, 124
assumptions	120
basic principle	120
excluding	124
high-frequency, grounding	195
rational approaches	120
reduction	120, 124
bibliography	129
decoupling	194
grounding	193
sources	23, 120, 124
capacitively coupled	121
common-impedance	121
coupling—capacitive vs. magnetic	122
magnetically coupled	121
miscellaneous sources	121
possible solutions	123
power-line transients	121, 122
understanding	120
vs. "internal"	202
Noise power ratio (NPR)	108
Nonlinear effects on amplifier settling time	35
NPR, see Noise power ratio
A - B - C - D - E - F - G - H - I - J - K - L - M - N - O - P - Q - R - S - T - U - V - W - X - Y - Z
O
Offset:
adjustment, automatic, using TrimDAC™	206
input, trimming	186
integrator	3
output, trimming	186
Op amp, see Amplifier, operational
Oscillator:
programmable, using AD9500 delay generator	176
square wave, programmable, 8-bit	95
two-phase, voltage-controlled, using AD534	79
Wien-bridge, stabilized, using AD534	79
P
Potentiometers, problems of	147
Powers & roots—analog computation using AD538 y(z/x)m, multifunction	164
Power supply interference, bypassing	82
Power supply, linear vs switching	109
Practice, circuit:
bibliography	148
general	149
grounding	150
high speed	109
power supplies	150
using ICs	150
what to overlook (nothing!)	148
Printed-circuit boards, problems of:
dynamic	147
rules	149
static	147
Processing, signal-, digital, see DSP	171, 199
PTAT (proportional to absolute temperature)	71, 89, 192
Q
A - B - C - D - E - F - G - H - I - J - K - L - M - N - O - P - Q - R - S - T - U - V - W - X - Y - Z
R
R-2R ladder, in DAC	64
Reference, voltage	71
AD580	71
bandgap circuits	71, 72
IC	71
Zener	71
synthetic	71
Remez exchange algorithm in digital filter design	138
Request-to-send (RTS), in serial communication with 6B Series	183
Resistors	143
electrometer applications	48
problems of	145, 146
aging	146
excess noise	146
failures	146
parasitic effects	146
self-heating	145
temperature effects	145
thermoelectric effects	146
voltage effects	146
variable, vs. TrimDAC™	208
RMS, see Root mean-square
Roots and powers in analog computations using the AD538 y(z/x)m multifunction device	164
Root mean-square (RMS)	22, 78, 80, 81
and peak	22
decibel (dB) output	80, 81
measurement	80
multifunction device in	58
wideband, high-crest-factor, with AD534	78
-to-dB meter	81
-to-dc converter, monolithic, AD536	80, 81
applications	81
principle	81
vs. ac average	22
Root sum-of-squares (RSS)	21
computation with multifunction circuit	60
RTD (resistance temperature detector) to serial output, using 6B Series	181
RTS (request-to-send) in serial communications with the 6B Series	183
A - B - C - D - E - F - G - H - I - J - K - L - M - N - O - P - Q - R - S - T - U - V - W - X - Y - Z
S
Sample-hold (also track-hold)	51, 105
applications	53, 54
characteristics	51
design examples	52, 53
errors	51
hold mode
dielectric absorption	52
droop	52
feedthrough	52
hold-to-sample
acquisition time	52
hold-to-sample transients	52
sample mode
nonlinearity	51
sample mode offset	51
sample mode scale-factor error	51
sample mode settling time	52
sample-to-hold
aperture time	52
sample-to-hold offset	52
sample-to-hold settling time	52
sample-to-hold switching transients	52
uses	51
Sensor:
serial input/output (VO) using the 6B Series	181
-to-serial with the 6B Series	182
gain & rangmg	182
gate array	182
isolation	182
microcontrol	182
reference calibration	182
serial commumcations	183
temperature compensation	182
Sequencing, program-, in DSP	200
Serial input/output, sensors for usmg the 6B Series	181
Settling time	32
bibliography	42
definition	32, 33
long tails	36
measuring	39, 40
minimizing in op-amp circuit	36
pole-zero mismatch effects	41
sample-holds	52
specifications, limitations of	39
specifying	36
"specsmanship"	33
thermal effects	36
Shield:
driven	128
electrostatic	124-126
proper connection	125
mumetal	127
Shielding	124
attenuation, various materials	127
considerations, compared	129
effect vs. thickness	127
shielding, twisted pairs	127
vs. guarding	128
Signals:
analog to serial	183
analog transmission using VFC	187
handling for high speed and accuracy	82
Sine:
approximation using the AD534	78
multifunction-circuit approximation	61
Square root, multiplier as, using the AD534	79
Squares, difference of, using the AD534	78
Switches, analog, CMOS	116
dielectrically isolated	116
equivalent circuit	116
in DACs	64
in op amp circuits	117
RON vs VD(VS)	117
Systems, conversion, high-speed—practice	109
A - B - C - D - E - F - G - H - I - J - K - L - M - N - O - P - Q - R - S - T - U - V - W - X - Y - Z
T
Tan-l, using multifunction circuits	62
Temperature measurement	89
difference, using the AD590	91
isolation amplifiers in	111
multiplexing, with AD590 matrix	91
Testing, automatic	115, 118
A/D converters, using LTS-2000 family	118
linearity of A/D converters	119
Test system, automatic, for components, LTS-2000 family	115
Thermocouple to serial digital output, using 6B Series	181
Time delay, programmable, using the AD9500 IC	175
applications	176
how it works	175
Time, settling-, of op amps, see Settling time
Track-hold, see also Sample-hold	51
Transducer, absolute-temperature-to-current, AD590, 1 µA/K	89
accuracy	90
applications	91
ease of application	89
principle	89, 90
trimming	90
Transients, power line	122
Transition-finding in automatic A/D converter testing	105
TrimDAC™ vs. variable resistors	208
Trimming, automatic, TrimDAC™	206
Trimming: circuits, gain, and offsets	185, 186
A - B - C - D - E - F - G - H - I - J - K - L - M - N - O - P - Q - R - S - T - U - V - W - X - Y - Z
U
V
VFC, see Converter, voltage-to-frequency
VGA graphics, improvement with CEG/DAC™	209
Video converters	105
Video line driver, op amp as	180
Voltage offset, programmable	96
W
X
Y
Z
A - B - C - D - E - F - G - H - I - J - K - L - M - N - O - P - Q - R - S - T - U - V - W - X - Y - Z