Texas Instruments: Handbook of Operational Amplifier Applications

The handbook is SBOA092B on ti.com. That is 72 circuits from its circuit collection (pages 49 to 91) plus the fully clamped comparator of Figure 54. Each one is an example folder of its own; this folder groups them and is not itself an example.

73 circuits, 339 claims, every one holding in simulation. About a third of the pages print something the drawn circuit does not do, and each of those is written down in the circuit’s README under “Where the handbook is off”.

How a circuit is written

Each program says three things:

• The circuit. It is drawn with the parts in handbook.py: an op amp, terminals, the ground, diodes, potentiometers, switches, meters and cells.
• The claims. These are parameters of the system, tied to the parts by constraints, so fang check fails the moment a value and its claim disagree.
• What the program had to decide. Many figures are symbolic, and some are ambiguous or misprinted. Each such decision is recorded as a Chooses with the alternatives it rejected, and the handbook’s printed claim is quoted as a Cites.

The page is the citation. The simulation is the arbiter.

How it is simulated

A program declares a BENCH. Its runs are what examples/regenerate.py runs when it writes the example’s out/. Each run:

1. Compiles a plan and lowers the snapshot to SPICE with fang.simulation. fang writes the resistors, capacitors, inductors and cells itself, and names every other part as abstracted, which puts it in the plan’s assumptions.
2. Adds a card for each abstracted part: the op amp’s macro-model (one pole, clamped swing, offset), a 1N4148 or a zener, a potentiometer’s two halves, a switch. It also adds the drive the figure implies but does not draw. Node numbers come from spice_nodes, the function the deck was written with.
3. Runs ngspice across a process boundary and reads its measurements.
4. Checks each measurement against a claim. Where a claim names a system parameter, the value is read from the snapshot, so the number checked is the one the graph holds.

What each circuit’s out/ adds to the usual files:

File	What it is
views/interconnect.svg	fang’s interconnect view, with the parts named as the program names them
spice/<run>.cir	The deck ngspice ran: fang’s lowering, then the bench’s cards
simulation.txt	Each measurement against its claim, and what the plan abstracted

The default op amp is close to ideal: 120 dB of gain, 10 MHz of gain-bandwidth, ±13.5 V of swing and no offset. The handbook’s algebra is therefore what a run measures, and where a real limit is the point of the circuit it shows up. Examples are the differentiator’s peaking, the chopper’s offset, and the power booster’s two parts. A circuit whose point depends on a real part sets that part’s numbers and records where they came from.

tests/test_handbook.py fails if any committed simulation.txt reports a claim that does not hold. tests/test_examples.py rebuilds every out/ and compares it, so a committed result cannot drift from its program.

How it is drawn

Each circuit’s schematic is drawn by copperhead’s drafting engine, not by fang, and sits in figure/ beside out/:

File	What it is
figure/schematic.intent.json	The circuit’s netlist, with each part given the KiCad symbol that draws it
figure/<name>.kicad_sch	The sheet copperhead drew from it
figure/schematic.svg	KiCad’s render of that sheet, shown in the circuit’s README

draw_figures.py writes all three. The intent is fang’s own, from fang.copperhead.compile_intent, the lowering fang schematic --drafter copperhead runs, so the same program drafted from the command line gets the same symbols on the same pins. That lowering picks each part’s KiCad symbol: an op amp is KiCad’s generic Simulation_SPICE:OPAMP and a diode is drawn with its cathode on the symbol’s pin 1. draw_figures.py passes it only the labelling a figure asks for (OPTIONS in it): the ground net named GND, each terminal labelled with its name in the program and its net named after it, values printed short (10k), and a fixed date. It hands copperhead the result and writes the sheet only if KiCad reads back from it exactly the connections the circuit has. Copperhead is not a dependency of fang, so draw_figures.py is not part of regenerate.py; it needs a copperhead checkout (COPPERHEAD_DIR) and kicad-cli. The drawings here come from copperhead at acf53d8 on fix/draft-handbook-legibility, with that branch’s uncommitted edits to the drafting engine, which draw an inverting stage the way a textbook does. tests/test_handbook.py fails if the lowering, run on a circuit’s program today, no longer writes byte for byte the intent its drawing was made from.

The circuits

Section	Circuit	Page	Claims	Handbook off?
Comparators	clamped_comparator	47	7	threshold ratio inverted; clamps ignore the diode drop
Buffers	voltage_follower	49	3
	inverting_buffer_adjustable_gain	50	3
	balanced_output	50	7	“4E_I p-p” holds only with E_I as a peak
References	isolated_standard_cell	51	3
	constant_current_generator	51	5	op amp inputs drawn swapped; R1 formula; “R_L min” is a maximum
	buffer_variation	52	3
	presettable_voltage_source	52	5
	reference_voltage_supply	52	3
Basic amplifiers	noninverting_amplifier	53	2
	inverting_amplifier	54	2
Integrators	integrator	55	4
	simple_integrator	56	2
	zeroed_integrator	56	6	C_O printed as 1 mF
	regenerative_integrator	57	3
	summing_integrator	58	2
	double_integrator	58	7	drawn values break the page’s rule: -50, not -4
	differential_integrator	59	2	E_I for E_1 in the formula
	ac_integrator	59	8
	augmenting_integrator	60	2	integral term is 10x, not 1x
Differentiators	differentiator	61	4
	differentiator_with_stop	61	5	corners printed 0.6 kHz / 16 kHz; they are 1.59 kHz / 15.9 Hz
	low_noise_differentiator	62	4
	augmented_differentiator	62	5
Summers	voltage_summer	63	7
	adder	64	5
	scaling_adder	64	7	a stray leading -100
	direct_addition	65	6
	averager	65	4
	weighted_average	66	5	5.45 truncated to 5.4; the output is -E_I, not E_I
Differential input	differential_input_amplifier	67	4
	adder_subtractor	68	6
	balanced_output_amplifier	69	3
DC amplifiers	simple_inverting	70	3	bias resistor named, not drawn
	chopper_stabilized	70	3
	simple_gain_control	70	10
	linear_gain_control	71	7
	simple_non_inverting	71	5
	power_booster	72	8
	differential_output	73	3	a difference amp, not a floating-load driver
	gain_control	73	5
	inverting_gain_control	73	11
Differential amplifiers	subtractor	74	3
	difference_amplifier	74	3
	common_mode_rejection	75	6	as drawn no trim can null it; read R1 as 10 kΩ
	differential_input_output	75	3
AC amplifiers	simple_ac_amplifier	76	4
	single_supply	76	6
	ac_non_inverting	77	6	the printed corner is not the one that dominates
	double_rolloff	77	5	drawn values break C1R1 = C2R2: +9.3 dB peak
	ac_preamplifier	78	6	gain is 509 to 546, not 500; corner 0.8 Hz, not 1.6
Current output	feedback_loop	79	7
	simple_meter_amplifier	79	2
	meter_amplifier	80	2	a two-diode bridge reads 0.45 E_rms, not 0.9
	current_injector	80	3	I = -E_I/R2, not -E_I/R_L
	linear_current_source	81	5
	deflection_coil_driver	82	3	-100.1 mA/V: the load also carries E_I/R1
Oscillators	simple_oscillator	83	3
	wien_bridge_oscillator	83	8	the lamp regulates only near 55 V peak
Lead and lag	lag_element	84	3	drawn R_O/R_I is 0.01, not 10
	adjustable_lag	84	8
	linear_lag	85	4
	adjustable_lead	85	5	formula drops the 1
	lead_lag	86	4	formula drops the minus sign
	time_delay	86	4
Additional	absolute_value	87	9	as drawn the op amp saturates
	peak_follower	87	4	holds a diode drop below the peak
	precision_rectifier	88	4
	ac_to_dc_converter	88	2
	full_wave_rectifier	89	6	as drawn it gives -|E_I|
	rate_limiter	89	4	7.27 V/s, not 7.5: a diode drop
	time_delay_relay	90	5	delay formula runs about 5% long
	selective_amplifier	91	3	965 Hz, not 1000; gain 31.3, not 33

The handbook’s theory chapters draw more figures (Figures 10 to 53). Most are the same circuits with symbolic parts, used to explain Bode plots and stability, and so they are not repeated here. Figure 54 is the one with a full set of values, and it is the comparator above.

Running it

fang check examples/ti_opamp_handbook/summers/scaling_adder/scaling_adder.py
python examples/regenerate.py ti_opamp_handbook/summers/scaling_adder   # needs ngspice
python examples/draw_figures.py scaling_adder                             # needs copperhead and kicad-cli
python -m pytest tests/test_handbook.py

In this folder

• voltage_follower: SBOA092B page 49, The Voltage Follower: EI on the non-inverting input, the output wired straight back to the inverting input.
• gain_control: SBOA092B page 73, Gain Control: EI on the + input, a 10 kΩ potentiometer from the output to ground, and its wiper on the - input.
• buffer_variation: SBOA092B page 52, Buffer Variation: the cell Eref in the feedback path, between the output and the inverting input, with the non-inverting input on ground. The op amp is a TLC265x, a chopper-stabilized part.
• simple_gain_control: SBOA092B pages 70 and 71, Simple Gain Control: one 10 kΩ potentiometer with one end at EI, the other at EO, and its wiper on the inverting input; the non-inverting input on ground. The page says: “Wide range gain or attenuation. Unity gain with R centered. The gain is not linear with potentiometer setting. Zin drops as gain is increased.”
• simple_non_inverting: SBOA092B page 71, Simple Non-Inverting: EI on the + input, RO 90 kΩ from the output to the - input and RI 10 kΩ from there to ground.
• inverting_amplifier: SBOA092B page 54, The Inverting Amplifier: EI through RI into the summing point, RO from the output back to it, and the non-inverting input on ground.
• feedback_loop: SBOA092B page 79, Feedback Loop: EI through R1 (1 kΩ) into the summing point, and the load RL from there to the output, where an inverting amplifier’s feedback resistor would be. The + input is on ground.
• integrator: SBOA092B page 55, Integrators: the inverting amplifier with a capacitor in place of its feedback resistor. EI through RI into the summing point, CO from the output back to it.
• chopper_stabilized: SBOA092B page 70, Chopper Stabilized: the simple inverting amplifier above it (RI = 1 kΩ, RO = 100 kΩ, + input on ground) with the op amp named, a TLC265x chopper-stabilized part. The page claims only “improved drift and stability”.
• simple_inverting: SBOA092B page 70, Simple Inverting sign changing amplifier: the inverting amplifier with values. RI = 1 kΩ in, RO = 100 kΩ across, the + input on ground.
• linear_gain_control: SBOA092B page 71, Linear Gain Control: an inverting amplifier with RI 10 kΩ in and a 100 kΩ potentiometer wired as a rheostat across it, its wiper tied to the end at the output.
• isolated_standard_cell: SBOA092B page 51, Isolated Standard Cell: a standard cell Eref on the non-inverting input of a follower. The text’s point is that a low-impedance meter (it names 20 kΩ per volt) can then read the cell without drawing current from it.
• differentiator: SBOA092B page 61, Differentiators (also Figure 43 on page 38): EI through CI into the summing point, RO from the output back to it, and the non-inverting input on ground.
• linear_lag: SBOA092B page 85, Lag value linear with R setting: a voltage follower whose + input sits on an RC low-pass, EI through a 10 kΩ pot wired as a rheostat and C = 10 µF to ground.
• simple_ac_amplifier: SBOA092B page 76, Simple Amplifier: EI through CI 1 µF and RI 10 kΩ into the summing point, RO 100 kΩ from the output back to it, and the + input on ground.
• peak_follower: SBOA092B page 87, Peak Follower: EI through a diode onto a 1 µF capacitor, a switch across the capacitor to clear it, and a voltage follower reading it.
• augmenting_integrator: SBOA092B pages 59 and 60, Augmenting Integrator: EI through RI (10 kΩ) into the summing point, with RO (100 kΩ) in series with CO (10 µF) as the feedback. “Sums the input signal and its time integral.”
• simple_integrator: SBOA092B page 56, Simple Integrators (the first figure): EI through RI (100 kΩ) into the summing point, CO (1 µF) from the output back to it, and a switch across CO. “Close switch to reset to zero.”
• noninverting_amplifier: SBOA092B page 53, The Non-Inverting Amplifier: EI on the non-inverting input, RO from the output to the inverting input and RI from there to ground.
• lag_element: SBOA092B page 84, Lag Element: an inverting amplifier with CO across RO. The figure draws RI = 1 MΩ, RO = 10 kΩ and CO = 10 µF.
• adjustable_lead: SBOA092B page 85, Adjustable Lead: R = 10 kΩ in, and a 10 kΩ pot from the summing point to the output with its wiper through C = 10 µF to ground. It is the adjustable lag’s input network moved into the feedback path.
• inverting_gain_control: SBOA092B page 73, Inverting Gain Control: RI 10 kΩ into the summing point, RO 10 kΩ from there to the wiper of R2, a 10 kΩ pot from the output to ground. A T network in the feedback.
• adjustable_lag: SBOA092B page 84, Adjustable Lag: a 10 kΩ pot from EI to the summing point with its wiper through C = 10 µF to ground, and RO = 10 kΩ across.
• differentiator_with_stop: SBOA092B page 61, With “Stop”: the differentiator with a 1 kΩ RI in series with its 0.1 µF CI, and 100 kΩ RO from the output back to the summing point.
• absolute_value: SBOA092B page 87, Absolute Value: two 10 kΩ resistors, two diodes and one op amp, a follower for +EI and an inverter for -EI.
• deflection_coil_driver: SBOA092B page 82, Deflection Coil Driver: an inverting amplifier (R1 and R0, 10 kΩ each) whose feedback is taken from the top of R3 (10 Ω), with the floating load between the output and R3.
• presettable_voltage_source: SBOA092B page 52, Presettable Voltage Source: the cell Eref from the node RI and RO share to the inverting input, RO (a decade box) on to the output, RI to ground, and the non-inverting input on ground. The op amp is a TLC265x.
• differential_integrator: SBOA092B page 59, Differential Integrator: E1 through RI (100 kΩ) to the - input with CO (1 µF) to the output, and E2 through a second RI to the + input with a second CO to ground. The figure names a TLC265x.
• inverting_buffer_adjustable_gain: SBOA092B page 50, Inverting Buffer Adjustable Gain: EI through RI (10 kΩ), a 100 Ω potentiometer and RO (10 kΩ) in a row to the output, with the pot’s wiper on the inverting input.
• current_injector: SBOA092B page 80, Current Injector: a Howland current source. EI through R1 into the - input, R0 from the output back to it; R3 from the output to the + input, R2 from there to ground, and the load RL from there to ground. All four resistors are 1 kΩ.
• differential_output: SBOA092B page 73, Differential Output: EI between two input terminals, one through RI 10 kΩ to the - input with RO 100 kΩ back from the output, the other through RI 10 kΩ to the + input with RO 100 kΩ from there to ground. EO is taken from the output to ground.
• differential_input_amplifier: SBOA092B page 67, The Differential Input Amplifier: E1 through R1 into the inverting input with RO back from the output, and E2 through the divider R2 over R3 into the non-inverting input.
• augmented_differentiator: SBOA092B page 62, Augmented Differentiator: 0.1 µF CI and 100 kΩ RI side by side from EI to the inverting input, 100 kΩ RO back from the output, and 50 kΩ R2 from the non-inverting input to ground.
• precision_rectifier: SBOA092B page 88, Precision Rectifier: an inverting amplifier with RI (2 kΩ) in and two feedback paths, each an RO (10 kΩ) behind a diode. EO is taken from the upper path, between its RO and its diode.
• difference_amplifier: SBOA092B page 74, Difference Amplifier: the subtractor with gain. RI = 1 kΩ and RO = 100 kΩ in both legs; E1 into the inverting input, E2 divided by RI over RO onto the non-inverting input.
• subtractor: SBOA092B page 74, Subtractor: the differential input amplifier of page 67 with every resistor 10 kΩ. E1 goes through RI into the inverting input with RO back from the output; E2 is divided by RI over RO onto the non-inverting input.
• low_noise_differentiator: SBOA092B page 62, Low Noise: the differentiator with stop (1 kΩ RI and 0.1 µF CI in series, 100 kΩ RO) with a 0.001 µF CO across RO.
• lead_lag: SBOA092B page 86, Lead-Lag: the adjustable lag’s input network and the adjustable lead’s feedback network around one op amp. Two 10 kΩ pots, each with its wiper through 10 µF to ground: D2 and C2 at the input, D1 and C1 in the feedback.
• ac_non_inverting: SBOA092B page 77, Non-Inverting: EI through C2 1 µF onto the + input, R2 100 kΩ from there to ground; R0 90 kΩ from the output to the - input, and R1 10 kΩ in series with C1 100 µF from there to ground.
• double_rolloff: SBOA092B page 77, Double Rolloff: EI through C2 1 µF onto the + input; R0 90 kΩ from the output to the - input; C1 100 µF from the - input down to a junction, R1 10 kΩ from the junction to ground, and R2 100 kΩ from the + input to the same junction, so that R2 is bootstrapped.
• ac_integrator: SBOA092B page 59, AC Integrator: EI through RI (100 kΩ) to the - input, CO (0.01 µF) and a reset switch to the output. The op amp is drawn with two outputs. The one at the top is EO. The bubbled one at the bottom drives R2 (100 kΩ) to the + input, with CI (100 µF) from there to ground. “Integrates AC component only.” There is no formula.
• averager: SBOA092B page 65, Averager: E1, E2 and E3 each through 30 kΩ into the summing point, 10 kΩ from the output back to it.
• voltage_summer: SBOA092B page 63, The Voltage Summer: E1, E2 and E3 each through its own resistor into the summing point, RO from the output back to it, and the non-inverting input on ground.
• balanced_output_amplifier: SBOA092B page 69, The Differential (Balanced) Output Amplifier: an op amp with two outputs. E1 goes through RI into the inverting input with RO to the top output; E2 goes through RI into the non-inverting input with RO to the bottom output. The handbook calls the bottom output EP and the top one EO + EP, so EO is the difference between the two.
• adder: SBOA092B page 64, Adder: E1, E2 and E3 each through 10 kΩ into the summing point, 10 kΩ from the output back to it, and the non-inverting input on ground.
• scaling_adder: SBOA092B page 64, Scaling Adder: E1, E2 and E3 through 1, 10 and 100 kΩ into the summing point, 100 kΩ R0 back from the output.
• differential_input_output: SBOA092B page 75, Differential Input-Output: the balanced output amplifier of page 69 with values. RI = 1 kΩ and RO = 10 kΩ in both legs; E1 into the inverting input with RO to the top output, E2 into the non-inverting input with RO to the bottom output. The page says only “for use in driving floating loads. Input may be floating source.” The gain is page 69’s:
• summing_integrator: SBOA092B page 58, Summing Integrator: E1, E2 and E3 each through 100 kΩ into one summing point, CO (1 µF) across the op amp, and a reset switch across CO.
• constant_current_generator: SBOA092B page 51, Constant Current Generator: R1 (330 Ω) from +15 V to a 6 V zener, R2 (300 Ω) from the zener to the op amp’s summing point, and the load RL from there to the output.
• simple_meter_amplifier: SBOA092B page 79, Simple Meter Amplifier: EI through RI (10 kΩ) into the summing point, and a bridge from the output back to it: two diodes on the summing-point side, a 4.7 kΩ RO on each of the other two, and the meter in series with a third RO across the middle.
• direct_addition: SBOA092B page 65, Direct Addition: E1 and E2 each through a 10 kΩ R2 onto the non-inverting input, a third 10 kΩ R2 from there to ground, and a non-inverting gain set by 10 kΩ R1 from the inverting input to ground and 20 kΩ R0 back from the output.
• double_integrator: SBOA092B page 58, Double Integrator: two T networks and one op amp (a TLC265x). The input T is RI, RI (1 MΩ each) with CI (1 µF) from their junction to ground. The feedback T is CO, CO (1 µF each) with RO (10 kΩ) from their junction to ground.
• simple_oscillator: SBOA092B page 83, Simple Oscillator: two T networks in parallel from the output back to the - input, R, R with 2C to ground between them, and C, C with R/2 to ground between them. The op amp runs open loop through them.
• single_supply: SBOA092B page 76, Single Supply: the simple a.c. amplifier above it, with the + input held at half the supply by R2 10 kΩ and R2’ 10 kΩ and bypassed by C2 100 µF. “Equivalent to above, with the supply ‘floated’ above ground.”
• balanced_output: SBOA092B page 50, Balanced Output: two unity-gain inverters (10 kΩ / 10 kΩ each) in cascade. The first one’s output is the terminal labelled EO+, the second one’s is EO-.
• weighted_average: SBOA092B page 66, Weighted Average: E1, E2 and E3 through 10, 20 and 30 kΩ into the summing point, and back from the output 5.1 kΩ RO in series with a 1 kΩ pot RO’ wired as a rheostat.
• adder_subtractor: SBOA092B page 68, Adder-Subtractor or Floating Input Combiner: E1 and E2 each through a 10 kΩ R into the inverting input with a third R back from the output, and E3 and E4 each through a 10 kΩ RI into the non-inverting input with a third RI from there to ground.
• reference_voltage_supply: SBOA092B page 52, Reference Voltage Supply: the cell Eref through R1 (10 kΩ) into an inverter with R0 (100 kΩ) across it, whose output is -EO; R3 and R2 (10 kΩ each) make a second, unity-gain inverter whose output is +EO; and R4 (90 kΩ) runs from +EO back to the cell’s + terminal.
• zeroed_integrator: SBOA092B page 56, Simple Integrators (the second figure). This is the integrator above it, R1 100 kΩ into the summing point with CO and a reset switch, plus a trimmed current into the summing point. The + and - terminals feed the ends of the pot R3 through R2 and R4 (10 kΩ each), and the wiper reaches the summing point through R5 (10 MΩ). “With zero input and switch open, set R3 for zero output drift.”
• linear_current_source: SBOA092B page 81, Linear Current Source, and its Table 2. The first op amp sums EI (through R1) and the load voltage (through the upper R2) against R0, with CO across R0; the second inverts its output; R3 runs from the second output into the load.
• full_wave_rectifier: SBOA092B page 89, Full Wave Rectifier: a precision half-wave rectifier (R4, R3, R5, all 1 kΩ, and two diodes) followed by a summer that adds EI through R1 (2 kΩ) and the half-wave through R2 (1 kΩ) into RO (2 kΩ). The page prints no formula, only “Precision absolute value circuit.”
• common_mode_rejection: SBOA092B page 75, Common Mode Rejection: “subtraction by inverting and summing”. The bottom op amp inverts E2 (R4 and R5, 10 kΩ each). The top op amp sums: E1 through R1, and the inverted E2 through R2 (9.1 kΩ) in series with R3 (a 5 kΩ pot wired as a rheostat), both into its inverting input, with R0 (100 kΩ) as feedback.
• wien_bridge_oscillator: SBOA092B page 83, Wien Bridge Oscillator: R and C in series from the output to the + input, R and C in parallel from there to ground; R2 (1.8 kΩ) and the R1 rheostat (500 Ω) from the output to the - input, R3 (220 Ω) and a GE 1869 lamp from there to ground.
• ac_preamplifier: SBOA092B page 78, AC Preamplifier: the double-rolloff stage built for high gain. EI through C2 1 µF onto the + input; R2 100 kΩ from there to the junction at the foot of C1 1000 µF, which runs up to the - input; R1 200 Ω from the junction to ground, and beside it R3 2.2 kΩ in series with R4, a 10 kΩ rheostat; R0 100 kΩ feedback; C3 10 µF output coupling.
• selective_amplifier: SBOA092B page 91, Selective Amplifier: an inverting amplifier with CI (50 nF) and RI (10 kΩ) in series at the input, and RO (330 kΩ) and a twin-T notch (Ra 3.3 kΩ, 2 Ca 100 nF; Ca 50 nF, Ra/2 1.65 kΩ) side by side in the feedback. A notch in the feedback is a peak in the gain.
• time_delay: SBOA092B page 86, Time Delay: an inverting stage built to approximate a pure delay. The input is a ladder, R/6, 3.6C to ground, 2R/3, 3.6C to ground, R/6; the feedback is R beside a T of 0.8C, 0.8C with R/4 to ground. The page prints no formula, only “Unity gain phase or time shift” and a sketch: the step comes out inverted after RC and completes its edge over 1.1 RC.
• ac_to_dc_converter: SBOA092B page 88, AC to DC Converter: a precision half-wave rectifier (R1, R2, R4, all 10 kΩ, two diodes) and a summer with a filter across it: EI through R3 (10 kΩ), the half-wave through R6 (5 kΩ), R7 (10 kΩ) and a 2 kΩ rheostat R8 back from the output, and C (100 µF) across both.
• power_booster: SBOA092B pages 71 and 72, Power Booster: a compound amplifier. A precision OPA277 runs the outer loop at G = 1 + 20k/1k = +21; a power OPA512 inside it runs a local loop at 1 + 10k/4.7k = 3.13 (10 pF across its 10 kΩ); two 0.1 Ω in parallel sit between the OPA512 and EO, inside both loops; 47 pF from the OPA277’s output to its - input adds phase lead for stability. EI is on the OPA277’s + input with 100 kΩ to ground.
• time_delay_relay: SBOA092B page 90, Time Delay: a reset integrator that ramps down from half the supply and, when it runs out, drops its output onto a clamp and pulls in a 6 V, 1 kΩ relay.
• meter_amplifier: SBOA092B page 80, Meter Amplifier, “fully developed average reading meter”: a follower whose feedback current runs through a bridge of two diodes and two 10 µF capacitors, with the meter across it.
• clamped_comparator: SBOA092B page 47, Figure 54, Fully Clamped Voltage Comparator: EI through R1 (100 kΩ) and a -15 V reference through R2 (1 MΩ) into the inverting input; CR1 (1N4148) from there to the tap of Ra/Rb (15 kΩ / 10 kΩ, from +15 V to the output); CR2 from the tap of Rb’/Ra’ (3 kΩ / 15 kΩ, from the output to -15 V) back to it.
• regenerative_integrator: SBOA092B page 57, the integrator page 56 introduces with “Regeneration may be used to increase open loop DC gain to infinity”. There is no formula, only a four-step procedure for trimming the zero control R8 and the regeneration control R5.
• rate_limiter: SBOA092B page 89, Rate Limiter: an op amp with no feedback of its own comparing EI + EO (summed at its + input through R1 and R0, both 100 kΩ) against ground, a diode bridge fed from ±15 V through R3 and R4 (100 kΩ), and an integrator (R5 100 kΩ, C0 10 µF) whose output is EO and closes the loop.