BETABench supply12 V regulated
Frequency-to-voltage converter
LM2907-N Specifications
Review LM2907-N electrical specifications, operating conditions and package details.
Package view
Key specifications
Both input half cycles contribute charge. The external resistor sets the conversion scale, and the filter capacitor trades ripple against response time.
Example conversion1.2 V / kHz nominal
Selected packages8 pins · PDIP / SOIC
Operating grade−40 to +85 °C
Package details
LM2907N-8/NOPB · PDIP-8
| Property | Details |
|---|---|
| Manufacturer | Texas Instruments |
| Part number | LM2907N-8/NOPB |
| Package | PDIP-8 |
| Connections | 8 pins |
| Mounting | Through-hole |
| Lead pitch | 2.54 mm |
| Package code | PDIP-8 |
| Thermal reference | See operating and package limits |
Operating context
Selected eight-pin devices
Manufacturer specifications 6 parameters
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| Parameter | Value | Conditions / notes |
|---|---|---|
| Example supply | 12 V regulated | Datasheet electrical-characteristic test supply |
| Operating temperature | −40 to +85°C | Selected orderable-device grade |
| Amplifier common-mode input | 0 to VCC − 1.5 V | Electrical table at 12 V and 25°C |
| Supply current | 3.8 mA typical; 6 mA maximum | Manufacturer electrical test conditions |
| Supply / collector stress limit | 28 V absolute maximum | Not a normal operating target |
| Storage temperature | −65 to +150°C | Unpowered |
No specifications match. Try a parameter name or a unit.
Supply variation changes the conversion gain; select a clean, stable rail.
Input and charge pump
12 V, 25°C reference conditions
Manufacturer specifications 7 parameters
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| Parameter | Value | Conditions / notes |
|---|---|---|
| Input thresholds | ±25 mV typical; ±10 to ±40 mV specified | 250 mV peak-to-peak input at 1 kHz |
| Input hysteresis | 30 mV typical | Manufacturer threshold test |
| Eight-pin input offset | 5 mV typical; 15 mV maximum | Manufacturer threshold test |
| Charge/discharge current | 180 µA typical; 140–240 µA | CP1 / CP2 at 6 V |
| Pump voltage excursion | Approximately VCC / 2 | Difference between C1 charge and discharge levels |
| Conversion constant K | 1 typical; 0.9–1.1 specified | VOUT = K × VCC × f × C1 × R1 |
| C1 selection | Greater than 500 pF for accurate operation | Example uses 1 nF |
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Do not drive the eight-pin input with a waveform that never crosses ground.
Output amplifier
Separate collector and emitter
Manufacturer specifications 6 parameters
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| Parameter | Value | Conditions / notes |
|---|---|---|
| Input offset | 3 mV typical; 10 mV maximum | VIN = 6 V |
| Input bias | 50 nA typical; 500 nA maximum | VIN = 6 V |
| Output source current | 10 mA minimum | Emitter at VCC − 2 V |
| Output sink current | 40 mA minimum; 50 mA typical | Collector at 1 V |
| Follower configuration | COL to supply; EMIT to IN− | Example uses a high-impedance meter and 10 kΩ load |
| Example load at 1 kHz | 1.2 V / 10 kΩ = 0.12 mA | Nominal settled value |
No specifications match. Try a parameter name or a unit.
Source and sink capabilities are specified under different conditions; do not assume 50 mA is guaranteed in both directions.
12 V tachometer example
All ground symbols share one return
Manufacturer specifications 8 parameters
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| Parameter | Value | Conditions / notes |
|---|---|---|
| TACH+1 | 1 kHz sine, ±1 V peak | Zero DC offset; generator return to GND8 |
| CP1 pin 2 | C1 = 1 nF to GND | Sets charge transferred per cycle |
| CP2 / IN+ pin 3 | R1 = 100 kΩ and C2 = 1 µF to GND | Parallel averaging network |
| EMIT4 and IN−7 | Join as VOUT | Unity-gain buffer feedback |
| COL5 and V+6 | +12 V | Output transistor and controller share the bench supply |
| GND8 | Circuit return | Mandatory external connection |
| Supply bypass | 100 nF + 10 µF to GND | Close to V+6 and GND8 |
| Output load | 10 kΩ to GND plus voltmeter | Keep the instrument high impedance |
No specifications match. Try a parameter name or a unit.
No microcontroller or firmware is required. This is an illustrative reference circuit, not a live simulation.
Scale, ripple and response
Nominal example · K = 1
Manufacturer specifications 8 parameters
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| Parameter | Value | Conditions / notes |
|---|---|---|
| Conversion equation | VOUT ≈ K × VCC × fIN × C1 × R1 | Subject to pump current, amplifier range and tolerances |
| Scale | 1.2 mV / Hz | 12 V × 1 nF × 100 kΩ |
| 500 Hz / 1 kHz / 5 kHz | 0.6 V / 1.2 V / 6 V | Settled illustrative readings |
| Average current at 1 kHz | 12 µA | VCC × fIN × C1 |
| Filter time constant | 100 ms | 100 kΩ × 1 µF |
| Approximate 1% settling | About 0.46 s | 4.6 RC for an ideal first-order filter |
| Pump ripple at 1 kHz | About 5.6 mV peak-to-peak | Datasheet approximation with I2 = 180 µA |
| Stopped input | Output decays toward zero | The filter prevents an instantaneous step |
No specifications match. Try a parameter name or a unit.
These are calculated values. Capacitor/resistor tolerances, K, supply stability and amplifier errors affect the measured result.
Accuracy and design limits
Keep the operating point in range
Manufacturer specifications 6 parameters
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| Parameter | Value | Conditions / notes |
|---|---|---|
| Typical linearity | 0.3% | TI test network: C1 = 1 nF, R1 = 68 kΩ, C2 = 0.22 µF |
| Specified nonlinearity | −1% to +1% | 5 kHz deviation from line through 1 and 10 kHz test points |
| Gain error | K is specified 0.9–1.1 | Typical linearity is not total absolute accuracy |
| Larger C2 | Less ripple, slower response | It does not change ideal DC gain |
| Larger R1 or C1 | More volts per hertz | May reduce usable frequency/output range |
| Supply sensitivity | Output scale follows VCC | Use regulation or calibrate the complete system |
No specifications match. Try a parameter name or a unit.
The 100 kΩ example differs from the linearity test network; its total accuracy is not claimed to equal that test result.
Package selection
LM2907N-8/NOPB · PDIP-8
Manufacturer specifications 5 parameters
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| Parameter | Value | Conditions / notes |
|---|---|---|
| Through-hole | LM2907N-8/NOPB · PDIP-8 | 2.54 mm pitch; 7.62 mm nominal rows |
| Surface mount | LM2907M-8/NOPB · SOIC-8 | 1.27 mm pitch; narrow body |
| Fourteen-pin variants | Different map and internal connections | Not represented by these eight-pin views |
| LM2917 distinction | Adds an internal Zener regulator | Do not import its regulator limits into LM2907 |
| Footprint provenance | Original editable TEP land patterns | Verify the exact ordered package and fabricator rules |
No specifications match. Try a parameter name or a unit.
Pin functions and physical numbering stay consistent when switching between the two selected packages.
Connections by function
Select a pin for its function, connection guidance and electrical notes.