component
LT1172IS8#TRPBF
Public Made by Adomby adom
Analog Devices DC-DC Converters, SO-8. Pinout cross-checked by two models against the datasheet, KiCad symbol/footprint/3D.
3D Model
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Symbol & Footprint
Schematic Symbol
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PCB Footprint
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Datasheet
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Contents
README
markdownLT1172IS8#TRPBF
Analog Devices · DC-DC Converters · SO-8
LT1172IS8#TRPBF from Analog Devices, in a SO-8. Pinout and pin descriptions extracted from the manufacturer datasheet (extract_pins, cross-checked by a second model); symbol, footprint, and 3D from KiCad-official CAD.
Pinout
| Pin | Name | Type | Function |
|---|---|---|---|
| 1 | GND | power_in | Ground pin of the LT1172 8-lead SO package. |
| 2 | VC | passive | Error amplifier output/compensation pin; control pin threshold for zero duty cycle is typically 0.9V. |
| 3 | FB | input | Feedback input; reference voltage 1.244V typ (1.224V to 1.264V) and transient limit of ±15V for 1ms. |
| 4 | NC | unconnected | Do not connect to external circuitry because this pin may be active in future revisions. |
| 5 | VIN | power_in | Supply input, operating from 3V minimum up to 40V absolute maximum (60V for HV types). |
| 6 | E1 | passive | Switch emitter pin E1 of the internal power switch. |
| 7 | VSW | passive | Switch output (collector) pin; absolute maximum 60V for the LT1172S8. |
| 8 | E2 | passive | Switch emitter pin E2 of the internal power switch. |
Key specifications
| Parameter | Value |
|---|---|
| Manufacturer | Analog Devices |
| Package | SO-8 |
| Category | Power Management (PMIC) |
| Pins | 8 |
Electrical characteristics
Limits as printed in the datasheet (page.json metadata.characteristics carries them as data).
| Parameter | Symbol | Min | Typ | Max | Unit | Conditions | Page |
|---|---|---|---|---|---|---|---|
| Reference Voltage (measured at feedback pin), TA=25C | VREF | 1.224 | 1.244 | 1.264 | V | VC = 0.8V, TA = 25C | 4 |
| Reference Voltage (measured at feedback pin), full temp range | VREF | 1.214 | 1.244 | 1.274 | V | VC = 0.8V, full operating temp range (l) | 4 |
| Feedback Input Current, TA=25C | IB | 350 | 750 | nA | VFB = VREF, TA = 25C | 4 | |
| Feedback Input Current, full temp range | IB | 1100 | nA | VFB = VREF, full temp range (l) | 4 | ||
| Error Amplifier Transconductance, TA=25C | gm | 3000 | 4400 | 6000 | µmho | delta IC = ±25µA, TA = 25C | 4 |
| Error Amplifier Transconductance, full temp range | gm | 2400 | 7000 | µmho | delta IC = ±25µA, full temp range (l) | 4 | |
| Error Amplifier Source or Sink Current, TA=25C | 150 | 200 | 350 | µA | VC = 1.5V, TA = 25C | 4 | |
| Error Amplifier Source or Sink Current, full temp range | 120 | 400 | µA | VC = 1.5V, full temp range (l) | 4 | ||
| Error Amplifier Hi Clamp Voltage | 1.8 | 2.3 | V | Hi clamp, VFB = 1V | 4 | ||
| Error Amplifier Lo Clamp Voltage | 0.25 | 0.38 | 0.52 | V | Lo clamp, VFB = 1.5V | 4 | |
| Reference Voltage Line Regulation | 0.03 | %/V | 3V ≤ VIN ≤ VMAX, VC = 0.8V, full temp range (l) | 4 | |||
| Error Amplifier Voltage Gain | AV | 500 | 800 | V/V | 0.9V ≤ VC ≤ 1.4V | 4 | |
| Minimum Input Voltage | 2.6 | 3 | V | full temp range (l) | 4 | ||
| Supply Current | IQ | 6 | 9 | mA | 3V ≤ VIN ≤ VMAX, VC = 0.6V | 4 | |
| Control Pin Threshold, Duty Cycle = 0, TA=25C | 0.8 | 0.9 | 1.08 | V | Duty Cycle = 0, TA = 25C | 4 | |
| Control Pin Threshold, Duty Cycle = 0, full temp range | 0.6 | 1.25 | V | Duty Cycle = 0, full temp range (l) | 4 | ||
| Normal/Flyback Threshold on Feedback Pin | 0.4 | 0.45 | 0.54 | V | 4 | ||
| Flyback Reference Voltage, TA=25C | VFB | 15 | 16.3 | 17.6 | V | IFB = 50µA, TA = 25C (flyback mode, Note 5) | 4 |
| Flyback Reference Voltage, full temp range | VFB | 14 | 18 | V | IFB = 50µA, full temp range (l) (flyback mode, Note 5) | 4 | |
| Change in Flyback Reference Voltage | 4.5 | 6.8 | 9 | V | 0.05 ≤ IFB ≤ 1mA | 4 | |
| Flyback Reference Voltage Line Regulation | 0.01 | 0.03 | %/V | IFB = 50µA, 7V ≤ VIN ≤ VMAX (Note 5) | 4 | ||
| Flyback Amplifier Transconductance (gm) | gm | 150 | 300 | 650 | µmho | delta IC = ±10µA | 4 |
| Flyback Amplifier Source Current | 15 | 32 | 70 | µA | VC = 0.6V, IFB = 50µA, Source, full temp range (l) | 4 | |
| Flyback Amplifier Sink Current | 25 | 40 | 70 | µA | VC = 0.6V, IFB = 50µA, Sink, full temp range (l) | 4 | |
| Output Switch Breakdown Voltage (LT1172S8) | BV | 60 | 80 | V | 3V ≤ VIN ≤ VMAX, ISW = 1.5mA, LT1172S8, full temp range (l) | 4 | |
| Output Switch On Resistance (LT1172) | VSAT | 0.6 | 1 | Ω | LT1172, ISW = 1A (Note 3), full temp range (l) | 4 | |
| Switch Current Limit (LT1172), Duty Cycle 50%, TJ ≥ 25C | ILIM | 1.25 | 3 | A | Duty Cycle = 50%, TJ ≥ 25C (l) | 4 | |
| Switch Current Limit (LT1172), Duty Cycle 50%, TJ < 25C | ILIM | 1.25 | 3.5 | A | Duty Cycle = 50%, TJ < 25C (l) | 4 | |
| Switch Current Limit (LT1172), Duty Cycle 80% | ILIM | 1 | 2.5 | A | Duty Cycle = 80% (Note 4) (l) | 4 | |
| Supply Current Increase During Switch On-Time | ∆IIN/∆ISW | 25 | 35 | mA/A | 4 | ||
| Switching Frequency, TA=25C | f | 88 | 100 | 112 | kHz | TA = 25C | 4 |
| Switching Frequency, full temp range | f | 85 | 115 | kHz | full temp range (l) | 4 | |
| Maximum Switch Duty Cycle | DCMAX | 85 | 92 | 97 | % | full temp range (l) | 5 |
| Shutdown Mode Supply Current | 100 | 250 | µA | 3V ≤ VIN ≤ VMAX, VC = 0.05V | 5 | ||
| Shutdown Mode Threshold Voltage, TA=25C | 100 | 150 | 250 | mV | 3V ≤ VIN ≤ VMAX, TA = 25C | 5 | |
| Shutdown Mode Threshold Voltage, full temp range | 50 | 300 | mV | 3V ≤ VIN ≤ VMAX, full temp range (l) | 5 | ||
| Supply Voltage (LT1170/LT1171/LT1172, standard) | 40 | V | Note 2 | 2 | |||
| Feedback Pin Voltage (Transient) | -15 | 15 | V | Transient, 1ms | 2 | ||
| Storage Temperature Range | -65 | 150 | °C | 2 | |||
| Operating Junction Temperature Range (I grade) | TJ | -40 | 100 | °C | LT1172I, operating | 2 | |
| Junction Temperature Range (I grade, short circuit / intermittent fault) | TJ | -40 | 125 | °C | LT1172I, short circuit / intermittent fault | 2 | |
| Maximum Junction Temperature (S8 package, continuous) | TJMAX | 100 | °C | S8 plastic SO package, continuous operation | 2 | ||
| Junction-to-Ambient Thermal Resistance (S8 package) | θJA | 120 | 150 | °C/W | S8 package, depends on board layout | 2 |
Materials and finish
As the datasheet states them (page.json metadata.appearance; the 3D model's colours follow it).
| Part | Material | Colour / plating | Datasheet says | Page |
|---|---|---|---|---|
| contacts | tin | NOTE: LEAD DIMENSIONS APPLY TO SOLDER DIP/PLATE (1.143, 1.651) OR TIN PLATE LEADS | 17 |
CAD (KiCad official)
- Symbol:
LT1172IS8#TRPBF - Footprint:
Package_SO:SOIC-8_3.9x4.9mm_P1.27mm - 3D model: SO-8 (KiCad packages3D, STEP)
- 3D model files:
lt1172is8-trpbf-etched.step/lt1172is8-trpbf-etched.glbcarry the MPN laser-etched on the die in a toggleableAdom.LaserEtchgroup (Fusion-ready);lt1172is8-trpbf.step/lt1172is8-trpbf.glbare the bare package body.
Provenance
Data extracted from the manufacturer datasheet, not a distributor listing:
- Datasheet: Analog Devices datasheet (24 pp, sha256
bd330c64af46323e, retrieved 2026-10-18, tier: lcsc) - Extractor: parts-factory
2.0.0/extract_pins 0.3, primaryclaude-haiku-5-5(text), consensusclaude-sonnet-5-5(agreed), guards: pin_guards 0.1: passed. Pins are checked against the footprint pad set and their cited datasheet pages before publish. - CAD: KiCad official libraries (CC-BY-SA 4.0).