# LTC1871EMS#TRPBF

**Analog Devices** · DC-DC Converters · MSOP-10

LTC1871EMS#TRPBF from Analog Devices, in a MSOP-10. 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 | RUN | input | Enable pin with a falling threshold nominally 1.248V and 100mV of hysteresis; below the threshold the IC shuts down with VIN supply current typically 10μA, and the absolute maximum voltage on this pin is 7V. |
| 2 | ITH | passive | Error amplifier compensation pin whose voltage sets the current comparator input threshold, with a nominal range of 0V to 1.40V. |
| 3 | FB | input | Feedback input that receives the voltage from the external output resistor divider, with a nominal regulated voltage of 1.230V. |
| 4 | FREQ | input | A resistor from this pin to ground programs the operating frequency over 50kHz to 1000kHz, with a nominal pin voltage of 0.6V. |
| 5 | MODE/SYNC | input | Ground selects Burst Mode operation, while a DC level above 2V or INTVCC disables it for continuous operation; an external clock above 2V for at least 25ns synchronizes the oscillator. |
| 6 | GND | power_in | Ground pin for the IC. |
| 7 | GATE | output | Gate driver output for the external N-channel power MOSFET, with absolute maximum voltage of -0.3V to VINTVCC + 0.3V. |
| 8 | INTVCC | power_out | Internal 5.20V regulator output powering the gate driver and control circuits, which must be decoupled locally to IC ground with a minimum of 4.7μF low-ESR capacitor; output current absolute maximum is 50mA. |
| 9 | VIN | power_in | Main supply pin with a wide input range of 2.5V to 36V (absolute maximum 36V), which must be closely decoupled to ground. |
| 10 | SENSE | input | Current sense input connected to the power MOSFET drain for VDS sensing or to a source resistor, with absolute maximum pin voltage of 36V. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | Analog Devices |
| Package | MSOP-10 |
| Category | Power Management (PMIC) |
| Pins | 10 |

## Electrical characteristics

Limits as printed in the datasheet (page.json `metadata.characteristics` carries them as data).

| Parameter | Symbol | Min | Typ | Max | Unit | Conditions | Page |
|---|---|---|---|---|---|---|---|
| Minimum Input Voltage | VIN(MIN) | 2.5 |  |  | V |  | 3 |
| Falling RUN Input Threshold Voltage | VRUN- | 1.223 | 1.248 | 1.273 | V |  | 3 |
| Falling RUN Input Threshold Voltage | VRUN- | 1.198 |  | 1.298 | V | Full operating temperature range (●) | 3 |
| RUN Pin Input Threshold Hysteresis | VRUN(HYST) | 50 | 100 | 150 | mV |  | 3 |
| RUN Input Current | IRUN | 1 |  | 60 | nA |  | 3 |
| Feedback Voltage | VFB | 1.218 | 1.23 | 1.242 | V | VITH = 0.2V (Note 5) | 3 |
| Feedback Voltage | VFB | 1.212 |  | 1.248 | V | VITH = 0.2V (Note 5); full operating temperature range (●) | 3 |
| FB Pin Input Current | IFB |  | 18 | 60 | nA | VITH = 0.2V (Note 5) | 3 |
| Line Regulation | ΔVFB/ΔVIN |  | 0.002 | 0.02 | %/V | 2.5V ≤ VIN ≤ 30V | 3 |
| Load Regulation | ΔVFB/ΔVITH | -1 |  | -0.1 | % | VMODE/SYNC = 0V, VITH = 0.5V to 0.9V (Note 5); full operating temperature range (●) | 3 |
| FB Pin Overvoltage Lockout | ΔVFB(OV) | 2.5 | 6 | 10 | % | VFB(OV), VFB(NOM) in Percent | 3 |
| Maximum Current Sense Input Threshold | VSENSE(MAX) | 120 | 150 | 180 | mV | Duty Cycle < 20% | 3 |
| SENSE Pin Current (GATE High) | ISENSE(ON) | 35 |  | 50 | μA | VSENSE = 0V | 3 |
| SENSE Pin Current (GATE Low) | ISENSE(OFF) | 0.1 |  | 5 | μA | VSENSE = 30V | 3 |
| Oscillator Frequency | fOSC | 250 | 300 | 350 | kHz | RFREQ = 80k | 3 |
| Oscillator Frequency Range | fOSC | 50 |  | 1000 | kHz |  | 3 |
| Maximum Duty Cycle | DMAX | 87 | 92 | 97 | % |  | 4 |
| Recommended Maximum Synchronized Frequency Ratio | fSYNC/fOSC | 1.25 |  | 1.3 |  | fOSC = 300kHz (Note 6) | 4 |
| MODE/SYNC Minimum Input Pulse Width | tSYNC(MIN) | 25 |  |  | ns | VSYNC = 0V to 5V | 4 |
| Low Level MODE/SYNC Input Voltage | VIL(MODE) |  |  | 0.3 | V |  | 4 |
| High Level MODE/SYNC Input Voltage | VIH(MODE) | 1.2 |  |  | V |  | 4 |
| INTVCC Regulator Output Voltage | VINTVCC | 5 | 5.2 | 5.4 | V | VIN = 7.5V | 4 |
| INTVCC Regulator Line Regulation (7.5V to 15V) | ΔVINTVCC/ΔVIN1 |  | 8 | 25 | mV | 7.5V ≤ VIN ≤ 15V | 4 |
| INTVCC Regulator Line Regulation (15V to 30V) | ΔVINTVCC/ΔVIN2 |  | 70 | 200 | mV | 15V ≤ VIN ≤ 30V | 4 |
| INTVCC Load Regulation | VLDO(LOAD) | -2 |  | -0.2 | % | 0 ≤ IINTVCC ≤ 20mA, VIN = 7.5V | 4 |
| INTVCC Regulator Dropout Voltage | VDROPOUT |  |  | 280 | mV | VIN = 5V, INTVCC Load = 20mA | 4 |
| INTVCC Supply Current in Shutdown (Bootstrap Mode) | IINTVCC |  | 10 | 20 | μA | RUN = 0V, SENSE = 5V | 4 |
| GATE Driver Output Rise Time | tr |  | 17 | 100 | ns | CL = 3300pF (Note 7) | 4 |
| GATE Driver Output Fall Time | tf |  | 8 | 100 | ns | CL = 3300pF (Note 7) | 4 |
| Input Voltage Supply Current, Continuous Mode | IQ |  | 550 | 1000 | μA | VMODE/SYNC = 5V, VFB = 1.4V, VITH = 0.75V | 3 |
| Input Voltage Supply Current, Burst Mode Operation, No Load | IQ |  | 250 | 500 | μA | VMODE/SYNC = 0V, VITH = 0.2V (Note 5) | 3 |
| Input Voltage Supply Current, Shutdown Mode | IQ |  | 10 | 20 | μA | VRUN = 0V | 3 |
| Supply Voltage (absolute maximum) VIN | VIN | -0.3 |  | 36 | V |  | 2 |
| INTVCC Voltage | VINTVCC | -0.3 |  | 7 | V |  | 2 |
| INTVCC Output Current | IINTVCC |  |  | 50 | mA |  | 2 |
| GATE Voltage | VGATE | -0.3 |  |  | V | Maximum printed as VINTVCC + 0.3V | 2 |
| ITH, FB Voltages | VITH, VFB | -0.3 |  | 2.7 | V |  | 2 |
| RUN, MODE/SYNC Voltages | VRUN, VMODE/SYNC | -0.3 |  | 7 | V |  | 2 |
| FREQ Voltage | VFREQ | -0.3 |  | 1.5 | V |  | 2 |
| SENSE Pin Voltage | VSENSE | -0.3 |  | 36 | V |  | 2 |
| Operating Temperature Range, LTC1871E | TA | -40 |  | 85 | °C | LTC1871E; guaranteed performance 0°C to 85°C per Note 2 | 2 |
| Junction Temperature, LTC1871E | TJ |  |  | 125 | °C | LTC1871E/LTC1871I | 2 |
| Storage Temperature Range | TSTG | -65 |  | 150 | °C |  | 2 |
| Lead Temperature (Soldering) | TLEAD |  |  | 300 | °C | 10 sec soldering | 2 |
| Thermal Resistance, Junction to Ambient | θJA |  | 120 |  | °C/W | 10-lead MSOP package | 2 |
| Falling RUN Input Threshold Voltage (reference) | VRUN+ |  | 1.348 |  | V | Rising RUN input threshold voltage | 3 |
| Error Amplifier Transconductance | gm |  | 650 |  | μmho | ITH Pin Load = ±5μA (Note 5) | 3 |
| Burst Mode Operation ITH Pin Voltage | VITH(BURST) |  | 0.3 |  | V | ITH voltage falling (Note 5) | 3 |
| Nominal FREQ Pin Voltage | VFREQ |  | 0.62 |  | V |  | 4 |
| MODE/SYNC Input Pull-Down Resistance | RMODE/SYNC |  | 50 |  | kΩ |  | 4 |

## CAD (KiCad official)

- Symbol: `LTC1871EMS#TRPBF`
- Footprint: `Package_SO:MSOP-10_3x3mm_P0.5mm`
- 3D model: MSOP-10 (KiCad packages3D, STEP)
- 3D model files: `ltc1871ems-trpbf-etched.step` / `ltc1871ems-trpbf-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `ltc1871ems-trpbf.step` / `ltc1871ems-trpbf.glb` are the bare package body.

## Provenance

Data extracted from the manufacturer datasheet, not a distributor listing:

- **Datasheet:** [Analog Devices datasheet](https://jlcpcb.com/api/file/downloadByFileSystemAccessId/8588886140157349888) (36 pp, sha256 `5b84261840bec987`, retrieved 2026-10-18, tier: lcsc)
- **Extractor:** parts-factory `2.0.0` / `extract_pins 0.3`, primary `claude-haiku-5-5` (text), consensus `claude-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).

[Datasheet PDF](docs/ltc1871ems-trpbf-datasheet.pdf)