# LTC1261LCMS8#TRPBF

**Analog Devices** · DC-DC Converters · MSOP-8

LTC1261LCMS8#TRPBF from Analog Devices, in a MSOP-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 | VCC | power_in | Power supply input requiring 2.7V to 5.25V, bypassed to ground with at least a 1µF capacitor placed close to the chip. |
| 2 | C1+ | passive | Positive terminal of the flying capacitor, which connects to a 0.1µF capacitor between C1+ and C1-. |
| 3 | C1- | passive | Negative terminal of the flying capacitor, which connects to a 0.1µF capacitor between C1+ and C1-. |
| 4 | GND | power_in | Ground, which should connect to a low-impedance ground plane to minimize regulation errors. |
| 5 | ADJ (COMP) | input | Output adjust pin for adjustable parts (resistor divider from OUT, drawing at least 10µA recommended) and compensation pin for fixed-output parts, where an optional capacitor to ground reduces output ripple. |
| 6 | OUT | power_out | Negative voltage output that must be bypassed to ground with a 1µF or larger capacitor. |
| 7 | REG | output | Open-drain output that pulls low when the output is within 5% of the set value, sinks 5mA with a 5V supply, requires an external pull-up, and may be pulled up to 6V above ground. |
| 8 | SHDN | input | Shutdown input: at ground the part operates normally, while a high level disables the charge pump and drops quiescent current to 5µA typical, with an internal 5µA pull-down keeping it low when floating. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | Analog Devices |
| Package | MSOP-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 |
|---|---|---|---|---|---|---|---|
| Supply Voltage | VCC | 2.7 |  | 5.25 | V |  | 3 |
| Supply Current (SHDN floating) | ICC |  | 650 | 1500 | µA | VCC = 5.25V, No Load, SHDN Floating | 3 |
| Supply Current (SHDN high, shutdown) | ICC |  | 5 | 20 | µA | VCC = 5.25V, No Load, VSHDN = VCC | 3 |
| REG Output Low Voltage | VOL |  | 0.1 | 0.8 | V | IREG = 1mA, VCC = 5V, VOUT = -4V | 3 |
| REG Sink Current | IREG | 4 |  | 8 | mA | VREG = 0.8V, VCC = 3.3V | 3 |
| REG Sink Current | IREG | 5 |  | 12 | mA | VREG = 0.8V, VCC = 5V | 3 |
| Adjust Pin Current | IADJ |  | 0.01 | 1 | µA | VADJ = 1.23V | 3 |
| SHDN Input High Voltage | VIH | 2 |  |  | V | VCC = 5V | 3 |
| SHDN Input Low Voltage | VIL |  |  | 0.8 | V | VCC = 5V | 3 |
| SHDN Input Current | IIN |  | 2.5 | 25 | µA | VSHDN = VCC | 3 |
| Turn-On Time | tON | 250 |  | 1500 | µs | VCC = 5V, IOUT = 10mA, -1.5V ≤ VOUT ≤ -4V (LTC1261L) | 3 |
| Output Regulation (LTC1261L) | VOUT | -1.552 | -1.5 | -1.448 | V | 2.70V ≤ VCC ≤ 5.25V, 0mA ≤ IOUT ≤ 10mA | 3 |
| Output Regulation (LTC1261L) | VOUT | -2.07 | -2 | -1.93 | V | 2.70V ≤ VCC ≤ 5.25V, 0mA ≤ IOUT ≤ 5mA | 3 |
| Output Regulation (LTC1261L) | VOUT | -2.07 | -2 | -1.91 | V | 3.50V ≤ VCC ≤ 5.25V, 0mA ≤ IOUT ≤ 20mA | 3 |
| Output Regulation (LTC1261L) | VOUT | -2.587 | -2.5 | -2.413 | V | 2.95V ≤ VCC ≤ 5.25V, 0mA ≤ IOUT ≤ 5mA | 3 |
| Output Regulation (LTC1261L) | VOUT | -2.587 | -2.5 | -2.41 | V | 3.85V ≤ VCC ≤ 5.25V, 0mA ≤ IOUT ≤ 20mA | 3 |
| Output Regulation (LTC1261L) | VOUT | -3.105 | -3 | -2.895 | V | 3.40V ≤ VCC ≤ 5.25V, 0mA ≤ IOUT ≤ 5mA | 3 |
| Output Regulation (LTC1261L) | VOUT | -3.105 | -3 | -2.885 | V | 4.25V ≤ VCC ≤ 5.25V, 0mA ≤ IOUT ≤ 20mA | 3 |
| Output Regulation (LTC1261L) | VOUT | -3.622 | -3.5 | -3.378 | V | 3.85V ≤ VCC ≤ 5.25V, 0mA ≤ IOUT ≤ 5mA | 3 |
| Output Regulation (LTC1261L) | VOUT | -3.622 | -3.5 | -3.365 | V | 4.60V ≤ VCC ≤ 5.25V, 0mA ≤ IOUT ≤ 20mA | 3 |
| Output Regulation (LTC1261L/LTC1261L-4) | VOUT | -4.14 | -4 | -3.86 | V | 4.35V ≤ VCC ≤ 5.25V, 0mA ≤ IOUT ≤ 5mA | 3 |
| Output Regulation (LTC1261L/LTC1261L-4) | VOUT | -4.14 | -4 | -3.83 | V | 5.10V ≤ VCC ≤ 5.25V, 0mA ≤ IOUT ≤ 20mA | 3 |
| Output Regulation (LTC1261L/LTC1261L-4.5) | VOUT | -4.657 | -4.5 | -4.343 | V | 4.75V ≤ VCC ≤ 5.25V, 0mA ≤ IOUT ≤ 5mA | 3 |
| Output Short-Circuit Current | ISC | 100 | 220 |  | mA | VOUT = 0V, VCC = 5.25V | 3 |
| Output Voltage |  | -5.3 |  | 0.3 | V | Note 3 | 2 |
| Total Voltage VCC to VOUT |  |  |  | 10.8 | V | Note 2 | 2 |
| SHDN Pin |  | -0.3 |  |  | V | Upper limit printed as (VCC + 0.3V) | 2 |
| REG Pin |  | -0.3 |  | 6 | V |  | 2 |
| Storage Temperature Range |  | -65 |  | 150 | °C |  | 2 |
| Lead Temperature (Soldering) |  |  |  | 300 | °C | 10 sec | 2 |
| Commercial Temperature Range (LTC1261LC) |  | 0 |  | 70 | °C | Commercial grade; not tested at -40°C and 85°C (Note 4) | 2 |
| Maximum Junction Temperature (MS8) | TJMAX |  |  | 150 | °C | MS8 package | 2 |
| Thermal Resistance Junction-to-Ambient (MS8) | θJA |  | 200 |  | °C/W | MS8 package | 2 |

## CAD (KiCad official)

- Symbol: `LTC1261LCMS8#TRPBF`
- Footprint: `Package_SO:MSOP-8_3x3mm_P0.65mm`
- 3D model: MSOP-8 (KiCad packages3D, STEP)
- 3D model files: `ltc1261lcms8-trpbf-etched.step` / `ltc1261lcms8-trpbf-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `ltc1261lcms8-trpbf.step` / `ltc1261lcms8-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/8589848779974750208) (14 pp, sha256 `336624392408a8a5`, retrieved 2026-10-19, 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/ltc1261lcms8-trpbf-datasheet.pdf)