# LTC2909ITS8-3.3#TRPBF

**Analog Devices** · Monitors & Reset Circuits · TSOT-23-8

LTC2909ITS8-3.3#TRPBF from Analog Devices, in a TSOT-23-8. 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 | ADJ1 | input | Adjustable monitor input with a 0.5V threshold (VRT 0.4925V to 0.5075V), an input current of at most ±15nA at 0.55V, and an absolute maximum terminal voltage of -0.3V to 7.5V. |
| 2 | ADJ2 | input | Second adjustable monitor input with a 0.5V threshold (VRT 0.4925V to 0.5075V), an input current of at most ±15nA at 0.55V, and an absolute maximum terminal voltage of -0.3V to 7.5V. |
| 3 | REF | output | Buffered 1V reference output (0.985V to 1.015V) for negative-supply offset, valid when VCC is above 2.175V, with a terminal current limit of ±1mA. |
| 4 | GND | power_in | Ground reference for all device voltages. |
| 5 | RST | output | Open-drain active-low reset output, with VOL of 0.15V max at VCC=1V and 100µA and 0.30V max at VCC=3V and 2.5mA, high-level leakage of ±1µA max, and an absolute maximum of 7.5V. |
| 6 | VCC | power_in | Supply input monitored by the UVLO threshold (2.175V to 2.250V for the -2.5 part, 2.871V to 2.970V for the -3.3 part, 4.350V to 4.500V for the -5 part), with an absolute maximum of 6V and a 6.5V internal shunt regulator; supplies above 6V require a series dropping resistor. |
| 7 | TMR | passive | Reset timeout programming pin: tying it to GND selects the internal 200ms (typ) timeout, a capacitor sets an external timeout (20ms typ at 2.2nF), and tying it to VCC disables the timer, with an absolute maximum of VCC+0.3V and pull-up/pull-down currents of about 2.1µA. |
| 8 | SEL | input | Three-state input that sets each ADJ input polarity: below 0.4V for GND, above 1.4V for VCC, and left open for mixed polarity (about 0.9V), with an absolute maximum of 7.5V and input current of ±25µA. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | Analog Devices |
| Package | TSOT-23-8 |
| Category | Power Management ICs |
| 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 |
|---|---|---|---|---|---|---|---|
| Operating Supply Voltage (RST in correct state) | VCC(MIN) | 0.5 |  |  | V | RST in correct state | 3 |
| VCC Shunt Regulation Voltage | VCC(SHUNT) | 6 | 6.5 | 6.9 | V | IVCC = 1mA, IVREF = 0 | 3 |
| VCC Input Current | ICC |  | 50 | 150 | μA | 2.175 < VCC < 6V | 3 |
| ADJ Input Threshold | VRT | 0.4925 | 0.5 | 0.5075 | V |  | 3 |
| ADJ Hysteresis | ΔVRT | 1.5 | 3.5 | 10 | mV | TMR = VCC | 3 |
| ADJ Input Current | IADJ | -15 |  | 15 | nA | VADJ = 0.55V | 3 |
| VCC UVLO Threshold (LTC2909-3.3) | VCC(UVLO) | 2.871 | 2.921 | 2.97 | V | LTC2909-3.3 | 3 |
| UVLO Hysteresis | ΔVCC(UVLO) | 0.3 | 0.7 | 2 | % | TMR = VCC | 3 |
| Buffered Reference Voltage | VREF | 0.985 | 1 | 1.015 | V | VCC > 2.175V, IVREF = ±1mA | 3 |
| TMR Pull-Up Current | ITMR(UP) | -1.5 | -2.1 | -2.7 | μA | VTMR = 1V | 3 |
| TMR Pull-Down Current | ITMR(DOWN) | 1.5 | 2.1 | 2.7 | μA | VTMR = 1V | 3 |
| Reset Timeout Period, External | tRST(EXT) | 16 | 20 | 25 | ms | CTMR = 2.2nF | 3 |
| Reset Timeout Period, Internal | tRST(INT) | 150 | 200 | 260 | ms | VTMR = 0V | 3 |
| Timer Disable Voltage, VTMR Rising (offset from VCC) | VTMR(DIS) | -0.36 | -0.25 | -0.16 | V | Printed as VCC, 0.36 / VCC, 0.25 / VCC, 0.16; VTMR rising | 3 |
| Timer Disable Hysteresis | ΔVTMR(DIS) | 60 | 110 | 150 | mV | VTMR falling | 3 |
| Timer Internal Mode Voltage | VTMR(INT) | 0.14 | 0.21 | 0.27 | V | VTMR falling | 3 |
| Timer Internal Mode Hysteresis | ΔVTMR(INT) | 40 | 70 | 110 | mV | VTMR rising | 3 |
| ADJx Comparator Propagation Delay to RST | tPROP | 50 | 150 | 500 | μs | ADJx driven beyond reset threshold (VRTX) by 5mV | 3 |
| VCC Undervoltage Detect to RST | tUV | 50 | 150 | 500 | μs | VCC less than UVLO threshold (VCC(UVLO)) by 1% | 3 |
| RST Output Voltage Low | VOL(RST) |  | 0.01 | 0.15 | V | VCC = 0.5V, I = 5μA | 3 |
| RST Output Voltage Low | VOL(RST) |  | 0.1 | 0.3 | V | VCC = 3V, I = 2500μA | 3 |
| RST Output Voltage High Leakage | IOH(RST) | -1 |  | 1 | μA | RST = VCC | 3 |
| SEL Low Level Input Voltage | VIL |  |  | 0.4 | V |  | 3 |
| SEL High Level Input Voltage | VIH | 1.4 |  |  | V |  | 3 |
| Allowable Leakage in Open State (first printed value) | ISEL(Z) | -5 |  | 5 | μA |  | 3 |
| Allowable Leakage in Open State (second printed value) | ISEL(Z) | -10 |  | 10 | μA |  | 3 |
| SEL Input Current | ISEL | -25 |  | 25 | μA | SEL = VCC or SEL = GND | 3 |
| VCC Supply Voltage Absolute Maximum | VCC | -0.3 |  | 6 | V |  | 2 |
| SEL, RST Terminal Voltage | SEL, RST | -0.3 |  | 7.5 | V |  | 2 |
| ADJ1, ADJ2 Terminal Voltage | ADJ1, ADJ2 | -0.3 |  | 7.5 | V |  | 2 |
| TMR Terminal Voltage | TMR | -0.3 |  |  | V | Maximum printed as VCC + 0.3V | 2 |
| VCC Terminal Current | IVCC | -10 |  | 10 | mA |  | 2 |
| REF Terminal Current | IREF | -1 |  | 1 | mA |  | 2 |
| Storage Temperature Range (TSOT-23) |  | -65 |  | 150 | °C | TSOT-23 package | 2 |
| Lead Temperature (Soldering, 10 sec) (TSOT-23) |  |  |  | 300 | °C | TSOT-23, 10 sec soldering | 2 |
| Operating Temperature Range (LTC2909I) |  | -40 |  | 85 | °C | LTC2909I grade | 2 |
| Maximum Junction Temperature | TJMAX |  |  | 125 | °C | TS8 package | 2 |
| Thermal Resistance, Junction to Ambient | θJA |  | 250 |  | °C/W | TS8 package | 2 |

## CAD (KiCad official)

- Symbol: `LTC2909ITS8-3.3#TRPBF`
- Footprint: `Package_TO_SOT_SMD:TSOT-23-8`
- 3D model: TSOT-23-8 (KiCad packages3D, STEP)
- 3D model files: `ltc2909its8-3-3-trpbf-etched.step` / `ltc2909its8-3-3-trpbf-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `ltc2909its8-3-3-trpbf.step` / `ltc2909its8-3-3-trpbf.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [Analog Devices datasheet](https://www.analog.com/media/en/technical-documentation/data-sheets/2909fb.pdf) (16 pp, sha256 `35475090990f5abb`, retrieved 2026-10-30, tier: manufacturer)
- **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/ltc2909its8-3-3-trpbf-datasheet.pdf)