# TD1509PR

**Techcode Semicon** · DC-DC Converters · SOP-8

TD1509PR from Techcode Semicon, in a SOP-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 | Vin | power_in | Positive input supply for the switching regulator, specified at 3.6 V to 45 V, and a suitable input bypass capacitor must be present at this pin to minimize voltage transients. |
| 2 | Output | output | Internal switch output that swings between (+VIN - VSAT) and approximately -0.5 V at a duty cycle of about VOUT/VIN, so the PC board copper area connected to it should be kept minimal. |
| 3 | FB | input | Senses the regulated output voltage to complete the feedback loop; the adjustable version uses a 1.23 V reference, with FB rated from -0.3 V to Vin+0.3 V. |
| 4 | ON/OFF | input | Logic-level shutdown input: pulling it below about 1.3 V turns the regulator on and pulling it above 1.3 V (up to a maximum of 25 V) shuts it down, and leaving it open or tying it to ground keeps the regulator always on. |
| 5 | GND | power_in | Circuit ground, to be connected to a ground plane together with the input and output capacitors, with a maximized copper area recommended for heat dissipation. |
| 6 | GND | power_in | Circuit ground, to be connected to a ground plane together with the input and output capacitors, with a maximized copper area recommended for heat dissipation. |
| 7 | GND | power_in | Circuit ground, to be connected to a ground plane together with the input and output capacitors, with a maximized copper area recommended for heat dissipation. |
| 8 | GND | power_in | Circuit ground, to be connected to a ground plane together with the input and output capacitors, with a maximized copper area recommended for heat dissipation. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | Techcode Semicon |
| Package | SOP-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 |
|---|---|---|---|---|---|---|---|
| Output Voltage (ADJ) | Vout | 1.18 | 1.23 | 1.28 | V | 11V≤VIN≤45V, 0.2A≤ILOAD≤3A, VOUT for 9V | 6 |
| Feedback bias current | Ib |  | 10 | 100 | nA | Adjustable only, VFB=1.3V | 5 |
| Quiescent current | IQ |  | 5 | 10 | mA | VFB=12V force driver off | 5 |
| Standby quiescent current | ISTBY |  | 80 | 250 | uA | ON/OFF=5V, VIN=36V | 5 |
| Oscillator frequency | FOSC | 127 | 150 | 173 | KHz |  | 5 |
| Saturation voltage | VSAT |  | 1.2 | 1.5 | V | IOUT=3A | 5 |
| Current limit (peak current) | ICL | 3.8 |  | 4.2 | A | Peak Current (VFB=0V) | 5 |
| Output leakage current | IL |  |  | 50 | uA | Output=0V (VFB=12V) | 5 |
| Output leakage current | IL |  | 2 | 30 | mA | Output=-1V (VIN=36V) | 5 |
| ON/OFF pin threshold voltage, low (regulator ON) | VIL | 0.6 |  | 1.3 | V | Low (Regulator ON) | 5 |
| ON/OFF pin threshold voltage, high (regulator OFF) | VIH | 1.3 |  | 2 | V | High (Regulator OFF) | 5 |
| ON/OFF pin input current, high | IH |  | 5 | 15 | uA | VLOGIC=2.5V (Regulator OFF) | 5 |
| ON/OFF pin input current, low | IL |  | 0.02 | 5 | uA | VLOGIC=0.5V (Regulator ON) | 5 |
| Input voltage | VIN | 3.6 |  | 45 | V |  | 4 |
| Operating junction temperature | TJ | -40 |  | 125 | ºC |  | 4 |
| Operating ambient temperature | TA | -40 |  | 85 | ºC |  | 4 |
| Input voltage | VIN | -0.3 |  | 45 | V |  | 4 |
| Feedback pin voltage | VFB | -0.3 |  |  | V | Upper limit printed as Vin+0.3 V (not numeric) | 4 |
| ON/OFF pin voltage | VEN | -0.3 |  |  | V | Upper limit printed as Vin+0.3 V (not numeric) | 4 |
| Output pin voltage | VSW | -0.3 |  |  | V | Upper limit printed as Vin+0.3 V (not numeric) | 4 |
| Operating junction temperature | TJ |  |  | 150 | ºC |  | 4 |
| Storage temperature | TSTG | -65 |  | 150 | ºC |  | 4 |
| Lead temperature (soldering, 10 sec) | TLEAD |  |  | 260 | ºC | Soldering, 10 sec | 4 |
| ESD (HBM) |  |  |  | 2000 | V | HBM | 4 |
| Thermal resistance junction to ambient | RθJA |  | 85 |  | ºC/W | Note1: thermal resistance with copper area of approximately 3 in2 | 5 |
| Thermal resistance junction to case | RθJC |  | 45 |  | ºC/W |  | 5 |

## 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 | copper |  | this is the output (switch) pin, which should not have large areas of copper.) Large areas of copper provide the | 12 |

## CAD (KiCad official)

- Symbol: `TD1509PR`
- Footprint: `Package_SO:SOIC-8_3.9x4.9mm_P1.27mm`
- 3D model: SOP-8 (KiCad packages3D, STEP)
- 3D model files: `td1509pr-etched.step` / `td1509pr-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `td1509pr.step` / `td1509pr.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [Techcode Semicon datasheet](https://jlcpcb.com/api/file/downloadByFileSystemAccessId/8590905577361534976) (17 pp, sha256 `8d1cdb542e62ec93`, 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/td1509pr-datasheet.pdf)