component
TD1591
Public Made by Adomby adom
Techcode Semicon DC-DC Converters, SOIC-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
markdownTD1591
Techcode Semicon · DC-DC Converters · SOIC-8
TD1591 from Techcode Semicon, in a SOIC-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 | NC | unconnected | Not connected; leave this pin unconnected. |
| 2 | Vin | power_in | Supply voltage input; the TD1591 operates from a 3.6V to 32V DC supply, and Vin should be bypassed to GND with a suitably large capacitor to eliminate input noise. |
| 3 | SW | output | Power switch output and switch node that supplies power to the output; keep the PC board copper on this node to a minimum to limit coupling into sensitive circuitry. |
| 4 | GND | power_in | Ground pin; it must be placed outside the Schottky diode to output capacitor ground path so switching current spikes do not induce voltage noise into the TD1591. |
| 5 | FB | input | Feedback input that senses the output voltage through an external resistor divider and regulates it to a feedback threshold voltage of 1.222V. |
| 6 | NC | unconnected | Not connected; leave this pin unconnected. |
| 7 | EN | input | Digital enable input that turns the regulator on when driven high and off when driven low. |
| 8 | NC | unconnected | Not connected; leave this pin unconnected. |
Key specifications
| Parameter | Value |
|---|---|
| Manufacturer | Techcode Semicon |
| Package | SOIC-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 |
|---|---|---|---|---|---|---|---|
| Input voltage | VIN | 3.6 | 32 | V | 5 | ||
| Shutdown Supply Current | ISTBY | 30 | 90 | uA | VEN=0V | 5 | |
| Supply Current | ICC | 3.6 | 4 | mA | VEN=2V, VFB=1.3V | 5 | |
| Feedback Voltage | VFB | 1.185 | 1.222 | 1.26 | V | VIN = 3.6V to 28V | 5 |
| Feedback Bias Current | IFB | 0.1 | 0.5 | uA | VFB=1.3V | 5 | |
| Switch Current Limit | ILIM | 3 | 4 | A | 5 | ||
| Oscillator Frequency | FOSC | 320 | 380 | 440 | KHz | 5 | |
| EN Pin Threshold | VEN | 0.7 | 1.2 | 1.7 | V | VIN =12V, VFB=0V | 5 |
| EN Pin Input Leakage Current (high) | IH | -0.1 | -1 | uA | VEN=2.5V | 5 | |
| EN Pin Input Leakage Current (low) | IL | -3 | -10 | uA | VEN=0.5V | 5 | |
| Max. Duty Cycle | DMAX | 100 | % | VFB=0V, ISW=0.1A | 5 | ||
| Input Voltage (absolute maximum) | VIN | -0.3 | 32 | V | 4 | ||
| Feedback Pin Voltage | VFB | -0.3 | V | 4 | |||
| Enable Pin Voltage | VEN | -0.3 | 12 | V | 4 | ||
| Switch Pin Voltage | VSW | -0.3 | V | 4 | |||
| Operating Junction Temperature (absolute maximum) | TJ | 150 | ºC | 4 | |||
| Storage Temperature | TSTG | -65 | 150 | ºC | 4 | ||
| Lead Temperature (Soldering) | TLEAD | 260 | ºC | Soldering, 10 sec | 4 | ||
| ESD (HBM) | 2000 | V | HBM | 4 | |||
| Input Voltage (recommended) | VIN | 3.6 | 32 | V | 4 | ||
| Operating Junction Temperature | TJ | -40 | 125 | ºC | 4 | ||
| Operating Ambient Temperature | TA | -10 | 85 | ºC | 4 | ||
| Thermal Resistance Junction to Ambient | RθJA | 85 | ºC / W | 4 | |||
| Thermal Resistance Junction to Case | RθJC | 45 | ºC / W | 4 | |||
| Frequency of Current Limit or Short Circuit Protection | FOSC1 | 42 | KHz | VFB=0V | 5 | ||
| Internal PMOS RDSON | RDSON | 80 | mΩ | VIN =12V, VFB=0V; VEN=12V, Iout=2A | 5 | ||
| Efficiency | η | 92 | % | VIN=12V, Vout=5V; Iout=2A | 5 | ||
| Thermal Shutdown | TOTSD | 165 | ºC | 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 | 11 |
CAD (KiCad official)
- Symbol:
TD1591 - Footprint:
Package_SO:SOIC-8_3.9x4.9mm_P1.27mm - 3D model: SOIC-8 (KiCad packages3D, STEP)
- 3D model files:
td1591-etched.step/td1591-etched.glbcarry the MPN laser-etched on the die in a toggleableAdom.LaserEtchgroup (Fusion-ready);td1591.step/td1591.glbare the bare package body.
Provenance
Data extracted from the manufacturer datasheet, not a distributor listing:
- Datasheet: Techcode Semicon datasheet (16 pp, sha256
8d4f94f8ad7a92ea, retrieved 2026-10-28, 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).