# LD7535BL

**Leadtrend Tech** · AC-DC Controllers And Regulators · SOT-23-6

LD7535BL from Leadtrend Tech, in a SOT-23-6. 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 | GND | power_in | Ground reference pin for the controller (the datasheet lists only 'Ground' as its function). |
| 2 | COMP | input | Voltage feedback pin, same as the COMP pin in UC384X, driven from a photo-coupler to close the control loop; pulling it below 1.2V turns the gate output off, and the OLP trip level is 5.0V. |
| 3 | RT | input | Sets the switching frequency through a resistor to ground, with f_SW = 65.0 × (100 kΩ / RT) kHz and a recommended range of 50 kHz to 130 kHz; the gate output turns off if RT is shorted to ground or left floating. |
| 4 | CS | input | Current sense input that senses the MOSFET current for peak current mode control and pulse-by-pulse limit, with a maximum threshold of 0.85V and 350 ns leading-edge blanking; the gate output turns off if CS is left floating. |
| 5 | VCC | power_in | Supply voltage pin with a recommended range of 11V to 25V for the LD7535 (absolute maximum 30V), UVLO thresholds of 16.0V on and 10.0V off, and OVP at 28.0V ±1.5V. |
| 6 | OUT | output | Gate drive output that drives the external power MOSFET with a typical 300mA drive capability, with the maximum duty cycle limited to 75%. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | Leadtrend Tech |
| Package | SOT-23-6 |
| Category | Power Management (PMIC) |
| Pins | 6 |

## 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 (LD7535) recommended operating | Vcc | 11 |  | 25 | V |  | 5 |
| Switching Frequency recommended operating | fSW | 50 |  | 130 | KHz |  | 5 |
| Startup Resistor Value recommended operating |  | 1.2 |  | 4.4 | MΩ |  | 5 |
| UVLO (off) |  | 9 | 10 | 11 | V |  | 6 |
| UVLO (on) |  | 15 | 16 | 17 | V |  | 6 |
| OVP Level (LD7535) |  | 26.5 | 28 | 29.5 | V |  | 6 |
| Startup Current | Istartup | 8 |  | 20 | μA |  | 6 |
| Operating Current |  | 2 |  | 3 | mA | with 1nF load on OUT pin, VCOMP=0V | 6 |
| Operating Current |  |  |  | 2.5 | mA | with 1nF load on OUT pin, VCOMP=3V | 6 |
| Operating Current in protection tripped (OLP, OVP) |  |  | 0.5 |  | mA | with 1nF load on OUT pin | 6 |
| Short Circuit Current |  | 1.5 |  | 2.2 | mA | VCOMP=0V | 6 |
| Open Loop Voltage (COMP pin open) | VCOMP |  | 6 |  | V | COMP pin open | 6 |
| Green Mode Threshold | VCOMP |  | 2.35 |  | V |  | 6 |
| Maximum Input Voltage Vcs(off) | Vcs(off) | 0.8 | 0.85 | 0.9 | V |  | 6 |
| Leading Edge Blanking Time |  |  | 350 |  | nS |  | 6 |
| Input impedance (CS pin) |  |  | 1 |  | MΩ |  | 6 |
| Delay to Output |  |  | 100 |  | nS |  | 6 |
| Frequency (RT pin) | fOSC | 60 | 65 | 70 | KHz | RT=100KΩ | 6 |
| Green Mode Frequency |  |  | 20 |  | KHz | Fs=65KHz | 6 |
| Temp. Stability |  |  | 3 |  | % | -40°C ~105°C | 6 |
| Voltage Stability |  |  | 1 |  | % | VCC=11V-25V | 6 |
| Output Low Level (OUT pin) | VOL |  | 1 |  | V | VCC=15V, Io=20mA | 6 |
| Output High Level (OUT pin) | VOH |  | 8 |  | V | VCC=15V, Io=20mA | 6 |
| Rising Time (OUT pin) |  | 50 |  | 200 | nS | Load Capacitance=1000pF | 6 |
| Falling Time (OUT pin) |  | 30 |  | 100 | nS | Load Capacitance=1000pF | 6 |
| OLP Trip Level | VCOMP(OLP) |  | 5 |  | V |  | 6 |
| OLP Delay Time |  |  | 60 |  | mS | Fs=65KHz | 6 |
| Supply Voltage VCC absolute maximum | VCC |  |  | 30 | V |  | 5 |
| COMP, RT, CS voltage absolute maximum |  | -0.3 |  | 7 | V |  | 5 |
| Gate Output Current |  |  |  | 300 | mA |  | 5 |
| Junction Temperature | TJ |  |  | 150 | °C |  | 5 |
| Operating Ambient Temperature | TA | -40 |  | 85 | °C |  | 5 |
| Storage Temperature Range | TSTG | -65 |  | 150 | °C |  | 5 |
| Package Thermal Resistance (SOT-26) |  |  | 250 |  | °C/W |  | 5 |
| Power Dissipation (SOT-26) | PD |  |  | 250 | mW | at Ambient Temperature = 85°C | 5 |
| Lead temperature (Soldering) |  |  |  | 260 | °C | Soldering, 10sec | 5 |
| ESD Voltage Protection, Human Body Model |  |  |  | 3 | KV |  | 5 |
| ESD Voltage Protection, Machine Model |  |  |  | 250 | V |  | 5 |

## CAD (KiCad official)

- Symbol: `LD7535BL`
- Footprint: `Package_TO_SOT_SMD:SOT-23-6`
- 3D model: SOT-23-6 (KiCad packages3D, STEP)
- 3D model files: `ld7535bl-etched.step` / `ld7535bl-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `ld7535bl.step` / `ld7535bl.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [Leadtrend Tech datasheet](https://jlcpcb.com/api/file/downloadByFileSystemAccessId/8588881241508614144) (19 pp, sha256 `c6cca6fb87016e6c`, 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/ld7535bl-datasheet.pdf)