# IS31FL3733-QFLS4-TR

**ISSI Integrated Silicon Solution** · LED Drivers · QFN-48-EP(6x6)

IS31FL3733-QFLS4-TR from ISSI Integrated Silicon Solution, in a QFN-48-EP(6x6). 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 internally. |
| 2 | SW1 | output | Switch pin for LED matrix scanning (column SW1). |
| 3 | SW2 | output | Switch pin for LED matrix scanning (column SW2). |
| 4 | SW3 | output | Switch pin for LED matrix scanning (column SW3). |
| 5 | PGND | power_in | Power ground. |
| 6 | SW4 | output | Switch pin for LED matrix scanning (column SW4). |
| 7 | SW5 | output | Switch pin for LED matrix scanning (column SW5). |
| 8 | SW6 | output | Switch pin for LED matrix scanning (column SW6). |
| 9 | SW7 | output | Switch pin for LED matrix scanning (column SW7). |
| 10 | SW8 | output | Switch pin for LED matrix scanning (column SW8). |
| 11 | SW9 | output | Switch pin for LED matrix scanning (column SW9). |
| 12 | PGND | power_in | Power ground. |
| 13 | SW10 | output | Switch pin for LED matrix scanning (column SW10). |
| 14 | SW11 | output | Switch pin for LED matrix scanning (column SW11). |
| 15 | SW12 | output | Switch pin for LED matrix scanning (column SW12). |
| 16 | CS1 | output | Current source output for row control (CS1). |
| 17 | CS2 | output | Current source output for row control (CS2). |
| 18 | CS3 | output | Current source output for row control (CS3). |
| 19 | CS4 | output | Current source output for row control (CS4). |
| 20 | PVCC | power_in | Power supply for the current sources. |
| 21 | CS5 | output | Current source output for row control (CS5). |
| 22 | CS6 | output | Current source output for row control (CS6). |
| 23 | CS7 | output | Current source output for row control (CS7). |
| 24 | CS8 | output | Current source output for row control (CS8). |
| 25 | CS9 | output | Current source output for row control (CS9). |
| 26 | CS10 | output | Current source output for row control (CS10). |
| 27 | CS11 | output | Current source output for row control (CS11). |
| 28 | CS12 | output | Current source output for row control (CS12). |
| 29 | PVCC | power_in | Power supply for the current sources. |
| 30 | CS13 | output | Current source output for row control (CS13). |
| 31 | CS14 | output | Current source output for row control (CS14). |
| 32 | CS15 | output | Current source output for row control (CS15). |
| 33 | CS16 | output | Current source output for row control (CS16). |
| 34 | AGND | power_in | Analog ground. |
| 35 | R_EXT | passive | Input terminal for an external resistor that sets the current source DC current value. |
| 36 | NC | unconnected | Not connected internally. |
| 37 | AVCC | power_in | Power supply for analog circuits. |
| 38 | DVCC | power_in | Power supply for digital circuits. |
| 39 | VIO | power_in | Input logic reference voltage. |
| 40 | SYNC | bidirectional | Synchronization pin for multi-part operation; leave floating if not used. |
| 41 | SDA | bidirectional | I2C-compatible serial data. |
| 42 | SCL | input | I2C-compatible serial clock. |
| 43 | ADDR1 | input | I2C address setting. |
| 44 | ADDR2 | input | I2C address setting. |
| 45 | INTB | output | Interrupt output, active low when an interrupt event occurs; may be left floating if the interrupt function is not used. |
| 46 | SDB | input | Shuts down the chip when pulled low. |
| 47 | IICRST | input | Resets the I2C interface when pulled high; must be pulled low during normal operation. |
| 48 | GND | power_in | Ground; connect to GND. |
| 49 | EP | passive | Exposed pad (from the footprint; not named in the datasheet pin table). |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | ISSI Integrated Silicon Solution |
| Package | QFN-48-EP(6x6) |
| Category | LED Drivers |
| Pins | 49 |

## CAD (KiCad official)

- Symbol: `IS31FL3733-QFLS4-TR`
- Footprint: `Package_DFN_QFN:QFN-48-1EP_6x6mm_P0.4mm_EP4.4x4.4mm`
- 3D model: QFN-48-EP(6x6), generated from the KiCad footprint (body from the F.Fab outline, terminals on the pads, 0.9 mm nominal QFN height). Neither the vendor nor KiCad ships a 3D model for this package, so the dimensions are nominal, not the manufacturer's CAD (STEP)
- 3D model files: `is31fl3733-qfls4-tr-etched.step` / `is31fl3733-qfls4-tr-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `is31fl3733-qfls4-tr.step` / `is31fl3733-qfls4-tr.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [ISSI Integrated Silicon Solution datasheet](https://jlcpcb.com/api/file/downloadByFileSystemAccessId/8590174314994831360) (31 pp, sha256 `536d20da9f0b86c9`, retrieved 2026-10-09, 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/is31fl3733-qfls4-tr-datasheet.pdf)