SM16825E

## Description

The SM16825E is a 5-channel low-voltage linear constant current driver IC from Shenzhen Sunmoon Microelectronics. It uses a single-wire RZ code protocol at 800 Kbps for data input and supports daisy-chain cascading via DIN/DOUT. Each of the 5 output channels (OUTR/OUTG/OUTB/OUTW/OUTY) provides adjustable constant current from 10 to 300 mA with a 5-bit current gain control per channel. The IC features 16-bit PWM dimming (65536 grayscale levels) per channel, built-in over-temperature protection, data shaping without attenuation, and a standby mode consuming less than 2 mW.

## Features

- 5 constant-current output channels (R/G/B/W/Y)
- Operating voltage: 5-40 V
- Output current: 10-300 mA per channel (5-bit gain, 10 mA steps)
- Output current deviation: +/-5% or better
- Low knee voltage: 0.8 V at 300 mA (VDD = 5V)
- 16-bit PWM dimming: 65536 grayscale levels
- PWM frequency: 4.0 kHz typical (3.5-4.5 kHz)
- Single-wire RZ code protocol at 800 Kbps
- Daisy-chain cascade (DIN to DOUT)
- Built-in data shaping (no signal attenuation in cascade)
- Built-in over-temperature protection
- Standby mode with auto-wake on DIN data
- Standby current: < 100 uA
- Minimum output current turn-on pulse width: 160 ns
- Packages: ESOP8, EMSOP8

## Pin Configuration

| Pin | Name | Description |
|-----|------|-------------|
| 1 | OUTW | White LED drive current output |
| 2 | OUTY | Yellow/warm white LED drive current output |
| 3 | VIN | Power supply (5-40V) |
| 4 | DIN | RZ code data input |
| 5 | DOUT | Cascade data output |
| 6 | OUTB | Blue LED drive current output |
| 7 | OUTG | Green LED drive current output |
| 8 | OUTR | Red LED drive current output |
| Pad | GND | Ground (exposed pad) |

## Absolute Maximum Ratings

Ta = 25 C

| Parameter | Symbol | Range | Unit |
|-----------|--------|-------|------|
| Power supply voltage | VIN | 5-40 | V |
| Logic input voltage (DIN) | DIN | -0.4 to 5.5 | V |
| Output breakdown voltage | BVOUT | 45 | V |
| Maximum output current | IOUT_MAX | 300 | mA |
| Thermal resistance (ESOP8) | RthJA | 65 | C/W |
| Thermal resistance (EMSOP8) | RthJA | 60 | C/W |
| Power dissipation (ESOP8) | PD | 1.25 | W |
| Power dissipation (EMSOP8) | PD | 1.15 | W |
| Operating junction temperature | TJ | -40 to 150 | C |
| Storage temperature | TSTG | -55 to 150 | C |
| ESD (HBM) | VESD | 2 | kV |

## Electrical Characteristics

VIN = 24V, TA = 25 C

| Parameter | Symbol | Min | Typ | Max | Unit |
|-----------|--------|-----|-----|-----|------|
| External power supply | VIN | 5 | -- | 36 | V |
| Internal power supply | VDD | 4.5 | 5.0 | 5.3 | V |
| Quiescent current (all off) | IDD1 | -- | 0.6 | -- | mA |
| Quiescent current (150mA out) | IDD2 | -- | 3.0 | -- | mA |
| Standby current | ISTB | -- | -- | 100 | uA |
| DIN input high | VIH | 2.8 | -- | -- | V |
| DIN input low | VIL | -- | -- | 1.5 | V |
| Output current range | IOUT | 10 | -- | 300 | mA |
| Output current deviation (chip-to-chip) | dIOUT | -- | +/-5 | -- | % |
| Output current deviation (in-chip) | dIOUT | -- | +/-3 | -- | % |
| Knee voltage at 150 mA | VDS_S | -- | 0.5 | -- | V |
| Knee voltage at 300 mA | VDS_S | -- | 0.8 | -- | V |
| PWM dimming frequency | fPWM | 3.5 | 4.0 | 4.5 | kHz |
| Output rise time | tTLH | -- | 100 | -- | ns |
| Output fall time | tTHL | -- | 80 | -- | ns |

## Software API

### RZ Code Protocol Timing

| Symbol | Description | Min | Typ | Max | Unit |
|--------|-------------|-----|-----|-----|------|
| T | Code element period | 1200 | -- | -- | ns |
| T0H | 0 code, HIGH level | 200 | 300 | 400 | ns |
| T0L | 0 code, LOW level | 800 | 900 | -- | ns |
| T1H | 1 code, HIGH level | 800 | 900 | 1000 | ns |
| T1L | 1 code, LOW level | 200 | 300 | -- | ns |
| Trst | Reset, LOW level | 200 | -- | -- | us |

### Data Format

Each chip receives 80 bits of data per frame:
- 5 x 16-bit grayscale values (OUTR, OUTG, OUTB, OUTW, OUTY) = 80 bits
- Followed by a 32-bit trailer: 5 x 5-bit current gain values + 2-bit standby enable + 5-bit reserved

Current gain values set output current: gain x 10 mA (range 1-30, i.e., 10-300 mA).

## Packages

| Model | Package | Tube | Tape | Reel Size |
|-------|---------|------|------|-----------|
| SM16825E | ESOP8 | 100000 pcs/box | 4000 pcs/tape | 13 inches |
| SM16825E | EMSOP8 | -- | 4000 pcs/tape | 13 inches |

## Applications

- LED lighting (RGBWY multi-color)
- LED backlight
- Architectural and decorative lighting
- LED strip and pixel control