Datasheet HT16D35A/HT16D35B (Holtek) - 9
| Fabricante | Holtek |
| Descripción | RAM Mapping 28×8 Constant Current LED Driver |
| Páginas / Página | 71 / 9 — HT16D35A/HT16D35B. IROW v.s. VDS @ VDD=5V. ROI. VDS (V). Setting the … |
| Revisión | 1.00 |
| Formato / tamaño de archivo | PDF / 2.3 Mb |
| Idioma del documento | Inglés |
HT16D35A/HT16D35B. IROW v.s. VDS @ VDD=5V. ROI. VDS (V). Setting the Output Current. IROW v.s. REXT. A) (m. W IRO. REXT (Ω)
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HT16D35A/HT16D35B
The following IV curve is supplied for reference.
IROW v.s. VDS @ VDD=5V
60.000 50.000 Rext=300Ω 40.000 Rext=333Ω
A)
Rext=500Ω
(m
30.000
W
Rext=750Ω
ROI
20.000 Rext=1KΩ Rext=1.5KΩ 10.000 Rext=2KΩ Rext=4KΩ 0.000 00 20 40 60 80 00 20 40 60 80 00 20 40 60 80 00 20 40 60 Rext=5KΩ 0. 0. 0. 0. 0. 1. 1. 1. 1. 1. 2. 2. 2. 2. 2. 3. 3. 3. 3.
VDS (V) Setting the Output Current
The output current (IROW) is setup using an external resistor, R_EXT. The maximum LED current can be calculated using the following formula: IROW_MAX [A] = 15 / R_EXT (Ω) (Typ.) As a warning it should be noted that the maximum LED current value is 45mA. The default relationship between IROW and R_EXT is shown in the following figure.
IROW v.s. REXT
60.00 50.00 40.00
A) (m
30.00
W IRO
20.00 IROW 10.00 0.00 0 0 0 30 60 90 00 00 00 00 00 00 00 00 00 00 00 00 00 12 15 18 21 24 27 30 33 36 39 42 45 48
REXT (Ω)
The Maximum ROW current and Delta ROW current values are shown in the next table. If the R_EXT value is changed, the new LED current step can be seen from the table. The recommended value for R_EXT is 500Ω. R_EXT (Ω) 5K 3K 2.5K 1.5K 1K 750 600 500 375 300 IROW_MAX (mA) 3 5 6 10 15 20 25 30 40 50 Rev. 1.00 9 July 12, 2017 Document Outline Features Applications General Description Selection Table Block Diagram Pin Assignment Pin Description Absolute Maximum Ratings D.C. Characteristics A.C. Characteristics A.C. Characteristics – SPI 3-wire Serial Bus A.C. Characteristics – I2C Serial Bus Timing Diagrams SPI 3-Wire Serial Bus Timing I2C Bus Timing Power on Reset Timing Functional Description Power-on Reset LED Driver System Oscillator ROW Driver Outputs Column Driver Outputs Address Pointer Over Temperature Protection Constant Current Output Setting the Output Current Load Supply Voltage – LED_V Display Data RAM – DDRAM LED Driver Output Waveform Output Signal Timing Fade Data RAM Universal COM (UCOM) RAM Data Universal SEG (USEG) RAM Data Matrix Masking RAM Data Command Description – Command Table Software Reset Binary/Gray Select Number of COM Outputs Global Blinking Cascade Mode System Control Constant Current Ratio Global Brightness Mode Control Scrolling Control Scrolling Speed COM Pin Control ROW Pin Control Direct Pin Control Read Flag Read Status Write Display Data Write Fade Data Write UCOM Data Write USEG Data Write Matrix Masking Data SPI 3-wire Serial Interface I2C Serial Interface Power Supply Sequence Operation Flow Chart Application Circuits LED Matrix Circuit Single LED IC Application Cascade Function Cascade Control Flow Package Information 48-pin LQFP (7mm×7mm) Outline Dimensions (Exposed Pad)
The following IV curve is supplied for reference.
IROW v.s. VDS @ VDD=5V
60.000 50.000 Rext=300Ω 40.000 Rext=333Ω
A)
Rext=500Ω
(m
30.000
W
Rext=750Ω
ROI
20.000 Rext=1KΩ Rext=1.5KΩ 10.000 Rext=2KΩ Rext=4KΩ 0.000 00 20 40 60 80 00 20 40 60 80 00 20 40 60 80 00 20 40 60 Rext=5KΩ 0. 0. 0. 0. 0. 1. 1. 1. 1. 1. 2. 2. 2. 2. 2. 3. 3. 3. 3.
VDS (V) Setting the Output Current
The output current (IROW) is setup using an external resistor, R_EXT. The maximum LED current can be calculated using the following formula: IROW_MAX [A] = 15 / R_EXT (Ω) (Typ.) As a warning it should be noted that the maximum LED current value is 45mA. The default relationship between IROW and R_EXT is shown in the following figure.
IROW v.s. REXT
60.00 50.00 40.00
A) (m
30.00
W IRO
20.00 IROW 10.00 0.00 0 0 0 30 60 90 00 00 00 00 00 00 00 00 00 00 00 00 00 12 15 18 21 24 27 30 33 36 39 42 45 48
REXT (Ω)
The Maximum ROW current and Delta ROW current values are shown in the next table. If the R_EXT value is changed, the new LED current step can be seen from the table. The recommended value for R_EXT is 500Ω. R_EXT (Ω) 5K 3K 2.5K 1.5K 1K 750 600 500 375 300 IROW_MAX (mA) 3 5 6 10 15 20 25 30 40 50 Rev. 1.00 9 July 12, 2017 Document Outline Features Applications General Description Selection Table Block Diagram Pin Assignment Pin Description Absolute Maximum Ratings D.C. Characteristics A.C. Characteristics A.C. Characteristics – SPI 3-wire Serial Bus A.C. Characteristics – I2C Serial Bus Timing Diagrams SPI 3-Wire Serial Bus Timing I2C Bus Timing Power on Reset Timing Functional Description Power-on Reset LED Driver System Oscillator ROW Driver Outputs Column Driver Outputs Address Pointer Over Temperature Protection Constant Current Output Setting the Output Current Load Supply Voltage – LED_V Display Data RAM – DDRAM LED Driver Output Waveform Output Signal Timing Fade Data RAM Universal COM (UCOM) RAM Data Universal SEG (USEG) RAM Data Matrix Masking RAM Data Command Description – Command Table Software Reset Binary/Gray Select Number of COM Outputs Global Blinking Cascade Mode System Control Constant Current Ratio Global Brightness Mode Control Scrolling Control Scrolling Speed COM Pin Control ROW Pin Control Direct Pin Control Read Flag Read Status Write Display Data Write Fade Data Write UCOM Data Write USEG Data Write Matrix Masking Data SPI 3-wire Serial Interface I2C Serial Interface Power Supply Sequence Operation Flow Chart Application Circuits LED Matrix Circuit Single LED IC Application Cascade Function Cascade Control Flow Package Information 48-pin LQFP (7mm×7mm) Outline Dimensions (Exposed Pad)