Table 1-1 below compares key features and operating conditions for all orderable versions of the LP8860-Q1. Boost switching frequency, the number of channels, maximum LED current, and input brightness control method are considered critical specs and are highlighted in bold.
PARAMETER | A | B | C | D | E | F | G | H | |
---|---|---|---|---|---|---|---|---|---|
Boost | ƒSW | 300 kHz | 300 kHz | 2.2 MHz | 400 kHz | 400 kHz | 400 kHz | 400 kHz | 800 kHz |
Switching Current Limit | 9 A | 9 A | 9 A | 9 A | 4 A | 4 A | 4 A | 4 A | |
VDD | 5 V | 3.3 V | 5 V | 5 V | 5 V | 5 V | 5 V | 5 V | |
LED Driver | Number of Channels | 4 strings | 3 strings | 3 strings | 4 strings | 1 string | 2 strings | 1 string | 4 strings |
Maximum LED Current per Channel | 130 mA | 70 mA | 104 mA | 150 mA | 400 mA | 90 mA | 400 mA | 80 mA | |
ISET Resistor Control | Disabled | Enabled | Enabled | Enabled | Disabled | Disabled | Disabled | Disabled | |
Input Brightness Control Method | I2C/SPI BRT Register | PWM Pin Input | PWM Pin Input | PWM Pin Input | I2C/SPI BRT Register | PWM Pin Input (Direct) | I2C/SPI BRT Register | PWM Pin Input | |
LED Output Dimming Method | PWM | PWM | PWM | PWM | Hybrid Dimming | PWM | Hybrid Dimming | PWM | |
Output PWM Dimming Frequency | 4.883 kHz | Depends on VSYNC | 4.883 kHz | 4.883 kHz | = 11 × F_VSYNC | = F_PWMIN | 4.883 kHz | 4.883 kHz | |
Dimming Ratio | 1024:1 | 1024:1 | 1024:1 | 1024:1 | 15000:1 | > 32000:1 | > 4096:1 | 1024:1 | |
Fault Handling | Short LED Fault Threshold | 10.6 V | 10.6 V | 10.6 V | 10.6 V | 10.6 V | 10.6 V | 10.6 V | 6.9 V |
VIN OVP Level | 22.5 V | 22.5 V | Disabled | 22.5 V | 22.5 V | 22.5 V | Disabled | 22.5 V | |
VIN UVLO Level | 3 V | 3 V | 3 V | 3 V | 3 V | 3 V | 3 V | 5 V | |
VDD UVLO | 3 V | 3 V | 3 V | 3 V | 3 V | 3 V | 3 V | 3V | |
Input OCP Limit | 8 A | 8 A | 8 A | 8 A | 6 A | 6 A | 6 A | 6 A | |
TEMP COMP | Internal Temperature Compensation | Disabled | Enabled, 100°C | Disabled | Disabled | Disabled | Disabled | Disabled | Disabled |
External Temperature Compensation | Disabled | Enabled, current | Enabled, current | Disabled | Disabled | Disabled | Disabled | Disabled | |
SYNC | VSYNC Input | Disabled | Enabled | Disabled | Disabled | Enabled | Disabled | Disabled | Disabled |
PARAMETER | J | L | N | R | |
---|---|---|---|---|---|
Boost | ƒSW | 2.2 MHz | 400 kHz | 2.2 MHz | 2.2 MHz |
Switching Current Limit | 6 A | 3 A | 9 A | 9 A | |
VDD | 3.3 V | 3.3 V | 3.3 V | 3.3 V | |
LED Driver | Number of Channels | 3 strings | 3 strings | 2 strings | 4 strings |
Maximum LED Current per Channel | 80 mA | 80 mA | 150 mA | 150 mA | |
ISET Resistor Control | Enabled | Enabled | Enabled | Enabled | |
Input Brightness Control Method | I2C/SPI BRT Register | PWM Pin Input | I2C/SPI BRT Register | PWM Pin Input | |
LED Output Dimming Method | PWM | Hybrid Dimming | PWM | PWM | |
Output PWM Dimming Frequency | 9.766 kHz | 4.883 kHz | = 11 × F_VSYNC | 4.883 kHz | |
Dimming Ratio | 1024:1 | 4096:1 | 8192:1 | 1024:1 | |
Fault Handling | Short LED Fault Threshold | 6.9 V | 10.6 V | 10.6 V | 10.6 V |
VIN OVP Level | 22.5 V | Disabled | 22.5 V | Disabled | |
VIN UVLO Level | 5 V | 3 V | 3 V | 3 V | |
VDD UVLO | 3 V | 3 V | 2.5 V | 2.5 V | |
Input OCP Limit | 6 A | 6 A | 8 A | 8 A | |
TEMP COMP | Internal Temperature Compensation | Disabled | Disabled | Disabled | Disabled |
External Temperature Compensation | Enabled, current | Disabled | Disabled | Disabled | |
SYNC | VSYNC Input | Disabled | Disabled | Enabled | Disabled |
Detailed configuration information and reference schematics for each LP8860-Q1 version is listed in the rest of the document. The full bit descriptions for the EEPROM registers are found in the LP8860-Q1 data sheet.
The LP8860A-Q1 is configured for four strings × 130 mA using a 5-V VDD and I2C or SPI to control brightness. Table 2-1 lists detailed configurations and full EEPROM information for the LP8860A-Q1.
A | ||
---|---|---|
Boost | Switching Current Limit | 9 A |
SYNC Input | Disabled | |
2 × Charge Pump | Disabled | |
Spread Spectrum | Disabled | |
ƒSW | 300 kHz | |
VDD | 5 V | |
Initial Boost Voltage | 31.5 V | |
LED Driver | Input Brightness Control Method | I2C/SPI BRT Register |
Maximum LED Current per Channel | 130 mA | |
ISET Resistor Control | Disabled | |
Number of Channels | 4 strings | |
Channel Phase Shift | 90 degrees (4 phases) | |
LED Output Dimming Method | PWM | |
Current to PWM Switch Point | N/A | |
Current Linearity Correction Slope | N/A | |
Output PWM Dimming Frequency | 4.883 kHz | |
Dimming Resolution | 10-bit PWM + 4-bit dither | |
Drive Strength and Rise Time | 200 ns | |
Dimming Ratio | 1024:1 | |
Sloper | 105 ms + advanced slope | |
Driver Headroom Voltage | VSAT + 50 mV | |
Fault Handling | Short LED Fault Threshold | 10.6 V |
VIN OVP Level | 22.5 V | |
VIN UVLO Level | 3 V | |
VDD UVLO | 3 V | |
Input OCP Limit | 8 A | |
Powerline FET Type | PMOS | |
SD Pulldown Current | 440 µA | |
Temperature Compensation | Internal Temperature Compensation | Disabled |
External Temperature Compensation | Disabled | |
Current Dimming Knee Point | N/A | |
EXT_TEMP_GAIN[3:0] | N/A | |
EXT_TEMP_LEVEL_HIGH[3:0] | N/A | |
EXT_TEMP_LEVEL_LOW[3:0] | N/A | |
VSYNC and PLL | PLL | Disabled |
VSYNC input | Disabled | |
SYNC or HSYNC | N/A | |
PWM_SYNC | N/A | |
Pre-divider | N/A | |
Slow PLL Divider | N/A | |
R_SEL | N/A | |
SEL_Divider | N/A | |
PWM_FREQ | N/A | |
PWM_RES | N/A |
ADDRESS (HEX) | VALUE (BIN) | VALUE (HEX) |
---|---|---|
60 | 11101101 | ED |
61 | 11011111 | DF |
62 | 11011100 | DC |
63 | 11110000 | F0 |
64 | 11011111 | DF |
65 | 11100101 | E5 |
66 | 11110010 | F2 |
67 | 01110111 | 77 |
68 | 01110111 | 77 |
69 | 01110001 | 71 |
6A | 00111111 | 3F |
6B | 10110111 | B7 |
6C | 00010111 | 17 |
6D | 11101111 | EF |
6E | 10110000 | B0 |
6F | 10000111 | 87 |
70 | 11001110 | CE |
71 | 01110010 | 72 |
72 | 11100101 | E5 |
73 | 11011111 | DF |
74 | 00110101 | 35 |
75 | 00000110 | 06 |
76 | 11011100 | DC |
77 | 10001000 | 88 |
78 | 00111110 | 3E |
Figure 2-1 shows the use case for the LP8860A-Q1