ZHCSMJ4 March 2021 TPS92391
PRODUCTION DATA
The Six LED driver channels of the TPS92391 device is configured by the LED_SET resistor, which supports applications using one to Six LED strings. Resistor with 1% accuracy is needed to ensure proper operation. The driver channels can also be tied together in groups of one, two or three. This allows the TPS92391 device to drive three 400-mA LED strings, two 600-mA LED strings, or one 1200-mA LED string. The LED strings are always appropriately phase shifted for their string configuration. This reduces the ripple seen at the boost output, which allows smaller output capacitors and reduces audible ringing in the capacitors. Phase shift increases the load frequency, which can move potential capacitor noise above the audible band while still keeping PWM frequency low to support a higher dimming ratio.
When the TPS92391 device is firstly powered on, the string configuration is configured by the LED_SET resistor and the phases of each channel are automatically configured. The LED string configuration must not be changed unless the TPS92391 is powered off in shutdown state. The unused LEDx pins should be tied to ground.
R_LED_SET (kΩ) | CONFIGURATION | OUT1 | OUT2 | OUT3 | OUT4 | OUT5 | OUT6 | AUTOMATIC PHASE SHIFT |
---|---|---|---|---|---|---|---|---|
3.92 | 6 Channels | 200 mA | 200 mA | 200 mA | 200 mA | 200 mA | 200 mA | 60° |
4.75 | 5 Channels | 200 mA | 200 mA | 200 mA | 200 mA | 200 mA | (Tied to GND) | 72° |
5.76 | 4 Channels | 200 mA | 200 mA | 200 mA | 200 mA | (Tied to GND) | (Tied to GND) | 90° |
7.87 | 3 Channels | 200 mA | 200 mA | 200 mA | (Tied to GND) | (Tied to GND) | (Tied to GND) | 120° |
11 | 2 Channels | 200 mA | 200 mA | (Tied to GND) | (Tied to GND) | (Tied to GND) | (Tied to GND) | 180° |
17.8 | 3 Channels | 400 mA | 400 mA | 400 mA | 120° | |||
42.2 | 2 Channels | 600 mA | 600 mA | 180° | ||||
124 | 1 Channels | 1200 mA | None |