LP5030 datasheet(18/62 Pages) TI2

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RIREF=KIREF ×

VIREF

ISET

LP5030, LP5036

SLVSEH1B – SEPTEMBER 2018 – REVISED JANUARY 2019

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8.3.3 Current Range Setting

The maximum constant-current value of all 30 or 36 channels is set by a single external resistor, RIREF. The

value of RIREF can be calculated by Equation 1.

where:

•

KIREF = 105

•

VIREF = 0.7 V

(1)

With the IREF pin floating, the output current is close to zero. With the IREF pin shorted to GND, the LP503x

device provides internal current-limit protection, and the output-channel maximum current is limited to ILIM.

The LP503x device supports two levels of maximum output current, IMAX.

•

When VCC is in the range from 2.7 V to 5.5 V, and the Max_Current_Option (bit) = 0, IMAX= 25.5 mA.

•

When VCC is in the range from 3.3 V to 5.5 V, and the Max_Current_Option (bit) = 1, IMAX= 35 mA.

8.3.4 Automatic Power-Save Mode

When all the LED outputs are inactive, the LP503x device is able to enter power-save mode automatically, thus

lowering idle-current consumption down to 12 μA (maximum). Automatic power-save mode is enabled when

blocks are powered down in power-save mode. If any I2C command to the device occurs, the LP503x device

returns to NORMAL mode.

8.3.5 Protection Features

8.3.5.1 Thermal Shutdown

The LP503x device implements a thermal shutdown mechanism to protect the device from damage due to

overheating. When the junction temperature rises to 160°C (typical), the device switches into shutdown mode.

The LP503x device releases thermal shutdown when the junction temperature of the device is reduced to 145°C

(typical).

8.3.5.2 UVLO

The LP503x device has an internal comparator that monitors the voltage at VCC. When VCC is below VUVF, reset

is active and the LP503x device is in the INITIALIZATION state.

LP5030 bảng dữ liệu(PDF) 18 Page - Texas Instruments