LM36010 Datasheet, PDF (17/37 Pages) Texas Instruments – Synchronous-Boost, Single-LED Flash Driver With 1.5-A High-Side Current Source

www.ti.com
LM36010
SNVSAN4A – APRIL 2017 – REVISED JULY 2017
Device Functioning Modes (continued)
7.4.4.2 Input Voltage Flash Monitor (IVFM)
When the input voltage crosses the IVFM-D value, programmed by Configuration Register (0x02) bits [7:5], the
LM36010 sets the IVFM flag (bit [6]) of Flags Register (0x05).
7.4.4.3 LED and/or VOUT Short Fault
LM36010 enters stand-by mode from flash or torch mode and V_LED Short Fault flag (bit [5]) of Flags Register
(0x05) is set, if the LED output and/or VOUT experiences a short condition. An LED short condition occurs if the
voltage at the LED pin goes below 500 mV (typical). There is a deglitch time of 256 µs before the LED short flag
is valid, and a deglitch time of 2.048 ms before the VOUT short flag is valid. The LED and/or VOUT short fault
can be reset to 0 by removing power to the LM36010, or setting the software reset field (Register 0x06 bit [7]) to
a 1, or by reading back the Flags Register.
7.4.4.4 Current Limit (OCP)
The LM36010 features two selectable inductor current limits, 1.9A and 2.8A, programmable through the I²C-
compatible interface by writing to Register 0x01 bit [5] . When the inductor current limit is reached, the LM36010
terminates the charging phase of the switching cycle and sets the OCP flag (bit [4]) of Flags Register (0x05).
However, the mode M1, M0 (bits [1:0]) are not cleared as the device operates at current limit. Switching resumes
at the start of the next switching period.
In pass mode, there is no mechanism to limit the current as the current does not flow through the NMOS, which
senses the current limit.
In the boost mode or the pass mode, if V_OUT falls below 2.3 V, the device stops switching, and the PFET
operates as a current source limiting the current to 200 mA. This prevents the LM36010 from drawing excessive
current from the battery during output short-circuit conditions.
7.4.4.5 Thermal Scale-Back (TSB)
When the LM36010 die temperature reaches 125°C, the thermal scale-back (TSB) circuit trips and TSB flag (bit
[2]) of Flags Register (0x05) is set. The LED current then shifts to torch current level, set by the LED Torch
Brightness Register (0x04 bits [6:0]) for the duration of the flash pulse, set by the flash time-out in the
Configuration Register (0x02 bits [4:1]) After I²C read of the Flags Register and upon re-flash, if the die
temperature is still above 125°C, the LM36010 re-enters into torch current level and sets the TSB flag bit again.
7.4.4.6 Thermal Shutdown (TSD)
When the LM36010 die temperature reaches 150°C, the thermal shutdown (TSD) circuit trips, forcing the
LM36010 into standby and writing a 1 to the TSD flag (bit [2]) of the Flags Register (0x05). The LM36010 restarts
only after the Flags Register is read, which clears the fault flag. Upon restart, if the die temperature is still above
150°C, the LM36010 resets the TSD flag and re-enters standby.
7.4.4.7 Undervoltage Lockout (UVLO)
The LM36010 has an internal comparator that monitors the voltage at IN pin. If the input voltage drops to 2.5 V,
the UVLO flag (bit [1]) of Flags Register (0x05) is set and the LM36010 switches to stand-by mode. After the
UVLO flag is set, even if the input voltage rises above 2.5 V, the LM36010 is not available for operation until
there is an I²C read of the Flags Register. Upon an I²C read of the Flags Register, the UVLO fault is cleared and
normal operation can resume.
7.4.4.8 Flash Time-out (FTO)
The LM36010 sources the flash current for the time period set by Flash Time-out (0x02 bits [4:1]). The LED
current source has 16 time-out levels ranging from 40 ms to 1600 ms.
Copyright © 2017, Texas Instruments Incorporated
Product Folder Links: LM36010
Submit Documentation Feedback
17