BD9415FS Datasheet, PDF (7/34 Pages) Rohm – White LED Driver for 4Ch Large LCD Panels (DC/DC converter type)

BD9415FS
2.1 Pin Descriptions
○PIN1：VCC
This is the power supply pin of the IC. Input range is from 11.5V to 35V.
The operation starts at more than 7.5V(Typ) and shuts down at less than 7.2V(Typ).
○PIN2：FAILB
This is FAILB signal output (OPEN DRAIN) pin. At normal operation, NMOS will be in OPEN state, during abnormality
detection NMOS will be in ON (500 ohm(Typ))state.
○PIN3：UVLO
Under Voltage Lockout pin is the input voltage of the power stage. IC starts boost operation if UVLO is more than
2.5V(Typ) and stops if lower than 2.4V(Typ). It can also be used for reset when latched off by protection.
The power of step-up DC/DC converter needs to be set detection level by dividing the resistance.
○PIN4：REG90
The REG pin is used in the DC/DC converter driver block to output 9V. Available current is 20mA(Min). Using the REG pin
at current higher than 20mA can affect the IC base voltage, causing the IC to malfunction and leading to heat generation
of the IC itself. To avoid this problem, it is recommended to make load setting to the minimum level.
The characteristic of VCC line regulation at REG90 is shown as [Figure 6]. VCC must be used in more than 11.5V for
stable 9V output. Place the ceramic capacitor connected to REG90 pin (2.2uF to 10uF) closest to REG90-AGND pin.
○PIN5：STB
This is the ON/OFF setting terminal of the IC. It is allowed for use to reset the IC from shutdown.
※The IC state is switched according to voltages input in the STB pin.
※Avoid using the STB pin between two states (0.8 to 2.0V).
○PIN6：N
The N pin is used to output power to the external NMOS gate driver for the DC/DC converter in the amplitude range of
approximately 0V to 9V. Output ON resistance H - side is 2.5Ω (Typ) and L-side is 3.0Ω (Typ).
Frequency can be set by the resistor connected to RT. Refer to <RT> pin description for the frequency setting.
○PIN7：PGND
The PGND pin is a power ground pin for the driver block of the N output pin.
○PIN8：CS
CS pin is current detector for DC/DC current mode inductor current control pin.
Current flowing through the inductor is converted into voltage by the current sensing resistor RCS connected to the CS
pin and this voltage is compared with voltage set with the error amplifier to control the DC/DC output voltage. The CS pin
also incorporates the over current protection (OCP) function. If the CS voltage reaches 0.45V(Typ) or more, switching
operation will be forced to stopped.
○PIN9：DUTYON
This is the ON/OFF setting terminal of the LED PWM Over Duty Protection (ODP). By adjusting DUTYON input voltage, it
is ON/OFF of the ODP adjusted.
State
ODP=ON
ODP=OFF
DUTYON input voltage
DUTYON= -0.3V to +0.8V
DUTYON= +1.5V to +18.0V
○PIN10：OVP
The OVP pin is an input pin for over voltage protection and short circuit protection of DC/DC output voltage. When voltage
of it exceeds 3.0V(Typ), N pin will stop. This case is not CP count. When OVP pin voltage <0.2V(Typ) or lower, short
circuit protection (SCP) function is activated, and output of gate driver will become low immediately. And system is
stopped after a CP count. The setting example is separately described in the section ”3.2.6 OVP Setting”.
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TSZ02201-0F2F0C100140-1-2
23.May.2016 Rev.001