BD9E303EFJ-LB Datasheet, PDF (16/31 Pages) Rohm – Over-Current Protection

BD9E303EFJ-LB
(2) Under Voltage Lockout Protection (UVLO)
The under voltage lockout protection circuit monitors the VIN terminal voltage.
The operation enters standby when the VIN terminal voltage is 5.0V (Typ) or lower.
The operation starts when the VIN terminal voltage is 6.4V (Typ) or higher.
V_IN
UVLO OFF
hys
0V
UVLO ON
Datasheet
V_OUT
FB
terminal
High-side
MOSFET gate
Soft start
Low-side
MOSFET gate
Normal operation
UVLO
Figure 39. UVLO Timing Chart
Normal operation
(3) Thermal Shutdown (TSD)
When the chip temperature exceeds Tj = 175C, the DC/DC converter output is stopped. The thermal shutdown
circuit is intended for shutting down the IC from thermal runaway in an abnormal state with the temperature
exceeding Tjmax = 150C. It is not meant to protect or guarantee the soundness of the application. Do not use the
function of this circuit for application protection design.
(4) Over Current Protection (OCP)
The over-current protection function observes the current flowing in upper-side MOSFET by switching cycle and
when it detects over flow current, it limits ON duty and protects by dropping output voltage.
(5) Reverse Current Protection (RCP)
The reverse-current protection function observes the current flowing in low-side MOSFET and when it detects over
flow current, it turns off the MOSFET.
(6) Over Voltage Protection (OVP)
Over voltage protection function (OVP) compares FB terminal voltage with internal standard voltage VREF. When the
FB terminal voltage exceeds 1.30V (Typ), it turns output MOSFETs off. When output voltage drops until it reaches the
hysteresis, it will return to normal operation.
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16/28
TSZ02201-0J3J0AJ00650-1-2
13.Feb.2015 Rev.002