BD9A301MUV-LB Datasheet, PDF (4/35 Pages) Rohm – This is the product guarantees long time support in Industrial market

BD9A301MUV-LB
Datasheet
Description of Blocks
1. VREF
The VREF block generates the internal reference voltage.
2. UVLO
The UVLO block is for under voltage lockout protection. It will shut down the IC when the VIN falls to 2.45V (Typ) or lower.
The threshold voltage has a hysteresis of 100mV (Typ).
3. SCP
After the soft start is completed and when the feedback voltage of the output voltage has fallen below 0.4V (Typ) for
1msec (Typ), the SCP stops the operation for 16msec (Typ) and subsequently initiates restart.
4. OVP
Over voltage protection function (OVP) compares FB terminal voltage with the internal standard voltage VREF. When the
FB terminal voltage exceeds 0.88V (Typ) it turns MOSFET of output part MOSFET off. After output voltage drop it returns
with hysteresis.
5. TSD
The TSD block is for thermal protection. The thermal protection circuit shuts down the device when the internal
temperature of IC rises to 175C (Typ) or higher. Thermal protection circuit resets when the temperature falls. The circuit
has a hysteresis of 25°C (Typ).
6. SOFT START
The Soft Start circuit slows down the rise of output voltage during start-up and controls the current, which allows the
prevention of output voltage overshoot and inrush current. A built-in soft start function is provided and a soft start is
initiated in 1msec (Typ) when the SS terminal is open.
7. gm Amplifier
The gm Amplifier block compares the reference voltage with the feedback voltage of the output voltage. The error and
the ITH terminal voltage determine the switching duty. A soft start is applied at startup. The ITH terminal voltage is limited
by the internal slope voltage.
8. Current Comparator
The Current Comparator block compares the output ITH terminal voltage of the error amplifier and the slope block signal
to determine the switching duty. In the event of over current, the current that flows through the high-side MOSFET is
limited at each cycle of the switching frequency.
9. OSC
This block generates the oscillating frequency.
10.DRIVER LOGIC
This block is a DC/DC driver. A signal from current comparator is applied to drive the MOSFETs.
11. PGOOD
When the FB terminal voltage reaches 0.8V (Typ) within ±7%, the Nch MOSFET of the built-in open drain output turns off
and the output turns high.
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