bd4912 ROHM Co. Ltd., bd4912 Datasheet - Page 14

• Manufacturer Part Number: bd4912
• Description: Dmos System Power Supply Ics With Low Current Consumption Now Available
• Manufacturer: ROHM Co. Ltd.

14. Thermal shutdown circuit (TSD circuit)
15. Ground patterns
16. Bypass capacitors between the V
17. Grounding the P.CON and P.ANT pins
18. Applications with modes where the potentials of the input (V
19. Always verify the characteristics of example application circuits prior to their use. When changing other external circuit
The IC incorporates a built-in thermal shutdown circuit (TSD circuit). However, in the event that the IC continues to be
operated in excess of its power dissipation limits, the attendant rise in the chip's temperature Tj will trigger the thermal
shutdown circuit to turn off all output power elements. The circuit will automatically reset once the chip's temperature Tj
drops. The thermal shutdown circuit (TSD circuit) is designed only to shut the IC off to prevent runaway thermal operation.
It is not designed to protect the IC or guarantee its operation. Do not continue to use the IC after operating this circuit or
use the IC in an environment where the operation of this circuit is assumed.
Pattern routes connecting the ground points, indicated in application circuits example, to the GND pin (pin 1) should be
sufficiently short and should be positioned to avoid electrical interference.
It is recommended to insert a bypass capacitor from 0.47 µF to 10 mF between the V
it as close as possible to the pins.
When the IC's GND pin (pin 1) is open and the P.CON (pin 4) and P.ANT (pin 3) pins are connected to a negative battery
terminal (are grounded), a parasitic element may occur inside the IC, resulting in damage. To prevent such damage, it is
recommended to insert a schottky diode between the P.CON and P.ANT pins and the GND pin. (See Fig. 50.)
from their normal states may cause damage to the IC's internal circuitry. In particular, it is recommended to create a
bypass route with diodes or other components when loads including large inductance components are connected as with
the P.ANT and P.CON pins in applications, where BEMF may be generated during startup or when output is turned off.
constants, allow for sufficient margins after considering the variability of both the ROHM IC and external components,
including both static and transient characteristics.
Use caution when determining the supply voltage range to use.
(Example)
Power
supply
CC
Fig.51 Example of Protective Diode Insertion
1/V
Fig.50 Ground Prevention Circuit Diagram
Output pin
CC
2 and GND pins
14/16
Vcc1
P.CON
CC
1) and GND pins and other output pins may be reversed
P.ANT
GND
CC
1/V
CC
2 and GND pins, positioning