bd9526amuv ROHM Co. Ltd., bd9526amuv Datasheet - Page 4

• Manufacturer Part Number: bd9526amuv
• Description: Step Down Dc/dc Converter Controller For Laptop Pc
• Manufacturer: ROHM Co. Ltd.

○Output condition table
○NOTE FOR USE
(1) Absolute maximum rating
(2) Supply line
(3) GND potential
(4) Thermal design
(5) Operation in strong magnetic fields
(6) ASO
(7) Thermal shutdown circuit
(8) Ground wiring pattern
(9) Heat sink (FIN)
(11) Short-circuits between pins and and mounting errors
(10) For ICs with more than one power supply, it is possible that rush current may flow instantaneously due to the internal powering
sequence and delays. Therefore, give special consideration to power coupling capacitance, power wiring, width of GND wiring,
and routing of wiring.
In case the motor’s reverse electromotive force gives rise to the return of regenerative current, measures should be taken to
establish a channel for the current, such as adding a capacitor between the power supply and GND. In determining the
approach to take, make sure that no problems will be posed by the various characteristics involved, such as capacitance loss at
low temperatures with an electrolytic capacitor.
Make sure the potential for the GND pin is always kept lower than the potentials of all other pins, regardless of the operating
mode.
Be sure to factor in allowable power dissipation (Pd) in actual operation, and to build sufficient margin into the thermal design to
accommodate this power loss.
Set the parameters so that output Tr will not exceed the absolute maximum rating or ASO value when the IC is used.
This IC is provided with a built-in thermal shutdown (TSD) circuit, which is activated when the chip temperature reaches the
threshold value listed below. When TSD is on, the device goes to high impedance mode. Note that the TSD circuit is provided
for the exclusive purpose shutting down the IC in the presence of extreme heat, and is not designed to protect the IC per se or
guarantee performance when or after extreme heat conditions occur. Therefore, do not operate the IC with the expectation of
continued use or subsequent operation once the TSD is activated.
When both a small-signal GND and high current GND are present, single-point grounding (at the set standard point) is
recommended, in order to separate the small-signal and high current patterns, and to be sure the voltage change stemming from
the wiring resistance and high current does not cause any voltage change in the small-signal GND. In the same way, care must
be taken to avoid wiring pattern fluctuations in any connected external component GND.
Do not short-circuit between output pin and supply pin or ground, or between supply pin and ground. Mounting errors, such as
incorrect positioning or orientation, may destroy the device.
Use in strong electromagnetic fields may cause malfunctions. Exercise caution with respect to electromagnetic fields.
Since the heat sink (FIN) is connected with the Sub, short it to the GND.
The device may be destroyed when applied voltage or operating temperature exceeds its absolute maximum rating. Because the
source, such as short mode or open mode, cannot be identified if the device is destroyed, it is important to take physical safety
measures (such as fusing) if a special mode in excess of absolute rating limits is to be implemented.
High
High
High
High
CTL
Low
Low
Low
Low
TSD ON temperature [℃] (typ.)
Input
High
High
High
High
EN1
Low
Low
Low
Low
175
High
High
High
High
EN2
Low
Low
Low
Low
REG1(3.3V)
OFF
OFF
OFF
OFF
ON
ON
ON
ON
REV. B
REG2(3.3V)
Hysteresis temperature [℃] (typ.)
OFF
OFF
OFF
OFF
ON
ON
ON
ON
INTVCC
Output
15
OFF
OFF
OFF
OFF
ON
ON
ON
ON
DC/DC1
OFF
OFF
OFF
OFF
OFF
OFF
ON
ON
DC/DC2
OFF
OFF
OFF
OFF
OFF
OFF
ON
ON
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