BD9778F-E2 Rohm Semiconductor, BD9778F-E2 Datasheet - Page 14

• Manufacturer Part Number: BD9778F-E2
• Description: IC REG SW 2A P-CH MOSF STDN SOP8
• Manufacturer: Rohm Semiconductor
• Type: Step-Down (Buck)r

Specifications of BD9778F-E2

• Internal Switch(s): Yes
• Synchronous Rectifier: No
• Number Of Outputs: 1
• Voltage - Output: 1 ~ 35 V
• Current - Output: 2A
• Frequency - Switching: 50kHz ~ 500kHz
• Voltage - Input: 7 ~ 35 V
• Operating Temperature: -40°C ~ 125°C
• Mounting Type: Surface Mount
• Package / Case: 8-SOP
• Power - Output: 690mW
• No. Of Outputs: 1
• Output Voltage: 35V
• Output Current: 2A
• Voltage Regulator Case Style: SOP
• No. Of Pins: 8
• Operating Temperature Range: -40°C To +125°C
• Svhc: No SVHC (18-Jun-2010)
• Base Number: 9778
• Input Voltage: 35 V
• Switching Frequency: 102 KHz
• Mounting Style: SMD/SMT
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Lead free / RoHS Compliant
• Other names: BD9778F-E2TR

Cautions on use
SW
SW
EN(BD9778F/HFP, BD9001F)
EN
1) Absolute maximum ratings
2) GND potential
3) Thermal design
4) Inter-pin shorts and mounting errors
5) Operation in strong electromagnetic field
6) Inspection with set printed circuit board
7) IC pin input (Fig. 37)
(Pin A)
P layer
An excess in the absolute maximum ratings, such as supply voltage, temperature range of operating conditions, etc., can break down
the devices, thus making impossible to identify breaking mode, such as a short circuit or an open circuit. If any over rated values will
expect to exceed the absolute maximum ratings, consider adding circuit protection devices, such as fuses. Furthermore, don't turn on
the IC with a fast rising edge of V
GND potential should maintain at the minimum ground voltage level. Furthermore, no terminals should be lower than the GND
potential voltage including an electric transients.
Use a thermal design that allows for a sufficient margin in light of the power dissipation (Pd) in actual operating conditions.
Use caution when positioning the IC for mounting on printed circuit boards. The IC may be damaged if there is any connection error or
if positive and ground power supply terminals are reversed. The IC may also be damaged if pins are shorted together or are shorted to
other circuits power lines.
Use caution when using the IC in the presence of a strong electromagnetic field as doing so may cause the IC to malfunction.
When testing the IC on an application board, connecting a capacitor to a pin with low impedance subjects the IC to stress.
Always discharge capacitors after each process or step. Always turn the IC's power supply off before connecting it to, or removing it
from a jig or fixture, during the inspection process. Ground the IC during assembly steps as an
Use similar precaution when transporting and storing the IC.
This monolithic IC contains P+ isolation and P substrate layers between adjacent elements to keep them isolated.
P-N junctions are formed at the intersection of these P layers with the N layers of other elements, creating a parasitic diode or transistor.
For example, the relation between each potential is as follows:
the IC. The operation of parasitic diodes can result in mutual interference among circuits, operational faults, or physical damage.
Accordingly, methods by which parasitic diodes operate, such as applying a voltage that is lower than the GND (P substrate) voltage to
an input pin, should not be used.
N
When GND > Pin A and GND > Pin B, the P-N junction operates as a parasitic diode.
When Pin B > GND > Pin A, the P-N junction operates as a parasitic transistor. Parasitic diodes can occur inevitably in the structure of
VIN
P +
VIN
10kΩ
300kΩ
250kΩ
Resistor
VIN
N
P
Parasitic element
GND
RT
RT
FB(BD9001F)
IN
P +
Fig.37 Typical simple construction of monolithic IC
. ( rise time << 10V / μsec )
FB
N
VIN
VIN
2kΩ
(Pin B)
1kΩ
VREF
N
Fig.36 Equivalent circuit
Parasitic element
300kΩ
P +
1kΩ
50kΩ
C
14/16
Transistor (NPN)
VREF
B
N
N
E
FB
P
GND
FB(BD9778F/HFP, BD9781HFP)
P layer
VIN
1kΩ
EN/SYNC(BD9781HFP)
P +
EN/SYNC
N
GND
VREF
VIN
antistatic measure.
222
145
kΩ
kΩ
(PIN B)
(Pin A)
INV
139
221
kΩ
kΩ
INV
GND
B
VIN
1kΩ
Parasitic element
VREGA
2kΩ
GND
Parasitic element
C
E
VREF