BD9781HFP-TR Rohm Semiconductor, BD9781HFP-TR Datasheet - Page 8

• Manufacturer Part Number: BD9781HFP-TR
• Description: IC REG SW 4A P-CH MOSF STDN HRP7
• Manufacturer: Rohm Semiconductor
• Type: Step-Down (Buck)r
• Series: -r

Specifications of BD9781HFP-TR

• Internal Switch(s): Yes
• Synchronous Rectifier: No
• Number Of Outputs: 1
• Voltage - Output: 1 ~ 35 V
• Current - Output: 4A
• Frequency - Switching: 50kHz ~ 500kHz
• Voltage - Input: 7 ~ 35 V
• Operating Temperature: -40°C ~ 125°C
• Mounting Type: Surface Mount
• Package / Case: HRP-7
• Power - Output: 5.5W
• Output Voltage: 1 V
• Output Current: 4 A
• Input Voltage: 35 V
• Switching Frequency: 102 KHz
• Operating Temperature Range: - 40 C to + 125 C
• Mounting Style: SMD/SMT
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Timing chart
(BD9781HFP)
External synchronizing function (BD9781HFP)
In order to activate the external synchronizing function, connect the frequency setting resistor to the RT pin and then input
a synchronizing signal to the EN/SYNC pin. As the synchronizing signal, input a pulse wave higher than a frequency determined
with the setting resistor (RT). On the BD9781HFP, design the frequency difference to be within 50%. Furthermore,
set the pulse wave duty between 10% and 90%.
-
-
While in basic operation mode
While in overcurrent protection mode
Internal
OSC
Internal
OSC
Internal
OSC
V
SW
EN/SYNC
I
SW
O
IN
F
SYNC
FB
FB
Output short circuit
Auto reset
Fig.29
Fig.27
Fig.28
8/16
Auto reset
Auto reset
Auto reset
: For RT only
: For external
synchronization