BD8314NUV-E2 Rohm Semiconductor, BD8314NUV-E2 Datasheet - Page 4

• Manufacturer Part Number: BD8314NUV-E2
• Description: IC SWITCHING REG W/MOSFET SON10
• Manufacturer: Rohm Semiconductor
• Series: -r
• Type: Step-Up (Boost), PWMr

Specifications of BD8314NUV-E2

• Internal Switch(s): Yes
• Synchronous Rectifier: No
• Number Of Outputs: 1
• Voltage - Output: 4 V ~ 12 V
• Current - Output: 2.5A
• Frequency - Switching: 1.2MHz
• Voltage - Input: 3 V ~ 12 V
• Operating Temperature: -25°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 10-VFDFN Exposed Pad
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

●Description of Blocks
BD8314NUV
© 2010 ROHM Co., Ltd. All rights reserved.
www.rohm.com
1.
2.
3.
4.
5.
6.
7.
8.
9.
10. Nch FET SW
VREF
This block generates ERROR AMP reference voltage.
The reference voltage is 1.0 V.
UVLO
Circuit for preventing low voltage malfunction
Prevents malfunction of the internal circuit at activation of the power supply voltage or at low power supply voltage.
Monitors VREG pin voltage to turn off all output FET and DC/DC converter output when VREG voltage is lower than
2.4 V, and reset the timer latch of the internal SCP circuit and soft-start circuit. This threshold contains 100 mV
hysteresis.
SCP
Timer latch system short-circuit protection circuit
When the INV pin is the set 1.0 V or lower voltage, the internal SCP circuit starts counting. The internal counter is in
synch with OSC; the latch circuit activates after a lapse of 13.3 msec after the counter counts about 16000 oscillations
and then, turn off DC/DC converter output. To reset the latch circuit, turn off the STB pin once. Then, turn it on again or
turn on the power supply voltage again.
OSC
Circuit for oscillating saw tooth waves with an operation frequency fixed at 1.2 MHz
ERROR AMP
Error amplifier for detecting output signals and outputting PWM control signals
The internal reference voltage is set at 1.0 V.
A primary phase compensation device of 200 pF, 62 kΩ is built in between the inverting input terminal and the output
terminal of this ERROR AMP.
PWM COMP
Voltage-pulse width converter for controlling output voltage corresponding to input voltage
Comparing the internal SLOPE waveform with the ERROR AMP output voltage, PWM COMP controls the pulse width
to the output to the driver.
Max Duty is set at 85%.
SOFT START
Circuit for preventing in-rush current at startup by bringing the output voltage of the DC/DC converter into a soft-start
Soft-start time is in synch with the internal OSC, and the output voltage of the DC/DC converter reaches the set voltage
after about 10000 oscillations.
PRE DRIVER
CMOS inverter circuit for driving the built-in Nch FET.
STBY_IO
Voltage applied on STB pin (8 pin) to control ON/OFF of IC
Turned ON when a voltage of 2.5 V or higher is applied and turned OFF when the terminal is open or 0 V is applied.
Incorporates approximately 400 kΩ pull-down resistance.
Built-in SW for switching the coil current of the DC/DC converter. Incorporates an 80 mΩ NchFET SW capable of
withstanding 14 V. Since the current rating of this FET is 2.5 A, it should be used within 2.5 A including the DC current
and ripple current of the coil.
4/15
Technical Note
2010.11 - Rev.C