bd9328efj ROHM Co. Ltd., bd9328efj Datasheet
bd9328efj
Available stocks
Related parts for bd9328efj
bd9328efj Summary of contents
Page 1
... Switching Regulator with Built-in Power MOSFET BD9328EFJ ●Description The BD9328EFJ is a synchronous step-down switching regulator that integrates 2 low resistance N-channel MOSFETs. It achieves 2A continuous output current over a wide input supply range. Current mode operation provides fast transient response and easy phase compensation. ●Features 1) Wide operating INPUT Range 4.2V～ ...
Page 2
... BD9328EFJ ●Operation Range (Ta= -40～85℃) Parameter Supply Voltage SW Voltage Output current Output voltage range ●Electrical characteristics (Unless otherwise specified VIN=12V Ta=25℃) Parameter Error amplifier block FB input bias current Feedback voltage1 Feedback voltage2 SW block – SW Hi-side FET On-resistance Lo-side FET On-resistance ...
Page 3
... BD9328EFJ ●Block Diagram VIN EN VREF ERR - COMP SS Soft Start ●Typical Application Circuit VIN 12V C_VC1 10μF Symbol Input capacitor C_VC1 Output capacitor C_CO1 Inductor L www.rohm.com © 2011 ROHM Co., Ltd. All rights reserved. 5V OSC VREG UVLO IBIAS TSD S DRV LOGIC SLOPE + R PWM － ...
Page 4
... BD9328EFJ ●Block Operation ・VREG A block to generate constant-voltage for DC/DC boosting. ・VREF A block that generates internal reference voltage of 5.1 V (Typ.). ・TSD/UVLO TSD (Thermal shutdown)/UVLO (Under Voltage Lockout) protection block. The TSD circuit shuts down IC at high temperature. The UVLO circuit shuts down the IC when the VCC is Low Voltage. ...
Page 5
... BD9328EFJ ●Outward form ●Pin Assignment and Pin Function Pin No. Pin name 1 BST 2 VIN GND COMP www.rohm.com © 2011 ROHM Co., Ltd. All rights reserved. 4.9±0.1 (Max5.25 include.BURR) (3. 0.545 1PIN MARK +0.05 0.08 0.42 1.27 -0.04 0.08 S Fig.3 HTSOP-J8 Package (Unit:mm) ...
Page 6
... BD9328EFJ ●Typical Performance Characteristics (Unless otherwise specified, VIN= 12V Ta = 25℃) 1.6 1.4 1.2 1 0.8 0.6 0 VIN (V) Fig.4 Circuit Current (No switching) 0.92 0.91 0.90 0.89 0.88 -40 - TEMP[ ℃ ] Fig.7 Feedback voltage 500 1000 1500 2000 2500 Io[mA] Fig.10 STEP Down Efficiency (VIN= 12V V = 3.3V L=10µ ...
Page 7
... BD9328EFJ V -MAX: +48mV OUT V OUT V -MIN: -50m V OUT 1 Div OUT OUT Fig.13 Transient Response (VIN= 12V V = 3.3V L= 10µH Cout =20µF Iout= 0.2-1.0A ) OUT V -MAX: +100mV OUT V OUT V -MIN: -100mV OUT I OUT Div OUT Fig.15 Transient Response (VIN= 12V V = 3.3V L= 10µH Cout =20µF Iout= 0.2-2.0A) ...
Page 8
... BD9328EFJ ●Selecting Application Components (1) Output LC filter constant selection (Buck Converter) The Output LC filter is required to supply constant current to the output load. A larger value inductance at this filter results in less inductor ripple current(∆I have less fast load transient-response, a larger physical size, a lower saturation current and higher series resistance. A smaller value inductance has almost opposite characteristics above. So Choosing the Inductor ripple current(∆ ...
Page 9
... BD9328EFJ (2) Loop Compensation Choosing compensation capacitor C The current-mode buck converter has 2-poles and 1-zero system. Choosing the compensation resistor and capacitor is important for a good load-transient response and good stability. The example of DC/DC converter application bode plot is shown below. The compensation resistor R loop-gain falls to 0dB). ...
Page 10
... BD9328EFJ (3) Design of Feedback Resistance constant Set the feedback resistance as shown below. 0.9V V OUT + R1 ERR － Fig.22 ●Soft Start Function ERRAMP I SS ↓ COMP + + - Fig.23 ●EN Function VIN EN 66 kΩ(typ.) REN ON/OFF Signal Fig.24 www.rohm.com © 2011 ROHM Co., Ltd. All rights reserved. ...
Page 11
... BD9328EFJ ●Layout Pattern Consideration Two high pulsing current flowing loops exist in the buck regulator system. The first loop, when FET is ON, starts from the input capacitors, to the VIN terminal, to the SW terminal, to the inductor, to the output capacitors, and then returns to the input capacitor through GND. The second loop, when FET is OFF, starts from the low FET, to the inductor, to the output capacitor, and then returns to the low FET through GND ...
Page 12
... BD9328EFJ ●I/O Equivalent Circuit Diagram 1.BST REG SW 6.COMP VIN VIN EF ●Power Dissipation 4000 (4)3760mW 3000 (3)2110mW 2000 (2)1100mW 1000 (1)820mW AMBIENT TEMPERATURE: Ta [°C] www.rohm.com © 2011 ROHM Co., Ltd. All rights reserved. 3.SW VIN VIN 7.EN VIN HTSOP-J8 Package On 70 70 1.6 mm glass epoxy PCB (1) 1-layer board (Backside copper foil area 0 mm ...
Page 13
... BD9328EFJ ●Notes for use 1) Absolute maximum ratings Use of the IC in excess of absolute maximum ratings such as the applied voltage or operating temperature range may result in IC damage. Assumptions should not be made regarding the state of the IC (short mode or open mode) when such damage is suffered. A physical safety measure such as a fuse should be implemented when use of the special mode where the absolute maximum ratings may be exceeded is anticipated ...
Page 14
... BD9328EFJ 9) Overcurrent protection circuits An overcurrent protection circuit designed according to the output current is incorporated for the prevention of IC damage that may result in the event of load shorting. This protection circuit is effective in preventing damage due to sudden and unexpected accidents. However, the IC should not be used in applications characterized by the continuous operation or transitioning of the protection circuits ...
Page 15
... BD9328EFJ ●Ordering part number Part No. Part No. HTSOP-J8 4.9±0.1 (MAX 5.25 include BURR) (3.2) + 6° 4° −4° 1PIN MARK 0.545 0.17 S 1.27 +0.05 0.42 -0.04 0.08 M 0.08 S www.rohm.com © 2011 ROHM Co., Ltd. All rights reserved Package EFJ: HTSOP-J8 <Tape and Reel information> ...
Page 16
No copying or reproduction of this document, in part or in whole, is permitted without the consent of ROHM Co.,Ltd. The content specified herein is subject to change for improvement without notice. The content specified herein is for the purpose ...