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Linear Regulator Series
BDxxHC5 Series Application Information
The information in this application note only provides hints for IC mounting. For this reason, these notes should not be considered as
an IC quality explanation or a warranty. See the latest data sheet for the IC standard values. Also, note that the application circuits
used in the explanations for each item have been simplified. Be sure to verify operations using the actual application.
Table of contents
1. Typical Application Circuit ................................................................................................................................................................................................... 2
1.1. Adjustable output type BD00HC5WEFJ, BD00HC5MEFJ-LB, BD00HC5MEFJ-M ............................................................................................... 2
1.2. Fixed output type BDxxHC5WEFJ, BDxxHC5MEFJ-LB, BDxxHC5MEFJ-M ........................................................................................................ 3
2. Output voltage setting (Adjustable output type) ................................................................................................................................................................ 4
3. Kelvin connection ............................................................................................................................................................................................................... 5
4. Output voltage tolerance .................................................................................................................................................................................................... 5
5. Study of input/output voltage difference and characteristics ............................................................................................................................................ 6
6. Output control (EN) pin ...................................................................................................................................................................................................... 6
7. Output capacitor ................................................................................................................................................................................................................. 7
8. Input capacitor .................................................................................................................................................................................................................... 8
9. Load .................................................................................................................................................................................................................................... 8
10. Efficiency ........................................................................................................................................................................................................................... 9
11. Thermal design ............................................................................................................................................................................................................... 10
12. Terminal protection ......................................................................................................................................................................................................... 13
13. Soft start .......................................................................................................................................................................................................................... 16
14. Sequence for turning power on ..................................................................................................................................................................................... 17
15. Sequence for turning power off ..................................................................................................................................................................................... 21
16. Inrush current .................................................................................................................................................................................................................. 24
17. Over current protection (OCP)....................................................................................................................................................................................... 25
18. Thermal shutdown (TSD) .............................................................................................................................................................................................. 25
19. Input-output equivalent circuit ........................................................................................................................................................................................ 26
20. Lineup ............................................................................................................................................................................................................................. 27
© 2018 ROHM Co., Ltd.
Application Note
1/27
No. 61AN084E Rev.003
FEBRUARY 2020
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Summary of Contents for Rohm BD HC5 Series
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Page 1: Table Of Contents
15. Sequence for turning power off ..................................... 21 16. Inrush current ..........................................24 17. Over current protection (OCP)....................................... 25 18. Thermal shutdown (TSD) ......................................25 19. Input-output equivalent circuit ......................................26 20. Lineup ............................................. 27 © 2018 ROHM Co., Ltd. No. 61AN084E Rev.003 1/27 FEBRUARY 2020... -
Page 2: Typical Application Circuit
E-Pad pad to a ground plane with a wide copper foil area to improve heat dispersion efficiency. Also, exposed pad is electrically connected to GND in the package internally via substrate. © 2018 ROHM Co., Ltd. No. 61AN084E Rev.003 2/27... -
Page 3: Fixed Output Type Bdxxhc5Wefj, Bdxxhc5Mefj-Lb, Bdxxhc5Mefj-M
E-Pad pad to a ground plane with a wide copper foil area to improve heat dispersion efficiency. Also, exposed pad is electrically connected to GND in the package internally via substrate. © 2018 ROHM Co., Ltd. No. 61AN084E Rev.003 3/27... -
Page 4: Output Voltage Setting (Adjustable Output Type)
(01005 inch), select the parts while using caution for the rated 3.300 3.400 power of the resistor and the maximum voltage. 33+0.75 3.500 36+7.5 3.700 51+12 5.000 56+1.5 5.400 47+18 6.000 68+0.75 6.300 24+3.9 7.000 © 2018 ROHM Co., Ltd. No. 61AN084E Rev.003 4/27 FEBRUARY 2020... -
Page 5: Kelvin Connection
On this regulator LARGE BULK LOAD LARGE Figure 3-1. Kelvin connection (Adjustable output type) LARGE Vo_s BULK LOAD LARGE Figure 3-2. Kelvin connection (Fixed output type) © 2018 ROHM Co., Ltd. No. 61AN084E Rev.003 5/27 FEBRUARY 2020... -
Page 6: Study Of Input/Output Voltage Difference And Characteristics
There are no restrictions on the start sequence for Vcc and EN. When not using the output control function, connect the EN pin to Vcc. At this time, a series resistor is unnecessary. © 2018 ROHM Co., Ltd. No. 61AN084E Rev.003 6/27... -
Page 7: Output Capacitor
Figure 7-2, and is not perfectly equal to the constant multilayer ceramic capacitor capacitor that is actually used. Also, as this is based on the IC © 2018 ROHM Co., Ltd. No. 61AN084E Rev.003 7/27 FEBRUARY 2020... -
Page 8: Input Capacitor
IC or solder input capacitor that is appropriate for the output capacitance. melting. For this reason, use of constant current load is not recommended. © 2018 ROHM Co., Ltd. No. 61AN084E Rev.003 8/27 FEBRUARY 2020... -
Page 9: Efficiency
�� ������ × 100 [ % ] η＝ (10-2) �� ���� We can see from the equation that smaller voltage differences between inputs/outputs result in better efficiency. © 2018 ROHM Co., Ltd. No. 61AN084E Rev.003 9/27 FEBRUARY 2020... -
Page 10: Thermal Design
：Thermal characteristics parameter from junction �� Figure 11-1 through 11-13 and Table 11-1 to 11-3 shows the ���� to center of package surface [ ℃/�� ] specifications for the PCB used in measurement. © 2018 ROHM Co., Ltd. No. 61AN084E Rev.003 10/27 FEBRUARY 2020... - Page 11 Bottom (Finish thickness) Lead width 0.254 mm Table 11-1. 1-layer PCB specifications Footprint Copper foil area Bottom 5505 mm (74.2 mm × 74.2 mm) Table 11-2. 2-layer PCB specifications © 2018 ROHM Co., Ltd. No. 61AN084E Rev.003 11/27 FEBRUARY 2020...
- Page 12 (74.2 mm × 74.2 mm) Table 11-3. 4-layer PCB specifications Figure 11-10. Figure 11-11. Middle 2 Layer Trace Bottom Layer Trace Thermal via φ0.30mm, 1.2mm pitch 1.35 Figure 11-12. Footprint © 2018 ROHM Co., Ltd. No. 61AN084E Rev.003 12/27 FEBRUARY 2020...
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Page 13: Terminal Protection
For this reason, a small value (around 1 µA or less) must be selected. Select an inverse rated Figure 12-3. Conductive load current path (when output is off) © 2018 ROHM Co., Ltd. No. 61AN084E Rev.003 13/27... - Page 14 The prerequisites for this circuit are either to protect the circuit from accidental mistakes over the short-term, or for an over current protection circuit to be present in the previous stage. Figure 12-9. Countermeasure #5 against reverse connection © 2018 ROHM Co., Ltd. No. 61AN084E Rev.003 14/27 FEBRUARY 2020...
- Page 15 LOAD1 LOAD3 LOAD2 Figure 12-11. Current path and diode insertion between disparate power sources © 2018 ROHM Co., Ltd. No. 61AN084E Rev.003 15/27 FEBRUARY 2020...
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Page 16: Soft Start
EN, as well as the capacitance of the output capacitor. Refer to “Sequence for turning power supply on” for more details. Figure 13-1. Definition of soft start time © 2018 ROHM Co., Ltd. No. 61AN084E Rev.003 16/27 FEBRUARY 2020... -
Page 17: Sequence For Turning Power On
Figure 14-3 shows the startup characteristics for when EN is turned on after the soft start time. The soft start circuit begins operating from the time that the voltage of EN exceeds the threshold value, and the output voltage rises in accordance with the soft start time. © 2018 ROHM Co., Ltd. No. 61AN084E Rev.003... - Page 18 V . For this reason, the start time will be longer and will exceed the soft start time. © 2018 ROHM Co., Ltd. No. 61AN084E Rev.003 18/27...
- Page 19 V . For this reason, the start time will be longer and will exceed the soft start time. © 2018 ROHM Co., Ltd. No. 61AN084E Rev.003 19/27...
- Page 20 When starting while the When starting while the current limit is applied partway current limit is applied by the over current protection through by the over current circuit protection circuit © 2018 ROHM Co., Ltd. No. 61AN084E Rev.003 20/27 FEBRUARY 2020...
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Page 21: Sequence For Turning Power Off
Figure 15-2 shows the power off characteristics when EN gradually turns off. The output transistor turns off when the voltage of EN falls below the threshold value. The output voltage will fall. The fall time for the output voltage is the same as that shown on Figure 15-1. © 2018 ROHM Co., Ltd. No. 61AN084E Rev.003 21/27... - Page 22 When the V reaches 0 V, the body diode voltage (approximately 0.5 V) is left and falls even more gradually. Then, the voltage falls in time constant with the load resistance. © 2018 ROHM Co., Ltd. No. 61AN084E Rev.003 22/27...
- Page 23 (parasitic diode). As a result, the output voltage falls following the input voltage; and when V reaches 0 V, the body diode voltage (approximately 0.5 V) is left and falls even more gradually. Then, the voltage falls in time constant with the load resistance. © 2018 ROHM Co., Ltd. No. 61AN084E Rev.003 23/27 FEBRUARY 2020...
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Page 24: Inrush Current
= 60 °�� + 5 × ( 5 �� − 3.3 �� ) × 3 �� = 85.5 °�� The junction temperature Tj is 150°C or less, so there is no © 2018 ROHM Co., Ltd. No. 61AN084E Rev.003 24/27... -
Page 25: Over Current Protection (Ocp)
Output Current : I Ambient Temperature : T [℃] Figure 17-1. Characteristics of over current protection Figure 18-1. Thermal shutdown characteristics © 2018 ROHM Co., Ltd. No. 61AN084E Rev.003 25/27 FEBRUARY 2020... -
Page 26: Input-Output Equivalent Circuit
30.1 34.4 BD18HC5 43.0 34.4 BD25HC5 54.8 25.8 BD30HC5 47.3 17.2 BD33HC5 80.6 25.8 BD50HC5 33.9 6.45 BD60HC5 41.9 6.45 BD70HC5 12.9 Figure 19-2. Fixed output type equivalent circuit © 2018 ROHM Co., Ltd. No. 61AN084E Rev.003 26/27 FEBRUARY 2020... -
Page 27: Lineup
-40 to +105 ✔ BDxxIC0MEFJ -M -40 to +105 2.4 to 5.5 ✔ BDxxIA5WEFJ -25 to +85 ✔ BDxxIA5MEFJ -LB -40 to +105 ✔ BDxxIA5MEFJ -M -40 to +105 © 2018 ROHM Co., Ltd. No. 61AN084E Rev.003 27/27 FEBRUARY 2020... - Page 28 Products. ROHM does not grant you, explicitly or implicitly, any license to use or exercise intellectual property or other rights held by ROHM or any other parties. ROHM shall have no responsibility whatsoever for any dispute arising out of the use of such technical information.
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