Datasheet
Quasi-resonant AC/DC Converter
Built-in 1700 V SiC-MOSFET
BM2SC12xFP2-LBZ Series
General Description
Key Specifications
This is the product guarantees long time support in
industrial market.
BM2SC12xFP2-LBZ series is a quasi-resonant AC/DC
converter that provides an optimum system for all
products which has an electrical outlet. Quasi-resonant
operation enables soft switching and helps to keep the
EMI low.
This IC can be designed easily because it includes the
1700 V SiC (Silicon-Carbide) MOSFET.
Design with a high degree of flexibility is achieved with
current detection resistors as external devices. The burst
operation reduces an electric power at light load.
BM2SC12xFP2-LBZ series includes various protection
functions, such as soft start function, burst operation
function, over current limiter per cycle, over voltage
protection, overload protection.
◼ Operating Power Supply Voltage Range:
VCC:
15.0 V to 27.5 V
DRAIN:
1700 V (Max)
◼ Normal Operating Current:
800 µA (Typ)
◼ Burst Operating Current:
500 µA (Typ)
◼ Maximum Operating Frequency:
120 kHz (Typ)
◼ Operating Temperature:
-40 °C to +105 °C
Package
TO263-7L
W (Typ) x D (Typ) x H (Max)
10.18 mm x 15.5 mm x 4.43 mm
Features
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Long Time Support Product for Industrial Applications
TO263-7L Package
Built-in 1700 V SiC-MOSFET
Quasi-resonant Type (Low EMI)
Frequency Reduction Function
Low Current Consumption (19 µA) during Standby
Burst Operation at Light Load
SOURCE Pin Leading Edge Blanking
VCC UVLO (Under Voltage Lock Out)
VCC OVP (Over Voltage Protection)
Over Current Protection Circuit per Cycle
Soft Start Function
ZT Pin Trigger Mask Function
ZT OVP (Over Voltage Protection)
BR UVLO (Under Voltage Lock Out)
Lineup
Product name
BM2SC121FP2-LBZ
BM2SC122FP2-LBZ
BM2SC123FP2-LBZ
BM2SC124FP2-LBZ
FB OLP
Auto Restart
Latch
Auto Restart
Latch
VCC OVP
Latch
Latch
Auto Restart
Auto Restart
Applications
Industrial Equipment, AC Adaptor, Household Appliances
Typical Application Circuit
FUSE
Filter
Diode
Bridge
DRAIN
ZT VCC GND FB BR
SOURCE SOURCE
ERROR
/AMP
〇Product structure : Silicon integrated circuit
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〇This product has no designed protection against radioactive rays.
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BM2SC12xFP2-LBZ Series
Pin Configuration
(TOP VIEW)
Pin Descriptions
Pin No.
Pin Name
I/O
1
2
3
4
5
6
7
EXP-PAD
ZT
VCC
GND
FB
BR
SOURCE
SOURCE
DRAIN
I
I
I/O
I
I
I
I
I/O
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Function
Zero current detection pin
Power supply input pin
GND pin
Feedback signal input pin
AC voltage detect pin
MOSFET SOURCE pin
MOSFET SOURCE pin
MOSFET DRAIN pin
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ESD Diode
VCC
GND
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○
○
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○
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BM2SC12xFP2-LBZ Series
Block Diagram
VOUT
VH
FUSE
Filter
Diode
Bridge
Va
EXP
DRAIN
2
5
VCC
BR
+
BR UVLO
VCC UVLO
+
-
-
Internal
Supply
+
-
Gate
Clamper
Regulator
NOUT
ZT ACSNS Comp.
+
VCC OVP
+
-
ZT
1
+
ZT OVP Comp.
OSC
ZT
Comp.
1700 V
SiC-MOSFET
OSC
1 shot
-
ERROR
AMP
OR
AND
Time Out
AND
ZT
Blanking
S Q
NOUT
POUT
FBOLP_OH AND
OR
Internal
Supply
Maximum
Blanking
Frequency
+
+
-
FB
4
+
PRE
Driver
OUT
NOUT
R
Burst
Comp.
-
OLP
+
-
Timer
FBOLP_OH
Soft Start
DCDC
FB/2 -Comp.
+
CURRENT SENSE
(V-V Change)
Leading
Edge
Blanking
SOURCE
6,7
3
GND
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BM2SC12xFP2-LBZ Series
Description of Blocks
1
Startup Sequences (FB OLP: Auto Restart Mode)
The BM2SC12xFP2-LBZ’s startup sequence is shown in Figure 1.
See the sections below for the detailed descriptions.
Input
Voltage
VH
VUVLO1
VCC Pin
Voltage
VUVLO2
tFOLP
Internal REF
Pull Up
VFLOP1
VFLOP2
tFOLP
tFOLP
FB Pin
Voltage
VOUT
Over
Load
Normal
Load
Light
Load
IOUT
Burst Mode
Switching
Soft Start
Time
A
B C
D
E
F
GH
IJ
K
Figure 1. Startup Sequence Timing Chart
A:
B:
C:
The input voltage VH is applied. The VCC pin voltage rises due to start resistor RSTART.
This IC starts operating when the VCC pin voltage becomes higher than VUVLO1 (Typ = 19.5 V).
When the protection functions are judged as normal status, the switching operation starts. At that time, since the
VCC pin voltage value always drops due to the pin's consumption current, it is necessary to set the VCC pin voltage
to more than VUVLO2 (Typ = 14.0 V). The IC has a soft start function which regulates the voltage level at the SOURCE
pin to prevent an excessive rise in voltage and current. And when the switching operation starts, VOUT rises.
D: At startup, the output voltage should be set to the regulated voltage within tFOLP period (Typ = 128 ms).
E: At a light load, the IC starts burst operation in order to keep power consumption down.
F: Overload operation.
G: When the FB pin voltage keeps being more than VFOLP1 (Typ = 2.8 V) for tFOLP (Typ = 128 ms) or more, the switching
operation is stopped by the overload protection circuit. If the FB pin voltage status becomes less than VFOLP2 (Typ =
2.6 V) even once, tFOLP (Typ = 128 ms) timer is reset.
H: When the VCC pin voltage becomes less than VUVLO2 (Typ = 14.0 V), IC is restarted.
I: Same as B.
J: Same as F.
K: Same as G.
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1
Startup Sequences (FB OLP: Auto Restart Mode) – continued
Start resistance RSTART is the resistance required to start the IC. If the start resistance RSTART value is set to low, the
standby power becomes high and the startup time becomes short. Conversely, if the start resistance R START value is set
to high, standby power becomes low and the startup time becomes long. The standby current I OFF of BM2SC12xFP2LBZ is 30 µA (Max). However, this is the minimum current required to start the IC. It is necessary to set the appropriate
current value for the set target.
e.g. Start Resistance RSTART Setting
𝑅𝑆𝑇𝐴𝑅𝑇 < (𝑉𝑀𝐼𝑁 − 𝑉𝑈𝑉𝐿𝑂 (𝑀𝑎𝑥)) ÷ 𝐼𝑂𝐹𝐹
[Ω]
Where:
𝑅𝑆𝑇𝐴𝑅𝑇 is the start resistance.
𝑉𝑀𝐼𝑁 is the minimum DC input voltage.
𝑉𝑈𝑉𝐿𝑂 is the VCC UVLO voltage.
𝐼𝑂𝐹𝐹 is the operation current at standby.
When the AC input voltage is AC 80 V, VMIN = 113 V.
At this time, it can be calculated as (113 - 20) / 30 μA = 3.1 MΩ because VUVLO1 (Max) = 20.0 V.
Considering the optimal value for the resistor which is 3.1 MΩ or less and set RSTART to 3.0 MΩ.
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Description of Blocks – continued
2
VCC Pin Protection Function
BM2SC12xFP2-LBZ includes the VCC low voltage protection function VCC UVLO and the VCC over voltage protection
function VCC OVP. These functions prevent the abnormal voltage-related break in MOSFETs used for switching. The
VCC UVLO function is an auto restart type comparator with voltage hysteresis and the VCC OVP function is the
comparator uses latch mode or auto restart mode. After latch function is detected by VCC OVP, latching is released
(reset) when the condition the VCC pin voltage < VLATCH (Typ = VUVLO2 – 3.5 V) is met. Figure 2 is shown about VCC OVP
Latch Mode and Figure 3 is shown about VCC OVP Auto Restart Mode. VCC OVP has a built-in mask time tLATCH (Typ =
150 µs). This function masks such as the surges occur at the pin.
Input
Voltage
VH
VOVP1
VUVLO1
VCC Pin
Voltage
VUVLO2
VLATCH
0V
ON
ON
VCC UVLO
OFF
OFF
ON
VCC OVP
OFF
ON
Switching
OFF
ON
OFF
OFF
OFF
L : Normal
H : Latch
Internal
Latch Signal
A
B C
DE
F
G
H
I
J
K
L
M
N
A
B
Time
Figure 2. VCC UVLO/OVP (Latch Mode)
A:
B:
VH is applied, the VCC pin voltage rises.
When the VCC pin voltage becomes higher than VUVLO1 (Typ = 19.5 V), the VCC UVLO function is released and the
switching operation starts.
C: When the VCC pin voltage becomes lower than VUVLO2 (Typ = 14.0 V), the switching operation stops by the VCC
UVLO function.
D: When the VCC pin voltage becomes higher than VUVLO1 (Typ = 19.5 V), the VCC UVLO function is released the
switching operation starts.
E: The VCC pin voltage drops until the output voltage is stabilized.
F: The VCC pin voltage rises.
G: When the VCC pin voltage becomes higher than VOVP1 (Typ = 29.5 V), the switching is stopped by an internal latch
signal. When the switching operation stops, power supply from the auxiliary coil stops and the VCC pin voltage
drops.
H: When the VCC pin voltage becomes lower than VUVLO2 (Typ = 14.0 V), the VCC pin voltage rises because the IC
consumption current drops.
I: When the VCC pin voltage becomes higher than VUVLO1 (Typ = 19.5 V), there are no switching operations because
the IC is during latch operation. The VCC pin voltage drops because the switching stops.
J: Same as H.
K: Same as I.
L: VH is OPEN (unplugged). The VCC pin voltage drops.
M: When the VCC pin voltage lower than VLATCH (Typ = VUVLO2 - 3.5 V), it is latch-released.
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2
VCC Pin Protection Function – continued
Input
Voltage
VH
VOVP1
VOVP2
VUVLO1
VCC Pin
Voltage
VUVLO2
0V
ON
ON
VCC UVLO
OFF
OFF
ON
VCC OVP
OFF
ON
Switching
OFF
ON
ON
OFF
OFF
OFF
OFF
A
B C
DE
F
I
G H
J
K
L
A
B
Time
Figure 3. VCC UVLO/OVP (Auto Restart Mode)
A:
B:
VH is applied, the VCC pin voltage rises.
When the VCC pin voltage becomes higher than VUVLO1 (Typ = 19.5 V), the VCC UVLO function is released and the
switching operation starts.
C: When the VCC pin voltage becomes lower than VUVLO2 (Typ = 14.0 V), the switching operation stops by the VCC
UVLO function.
D: When the VCC pin voltage becomes higher than VUVLO1 (Typ = 19.5 V), the VCC UVLO function is released and the
switching operation starts.
E: The VCC pin voltage drops until the output voltage is stabilized.
F: The VCC pin voltage rises.
G: When the VCC pin voltage becomes higher than VOVP1 (Typ = 29.5 V), the switching is stopped by the VCC OVP
function. When the switching operation stops, power supply from the auxiliary coil stops and the VCC pin voltage
drops.
H: When the VCC pin voltage becomes lower than VOVP2 (Typ = 23.0 V), the switching operation starts by auto restart.
I: VH is OPEN (unplugged). The VCC pin voltage drops.
J: Same as C.
K: When the VCC pin voltage becomes higher than VUVLO1 (Typ = 19.5 V), the VCC UVLO function is released and the
VCC pin voltage drops. However, the switching operation doesn’t restart because VH is OPEN.
L: When the VCC pin voltage becomes lower than VUVLO2 (Typ = 14.0 V), the VCC UVLO function operates. However,
the VCC pin voltage continues to drop because VH is OPEN.
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Description of Blocks – continued
3
DC/DC Converter Function
BM2SC12xFP2-LBZ uses PFM (Pulse Frequency Modulation) mode control. The FB pin, the ZT pin, and the SOURCE
pin are monitored to provide a system optimized as DC/DC. The switching MOSFET ON width (turn OFF) is controlled
by the FB pin and the SOURCE pin, and the OFF width (turn ON) is controlled by the ZT pin. By setting maximum
frequency, PFM mode will control it to meet noise regulation. A detailed description is below. (Refer to Figure 4)
VOUT
VH
Va
EXP
DRAIN
2
5
VCC
BR
NOUT
Internal
Supply
Gate
Clamper
+
-
ZT ACSNS Comp.
1700 V
SiC-MOSFET
+
-
ZT
1
+
ZT OVP Comp.
ZT
Comp.
1 shot
-
ERROR
AMP
OR
AND
Time Out
ZT
Blanking
S Q
AND
POUT
NOUT
FBOLP_OH
OR
Maximum
Blanking
Frequency
+
Internal
Supply
+
-
FB
4
+
AND
PRE
Driver
OUT
NOUT
R
Burst
Comp.
-
OLP
+
Timer
-
FBOLP_OH
Soft Start
FB/2
-
DCDC
Comp.
+
CURRENT SENSE (V-V Change)
Leading Edge
Blanking
SOURCE
6,7
3
GND
Figure 4. Block Diagram of DC/DC Operations
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3
DC/DC Converter Function – continued
3.1
Determination of ON Width (Turn OFF)
ON width is controlled by the FB pin and the SOURCE pin. The ON width is determined by comparing the FB pin
voltage at 1/AV (Typ = 1/2) with the SOURCE pin voltage. In addition, the comparator level is changed by comparing
with the IC's internally generated VLIM1A (Typ = 1.0 V), as is shown in Figure 5. The SOURCE pin is also used for the
over current limiter circuit per pulse. Changes at the FB pin changes in the maximum blanking frequency and over
current limiter level.
mode 1: Burst operation
mode 2: Frequency reduction operation (reduces maximum frequency)
mode 3: Maximum frequency operation (operates at maximum frequency)
mode 4: Overload operation (pulse operation is stopped when overload is detected)
Maximum Operating
Frequency [kHz]
mode 1
mode 2
mode 3
mode 4
fSW1
fSW2
0.0
CS
Limiter [V]
0.5
mode 1
2.0
1.25
mode 3
mode 2
FB Pin
Voltage
[V]
2.8
mode 4
VLIM1
VLIM2
0.0
0.5
1.25
2.0
2.8
FB Pin
Voltage
[V]
Figure 5. Relationship of FB Pin Voltage to Over Current Limiter and Maximum Frequency
The switch of over current protection in the soft start function and input voltage is performed by adjusting the
over current limiter level. In this case, the VLIM1 and VLIM2 values are as listed below.
Soft Start
Table 1. Over Current Protection Voltage
IZT ≥ -1.0 mA
IZT < -1.0 mA
VLIM1A
VLIM2A
VLIM1B
VLIM2B
from startup to less than 1 ms
0.250 V
0.075 V
0.175 V
0.053 V
from 1 ms to less than 4 ms
0.500 V
0.150 V
0.350 V
0.105 V
4 ms or more
1.000 V
0.300 V
0.700 V
0.210 V
3.2
L.E.B. (Leading Edge Blanking) Function
When the switching MOSFET is turned ON, surge current occur at each capacitor component and drive current.
Therefore, when the SOURCE pin voltage rises temporarily, detection errors may occur in the over current limiter
circuit. To prevent detection errors, BM2SC12xFP2-LBZ has the blanking function. This function masks the SOURCE
pin voltage for tLEB (Typ = 250 ns) after the DRAIN pin changes from high to low. This blanking function reduces the
SOURCE pin noise filter.
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3
DC/DC Converter Function – continued
SOURCE Over Current Protection Switching Function
When the input voltage (VH) becomes high, the ON time is shortened and the operating frequency increases. As a
result, the maximum allowable power is increased for a certain over current limiter. As a countermeasure, the IC will
use its internal over current protection function to switch. In case of high voltage, the over current comparator value
which determines the ON time is multiplied by 0.7 of normal operation.
Detection and switch are performed by monitoring the ZT inflow current. When the MOSFET is turned ON, Va
becomes a negative voltage dependent on the input voltage (VH). The ZT pin is clamped to nearly 0 V in the IC. The
formula used to calculate this is shown below. A block diagram is shown in Figure 6. Also, graphs are shown in
Figure 7, Figure 8 and Figure 9.
3.3
𝐼𝑍𝑇 = (𝑉𝑎 − 𝑉𝑍𝑇 ) ÷ 𝑅𝑍𝑇1 = 𝑉𝑎 ÷ 𝑅𝑍𝑇1 = (𝑉𝐻 × 𝑁𝑎) ÷ (𝑁𝑝 × 𝑅𝑍𝑇1 )
𝑅𝑍𝑇1 = 𝑉𝑎 ÷ 𝐼𝑍𝑇
[Ω]
[A]
Where:
𝐼𝑍𝑇 is the ZT inflow current.
𝑉𝑎 is the auxiliary winding voltage.
𝑉𝑍𝑇 is the ZT pin voltage.
𝑅𝑍𝑇1 is the ZT pin resistance 1.
𝑉𝐻 is the input voltage.
𝑁𝑝 is the primary side winding.
𝑁𝑎 is the auxiliary winding.
From the above, the VH voltage is set with a resistance value (RZT1). The ZT bottom detection voltage is determined
at that time, therefore, set the timing with CZT.
VOUT
VH
Va
EXP
DRAIN
2
5
VCC
BR
NOUT
Internal
Supply
Gate
Clamper
+
-
ZT ACSNS Comp.
1700 V
SiC-MOSFET
+
RZT1
-
ZT
CZT
1
+
ZT OVP Comp.
ZT
Comp.
1 shot
-
ERROR
AMP
OR
AND
Time Out
RZT2
ZT
Blanking
S Q
AND
POUT
NOUT
FBOLP_OH
OR
Maximum
Blanking
Frequency
+
Internal
Supply
+
-
FB
4
+
AND
PRE
Driver
OUT
NOUT
R
Burst
Comp.
-
OLP
+
Timer
-
FBOLP_OH
Soft Start
FB/2
-
DCDC
Comp.
+
CURRENT SENSE (V-V Change)
Leading Edge
Blanking
SOURCE
6,7
3
GND
Figure 6. Block Diagram of SOURCE Switching Current
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3.3
SOURCE Over Current Protection Switching Function – continued
SOURCE
Limiter [V]
mode 1
mode 2
mode 3
mode 4
VLIM1A
VLIM1B
IZT ≥ -1.0 mA
IZT < -1.0 mA
VLIM2A
VLIM2B
0.0
0.5
1.0
2.0
1.5
2.8
FB pin voltage [V]
Figure 7. SOURCE Switching: SOURCE Limiter vs FB Pin Voltage
SOURCE
Limiter [V]
VLIM1
VLIM1 x 0.7
1.0
ZT Pin Current [mA]
Figure 8. SOURCE Switching: SOURCE Limiter vs ZT Pin Current
e.g. Setup method (for switching between 100 V AC and 220 V AC.)
100 V AC: 141 V ±42 V (±30 % margin)
220 V AC: 308 V ±62 V (±20 % margin)
In the above cases, the SOURCE current is switched in the range from 182 V to 246 V.
→ This is done when VH = 214 V.
Given: Np = 100, Na = 15.
𝑉𝑎 = 𝑉𝐼𝑁 × 𝑁𝑎 ÷ 𝑁𝑝 = 214 𝑉 × 15 ÷ 100 × (−1) = −32.1
𝑅𝑍𝑇1 = 𝑉𝑎 ÷ 𝐼𝑍𝑇 = −32.1 𝑉 ÷ −1 𝑚𝐴 = 32.1 [kΩ]
[V]
Where:
𝑉𝑎 is the auxiliary winding voltage.
𝑉𝐼𝑁 is the input voltage.
𝑁𝑝 is the primary side winding.
𝑁𝑎 is the auxiliary side winding.
𝑅𝑍𝑇1 is the ZT pin resistance.
𝐼𝑍𝑇 is the ZT pin inflow current.
According to the above, RZT1 = 32 kΩ is set.
SOURCE
Limiter [V]
VLIM1
VLIM1 x 0.7
214
VH Pin Voltage [V]
Figure 9. Example of SOURCE Switching: SOURCE Limiter vs VH Pin Voltage
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3
DC/DC Converter Function – continued
3.4
Determination of OFF Width (Turn ON)
The OFF width is controlled at the ZT pin. While switching is OFF, the power stored in the coil is supplied to the
secondary side output capacitor. When this power supply ends, there is no more current flowing to the secondary
side, so the DRAIN pin voltage of switching MOS drops. Consequently, the voltage on the auxiliary coil side also
drops. A voltage that was resistance-divided by RZT1 and RZT2 is applied to the ZT pin. When this voltage level drops
to VZT1 (Typ = 100 mV) or less, switching is turned ON by the ZT comparator. To detect zero current status at the ZT
pin, time constants are generated using CZT, RZT1, and RZT2. Additionally, the ZT pin trigger mask and the ZT pin
trigger timeout function are built-in.
3.5
ZT Pin Trigger Mask Function
When the switching is set OFF from ON, superposition of noise may occur at the ZT pin. At this time, the ZT
comparator is masked for the tZTMASK (Typ = 0.60 µs) to prevent the ZT comparator operate errors. (Refer to Figure
10)
ON
Switching
OFF
ON
OFF
ON
OUT
ZT Pin
Voltage
tZTMASK
ZT Trigger
Mask Pin
A
B
C
tZTMASK
D
E
F
G
Time
Figure 10. ZT Pin Trigger Mask Function
A:
B:
C:
D:
E:
F:
G:
Switching is OFF→ON.
Switching is ON→OFF.
Because noise occurs at the ZT pin, the ZT comparator is not operated during t ZTMASK (Typ = 0.60 µs).
Same as A.
Same as B.
Same as C.
Same as A.
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3
DC/DC Converter Function – continued
3.6
ZT Pin Trigger Timeout Function
ZT Pin Trigger Timeout Function 1
When the ZT pin voltage is not higher than VZT2 (Typ = 200 mV) during tZTOUT1 (Typ = 45 µs) because of the
decrease of output voltage or the shorted ZT pin such as at startup, this function turns on the switching by force.
ZT Pin Trigger Timeout Function 2
After the ZT comparator detects the bottom, the IC turns on the switching by force when the IC does not operate
next detection within tZTOUT2 (Typ = 5.0 µs). After the ZT comparator detected signal once, this function operates.
For that, it does not operate at startup or at low output voltage. When the IC is not able to detect bottom by
decreasing auxiliary winding voltage, the function operates.
ZT pin GND
short
ZT Pin VZT2
voltage VZT1
Bottom
Detection
5 µs
5 µs
5 µs
Timeout
45 µs
45 µs
Timeout
45 µs
SOURCE
Pin Voltage
DRAIN
Pin Voltage
A
BC
D
E
F
G
H
I
Time
Figure 11. ZT Pin Trigger Timeout Function
A:
B:
C:
D:
E:
F:
G:
H:
I:
At startup, the IC starts to operate by ZT pin trigger timeout function1 because of the ZT pin voltage is 0 V.
MOSFET turns ON.
MOSFET turns OFF.
The ZT pin voltage drops to lower than VZT2 (Typ = 200 mV) by the oscillation decreasing.
MOSFET turns ON after tZTOUT2 (Typ = 5.0 µs) from D point by ZT pin trigger timeout function 2.
The ZT pin voltage drops to lower than VZT2 (Typ = 200 mV) by the oscillation decreasing.
MOSFET turns ON after tZTOUT2 (Typ = 5.0 µs) from F point by ZT pin trigger timeout function 2.
The ZT pin is shorted to GND.
MOSFET turns ON after tZTOUT1 (Typ = 45.0 µs) by ZT pin trigger timeout function 1.
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BM2SC12xFP2-LBZ Series
Description of Blocks – continued
4
Soft Start Function
Normally, a large current flows to the AC/DC power supply when the AC power supply is turned ON. BM2SC12xFP2LBZ includes a soft start function to prevent large changes in the output voltage and current during startup. This function
is performed when the VCC pin voltage drops to VUVLO2 (Typ = 14.0 V) or less.
Soft start function performs the following operation after startup. (Refer to turn OFF described above in section 3.1).
・ from startup to less than 1 ms → Set the SOURCE limiter value to 25 % of normal
・ from 1 ms to less than 4 ms
→ Set the SOURCE limiter value to 50 % of normal
・ 4 ms or more
→ Normal operation
5
FB Over Limited Protection
The overload protection function operates in a latch mode or an auto restart mode. This function monitors the overload
status of the secondary output current at the FB pin and fixes the OUT pin at low level when the overload status is
detected. During overload status, current no longer flows to the photo-coupler, so the FB pin voltage rises. When this
status continues for the tFOLP (Typ = 128 ms), it judges the status as an overload and the OUT pin is fixed at low level. If
the FB pin voltage drops to lower than VFOLP2 (Typ = 2.6 V) within tFOLP (Typ = 128 ms) after once it exceeds VFOLP1 (Typ
= 2.8 V), the overload protection timer is reset.
At startup, the FB pin voltage is pulled up to the internal voltage by a pull-up resistor, so operation starts from VFOLP1 (Typ
= 2.8 V) or above. Therefore, it is necessary for the design to set the FB pin voltage at VFOLP2 (Typ = 2.6 V) or less within
tFOLP (Typ = 128 ms). In other words, the startup time of the secondary output voltage must be set to within t FOLP (Typ =
128 ms) after the IC starts.
To release latching at selecting latch mode is operated when the VCC pin voltage becomes lower than VLATCH (Typ =
VUVLO2 – 3.5 V) by unplugging power supply.
6
ZT OVP (Over Voltage Protection) Function
ZT OVP (Over Voltage Protection) function is built-in the ZT pin. When the ZT pin voltage reaches VZTL (Typ = 3.5 V), this
function operates detection. The ZT pin OVP function is performed in latch mode.
ZT OVP function has a built-in mask time defined as tLATCH (Typ = 150 µs). This operates detection when ZT OVP status
continues for tLATCH (Typ = 150 µs). This function masks such as surges those occur at the pin. Refer to Figure 12. (A
similar tLATCH (Typ = 150 µs) is built-in VCC OVP.)
ΔT1 < tLATCH (Typ = 150 µs)
ΔT2 = tLATCH (Typ = 150 µs)
ΔT1
ΔT2
VZTL
PULSE
ZT Pin
Voltage
PULSE
ON
Switching
OFF
A
B
C
D
E
Figure 12. ZT OVP and Latch Mask Function
A:
B:
C:
D:
E:
Switching turns ON and the ZT pin starts pulse operation.
The ZT pin voltage higher than VZTL (Typ = 3.5 V).
The status of the ZT pin voltage higher than VZTL (Typ = 3.5 V) is within tLATCH (Typ = 150 µs), so the switching
is reset to the normal operations.
The ZT pin voltage higher than VZTL (Typ = 3.5 V).
The status of ZT pin voltage higher than VZTL (Typ = 3.5 V) continues for tLATCH (Typ = 150 µs), so latching occurs
and the switching turned OFF.
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BM2SC12xFP2-LBZ Series
Description of Blocks – continued
7
Thermal Shutdown Function
Thermal shutdown function is auto restart type. Thermal shutdown function is worked when the ambient temperature >
T2 (Typ = 185 °C), switching is stopped. Switching restart when the ambient temperature < T1 (Typ = 135 °C).
Switching
State 2
OFF
State 1
ON
T1
(Typ = 135 °C)
T2
(Typ = 185 °C)
Temperature [°C]
Figure 13. Thermal Shutdown Function
8
BR UVLO (Under Voltage Lock Out) Function
This IC has the BR UVLO function which monitoring the input voltage through the BR pin. If input voltage VH is lower,
DC/DC function is stopped. Input is connected the BR pin dividing by registers. When the BR pin voltage is over VBR1
(Typ = 1.0 V), the circuit detects the normal status and DC/DC function is operated.
This comparator has the voltage hysteresis VBR3 (Typ = 0.2 V).
VH
FUSE
Diode
Filter
RH
Bridge
RL
BR
BR
Comp.
+
-
Controller
BM2SC12xFP2-LBZ
Figure 14. BR UVLO Function
Operation Modes of Protection Circuit
Table 2 below lists the operation modes of the various protection functions.
Table 2. Operation Modes of Protection Circuit
Item
Operation Mode
VCC Under Voltage Locked Out
Auto Restart
VCC Over Voltage Protection
BM2SC121FP2-LBZ/BM2SC122FP2-LBZ = Latch
BM2SC123FP2-LBZ/BM2SC124FP2-LBZ = Auto Restart
FB Over Limited Protection
BM2SC121FP2-LBZ/BM2SC123FP2-LBZ = Auto Restart
BM2SC122FP2-LBZ/BM2SC124FP2-LBZ = Latch
ZT Over Voltage Protection
Latch
Thermal Shutdown
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BM2SC12xFP2-LBZ Series
Absolute Maximum Ratings (Ta = 25 °C)
Parameter
Symbol
Rating
Unit
Maximum Applied Voltage 1
VMAX1
-0.3 to +32.0
V
VCC pin
Maximum Applied Voltage 2
VMAX2
-0.3 to +6.5
V
SOURCE pin, FB pin, ZT pin
Maximum Applied Voltage 3
VMAX3
-0.3 to +15.0
V
BR pin
Maximum Applied Voltage 4
VMAX4
-0.3 to +1700
V
DRAIN pin
DRAIN Pin Current (Pulse)
IDD
9.2
A
PW = 10 µs, Duty cycle = 1 %
ZT Pin Maximum Current
Maximum Junction Temperature
ISZT
±3.0
mA
Tjmax
150
°C
Tstg
-55 to +150
°C
Storage Temperature Range
Conditions
Caution 1: Operating the IC over the absolute maximum ratings may damage the IC. The damage can either be a short circuit between pins or an open circuit
between pins and the internal circuitry. Therefore, it is important to consider circuit protection measures, such as adding a fuse, in case the IC is
operated over the absolute maximum ratings.
Caution 2: Should by any chance the maximum junction temperature rating be exceeded the rise in temperature of the chip may result in deterioration of the
properties of the chip. In case of exceeding this absolute maximum rating, design a PCB with thermal resistance taken into consideration by increasing
board size and copper area so as not to exceed the maximum junction temperature rating.
Thermal Resistance (Note 1)
Parameter
Thermal Resistance (Typ)
Symbol
Unit
1s(Note 3)
2s2p(Note 4)
θJA
77.5
20.4
°C/W
ΨJT
18
5
°C/W
TO263-7L
Junction to Ambient
Junction to Top Characterization
Parameter(Note 2)
(Note 1) Based on JESD51-2A (Still-Air), using a BM2SC12xFP2-LBZ chip.
(Note 2) The thermal characterization parameter to report the difference between junction temperature and the temperature at the top center of the outside surface
of the component package.
(Note 3) Using a PCB board based on JESD51-3.
(Note 4) Using a PCB board based on JESD51-5, 7.
Layer Number of
Measurement Board
Single
Material
Board Size
FR-4
114.3 mm x 76.2 mm x 1.57 mmt
Top
Copper Pattern
Thickness
Footprints and Traces
70 μm
Layer Number of
Measurement Board
4 Layers
Material
Board Size
FR-4
114.3 mm x 76.2 mm x 1.6 mmt
Top
Thermal Via(Note 5)
Pitch
Diameter
1.20 mm
Φ0.30 mm
2 Internal Layers
Bottom
Copper Pattern
Thickness
Copper Pattern
Thickness
Copper Pattern
Thickness
Footprints and Traces
70 μm
74.2 mm x 74.2 mm
35 μm
74.2 mm x 74.2 mm
70 μm
(Note 5) This thermal via connects with the copper pattern of all layers.
Recommended Operating Conditions
Parameter
Symbol
Min
Typ
Max
Unit
Operating Power Supply Voltage Range 1
VCC
15.0
24.0
27.5
V
VCC pin voltage
DRAIN pin voltage
Operating Power Supply Voltage Range 2 VDRAIN
-0.3
-
+1700
V
Operating Temperature
-40
+25
+105
°C
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Conditions
TSZ02201-0F1F0A200770-1-2
09.Apr.2021 Rev.001
BM2SC12xFP2-LBZ Series
Electrical Characteristics (Unless otherwise specified VCC = 24 V, Ta = 25 °C)
Parameter
Symbol
Min
Typ
Max
Unit
Conditions
Voltage between DRAIN and SOURCE Pins
V(BR)DDS
1700
-
-
V
ID = 1 mA
IDSS
-
-
100
nA
VDS = 1700 V
RDS(ON)
-
1.15
2.00
Ω
ID = 1.1 A
Standby Operating Current
IOFF
10
19
30
µA
VCC = 18.0 V
(VCC UVLO = Disable)
Normal Operating Current
ION1
300
800
1300
µA
FB Pin Voltage = 2.0 V
(At Pulse Operation)
Burst Operating Current
ION2
150
500
1000
µA
FB Pin Voltage = 0.0 V
(At Burst Operation)
IPROTECT
800
1600
2200
µA
FB OLP, VCC OVP,
ZT OVP
VCC UVLO Voltage 1
VUVLO1
19.00
19.50
20.00
V
VCC pin voltage rising
VCC UVLO Voltage 2
VUVLO2
13.00
14.00
15.00
V
VCC pin voltage falling
VCC UVLO Hysteresis Voltage
VUVLO3
-
5.50
-
V
VUVLO3 = VUVLO1 - VUVLO2
VCC OVP Voltage 1
VOVP1
27.50
29.50
31.50
V
VCC pin voltage rising
VCC OVP Voltage 2
VOVP2
21.00
23.00
25.00
V
VCC pin voltage falling
VCC OVP Hysteresis Voltage
VOVP3
-
6.50
-
V
VOVP3 = VOVP1 - VOVP2
VCC pin Voltage
[MOSFET]
DRAIN Leak Current
On Resistance
[Operating Current]
Protection Circuit Operating Current
[VCC Pin Protection Function]
Latch Released Voltage
VLATCH
-
Latch Mask Time
tLATCH
50
VUVLO2 –
3.5
150
Over Temperature Protection 1(Note 6)
TSD1
160
185
200
C
Over Temperature Protection 2(Note 6)
TSD2
120
135
150
C
TSD3
-
50
-
C
BR UVLO Voltage 1
VBR1
0.920
1.000
1.080
V
BR UVLO Voltage 2
VBR2
-
0.800
-
V
BR UVLO Hysteresis Voltage
VBR3
0.140
0.200
0.260
V
RFB
15
20
25
kΩ
SOURCE Pin
Over Current Detection Voltage 1A
VLIM1A
0.950
1.000
1.050
V
FB pin voltage = 2.2 V
(IZT ≥ -1.0 mA)
SOURCE Pin
Over Current Detection Voltage 1B
VLIM1B
0.620
0.700
0.780
V
FB pin voltage = 2.2 V
(IZT < -1.0 mA)
SOURCE Pin
Over Current Detection Voltage 2A
VLIM2A
0.200
0.300
0.400
V
FB pin voltage = 0.6 V
(IZT ≥ -1.0 mA)
SOURCE Pin
Over Current Detection Voltage 2B
VLIM2B
0.140
0.210
0.280
V
FB pin voltage = 0.6 V
(IZT < -1.0 mA)
SOURCE Pin Switching
ZT Pin Current
IZT
0.900
1.000
1.100
mA
SOURCE Pin
Leading Edge Blanking Time
tLEB
-
250
-
ns
Minimum ON Width
tMIN
-
0.500
-
µs
Over Temperature Protection
Hysteresis
[BR Pin Protection Function)]
-
V
250
µs
Control IC block’s Tj
rising
Control IC block’s Tj
falling
VBR3= VBR1-VBR2
[DC/DC Converter Block (Turn OFF)]
FB Pin Pull-up Resistance
(Note 6) Over temperature protection operates over Maximum Junction Temperature. This IC cannot guarantee for the thermal destruction in case of the operation
over Maximum Junction Temperature, always operate at Maximum Junction Temperature or less.
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BM2SC12xFP2-LBZ Series
Electrical Characteristics (Unless otherwise specified VCC = 24 V, Ta = 25 °C) – continued
Parameter
Symbol
Min
Typ
Max
Unit
Conditions
Maximum Operating Frequency 1
fSW1
106
120
134
kHz
FB pin voltage = 2.0 V
Maximum Operating Frequency 2
fSW2
20
30
40
kHz
FB pin voltage = 0.5 V
FB Pin Frequency Reduction Start Voltage
VFBSW1
1.100
1.250
1.400
V
FB Pin Frequency Reduction End Voltage 1
VFBSW2
0.400
0.500
0.600
V
FB Pin Frequency Reduction End Voltage 2
VFBSW3
-
0.550
-
V
Voltage Gain
AV
1.700
2.000
2.300
V/V
ΔVFB/ΔVSOURCE
ZT Pin Comparator Voltage 1
VZT1
60
100
140
mV
ZT pin voltage falling
ZT Pin Comparator Voltage 2
VZT2
120
200
280
mV
ZT pin voltage rising
ZT Pin Trigger Mask Time
tZTMASK
0.25
0.60
0.95
µs
For noise prevention
after OUT pin voltage
H→L
ZT Pin Trigger Timeout Period 1
tZTOUT1
30.0
45.0
90.0
µs
Count from final ZT pin
trigger
ZT Pin Trigger Timeout Period 2
tZTOUT2
2.0
5.0
8.0
µs
Count from final ZT pin
trigger (2 stages)
tZTON
27.0
45.0
62.0
µs
Soft Start Time 1
tSS1
0.600
1.000
1.400
ms
Soft Start Time 2
tSS2
2.400
4.000
5.600
ms
FB OLP Voltage 1
VFOLP1
2.500
2.800
3.100
V
FB pin voltage rising
FB OLP Voltage 2
FB pin voltage falling
[DC/DC Converter Block (Turn ON)]
Maximum ON Time
[DC/DC Protection Functions]
VFOLP2
2.300
2.600
2.900
V
FB OLP Timer
tFOLP
90
128
166
ms
ZT OVP Voltage
VZTL
3.250
3.500
3.750
V
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BM2SC12xFP2-LBZ Series
Typical Performance Curves
1300
Normal Operating Current: ION1 [µA]
Standby Operating Current: IOFF [µA]
30
25
20
15
10
-40 -20 0
1100
900
700
500
300
-40 -20 0
20 40 60 80 100 120
Temperature [℃]
Temperature [℃]
Figure 16. Normal Operating Current vs Temperature
Figure 15. Standby Operating Current vs Temperature
2000
Protection Circuit Operating Current:
IPROTECT [µA]
900
Burst Operating Current: ION2 [µA]
20 40 60 80 100 120
750
600
450
300
150
1800
1600
1400
1200
1000
-40 -20 0
20 40 60 80 100 120
-40 -20 0 20 40 60 80 100 120
Temperature [℃]
Temperature [℃]
Figure 18. Protection Circuit Operating Current
vs Temperature
Figure 17. Burst Operating Current vs Temperature
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BM2SC12xFP2-LBZ Series
Typical Performance Curves - continued
15.0
VCC UVLO Voltage 2: VUVLO2 [V]
VCC UVLO Voltage 1: VUVLO1 [V]
20.0
19.8
19.6
19.4
19.2
19.0
-40 -20 0
14.5
14.0
13.5
13.0
20 40 60 80 100 120
-40 -20 0
Temperature [℃]
Temperature [℃]
Figure 20. VCC UVLO Voltage 2 vs Temperature
Figure 19. VCC UVLO Voltage 1 vs Temperature
6.5
31.5
VCC OVP Voltage 1: VOVP1 [V]
VCC UVLO Hysteresis: VUVLO3 [V]
20 40 60 80 100 120
6.0
5.5
5.0
4.5
30.5
29.5
28.5
27.5
-40 -20 0
20 40 60 80 100 120
-40 -20 0
Temperature [℃]
Temperature [℃]
Figure 21. VCC UVLO Hysteresis Voltage vs Temperature
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Figure 22. VCC OVP Voltage 1 vs Temperature
TSZ02201-0F1F0A200770-1-2
09.Apr.2021 Rev.001
BM2SC12xFP2-LBZ Series
Typical Performance Curves - continued
1.05
SOURCE Pin Over Current Detection
Voltage 1A: VLIM1A [V]
FB Pin Pull-up Resistance: RFB [kΩ]
25
23
21
19
17
15
-40 -20 0
20 40 60 80 100 120
1.03
1.01
0.99
0.97
0.95
-40 -20 0
Temperature [℃]
Temperature [℃]
Figure 24. SOURCE Pin Over Current Detection Voltage 1A
vs Temperature
0.80
0.40
SOURCE Pin Over Current Detection
Voltage 2A: VLIM2A [V]
SOURCE Pin Over Current Detection
Voltage 1B: VLIM1B [V]
Figure 23. FB Pin Pull-up Resistance vs Temperature
20 40 60 80 100 120
0.75
0.70
0.65
0.60
-40 -20 0
20 40 60 80 100 120
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0.30
0.25
0.20
-40 -20 0 20 40 60 80 100 120
Temperature [℃]
Figure 25. SOURCE Pin Over Current Detection Voltage 1B
vs Temperature
0.35
Temperature [℃]
Figure 26. SOURCE Pin Over Current Detection Voltage 2A
vs Temperature
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BM2SC12xFP2-LBZ Series
Typical Performance Curves - continued
1.10
SOURCE Pin Switching ZT Pin
Current: IZT [mA]
SOURCE Pin Over Current Detection
Voltage 2B: VLIM2B[V]
0.30
0.26
1.05
0.22
1.00
0.18
0.95
0.14
0.90
-40 -20 0 20 40 60 80 100 120
-40 -20 0
Temperature [℃]
Temperature [℃]
Figure 27. SOURCE Pin Over Current Detection Voltage 2B
vs Temperature
Figure 28. SOURCE Pin Switching ZT Pin Current
vs Temperature
Maximum Operating Frequency 1:
fSW1 [kHz]
0.9
Minimum ON Width: tMIN [µs]
20 40 60 80 100 120
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
130
125
120
115
110
-40 -20 0
20 40 60 80 100 120
-40 -20 0
Temperature [℃]
Temperature [℃]
Figure 29. Minimum ON Width vs Temperature
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Figure 30. Maximum Operating Frequency 1
vs Temperature
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BM2SC12xFP2-LBZ Series
Typical Performance Curves - continued
1.40
1.40
FB Pin
Pin Frequency
Frequency Reduction
FB
Reduction Start
Start
Voltage: VVFBSW1
[V]
FBSW1[μA]
Voltage:
Maximum Operating Frequency 2:
fSW2 [kHz]
40
1.35
1.35
35
1.30
1.30
1.25
1.25
30
1.20
1.20
25
1.15
1.15
20
-40 -20 0
1.10
1.10
-40 -20
-20 00 20
20 40
40 60
60 80
80100
100120
120
-40
20 40 60 80 100 120
Temperature
Temperature[℃]
[℃]
Temperature [℃]
Figure 31. Maximum Operating Frequency 2 vs
Temperature
Figure 32. FB Pin Frequency Reduction Start Voltage vs
Temperature
0.65
FB Pin Frequency Reduction End
Voltage 2: VFBSW3 [V]
FB Pin Frequency Reduction End
Voltage 1: VFBSW2 [V]
0.60
0.55
0.50
0.45
0.40
-40 -20 0
20 40 60 80 100 120
0.55
0.50
0.45
-40 -20 0
Temperature [℃]
20 40 60 80 100 120
Temperature [℃]
Figure 34. FB Pin Frequency Reduction End Voltage 2
vs Temperature
Figure 33. FB Pin Frequency Reduction End Voltage 1
vs Temperature
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BM2SC12xFP2-LBZ Series
Typical Performance Curves - continued
140
ZT Pin Comparator Voltage 1:
VZT1 [mV]
2.3
Voltage Gain: AV [V/V]
2.2
2.1
2.0
1.9
1.8
1.7
120
100
80
60
-40 -20 0
-40 -20 0 20 40 60 80 100 120
20 40 60 80 100 120
Temperature [℃]
Temperature [℃]
Figure 36. ZT Pin Comparator Voltage 1 vs Temperature
Figure 35. Voltage Gain vs Temperature
1.4
Soft Start Time 1: tSS1 [ms]
Maximum ON Timer: tZTON [µs]
60
55
50
45
40
35
30
1.2
1.0
0.8
0.6
-40 -20 0
20 40 60 80 100 120
-40 -20 0
Temperature [℃]
Figure 38. Soft Start Time 1 vs Temperature
Figure 37. Maximum ON Time vs Temperature
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Temperature [℃]
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BM2SC12xFP2-LBZ Series
Typical Performance Curves - continued
3.1
FB OLP Voltage 1: VFOLP1 [V]
Soft Start Time 2: tSS2 [ms]
6.0
5.0
4.0
3.0
2.0
1.0
3.0
2.9
2.8
2.7
2.6
2.5
-40 -20 0
20 40 60 80 100 120
-40 -20 0
Temperature [℃]
Temperature [℃]
Figure 40. FB OLP Voltage 1 vs Temperature
Figure 39. Soft Start Time 2 vs Temperature
2.9
180
2.8
FB OLP Timer: tFOLP [ms]
FB OLP Voltage 2: VFOLP2 [V]
20 40 60 80 100 120
2.7
2.6
2.5
2.4
2.3
160
140
120
100
80
-40 -20 0
20 40 60 80 100 120
-40 -20 0
Temperature [℃]
Temperature [℃]
Figure 42. FB OLP Timer vs Temperature
Figure 41. FB OLP Voltage 2 vs Temperature
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Typical Performance Curves - continued
1.10
BR UVLO Voltage 1: VBR1 [V]
ZT OVP Voltage: VZTL [V]
3.8
3.7
3.6
3.5
3.4
3.3
3.2
-40 -20 0
1.05
1.00
0.95
0.90
20 40 60 80 100 120
-40 -20 0
Temperature [℃]
Temperature [℃]
Figure 44. BR UVLO Voltage 1 vs Temperature
Figure 43. ZT OVP Voltage vs Temperature
0.28
BR UVLO Hysteresis Voltage:
VBR3 [V]
0.90
BR UVLO Voltage 2: VBR2 [V]
20 40 60 80 100 120
0.85
0.80
0.75
0.70
0.26
0.24
0.22
0.20
0.18
0.16
0.14
-40 -20 0
20 40 60 80 100 120
-40 -20 0 20 40 60 80 100 120
Temperature [℃]
Temperature [℃]
Figure 46. BR UVLO Hysteresis Voltage vs Temperature
Figure 45. BR UVLO Voltage 2 vs Temperature
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Typical Performance Curves - continued
1.0
DRAIN Leak Current: IDSS [nA]
ON Resistance: RDS(ON) [Ω]
2.0
1.6
1.2
0.8
0.4
0.0
-40 -20 0
20 40 60 80 100 120
0.6
0.4
0.2
0.0
-40 -20 0
Temperature [℃]
20 40 60 80 100 120
Temperature [℃]
Figure 48. DRAIN Leak Current vs Temperature
Figure 47. On Resistance vs Temperature
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I/O Equivalence Circuits
1
ZT
2
VCC
3
GND
4
FB
VCC
Internal Reg
GND
ZT
5
BR
6
SOURCE
7
VCC
SOURCE
EXP-PAD
DRAIN
DRAIN
VCC
BR
Internal MOSFET
SOURCE
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Operational Notes
1.
Reverse Connection of Power Supply
Connecting the power supply in reverse polarity can damage the IC. Take precautions against reverse polarity when
connecting the power supply, such as mounting an external diode between the power supply and the IC’s power supply
pins.
2.
Power Supply Lines
Design the PCB layout pattern to provide low impedance supply lines. Furthermore, connect a capacitor to ground at
all power supply pins. Consider the effect of temperature and aging on the capacitance value when using electrolytic
capacitors.
3.
Ground Voltage
Ensure that no pins are at a voltage below that of the ground pin at any time, even during transient condition.
4.
Ground Wiring Pattern
When using both small-signal and large-current ground traces, the two ground traces should be routed separately but
connected to a single ground at the reference point of the application board to avoid fluctuations in the small-signal
ground caused by large currents. Also ensure that the ground traces of external components do not cause variations
on the ground voltage. The ground lines must be as short and thick as possible to reduce line impedance.
5.
Recommended Operating Conditions
The function and operation of the IC are guaranteed within the range specified by the recommended operating
conditions. The characteristic values are guaranteed only under the conditions of each item specified by the electrical
characteristics.
6.
Inrush Current
When power is first supplied to the IC, it is possible that the internal logic may be unstable and inrush current may flow
instantaneously due to the internal powering sequence and delays, especially if the IC has more than one power supply.
Therefore, give special consideration to power coupling capacitance, power wiring, width of ground wiring, and routing
of connections.
7.
Testing on Application Boards
When testing the IC on an application board, connecting a capacitor directly to a low-impedance output pin may subject
the IC to stress. Always discharge capacitors completely after each process or step. The IC’s power supply should
always be turned off completely before connecting or removing it from the test setup during the inspection process. To
prevent damage from static discharge, ground the IC during assembly and use similar precautions during transport and
storage.
8.
Inter-pin Short and Mounting Errors
Ensure that the direction and position are correct when mounting the IC on the PCB. Incorrect mounting may result in
damaging the IC. Avoid nearby pins being shorted to each other especially to ground, power supply and output pin.
Inter-pin shorts could be due to many reasons such as metal particles, water droplets (in very humid environment) and
unintentional solder bridge deposited in between pins during assembly to name a few.
9.
Unused Input Pins
Input pins of an IC are often connected to the gate of a MOS transistor. The gate has extremely high impedance and
extremely low capacitance. If left unconnected, the electric field from the outside can easily charge it. The small charge
acquired in this way is enough to produce a significant effect on the conduction through the transistor and cause
unexpected operation of the IC. So unless otherwise specified, unused input pins should be connected to the power
supply or ground line.
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Operational Notes – continued
10. Regarding the Input Pin of the IC
This IC contains P+ isolation and P substrate layers between adjacent elements in order to keep them isolated. P-N
junctions are formed at the intersection of the P layers with the N layers of other elements, creating a parasitic diode
or transistor. For example (refer to figure below):
When GND > Pin A and GND > Pin B, the P-N junction operates as a parasitic diode.
When GND > Pin B, the P-N junction operates as a parasitic transistor.
Parasitic diodes inevitably occur in the structure of the IC. The operation of parasitic diodes can result in mutual
interference among circuits, operational faults, or physical damage. Therefore, conditions that cause these diodes to
operate, such as applying a voltage lower than the GND voltage to an input pin (and thus to the P substrate) should be
avoided.
Resistor
Transistor (NPN)
Pin A
Pin B
C
E
Pin A
N
P+
P
N
N
P+
N
Pin B
B
Parasitic
Elements
N
P+
N P
N
P+
B
N
C
E
Parasitic
Elements
P Substrate
P Substrate
GND
GND
Parasitic
Elements
Parasitic
Elements
GND
GND
N Region
close-by
Figure 49. Example of IC Structure
11. Ceramic Capacitor
When using a ceramic capacitor, determine a capacitance value considering the change of capacitance with
temperature and the decrease in nominal capacitance due to DC bias and others.
12. Thermal Shutdown Circuit (TSD)
This IC has a built-in thermal shutdown circuit that prevents heat damage to the IC. Normal operation should always
be within the IC’s maximum junction temperature rating. If however the rating is exceeded for a continued period, the
junction temperature (Tj) will rise which will activate the TSD circuit that will turn OFF power output pins. When the Tj
falls below the TSD threshold, the circuits are automatically restored to normal operation.
Note that the TSD circuit operates in a situation that exceeds the absolute maximum ratings and therefore, under no
circumstances, should the TSD circuit be used in a set design or for any purpose other than protecting the IC from heat
damage.
13.
Over Current Protection Circuit (OCP)
This IC incorporates an integrated overcurrent protection circuit that is activated when the load is shorted. This
protection circuit is effective in preventing damage due to sudden and unexpected incidents. However, the IC should
not be used in applications characterized by continuous operation or transitioning of the protection circuit.
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BM2SC12xFP2-LBZ Series
Ordering Information
B
M
2
S
1
C
(FB OLP)
1: Auto Restart
2: Latch
3: Auto Restart
4: Latch
2
x
F
P
(VCC OVP)
Latch
Latch
Auto Restart
Auto Restart
2
-
Package
FP2:
TO263-7L
L
B
Z
E
2
Product Rank
LB: Industrial applications
Packaging and forming specification
E2: Embossed tape and reel
Lineup
Orderable Part Number
BM2SC121FP2-LBZE2
BM2SC122FP2-LBZE2
BM2SC123FP2-LBZE2
BM2SC124FP2-LBZE2
FB OLP
Auto Restart
Latch
Auto Restart
Latch
VCC OVP
Latch
Latch
Auto Restart
Auto Restart
Package
TO263-7L
Part Number Marking
M2SC121FP
M2SC122FP
M2SC123FP
M2SC124FP
Marking Diagram
TO263-7L (TOP VIEW)
Part Number Marking
LOT Number
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Physical Dimension and Packing Information
Package Name
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BM2SC12xFP2-LBZ Series
Revision History
Date
Revision
09.Apr.2021
001
Changes
New Release
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Notice
Precaution on using ROHM Products
1.
If you intend to use our Products in devices requiring extremely high reliability (such as medical equipment (Note 1),
aircraft/spacecraft, nuclear power controllers, etc.) and whose malfunction or failure may cause loss of human life,
bodily injury or serious damage to property (“Specific Applications”), please consult with the ROHM sales
representative in advance. Unless otherwise agreed in writing by ROHM in advance, ROHM shall not be in any way
responsible or liable for any damages, expenses or losses incurred by you or third parties arising from the use of any
ROHM’s Products for Specific Applications.
(Note1) Medical Equipment Classification of the Specific Applications
JAPAN
USA
EU
CHINA
CLASSⅢ
CLASSⅡb
CLASSⅢ
CLASSⅢ
CLASSⅣ
CLASSⅢ
2.
ROHM designs and manufactures its Products subject to strict quality control system. However, semiconductor
products can fail or malfunction at a certain rate. Please be sure to implement, at your own responsibilities, adequate
safety measures including but not limited to fail-safe design against the physical injury, damage to any property, which
a failure or malfunction of our Products may cause. The following are examples of safety measures:
[a] Installation of protection circuits or other protective devices to improve system safety
[b] Installation of redundant circuits to reduce the impact of single or multiple circuit failure
3.
Our Products are not designed under any special or extraordinary environments or conditions, as exemplified below.
Accordingly, ROHM shall not be in any way responsible or liable for any damages, expenses or losses arising from the
use of any ROHM’s Products under any special or extraordinary environments or conditions. If you intend to use our
Products under any special or extraordinary environments or conditions (as exemplified below), your independent
verification and confirmation of product performance, reliability, etc, prior to use, must be necessary:
[a] Use of our Products in any types of liquid, including water, oils, chemicals, and organic solvents
[b] Use of our Products outdoors or in places where the Products are exposed to direct sunlight or dust
[c] Use of our Products in places where the Products are exposed to sea wind or corrosive gases, including Cl2,
H2S, NH3, SO2, and NO2
[d] Use of our Products in places where the Products are exposed to static electricity or electromagnetic waves
[e] Use of our Products in proximity to heat-producing components, plastic cords, or other flammable items
[f] Sealing or coating our Products with resin or other coating materials
[g] Use of our Products without cleaning residue of flux (Exclude cases where no-clean type fluxes is used.
However, recommend sufficiently about the residue.); or Washing our Products by using water or water-soluble
cleaning agents for cleaning residue after soldering
[h] Use of the Products in places subject to dew condensation
4.
The Products are not subject to radiation-proof design.
5.
Please verify and confirm characteristics of the final or mounted products in using the Products.
6.
In particular, if a transient load (a large amount of load applied in a short period of time, such as pulse, is applied,
confirmation of performance characteristics after on-board mounting is strongly recommended. Avoid applying power
exceeding normal rated power; exceeding the power rating under steady-state loading condition may negatively affect
product performance and reliability.
7.
De-rate Power Dissipation depending on ambient temperature. When used in sealed area, confirm that it is the use in
the range that does not exceed the maximum junction temperature.
8.
Confirm that operation temperature is within the specified range described in the product specification.
9.
ROHM shall not be in any way responsible or liable for failure induced under deviant condition from what is defined in
this document.
Precaution for Mounting / Circuit board design
1.
When a highly active halogenous (chlorine, bromine, etc.) flux is used, the residue of flux may negatively affect product
performance and reliability.
2.
In principle, the reflow soldering method must be used on a surface-mount products, the flow soldering method must
be used on a through hole mount products. If the flow soldering method is preferred on a surface-mount products,
please consult with the ROHM representative in advance.
For details, please refer to ROHM Mounting specification
Notice-PAA-E
© 2015 ROHM Co., Ltd. All rights reserved.
Rev.004
Precautions Regarding Application Examples and External Circuits
1.
If change is made to the constant of an external circuit, please allow a sufficient margin considering variations of the
characteristics of the Products and external components, including transient characteristics, as well as static
characteristics.
2.
You agree that application notes, reference designs, and associated data and information contained in this document
are presented only as guidance for Products use. Therefore, in case you use such information, you are solely
responsible for it and you must exercise your own independent verification and judgment in the use of such information
contained in this document. ROHM shall not be in any way responsible or liable for any damages, expenses or losses
incurred by you or third parties arising from the use of such information.
Precaution for Electrostatic
This Product is electrostatic sensitive product, which may be damaged due to electrostatic discharge. Please take proper
caution in your manufacturing process and storage so that voltage exceeding the Products maximum rating will not be
applied to Products. Please take special care under dry condition (e.g. Grounding of human body / equipment / solder iron,
isolation from charged objects, setting of Ionizer, friction prevention and temperature / humidity control).
Precaution for Storage / Transportation
1.
Product performance and soldered connections may deteriorate if the Products are stored in the places where:
[a] the Products are exposed to sea winds or corrosive gases, including Cl 2, H2S, NH3, SO2, and NO2
[b] the temperature or humidity exceeds those recommended by ROHM
[c] the Products are exposed to direct sunshine or condensation
[d] the Products are exposed to high Electrostatic
2.
Even under ROHM recommended storage condition, solderability of products out of recommended storage time period
may be degraded. It is strongly recommended to confirm solderability before using Products of which storage time is
exceeding the recommended storage time period.
3.
Store / transport cartons in the correct direction, which is indicated on a carton with a symbol. Otherwise bent leads
may occur due to excessive stress applied when dropping of a carton.
4.
Use Products within the specified time after opening a humidity barrier bag. Baking is required before using Products of
which storage time is exceeding the recommended storage time period.
Precaution for Product Label
A two-dimensional barcode printed on ROHM Products label is for ROHM’s internal use only.
Precaution for Disposition
When disposing Products please dispose them properly using an authorized industry waste company.
Precaution for Foreign Exchange and Foreign Trade act
Since concerned goods might be fallen under listed items of export control prescribed by Foreign exchange and Foreign
trade act, please consult with ROHM in case of export.
Precaution Regarding Intellectual Property Rights
1.
All information and data including but not limited to application example contained in this document is for reference
only. ROHM does not warrant that foregoing information or data will not infringe any intellectual property rights or any
other rights of any third party regarding such information or data.
2.
ROHM shall not have any obligations where the claims, actions or demands arising from the combination of the
Products with other articles such as components, circuits, systems or external equipment (including software).
3.
No license, expressly or implied, is granted hereby under any intellectual property rights or other rights of ROHM or any
third parties with respect to the Products or the information contained in this document. Provided, however, that ROHM
will not assert its intellectual property rights or other rights against you or your customers to the extent necessary to
manufacture or sell products containing the Products, subject to the terms and conditions herein.
Other Precaution
1.
This document may not be reprinted or reproduced, in whole or in part, without prior written consent of ROHM.
2.
The Products may not be disassembled, converted, modified, reproduced or otherwise changed without prior written
consent of ROHM.
3.
In no event shall you use in any way whatsoever the Products and the related technical information contained in the
Products or this document for any military purposes, including but not limited to, the development of mass-destruction
weapons.
4.
The proper names of companies or products described in this document are trademarks or registered trademarks of
ROHM, its affiliated companies or third parties.
Notice-PAA-E
© 2015 ROHM Co., Ltd. All rights reserved.
Rev.004
Datasheet
General Precaution
1. Before you use our Products, you are requested to carefully read this document and fully understand its contents.
ROHM shall not be in any way responsible or liable for failure, malfunction or accident arising from the use of any
ROHM’s Products against warning, caution or note contained in this document.
2. All information contained in this document is current as of the issuing date and subject to change without any prior
notice. Before purchasing or using ROHM’s Products, please confirm the latest information with a ROHM sales
representative.
3.
The information contained in this document is provided on an “as is” basis and ROHM does not warrant that all
information contained in this document is accurate and/or error-free. ROHM shall not be in any way responsible or
liable for an y damages, expenses or losses incurred b y you or third parties resulting from inaccuracy or errors of or
concerning such information.
Notice – WE
© 2015 ROHM Co., Ltd. All rights reserved.
Rev.001