BD8643FV-E2 Rohm Semiconductor, BD8643FV-E2 Datasheet - Page 6

• Manufacturer Part Number: BD8643FV-E2
• Description: IC SWITCH REG 3A W/FET 20SSOP
• Manufacturer: Rohm Semiconductor
• Series: -r
• Type: Step-Down (Buck), PWM - Current Moder

Specifications of BD8643FV-E2

• Internal Switch(s): Yes
• Synchronous Rectifier: Yes
• Number Of Outputs: 1
• Voltage - Output: 1 V ~ 12.6 V
• Current - Output: 3A
• Frequency - Switching: 100kHz ~ 600kHz
• Voltage - Input: 4.5 V ~ 18 V
• Operating Temperature: -20°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 20-LSSOP (0.240", 6.10mm Width)
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

●Protection function
BD8643FV
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1 Low voltage protection function (LVP)
The voltage of the terminal FB (11pin) is compared with internal reference voltage VREF.
If FB terminal voltage falls below V
state is fixed.
Table 1 output low voltage protection function
2 Over voltage protection function (OVP)
The voltage of the terminal FB is compared with internal reference voltage VREF.
If FB terminal voltage is over Vovp (=VREF +120mV) and the state is continues, output changes to low voltage and the
state is fixed.
Table 2 output low voltage protection function
※ Low voltage protection function is available when SS terminal voltage becomes more than 1.4V (typ) in the transition to ON control (during soft start).
※ Over voltage protection function is available when SS terminal voltage becomes more than 1.4V (typ) in the transition to ON control (during soft start).
Protection circuit is effective for destruction prevention due to accident so that avoid using under continuous protection
operation.
FB terminal voltage
EN terminal
EN terminal
Protection
>V
>V
<V
<V
ENH
ENH
ENL
ENL
V
OFF
ON
FB
0
LVP
SS terminal
SS terminal
>1.4V(typ)
<1.4V(typ)
>1.4V(typ)
<1.4V(typ)
-
-
LVP
Fig.14 Output voltage error detection range
(= VREF -120mV) and the state continues, output changes to low voltage and the
FB terminal
FB terminal
＞V
＜V
＜V
＞V
6/13
OVP
-
-
-
-
OVP
OVP
LVP
LVP
Protection function
Protection function
Low voltage
Low voltage
Invalidity
Invalidity
Invalidity
Invalidity
Effective
Effective
LVP
VREF＋120ｍV
VREF
VREF-120ｍV
Protection operation
Protection operation
Low voltage
Low voltage
Technical Note
2010.09 - Rev.A
OFF
OFF
OFF
OFF
OFF
OFF
ON
ON