ROHM BD3988FV

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STRUCTURE
Silicon Monolithic Integrated Circuit
TYPE
Positive and Negative Variable Linear Regulator
PRODUCT SERIES
BD3988FV
FEATURES
1. Built-in positive (REG1) and negative (REG2) Linear Regulator for CCDs/ Variable output/
Low saturation voltage type.
2. Built-in Discharge circuit. Negative output voltage (REG2) turns off immediately,
after STB turns off.
○ABSOLUTE MAXIMUM RATINGS (Ta=25℃)
Parameter
Symbol
Limit
Positive Supply Voltage
VCC
+18
※1
Unit
V
Negative Supply Voltage
VEE
-18
※1
V
※2
mW
Power Dissipation
Pd
380
Operating Temperature Range
Topr
-40~+85
℃
Storage Temperature Range
Tstg
-55~+125
℃
Maximum Junction Temperature
Tjmax
125
℃
※1 Not to exceed Pd.
※2 Reduced by 3.8mW/℃ over Ta=25℃ ,during IC without heat sink operation.
○OPERATING CONDITIONS
Parameter
Symbol
Min
Max
Unit
Positive Supply Voltage
VCC
+15.0
+18.0
V
Negative Supply Voltage
VEE
-14.0
-7.5
V
REG1 Output Voltage
Vo1
+14.0
+16.0
V
REG2 Output Voltage
Vo2
Output Current 1
Io1
-8.5
-
-6.5
25
mA
Output Current 2
Io2
-
50
mA
V
※ Vdropout(Reg1) × Io(Reg1) + Vdropout(Reg2) × Io(Reg2) not to exceed Pd=380mW.
REV. B
2/4
○ELECTRICAL CHARACTERISTICS(Unless otherwise specified, Ta=25℃, VCC=16.5V, VEE=-10V, Set REG1=15V, Set REG2=-7.5V)
Parameter
Limits
Symbol
Unit
Conditions
MIN
Typ
MAX
-
500
850
μA
Io1=0mA
Io2=0mA
【Bias current】
Bias Current (VCC)
ICC
Bias Current (VEE)
IEE
-
200
300
μA
【STB】
STB OFF Voltage
STBOFF
0
-
0.6
V
STB ON Voltage
STBON
1.6
-
3.5
V
Io1,2=0mA
Io1,2=0mA
STB OFF Bias Current (VEE)
IOFF
0.7
1.6
2.5
mA
Io1,2=0mA
STB ON Input Current
Iin
10
30
60
μA
VSTB=2V, Io1,2=0mA
Idis
1.5
3.5
6.0
mA
CTL1 Voltage
Vctl1
1.372
1.400
1.428
V
Io1=10mA
Dropout Voltage 1
ΔVd1
-
0.25
0.35
V
Vcc=14.2V, Io1=25mA
mA
【Discharge block】
Discharge Current
【REG1】
Peak Output Current 1
Io1
25
-
-
Load Regulation 1
Vload1
-
100
-
mV
Io1=0~25mA
Short –
Ishort1
-
50
-
mA
Vo1=0V
Ripple Rejection 1
R.R.1
-
50
-
dB
f=120Hz, ein=1Vrms, Io1=2mA
Temperature Coefficient of Output Voltage 1 ※
Tcvo1
-
±0.02
-
CTL2 Voltage
Vctl1
-1.275
-1.250
-1.225
V
Io2=10mA
Dropout Voltage2
ΔVd2
-
0.35
0.45
V
VEE=-7.1V, Io2=50mA
Io2
50
-
-
mA
Load Regulation2
Vload2
-
100
-
mV
Io2=0~50mA
Short –
Circuit Output Current 1
%/℃ Io1=1mA, Tj=0~125℃
【REG2】
Peak Output Current2
Ishort2
-
120
-
mA
Vo2=0V
Ripple Rejection2
Circuit Output Current 2
R.R.2
-
50
-
dB
f=120Hz, ein=1Vrms, Io2=2mA
Temperature Coefficient of Output Voltage 2 ※
Tcvo2
-
±0.02
-
%/℃ Io2=1mA, Tj=0~125℃
◎ Discharge time
t=(Reg2×Co)/Idis [s]
(VEE=-10V)
Co:Reg2 Output capacitor(μF)
※ Design Guarantee (Shipment inspection is not done on all products.)
This product is not designed for protection against radio active rays.
○PHYSICAL DIMENSIONS・MARKING
Part No.
3988
Lot No.
SSOP-B8 (UNIT:mm)
REV. B
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○BLOCK DIAGRAM
○PIN No.・PIN NAME
VCC
VCC 2
BandGap
+
1 REG1
TSD
8 CTL1
OCP
7 GND
Pin No.
Pin Name
1
REG1
2
VCC
3
REG2
4
VEE
5
CTL2
6
STB
7
GND
8
CTL1
STB 6
Discharge
Block
5 CTL2
VEE 4
3 REG2
+
VEE
※Refer to the Technical Note about the details of the application.
○OPERATING NOTES
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 IC in a special mode where the
absolute maximum ratings may be exceeded is anticipated.
2) VEE potential
Ensure a minimum VEE pin potential in all operating conditions.
3) Thermal design
Use a thermal design that allows for a sufficient margin in light of the power dissipation (Pd) in actual operating
conditions.
4) Pin short and mistake mounting
Use caution when orienting and positioning the IC for mounting on printed circuit boards. Improper mounting may result
in damage to the IC. Shorts between output pins and the power supply and GND pins caused by the presence of a foreign object
may result in damage to the IC. Ensure a minimum GND pin potential in all operating conditions.
5) Actions in strong magnetic field
Keep in mind that the IC may malfunction in strong magnetic fields.
6) Testing on application boards
When testing the IC on an application board, connecting a capacitor to a pin with low impedance subjects the IC to stress.
Always discharge capacitors after each process or step. Always turn the IC's power supply off before connecting it to or
removing it from a jig or fixture during the inspection process. Ground the IC during assembly steps as an antistatic measure,
and use similar caution when transporting or storing the IC.
7) This monolithic 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 these P layers with the N layers of other elements to create a variety
of parasitic elements. For example, when the resistors and transistors are connected to the pins as shown in the following
figure,
The P/N junction functions as a parasitic diode when VEE > Pin A for the resistor or VEE > Pin B for the transistor(NPN).
Similarly, when VEE > Pin B for the transistor (NPN), the parasitic diode described above combines with the N layer
of other adjacent elements to operate as a parasitic NPN transistor.
REV. B
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The formation of parasitic elements as a result of the relationships of the potentials of different pins is an inevitable
result of the IC's architecture. The operation of parasitic elements can cause interference with circuit operation as well
as IC malfunction and damage. For these reasons, it is necessary to use caution so that the IC is not used in a way that
will trigger the operation of parasitic elements, such as by the application of voltages lower than the VEE (P substrate)
voltage to input pins. Keep in mind that the IC may malfunction in strong magnetic fields.
Transistor (NPN)
B
Resistor
(Pin A)
(Pin B) C
(Pin B)
E
B
E
N
P
P+
P+
N
P
P
P+
N
N
VEE
P+
N
N
Parasitic elements
C
Parasitic elements or
Transistors
N
P substrate
(Pin A)
VEE
Parasitic elements
or Transistors
VEE
Parasitic elements
8) Ground patterns
When using both small signal and large current GND patterns, it is recommended to isolate the two ground patterns, placing
a single ground point at the application's reference point so that the pattern wiring resistance and voltage variations
caused by large currents do not cause variations in the small signal ground voltage. Be careful not to change the GND wiring
pattern of any external parts, either.
9) Applications or inspection processes where the potentials of the VCC pin and other pins may be reversed from their normal
states may cause damage to the IC's internal circuitry or elements. Use an output pin capacitance of 1,000μF or lower
in case VCC is shorted with the GND pin while the external capacitor is charged. It is recommended to insert a diode for
preventing back current flow in series with VCC or bypass diodes between VCC and each pin.
Back current prevention diode
Bypass diode
VCC
Pin
10) Thermal shutdown circuit (TSD)
This IC incorporates a built-in TSD circuit for the protection from thermal destruction. The IC should be used within the
specified power dissipation range. However, in the event that the IC continues to be operated in excess of its power dissipation
limits, the attendant rise in the junction temperature (Tj) will trigger the TSD circuit to turn off all output power elements.
The circuit automatically resets once the junction temperature (Tj) drops. Operation of the TSD circuit presumes that the
IC's absolute maximum ratings have been exceeded. Application designs should never make use of the TSD circuit.
11) Overcurrent protection circuit (OCP)
The IC incorporates a built-in overcurrent protection circuit that operates according to the output current capacity. This
circuit serves to protect the IC from damage when the load is shorted. The protection circuit is designed to limit current
flow by not latching in the event of a large and instantaneous current flow originating from a large capacitor or other
component. This protection circuits 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. At the time of thermal designing, keep in mind that the current capacity has negative characteristics to
temperatures.
REV. B
Notice
Notes
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R1120A