ROHM BA51W12

BA51W12SAT
Regulator ICs
Dual output voltage regulator with power
saving
BA51W12SAT
The BA51W12SAT is a general-purpose, low saturation power supply with two outputs : 9V, 1A and 5V, 500mA. The IC is
available in a compact TO220FP-5 package. The outputs can be turned off during the power saving state with the built-in
switch. Also built in the IC is an overcurrent protection circuit, an overvoltage protection circuit, and a thermal shutdown
circuit.
!Applications
Car audio systems, VCRs, facsimiles, air conditioners, and other household and industrial equipment
!Features
1) Minimum I / O voltage differential is 0.5V or less.
2) Built-in protection circuits against overcurrent, over voltage, and overheat.
3) Available in a compact TO220FP-5 package (pins are bendable).
4) Zero power saving current. (Typ.)
!Absolute maximum ratings (Ta=25°C)
Parameter
Symbol
Power supply voltage
VCC
Power dissipation
Pd
Limits
Unit
35
V
2000∗1
mW
Topr
−40~+85
°C
Storage temperature
Tstg
−55~+150
°C
Peak applied voltage
VCCPeak
50∗2
V
Operating temperature
∗1 Reduced by 16mW for each increase in Ta of 1°C over 25°C.
∗2 Applied time is less than 200 ms (tr≥1ms).
tr≥1ms
50V
35V
Max.200ms
0V
!Recommended operating conditions (Ta=25°C)
Parameter
Power supply voltage
Symbol
Min.
Typ.
Max.
Unit
VCC
10
14
25
V
BA51W12SAT
Regulator ICs
!Measurement circuits
OUT1
VCC
OUT2
CTL
GND
0.33µ
+
22µ
V
VCC
5V
+
IO1
22µ
V
IO2
VCC=14V,
IO1=500mA
when measuring output voltage 1
VCC=14V,
IO2=350mA
when measuring output voltage 2
VCC=10→25V,
IO1=500mA
when measuring input stability 1
VCC=6→25V,
IO2=350mA
when measuring input stability 2
VCC=14V,
IO1=5mA→1A
when measuring load reguration 1
VCC=14V,
IO2=5mA→500mA
when measuring load reguration 2
VCC=14V
when measuring output current capacity 1
VCC=14V
when measuring output current capacity 2
Fig.1 Circuit for measuring output voltage, input stability, load regulation, and output current capacity
VCC
OUT1
10Ω5W
VCC
CTL
+
GND
OUT2
+ 22µ
0.33µ
100µ
υ
+
eIN=1Vrms
f=120Hz
5V
500mA
22µ
υ
350mA
VCC=14V, IO1=500mA when meauring the ripple rejection ratio 1
VCC=14V, IO2=350mA when meauring the ripple rejection ratio 2
Fig.2 Circuit for measuring ripple rejection ratio
BA51W12SAT
Regulator ICs
!Measurement circuits
OUT1
VCC
OUT2
CTL
GND
0.33µ
+
22µ
V
VCC
5V
+
IO1
22µ
V
IO2
VCC=14V,
IO1=500mA
when measuring output voltage 1
VCC=14V,
IO2=350mA
when measuring output voltage 2
VCC=10→25V,
IO1=500mA
when measuring input stability 1
VCC=6→25V,
IO2=350mA
when measuring input stability 2
VCC=14V,
IO1=5mA→1A
when measuring load reguration 1
VCC=14V,
IO2=5mA→500mA
when measuring load reguration 2
VCC=14V
when measuring output current capacity 1
VCC=14V
when measuring output current capacity 2
Fig.1 Circuit for measuring output voltage, input stability, load regulation, and output current capacity
VCC
OUT1
10Ω5W
VCC
CTL
+
GND
OUT2
+ 22µ
0.33µ
100µ
υ
+
eIN=1Vrms
f=120Hz
5V
500mA
22µ
υ
350mA
VCC=14V, IO1=500mA when meauring the ripple rejection ratio 1
VCC=14V, IO2=350mA when meauring the ripple rejection ratio 2
Fig.2 Circuit for measuring ripple rejection ratio
BA51W12SAT
Regulator ICs
V
V
OUT1
VCC
CTL
OUT2
GND
+ 22µ
V
0.33µ
VCC
+
500mA
22µ
5V
V
350mA
VCC=8.55V
when measuring minimum I / O voltage difference 1
VCC=4.75V
when measuring minimum I / O voltage difference 2
Fig.3 Circuit for measuring minimum I / O voltage difference
OUT1
VCC
A
CTL
GND
OUT2
+
0.33µ
VCC
+
22µ
22µ
5V
VCC=14V, IO=0mA, VCTL=5V
when measuring bias current
VCC=14V, IO=0mA, VCTL=0V
when measuring power save current
Fig.4 Circuit for measuring bias current power supply current
OUT1
VCC
CTL
GND
OUT2
+
0.33µ
22µ
VCC=25V
+
22µ
A
5V
A
Fig.5 Circuit for measuring output short-circuit current
BA51W12SAT
Regulator ICs
OUT1
VCC
OUT2
CTL
GND
+
22µ
0.33µ
VCC=14V
+
2.0V
V
22µ
V
0.8V
Fig.6 Circuit for measuring mode switching voltage
OUT1
VCC
OUT2
CTL
GND
+
VCC=14V
0.33µ
+
22µ
A
5V
Fig.7 Circuit for measuring input high level current
!Application circuit
OUTPUT1
+
22µ
Vcc
OUTPUT2
GND
CTL
+
0.33µ
5V
Fig.8
22µ
22µ
BA51W12SAT
Regulator ICs
!Operation notes
(1) Although the circuit examples included in this hand-book are highly recommendable for general use, you should be
thoroughly familiar with circuit characteristics as they relate to your own use conditions. If you intend to change the
number of external circuits, leave an ample margin, taking into account discrepancies in both static and dynamic
characteristics of external parts and Rohm ICs. In addition, please be advised that Rohm cannot provide complete
assurance regarding patent rights.
(2) Operating power supply voltage
When operating within the proper ranges of power supply voltage and ambient temperature, most circuit functions
are guaranteed. Although the rated values of electrical characteristics cannot be absolutely guaranteed,
characteristic values do not change drastically within the proper rages.
(3) Power dissipation (Pd)
Refer to the power dissipation characteristics in Fig.12. If power dissipation exceeds the allowable limit, the
functionality of the IC will be degraded (such as reduction of current capacity by increased chip temperature). Make
sure to use the IC within the allowable range of power dissipation with a sufficient margin.
(4) Preventing oscillation at each output and bypass capacitor
To stop output oscillation, make sure to connect a capacitor between GND and each output pin (capacitance of at
least 10µF over the whole operating temperature range is recommended). Oscillation can occur if capacitance
is susceptible to temperature. We recommended using a tantalum capacitor with minimal changes in capacitance.
Also, output can be further stabilized by connecting a bypass capacitor of about 0.33µF between the input pin and
GND. Place the capacitor as near as possible to the input pin.
(5) Overcurrent protection circuit
An overcurrent protection circuit is installed in each output system, based on the respective output current. This
prevents IC destruction due to overcurrent, by limiting the current with a curve shape of “7” in the voltagecurrent graph. The IC is designed with margins so that current flow will be restricted and latching will be prevented
even if a large current suddenly flows through a large capacitor. Note that these protection circuits are only good for
preventing damage from sudden accidents. Make sure your design does not cause the protection circuit to operate
continuously under transitional conditions (for instance, if output is clamped at 1VF or higher, short mode circuit
operates at 1VF or lower). Note that the circuit ability is negatively correlated with temperature.
(6) Thermal protection circuit
A built-in thermal protection circuit prevents thermal damage to the IC. All outputs are turned off when the circuit
operates, and revert to the original state when the temperature drops to a certain level.
(7) We recommend installing a bypass line with a diode in your application if there is a mode where potential difference
between each output and input (VCC) or GND is reversed from the normal state. A reversed mode may cause
damage to the IC.
(8) Although the quality of this IC is rigorously controlled, the IC may be destroyed when the applied voltage or the
operating temperature exceeds their absolute maximum ratings. Because short mode or open mode cannot be
specified when the IC is destroyed, be sure to take physical safety measures, such as fusing, if any of the absolute
maximum ratings might be exceeded.
BA51W12SAT
Regulator ICs
(9) Recommended to put diode for protection in case of output pin connected with large load of impedance or reserve
current occurred at initial and output off.
(Example)
Output
(10) When used within a strong magnetic field, be aware that there is a slight possibility of malfunction.
(11) We are confident in recommending the above application circuit example, but we ask that you carefully check the
characteristics of this circuit before using it. If using circuit after modifying other external circuit constants, be careful to
ensure adequate margins for variation between external devices and this IC, including not only static characteristics
but also transient characteristics.
This IC is a bipolar IC which (as shown in Figure 9) has P+ isolation in the P substrate and between the various pins.
A P-N junction is formed form this P layer and the N layer of each pin. For example the relation between each
potentials is as follows,
(When GND > PinB and GND > PinA, the P-N junction operates as a parasitic diode.)
(When PinB > GND > PinA, the P-N junction operates as a parasitic transistor.)
Parasitic diodes can occur inevitably in the structure of the IC. The operation of parasitic diodes can result in mutual
interference among circuits as well as operation faults and physical damage. Accordingly, you must not use methods
by which parasitic diodes operate, such as applying a voltage that is lower than the GND (P substrate) voltage to an
input pin.
Transistor (NPN)
Resistance
(Pin B)
(Pin A)
B
C
E
GND
N
P
P
+
P
N
N
P substrate
P
+
+
P
N
Parasitic diode
N
N
N
P substrate
Parasitic diode or
transistor
(Pin B)
GND
+
P
GND
(Pin A)
C
Parasitic diode
B
E
GND
GND
Parasitic diode
or transistor
Fig.9 Simplified structure of bipolar IC
BA51W12SAT
Regulator ICs
!Electrical characteristic curves
12
10
OUTPUT VOLTAGE : VO (V)
OUTPUT VOLTAGE : VO (V)
10
VO1
9
8
7
6
VO2
5
4
3
2
28
Ta=25°C
IO=0mA
VO1
VO2
9
8
7
Over voltage
protection circuit,
ON Vcc=28V(Typ.)
6
5
4
3
2
20
16
12
(3)
4
0
0
500
1000
1500
(4)
0
0
2000
(2)
8
1
1
0
(1) With infinte heat sink
(2) With Al heat sink
100×100×2 (mm2)
(3) With Al heat sink
50×50×2 (mm2)
(4) Without heat sink
Note : When using AI
heat sink, a tightening
torque of 6 (kg cm) and
silicon grease is applied
24
POWER DISSIPATION : Pd (W)
VCC=14V
Ta=25˚C
11
6
12 18 24 30 36 42 48 54 60
0
25
50
75
100
125
150
OUTPUT CURRENT : IO (mA)
POWER SUPPLY VOLTAGE : VCC (V)
AMBIENT TEMPERATURE : Ta (˚C)
Fig.10 Output current capacity
characteristics (Typ.)
Fig.11 Output voltage
characteristics (Typ.)
Fig.12 Thermal derating characteristics
!External dimentions (Units : mm)
7.0
4.5
+ 0.3
− 0.1
φ 3.2 ± 0.1
+ 0.3
− 0.1
2.8
+ 0.2
− 0.1
17.5
25.8
17.0 − 0.2
31.5Max.
8.0 ± 0.2
0.7
10.0 − 0.1
(2.0)
2.8
+ 0.2
− 0.1
23.4
+ 0.3
− 0.1
+ 0.4
φ 3.2 ± 0.1
1.8 ± 0.2
4.5
12.0 ± 0.2
+ 0.3
− 0.1
8.0 ± 0.2
+ 0.3
− 0.1
7.0
1.2
1.2 ± 0.2
17.0
13.5Min.
12.0 ± 0.2
+ 0.4
− 0.2
1.8 ± 0.2
+ 0.3
10.0
0.8
1.2
0.8
0.5 ± 0.1
1 2 3 4 5
1.778
1.778
0.5 + 0.1
(2.85)
4.25
8.15
2.85
12345
TO220FP-5
TO220FP-5(V5)