AN7806 PANASONIC [Panasonic Semiconductor], AN7806 Datasheet - Page 9

• Manufacturer Part Number: AN7806
• Description: 3-pin positive output voltage regulator (1 A type)
• Manufacturer: PANASONIC [Panasonic Semiconductor]

Voltage Regulators
I Basic Regulator Circuit
I Usage Notes
I Application Circuit Examples
1. Cautions for a basic circuit
2. Other caution items
1. Current bootstrap circuit
1) Short-circuit between the input pin and GND pin
2) Floating of GND pin
V
0.33µF
I
off when a large capacitance capacitor has been con-
nected to the IC's load, a voltage of a capacitor con-
nected to an output pin is applied between input/out-
put of the IC and this likely results in damage of the
IC. It is necessary, therefore, to connect a diode, as
shown in figure 2, to counter the reverse bias between
input/output pins.
thermal protection circuit inside the IC does not normally operate. In this state, if the load is short-circuited or
overloaded, it is likely to damage the IC.
3Ω
If the input pin is short-circuitted to GND or is cut
If a GND pin is made floating in an operating mode, an unstabilized input voltage is outputted. In this case, a
V
I
C
Q
I
1
1
AN78xx
AN78xxF
Input
C
2
I
1
Figure 1
3
D
2
1
AN78xx
AN78xxF
i
2
I
3
O
0.1µF
Common
3
V
O
2. Adjustable output regulator
C
V
C
V
O
I
O
O
Output
C
C
1
AN78xx
AN78xxF
I
O
C
C
D
: C
: C
I
O
i
: When a wiring from a smoothing circuit to a three-pin regulator
: Normally unnecessary. But add it in the case that there is a
: When any sudden change of load current is likely to occur,
2
I
O
I
is necessary when the input line is long.
is long, it is likely to oscillate in output. A capacitor of 0.1µF to
0.47µF should be connected near an input pin.
connect an electrolytic capacitor of 10µF to 100µF to improve a
transitional response of output voltage.
residual voltage at the output capacitor Co even after switching
off the supply power because a current is likely to flow into an
output pin of the IC and damage the IC.
Bias
improves the transient response.
3
V
O
'
R
R
2
1
V
O
V
Note) V
O
= V
of I
Never fail to adjust individually with R
O
AN78xx/AN78xxF Series
In
O
' + I
varies due to sample to sample variation
Bias
1
GND
.
Bias
Figure 2
+
2
V
R
O
2
'
3
R
Out
1
+
−
C
O
Output
1
.
9