AN8049 Panasonic Semiconductor, AN8049 Datasheet - Page 11

• Manufacturer Part Number: AN8049
• Description: 1.8-volt 3-channel step-up/ step-down/ and polarity inverting DC-DC converter control IC
• Manufacturer: Panasonic Semiconductor

Voltage Regulators
[1] Allowable power dissipation
[2] Allowable V
careful to operate so that the loss does not exceed the allowable power dissipation, P
biased by V
output is shorted.
either by inserting a ripple filter in the V
locating that capacitor as close to the IC as possible.
differ depending on the actual structure of the power supply circuit. Also note that this allowable range is a design
target, and is not guaranteed by testing of all samples.
Usage Notes
Since the power dissipation (P) in this IC increases proportionally with the supply voltage, applications must be
V
The figure shows the allowable range for V
Note that the allowable range shown here is the result of testing the IC alone and that the allowable range may
CC
Reference formula:
P = (V
ripple due to the switching transistor being turned on and off can cause this IC's U.V.L.O. circuit, which is
P
CC
D
V
I
Du
V
I
Du
V
I
Du
I
SO(OUT)1
SO(OUT)2
OUT3
CC
, to operate incorrectly, and can cause the S.C.P. capacitor charging operation to fail to start when the
CC
(V
V
V
BEQ1
BEQ2
O(SAT)3
CC
1
2
3
O(SAT)3
CC
CC
V
ripple
BEQ1
V
I
CC
BEQ2
)
: The voltage between the base and emitter of the npn transistor Q1
: The OUT1 pin output source current
(When R
: The output 1 duty factor
: The voltage between the base and emitter of the npn transistor Q2
: The OUT2 pin output source current
(When R
: The output 2 duty factor
: The OUT3 pin saturation voltage (0.5 V maximum when OUT1 is 40 mA.)
: The OUT3 pin current (This will be {V
: The output 3 duty factor
: The V
I
OUT3
)
100 k
10 M
10 k
I
1 M
SO(OUT)1
I
SO(OUT)2
0
CC
Du
RB1
RB2
pin current
3
is 1 k , I
is 1 k , I
1
Du
CC
Du
1
line or by inserting a capacitor between the IC GND and V
Allowable range
when V
V
2
2
CC
Allowable V
CC
SO(OUT)1
SO(OUT)2
ripple voltage V
ripple. Applications should reduce V
CC
is 3 V.
3
Allowable range
when V
Power dissipation in the channel 1 output stage
Power dissipation in the channel 2 output stage
Power dissipation in the channel 3 output stage
Power dissipation between V
will be 38 mA, maximum.)
will be 38 mA, maximum.)
CC
4
CC
CC
ripple
is 10 V.
(AC) (V[p-p])
CC
5
V
BEQ3
6
V
7
O(SAT)3
CC
D
CC
, for the package.
8
ripple to be within this range,
and ground
}/R
O3
.)
AN8049FHN
CC
pins and
11