gm34063 Gamma Microelectronics, gm34063 Datasheet - Page 13

• Manufacturer Part Number: gm34063
• Description: Gm34063 1.5a Dc-to-dc Converter Control Circuit
• Manufacturer: Gamma Microelectronics

DESIGN FORMULAS
V
V = Forward voltage drop of the output rectifier.
V
V
I
f
V
equivalent series resistance and board layout. The ripple voltage should be kept to a low value since it will directly affect the line and
load regulation.
out
min
sat
F
IN
out
ripple(pp)
- Desired output current.
- Minimum desired output switching frequency at the selected values of V
- Nominal input voltage.
= Saturation voltage of the output switch.
- Desired output voltage,
Calculation
(t
I
pk(switch)
t
on
on
L
- Desired peak-to peak output ripple voltage. In practice, the calculated capacitor value will need to be increased due to its
R
MICROELECTRONICS
t
C
(min)
C
t
+ t )
off
on
/ t
SC
O
T
off
off
A
(
A
(V
2 I
V
IN(min)
out
out(max)
V
I
0.3/ I
pk(switch)
9
Step - Up
(t
IN(min)
4.0 x 10 t
+ V - V
t
on
on
V
t
t
- V )
on
off
I
npple(pp)
+ t ) -
F
+ t
out on
pk(switch)
1
(
f
sat
+ 1
t
t
- V
off
t
off
on
off
-5
IN(min)
)
sat
on
+ 1
t
t
on(max)
on
)
(
(V
IN(min)
1.5A DC-to-DC CONVERTER CONTROL CIRCUIT
V
I
pk(switch)
IN(min)
Step - Down
I
(t + t ) -
4.0 x 10 t
0.3/ I
pk(switch)
-
8V
on
2 I
V
t
V -
IN
on
out
t
t
sat
out(max)
on
off
ripple(pp)
and I .
- V
+ t
pk(switch)
1
Power Management
f
+ V
off
(t
+ 1
V
sat
off
on
-5
out
O
F
t
on
- V
+ t )
on
)
)
out
off
t
on(max)
(
(V
Voltage - Inverting
2 I
IN(min)
out(max)
I
(t + t ) -
4.0 x 10 t
0.3/ I
9
pk(switch)
GM34063
IV
V
on
t
on
V
out
IN
t
t
- V )
on
off
I
ripple(pp)
+ t
out
pk(switch)
I + V
- V
1
(
f
off
sat
+ 1
t
off
t
t
-5
on
sat
on
off
)
F
t
on
on
+ 1
t
on(max)
)
13