Output Voltage Setting; Input Signal Setting - Fujitsu MB39C026 Manual

Fujitsu ASSP Product
Power Management
8. Initialization
8. Initialization
(1)

Output Voltage Setting

The output voltage of VO1 can be adjusted by
the external resistor divider.
As illustrated below:
(
R 5
VO 1 = V ×
ref
(
R5
VO1 = V ×
ref
(2)

Input Signal Setting

EN1
Set EN1 to VIN to start the buck DC/DC converter (VO1). R1 pull-down EN1 to
GND and disable VO1 if EN1 has no input.
EN2
Set EN2 to VIN to start the LDO converter (VO2). R2 pull-down EN2 to GND
and disable VO2 if EN2 has no input.
Power On Reset (POR)
R3 and R4 are the pull-up resistors for POR (Pin 4). A 1M
to placed at either R3 or R4. When R3 has a 1M
POR will be connected VIN. When R4 has a 1M
POR pin will be connected to VO1.
By default, only R3 require a 1M
MB39C026 Evaluation Board
) (
+ R 6 300
.
= 0 3 V ×
R 6
) (
+ R6 499k
= 0.3V ×
R6
)
Ω Ω
k + 100 k
.
= 1
Ω
100 k
)
+ 100k
= 1.8V
100k
resistor and R4 is open; the
resistor and R3 is open; the
resistor while R4 is open.
R5-1
C2
300k
4.7uF
or
499k
R5-2
0R
FB 6
R6
100k
2 V
resistor is required
7/14
VO1
C3
22pF