Ricoh RH5RH13B Manual Do Utilizador
9
• RH5RH503B
V
OUT
=5.0V
RH5RH
Unless otherwise provided, V
IN
=3V, V
SS
=0V, I
OUT
=10mA, Topt=25˚C, and use External Circuit of Typical
Application (FIG. 3).
(Note 1) Soft-Start Circuit is operated in the following sequence :
(1) V
IN
is applied.
(2) The voltage (Vref) of the reference voltage unit is maintained at 0V for about 200µs after the application of V
IN
.
(3) The output of Error Amp. is raised to “H” level during the maintenance of the voltage (Vref) of the reference voltage unit.
(4) After the rise of Vref, the output of Internal Error Amp. is gradually decreased to an appropriate value by the function of Internal Phase Com
pensation Circuit, and the Output Voltage is gradually increased in accordance with the gradual decrease of the output of Internal Error Amp.
(Note 2) I
LX
is gradually increased after Lx Switch is turned ON. In accordance with the increase of I
LX
, V
LX
is also increased. When V
LX
reaches V
LX
lim,
Lx Switch is turned OFF by an Lx Switch Protection Circuit.
Symbol
Item
V
OUT
Output Voltage
V
IN
Input Voltage
Vstart
Start-up Voltage
Vhold
Hold-on Voltage
η
Efficiency
I
DD
1
Supply Current 1
I
DD
2
Supply Current 2
I
LX
Lx Switching Current
I
LX
leak
Lx Leakage Current
I
EXTH
EXT “H” Output Current
I
EXTL
EXT “L” Output Current
V
CEH
1
CE “H” Level 1
V
CEL
1
CE “L” Level 1
V
CEH
2
CE “H” Level 2
V
CEL
2
CE “L” Level 2
I
CEH
CE “H” Input Current
I
CEL
CE “L” Input Current
fosc
Oscillator Frequency
Maxdty
Oscillator Maximum Duty
Cycle
Cycle
t
start
Soft-Start Time
V
LX
lim
V
LX
Voltage Limit
Conditions
MIN.
TYP.
MAX.
Unit
Note
4.875
5.000
5.125
V
8
V
I
OUT
=1mA,V
IN
: 0
→
2V
0.8
0.9
V
I
OUT
=1mA,V
IN
: 2
→
0V
0.7
V
70
85
%
To be measured at OUT pin
60
90
µA
To be measured at OUT pin
2
5
µA
V
IN
=5.5V
V
LX
=0.4V
80
mA
V
LX
=6V,V
IN
=5.5V
0.5
µA
V
EXT
=V
OUT
–0.4V
–2.0
mA
V
EXT
=0.4V
2.0
mA
V
OUT
≥
1.5V
V
OUT
–0.4
V
V
OUT
≥
1.5V
0.4
V
0.8V
≤
V
OUT
<1.5V
V
OUT
–0.1
V
0.8V
≤
V
OUT
<1.5V
0.1
V
CE=5V
0.5
µA
CE=0V
–0.5
µA
80
100
120
kHz
on (V
LX
“L” )side
70
80
90
%
Time required for the rising
0.5
2.0
ms
Note1
of V
OUT
up to 5V.
Lx Switch ON
0.65
0.8
1.0
V
Note2