Rh5rh – Ricoh RH5RH13B User Manual
Page 10
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RH5RH
• RH5RH501A
V
OUT
=5.0V
Unless otherwise provided, V
IN
=3V, Vss=0V, I
OUT
=10mA, Topt=25˚C, and use External Circuit of Typical
Application (FIG. 1).
(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
Compensation 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
I
DD
1
Supply Current 1
I
DD
2
Supply Current 2
I
LX
Lx Switching Current
I
LX
leak
Lx Leakage Current
fosc
Oscillator Frequency
Maxdty
Oscillator Maximum Duty
Cycle
η
Efficiency
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
Iout=1mA,Vin:0
→
2V
0.8
0.9
V
Iout=1mA,Vin:2
→
0V
0.7
V
To be measured at OUT Pin
(excluding Switching Current)
30
45
µA
To be measured at OUT Pin
(excluding Switching Current)
2
5
µA
V
IN
=5.5V
V
LX
=0.4V
80
mA
V
LX
=6V,V
IN
=5.5V
0.5
µA
40
50
60
kHz
on (V
LX
“L” ) side
70
80
90
%
70
85
%
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