RH5RH
• RH5RH501A
Symbol
Item
Conditions
MIN.
TYP.
MAX.
Unit
V
OUT
=5.0V
Note
V
OUT
V
IN
Vstart
Vhold
I
DD
1
Output Voltage
Input Voltage
Start-up Voltage
Hold-on Voltage
Supply Current 1
Iout=1mA,Vin:0→2V
Iout=1mA,Vin:2→0V
To be measured at OUT Pin
(excluding Switching Current)
To be measured at OUT Pin
4.875
5.000
5.125
8
V
V
V
V
0.8
0.7
30
0.9
45
µA
I
DD
2
Supply Current 2
(excluding Switching Current)
V
IN
=5.5V
2
5
µA
I
LX
I
LXleak
fosc
Maxdty
η
Lx Switching Current
Lx Leakage Current
Oscillator Frequency
Oscillator Maximum Duty
Cycle
Efficiency
Soft-Start Time
V
LX
=0.4V
V
LX
=6V,V
IN
=5.5V
80
0.5
40
50
80
85
2.0
60
90
mA
µA
kHz
%
%
ms
Note1
on (V
LX
“L” ) side
70
70
t
start
V
LX
lim
Time required for the rising
of V
OUT
up to 5V.
0.5
V
LX
Voltage Limit
Lx Switch ON
0.65
0.8
1.0
V
Note2
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.
6
RICOH [ RICOH ELECTRONICS DEVICES DIVISION ]
