RH5RH
• RH5RH303B
Symbol
Item
Conditions
MIN.
TYP.
MAX.
Unit
V
OUT
=3.0V
Note
V
OUT
V
IN
Vstart
Vhold
η
I
DD
1
I
DD
2
I
LX
I
LXleak
I
EXTH
I
EXTL
V
CEH
1
V
CEL
1
V
CEH
2
V
CEL
2
I
CEH
I
CEL
fosc
Maxdty
Output Voltage
Input Voltage
Start-up Voltage
Hold-on Voltage
Efficiency
Supply Current 1
Supply Current 2
Lx Switching Current
Lx Leakage Current
EXT “H” Output Current
EXT “L” Output Current
CE “H” Level 1
CE “L” Level 1
CE “H” Level 2
CE “L” Level 2
CE “H” Input Current
CE “L” Input Current
Oscillator Frequency
Oscillator Maximum Duty
Cycle
on (V
LX
“L” )side
To be measured at OUT pin
To be measured at OUT pin
V
IN
=3.5V
V
LX
=0.4V
V
LX
=6V,V
IN
=3.5V
V
EXT
=V
OUT
–0.4V
V
EXT
=0.4V
V
OUT
≥1.5V
V
OUT
≥1.5V
0.8V≤V
OUT
<1.5V
0.8V≤V
OUT
<1.5V
CE=3V
CE=0V
I
OUT
=1mA,V
IN
: 0
→
2V
I
OUT
=1mA,V
IN
: 2
→
0V
2.925
3.000
3.075
8
V
V
V
V
0.8
0.7
70
85
30
2
60
0.9
%
50
5
µA
µA
mA
0.5
–1.5
µA
mA
mA
V
0.4
V
V
0.1
0.5
V
µA
µA
1.5
V
OUT
–0.4
V
OUT
–0.1
–0.5
80
70
100
80
120
90
kHz
%
t
start
V
LX
lim
Soft-Start Time
V
LX
Voltage Limit
Time required for the rising
of V
OUT
up to 3V.
Lx Switch ON
0.5
0.65
2.0
0.8
1.0
ms
V
Note1
Note2
Unless otherwise provided, V
IN
=1.8V, 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.
8
RICOH [ RICOH ELECTRONICS DEVICES DIVISION ]
