LOW RIPPLE VOLTAGE REGULATOR
WITH EXTERNAL TRANSISTOR
1
NO. EA-043-0204
OUTLINE
!"!"#$%%
%!&%!!&
#%
%%&'&'#""!
%"%"#
&!& %&&
!()'!*"*#+,-.*#
FEATURES
• /0" ###########################################"#,12'
• " ###############################################################"#1#32'
• 4'"5 ####################################6+#17
• 4 ##################################################"#819:%;3*4<
• 0)5 ###################################################"#1#35:;311&'!$#
• 0&)% ################################################"#6311&:=
• 40 ###################################################"#1#17:5
• 5############################################################## % 1#35 % 3#+5
8#15
• 0&% ######################################"#>&'!0&
APPLICATIONS
• (%"?&
• &&!&!5
• (%&
RN5RF
2
BLOCK DIAGRAM
RN5RFxxA RN5RFxxB
2
51
VOUT
GND
VDD
CE
Vref
3
Current Limit
+
-
4
EXT
2
51
VOUT
GND
VDD
CE
Vref
3
Current Limit
+
-
4
EXT
SELECTION GUIDE
!"!*""%
@?#
&"&A
B←(&
↑↑↑ ↑
Code Contents
5-5.A
%1#35%3#+58#15#
)%'"
'AC0D"
9AC4D"
)%(*"
'A
A'"%&
)%"
$#!0-%%!"#.
RN5RF
3
PIN CONFIGURATION
SOT-23-5
12
3
54
(mark side)
CE/CE EXT
GND V
DD
V
OUT
PIN DESCRIPTION
Pin No. Symbol Pin Description
3 E) E(
+5
(
,5
(
F $G $)(-.
$$ $(
ABSOLUTE MAXIMUM RATINGS
Symbol Item Rating Unit
5 5 3+ 5
5 5%$:$( 1#,5H1#, 5
5 $G5 1#,5H1#, 5
$G 1 &'
(() 31 &I
& F1H> =
& H3+ =
ABSOLUTE MAXIMUM RATINGS
'&&&&%"
#!%"&&&"#
&&&&"&&#"
"&"%&#
RN5RF
4
ELECTRICAL CHARACTERISTICS
• RN5RFxxA
;+=
Symbol Item Conditions Min. Typ. Max. Unit
5 5
'';'
;1&'
'
×1#J>
'
×3#1+ 5
55;3#15 3#1 '
$G 5;F#15!5;+#15 > 3 &'
∆5:∆ 0 55;3#15
3&'≤≤311&' 81 81 &5
5 )5 ;311&'!;1&' 1#3 1#+ 5
" 55;3#15 ,1 1 2'
" " 5;31#15 1#13 1#31 3#11 2'
$G0* 1# 2'
∆5:∆5 0 ;1&'
5H1#5≤5≤315 1#11 1#1 1#,1 7:5
%;3*4<!1#5
55;3#15 81 9
5 5 31 5
5 $G5 31 5
∆5:∆ 5&
%%
;31&'
F1=≤ ≤>= 6311 &:=
(%$ F Ω
5 CE 5C4D 3# 5 5
5 CE 5C0D 1#11 1#+ 5
*1) The output current depends on the performance of external PNP transistor. Use External PNP transis-
tor of a low saturation type, with an hFE between 100 and 300.
*) With respect to Test Circuit, refer to Typical Application.
RN5RF
5
• RN5RFxxB
;+=
Symbol Item Conditions Min. Typ. Max. Unit
5 5 55;3#15
;1&'
'
×1#J>
'
×3#1+ 5
55;3#15 3#1 '
$G 5;F#15!5;+#15 > 3 &'
∆5:∆ 0 55;3#15
3&'≤≤311&' 81 81 &5
5 )5 ;311&' 1#3 1#+ 5
" 5B5;3#15
;1&' ,1 1 2'
" " 5;31#15 1#13 1#31 3#11 2'
$G0* 1# 2'
∆5:∆V 0 ;1&'
5H1#5≤5≤315 1#11 1#1 1#,1 7:5
%;3*4<!1#5
5B5;3#15 81 9
5 5 31 5
5 $G5 31 5
∆5:∆ 5&
%%
;31&'
F1=≤ ≤>= 6311 &:=
(%$
FΩ
5 $5C4D 3# 5 5
5 $5C0D 1#11 1#+ 5
*1) The output current depends on the performance of external PNP transistor. Use External PNP transis-
tor of a low saturation type, with an hFE between 100 and 300.
*) With respect to Test Circuit, refer to Typical Application.
RN5RF
6
OPERATION
2
51
VOUT
GND
VDD
CE
Vref
3
Current Limit
+
-
4
EXT
IN
GND
RN5RFxxA
PNP Tr
Ra
Rb CLC
OUT
GND
!55"%*!
&%"&%%((
5#
%#&"&*
#&!&&
"!5&#
Notes on selecting external components
-3. ((
9%%!%((#
$((5-.311,11#
-+. &!&&%%
#!-&".%312%
&#&"*&$
!%"%?"#
RN5RF
7
TEST CIRCUITS
PNP
EXT
V
OUT
OUT
10µF
GND
CE
10µF
V
DD
IN
RN5RFxxA
5
1
3
4
2
I
OUT
PNP
EXT
V
OUT
OUT
10µF
GND
CE
10µF
V
DD
IN
RN5RFxxA
5
1
3
4
2
I
SS
Basic Test Circuit Test Circuit for Supply Current
PNP
EXT
VOUT OUT
10µF
GND
CE
VDD
IN
RN5RFxxA
5
1
3
4
2
P.G
IOUT
PNP
EXT
V
OUT
OUT
10µF
GND
CE
10µF
V
DD
IN
RN5RFxxA
5
1
3
4
2
Test Circuit for Ripple Rejection and Line
Transient Response
Test Circuit for Load Transient Response
RN5RF
8
TYPICAL CHARACTERISTICS
1) Output Voltage vs. Input Voltage (Topt=25°C)
RN5RF30A RN5RF50A
3.20
2.60
2.40
2.20
3.00
2.80
2.00
Input Voltage V
IN
(V)
Output Voltage V
OUT
(V)
2345678910
I
OUT
=0mA
I
OUT
=100mA
I
OUT
=500mA
5.20
4.60
4.40
4.20
5.00
4.80
4.00
Input Voltage V
IN
(V)
Output Voltage V
OUT
(V)
45678910
I
OUT
=0mA
I
OUT
=100mA
I
OUT
=500mA
2) Output Voltage vs. Output Current (Topt=25°C)
RN5RF30A RN5RF50A
3.10
2.95
2.90
2.85
3.05
3.00
2.80
Output Current I
OUT
(mA)
Output Voltage V
OUT
(V)
0 100 200 300 400 500
V
IN
=4V 5.10
4.95
4.90
4.85
5.05
5.00
4.80
Output Current I
OUT
(mA)
Output Voltage V
OUT
(V)
0 100 200 300 400 500
V
IN
=6V
3) Dropout Voltage vs. Output Current
RN5RF30A RN5RF50A
0.50
0.20
0.40
0.30
0.10
0.00
Output Current IOUT(mA)
Dropout Voltage VDIF(V)
0 300100 200 400 500
Topt=-40
Topt=25
Topt=85
0.50
0.20
0.40
0.30
0.10
0.00
Output Current IOUT(mA)
Dropout Voltage VDIF(V)
0 300100 200 400 500
Topt=-40
Topt=25
Topt=85
RN5RF
9
4) Output Voltage vs. Temperature
RN5RF30A RN5RF50A
3.10
3.00
3.05
2.95
2.90
Temperature Topt( )
Output Voltage V
OUT
(V)
-50 25-25 0 50 75 100
V
IN
=4V,I
OUT
=10mA
5.10
5.00
5.05
4.95
4.90
-50 25-25 0 50 75 100
V
IN
=6V,I
OUT
=10mA
Temperature Topt( )
Output Voltage VOUT(V)
5) Supply Current vs. Input Voltage (Topt=25°C)
RN5RF30A RN5RF50A
100
60
50
80
70
90
40
30
20
10
0
Input Voltage VIN(V)
Supply Current ISS(µA)
0426810
I
OUT
=0mA 100
60
50
80
70
90
40
30
20
10
0
Input Voltage VIN(V)
Supply Current ISS(µA)
0426810
I
OUT
=0mA
6) Supply Current vs. Temperature
RN5RF30A RN5RF50A
50
30
40
20
10
0
Temperature Topt( )
Supply Current I
SS
(µA)
-50 0-25 25 50 75 100
V
IN
=4V,I
OUT
=0mA 50
30
40
20
10
0
Temperature Topt( )
Supply Current I
SS
(µA)
-50 0-25 25 50 75 100
V
IN
=6V,I
OUT
=0mA
RN5RF
10
7) Ripple Rejection vs. Frequency (Topt=25°C)
RN5RF30A RN5RF50A
80
70
50
60
40
20
30
10
0
Frequency (kHz)
Ripple Rejection (dB)
0.01 0.1 1 10 100
V
IN
=4Vdc+0.5Vp-p,I
OUT
=100mA,C
L
=10µF80
70
50
60
40
20
30
10
0
Frequency (kHz)
Ripple Rejection (dB)
0.01 0.1 1 10 100
V
IN
=6Vdc+0.5Vp-p,I
OUT
=100mA,C
L
=10µF
8) Line Transient Response (Topt=25°C)
RN5RF30A RN5RF50A
6
5
4
3
2
1
0
Time T(µs)
Input Voltage V
IN
(V)
-50 0-25 25 50 75 100 125 150
I
OUT
=300mA,C
L
=10µF3.3
3.2
3.1
3
2.9
2.8
2.7
Output Voltage V
OUT
(V)
Input Voltage
Output Voltage
8
7
6
5
4
3
2
Time T(µs)
Input Voltage V
IN
(V)
-50 0-25 25 50 75 100 125 150
I
OUT
=300mA,C
L
=10µF5.3
5.2
5.1
5
4.9
4.8
4.7
Output Voltage V
OUT
(V)
Input Voltage
Output Voltage
9) Load Transient Response (Topt=25°C)
RN5RF30A RN5RF50A
200
100
0
-100
-200
-300
-400
3.3
3.2
3.1
3
2.9
2.8
2.7
Time T(µs)
Output Current IOUT(mA)
Output Voltage VOUT(V)
-100 0 100 200 300 400
V
IN
=4V,C
L
=10µF
Output Current
Output Voltage
200
100
0
-100
-200
-300
-400
Time T(µs)
Output Current IOUT(mA)
-100 0 100 200 300 400
V
IN
=6V,C
L
=10µF5.3
5.2
5.1
5
4.9
4.8
4.7
Output Voltage VOUT(V)
Output Current
Output Voltage
RN5RF
11
TYPICAL APPLICATION
PNP Tr
EXT
OUT
Cap.
+
GND
CE
VDDIN RN5RFxxA VOUT
Cap.
+
Components
Transistor: 2SB766A
Capacitor: 10µF (Tantalum type)
